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2025 Volume 41 Issue 5
2025, 41(5): 100041
doi: 10.1016/j.actphy.2024.100041
Abstract:
The interfacial electrical double layer (EDL) is the interfacial space filled with a complex and dynamic reaction network forming by catalyst's surface atoms, reactants, intermediates, products, solvent molecules, ions, and other components. EDL has a profound impact on electrocatalytic reactions, affecting both the thermodynamics and kinetics of these processes. Manipulating the composition and structure of the EDL microenvironment sets an additional level of tuning toward the electrocatalysis, to the traditional catalyst optimization. It resembles the delicate manipulation of the environment around the active sites by protein scaffold in enzymes. However, the rational optimization of the EDL demands a deep understanding about its structure and dynamics. Problem lies in the complexities of interfacial EDL, which includes complicated multi-body interactions, few molecular-level characterization techniques, and scarce EDL modification strategies. In this tutorial, we delve into the intricacies of the interfacial EDL in electrocatalytic reactions, and seek to provide those who are new to this field a thorough summary of the theory, characterization, history, recent progresses within the regime of EDL for electrocatalysis. We begin by discussing the theoretical models that describe the structure and properties of EDL, including 4 classical EDL models, their applications in electrocatalytic analysis and modifications, and relevant calculation modulation methods. These models are arranged in the chronical order, such that a historical summary of how the EDL theory evolves from simple models to complicated details is provided. We then provide an overview of cutting-edge techniques in electrochemical measurement methods, in situ spectroscopic characterization techniques and scanning probe microscopy methods. Specifically, we aim to summarize the advantages and disadvantages of each technique, with an emphasis on their capability of probing the EDL region. The summary table can provide junior students a quick overview and a useful tool for selecting the appropriate techniques toward addressing the EDL properties for electrocatalysis. Furthermore, by combining the theory and characterization techniques, we list several pivotal studies from the past five years emphasizing on the "electrode side interfacial modification" approach and "solution side interfacial modification" approach, toward modulating the EDL to optimize the electrocatalytic properties. These examples not only show the recent progresses in this field and offer fundamental details about how researchers in this field address the problems from the aspect of EDL. With these combined theory, characterization and research samples, we hope that the new-comings can gain interest to this field, sense the enormous opportunities and understand the general principles of EDL toward electrocatalysis. ![]()
The interfacial electrical double layer (EDL) is the interfacial space filled with a complex and dynamic reaction network forming by catalyst's surface atoms, reactants, intermediates, products, solvent molecules, ions, and other components. EDL has a profound impact on electrocatalytic reactions, affecting both the thermodynamics and kinetics of these processes. Manipulating the composition and structure of the EDL microenvironment sets an additional level of tuning toward the electrocatalysis, to the traditional catalyst optimization. It resembles the delicate manipulation of the environment around the active sites by protein scaffold in enzymes. However, the rational optimization of the EDL demands a deep understanding about its structure and dynamics. Problem lies in the complexities of interfacial EDL, which includes complicated multi-body interactions, few molecular-level characterization techniques, and scarce EDL modification strategies. In this tutorial, we delve into the intricacies of the interfacial EDL in electrocatalytic reactions, and seek to provide those who are new to this field a thorough summary of the theory, characterization, history, recent progresses within the regime of EDL for electrocatalysis. We begin by discussing the theoretical models that describe the structure and properties of EDL, including 4 classical EDL models, their applications in electrocatalytic analysis and modifications, and relevant calculation modulation methods. These models are arranged in the chronical order, such that a historical summary of how the EDL theory evolves from simple models to complicated details is provided. We then provide an overview of cutting-edge techniques in electrochemical measurement methods, in situ spectroscopic characterization techniques and scanning probe microscopy methods. Specifically, we aim to summarize the advantages and disadvantages of each technique, with an emphasis on their capability of probing the EDL region. The summary table can provide junior students a quick overview and a useful tool for selecting the appropriate techniques toward addressing the EDL properties for electrocatalysis. Furthermore, by combining the theory and characterization techniques, we list several pivotal studies from the past five years emphasizing on the "electrode side interfacial modification" approach and "solution side interfacial modification" approach, toward modulating the EDL to optimize the electrocatalytic properties. These examples not only show the recent progresses in this field and offer fundamental details about how researchers in this field address the problems from the aspect of EDL. With these combined theory, characterization and research samples, we hope that the new-comings can gain interest to this field, sense the enormous opportunities and understand the general principles of EDL toward electrocatalysis.
2025, 41(5): 100044
doi: 10.1016/j.actphy.2024.100044
Abstract:
Hydrogen energy is a widely available, flexible and efficient secondary energy source, and it is also an important energy medium. The development of low-cost, high-density hydrogen storage technology is a significant issue for the industrial application of hydrogen energy. Liquid organic hydrogen storage has attracted extensive attention due to advantages such as high mass hydrogen storage density, safe storage and transportation, as well as ease of long-distance transportation. However, compared with the relatively mature hydrogenation process, the dehydrogenation of liquid organic hydrogen carriers (LOHCs) still suffers from high reaction temperature and low efficiency. The key to solving these problems is the development of efficient dehydrogenation catalysts. In recent years, carbon-based catalysts have shown excellent reaction performance in the dehydrogenation of LOHCs due to their advantages of high dispersion of active components, tunable composition structure and surface physicochemical properties, and outstanding electrical and thermal conductivity, etc. In this review, we initially analyze the thermodynamics and kinetics of dehydrogenation, as well as the physicochemical properties of LOHCs, including cyclohexane, methylcyclohexane, decalin, and perhydro-N-ethylcarbazole. The special features of carbon supports are then outlined in terms of the activated carbon, carbon nanotubes, carbon fibers, and reduced graphene oxide. In addition, the structural characteristics, catalytic performance, structure-property relationship, and dehydrogenation mechanism of carbon-supported metal catalysts are summarized and analyzed. Based on this, we point out the main challenges of liquid organic hydrogen storage. Furthermore, future opportunities in this field are envisioned, with an emphasis on the modification and structuration of carbon support, the study of catalytic mechanisms and chemical process intensification. ![]()
Hydrogen energy is a widely available, flexible and efficient secondary energy source, and it is also an important energy medium. The development of low-cost, high-density hydrogen storage technology is a significant issue for the industrial application of hydrogen energy. Liquid organic hydrogen storage has attracted extensive attention due to advantages such as high mass hydrogen storage density, safe storage and transportation, as well as ease of long-distance transportation. However, compared with the relatively mature hydrogenation process, the dehydrogenation of liquid organic hydrogen carriers (LOHCs) still suffers from high reaction temperature and low efficiency. The key to solving these problems is the development of efficient dehydrogenation catalysts. In recent years, carbon-based catalysts have shown excellent reaction performance in the dehydrogenation of LOHCs due to their advantages of high dispersion of active components, tunable composition structure and surface physicochemical properties, and outstanding electrical and thermal conductivity, etc. In this review, we initially analyze the thermodynamics and kinetics of dehydrogenation, as well as the physicochemical properties of LOHCs, including cyclohexane, methylcyclohexane, decalin, and perhydro-N-ethylcarbazole. The special features of carbon supports are then outlined in terms of the activated carbon, carbon nanotubes, carbon fibers, and reduced graphene oxide. In addition, the structural characteristics, catalytic performance, structure-property relationship, and dehydrogenation mechanism of carbon-supported metal catalysts are summarized and analyzed. Based on this, we point out the main challenges of liquid organic hydrogen storage. Furthermore, future opportunities in this field are envisioned, with an emphasis on the modification and structuration of carbon support, the study of catalytic mechanisms and chemical process intensification.
2025, 41(5): 100039
doi: 10.1016/j.actphy.2024.100039
Abstract:
Photocatalytic nitric oxide (NO) conversion technology has the characteristics of high efficiency, economy, and environment friendly to remove NO using g-C3N4. Introducing new adsorption sites on the surface of g-C3N4 through microstructure control can alter the structure-activity relationship between g-C3N4 and gas molecules, thereby improving photocatalytic NO conversion activity and inhibiting NO2 generation. However, few review articles have focused on the microscopic effects of microstructural changes in g-C3N4 based materials on the adsorption and activation of NO and O2. This has important guiding significance for material design work in the field of NO conversion and strategies to fundamentally improve NO conversion activity and selectivity. Therefore, our work systematically summarizes the strategy of introducing adsorption and activation sites through microstructure control, and emphasizes the role of these sites in the photocatalytic NO conversion process. The aim is to clarify the influence of adsorption and activation sites on adsorption behavior and the correlation between these sites and reaction paths. Finally, the development trend and future prospects of increasing the level of g-C3N4 adsorption and activation in the field of photocatalytic NO conversion are introduced, which is expected to provide an important reference for the development and practical application of g-C3N4-based photocatalytic materials. ![]()
Photocatalytic nitric oxide (NO) conversion technology has the characteristics of high efficiency, economy, and environment friendly to remove NO using g-C3N4. Introducing new adsorption sites on the surface of g-C3N4 through microstructure control can alter the structure-activity relationship between g-C3N4 and gas molecules, thereby improving photocatalytic NO conversion activity and inhibiting NO2 generation. However, few review articles have focused on the microscopic effects of microstructural changes in g-C3N4 based materials on the adsorption and activation of NO and O2. This has important guiding significance for material design work in the field of NO conversion and strategies to fundamentally improve NO conversion activity and selectivity. Therefore, our work systematically summarizes the strategy of introducing adsorption and activation sites through microstructure control, and emphasizes the role of these sites in the photocatalytic NO conversion process. The aim is to clarify the influence of adsorption and activation sites on adsorption behavior and the correlation between these sites and reaction paths. Finally, the development trend and future prospects of increasing the level of g-C3N4 adsorption and activation in the field of photocatalytic NO conversion are introduced, which is expected to provide an important reference for the development and practical application of g-C3N4-based photocatalytic materials.
Research on Cu-Based and Pt-Based Catalysts for Hydrogen Production through Methanol Steam Reforming
2025, 41(5): 100049
doi: 10.1016/j.actphy.2025.100049
Abstract:
Methanol steam reforming (MSR) is a critical pathway for on-board hydrogen production from methanol, playing a significant role in clean energy applications. The catalytic performance in MSR reactions directly influences hydrogen yield and byproduct composition, with Cu-based and Pt-based catalysts extensively studied for their high efficiency. The catalytic mechanism primarily involves the cleavage of C―H and O―H bonds in methanol and water molecules. The activity of Cu-based catalysts depends on the ratio and synergistic interaction of Cu0 and Cu+ active sites, while Pt-based catalysts operate through Pt0, Ptδ+ or Pt2+ active sites, in conjunction with oxygen vacancies. However, the electron transfer and interaction mechanisms between active metals and supports remain contentious, impacting the metal oxidation states, adsorption sites, and reaction pathway selectivity. This is particularly evident in the pathways for methanol dehydrogenation and intermediate product formation (e.g., formaldehyde, formic acid, and methyl formate), which lack a unified understanding. This review systematically examines the unitary and synergistic roles of Cu0 and Cu+ sites, explores the direct and synergistic pathways of Pt-based catalysts, and analyzes the effects of additives such as In2O3 on Pt site modulation and oxygen vacancy generation. By integrating catalytic performance evaluations with mechanistic insights, strategies are proposed to enhance catalyst activity and stability. This comprehensive review not only advances the understanding of MSR mechanisms but also provides a theoretical foundation and research direction for the development of high-performance catalysts for on-board hydrogen production. ![]()
Methanol steam reforming (MSR) is a critical pathway for on-board hydrogen production from methanol, playing a significant role in clean energy applications. The catalytic performance in MSR reactions directly influences hydrogen yield and byproduct composition, with Cu-based and Pt-based catalysts extensively studied for their high efficiency. The catalytic mechanism primarily involves the cleavage of C―H and O―H bonds in methanol and water molecules. The activity of Cu-based catalysts depends on the ratio and synergistic interaction of Cu0 and Cu+ active sites, while Pt-based catalysts operate through Pt0, Ptδ+ or Pt2+ active sites, in conjunction with oxygen vacancies. However, the electron transfer and interaction mechanisms between active metals and supports remain contentious, impacting the metal oxidation states, adsorption sites, and reaction pathway selectivity. This is particularly evident in the pathways for methanol dehydrogenation and intermediate product formation (e.g., formaldehyde, formic acid, and methyl formate), which lack a unified understanding. This review systematically examines the unitary and synergistic roles of Cu0 and Cu+ sites, explores the direct and synergistic pathways of Pt-based catalysts, and analyzes the effects of additives such as In2O3 on Pt site modulation and oxygen vacancy generation. By integrating catalytic performance evaluations with mechanistic insights, strategies are proposed to enhance catalyst activity and stability. This comprehensive review not only advances the understanding of MSR mechanisms but also provides a theoretical foundation and research direction for the development of high-performance catalysts for on-board hydrogen production.
2025, 41(5): 100040
doi: 10.1016/j.actphy.2024.100040
Abstract:
As a primary energy storage device, the thermal battery offers advantages such as high specific energy and high-power density. However, developing new cathode materials with high specific capacity and thermal stability to meet the evolving needs of thermal batteries remains a significant challenge. Moreover, the high discharge temperatures of thermal batteries and the instability of the molten salt electrolyte system complicate the electrochemical in situ characterization of these systems. In this context, in situ electrochemical impedance spectroscopy (EIS) has become widely employed in electrochemistry and represents a promising technique for in situ monitoring of thermal battery systems. Niobium-tungsten oxides, which possess a Wadsley-Roth crystal shear structure, exhibit excellent rate capability and cyclic stability as anode materials for lithium-ion batteries. Among them, Nb12WO33 demonstrates remarkable lithium storage performance due to its unique 3D tunneling structure, which provides rapid de-intercalation channels for Li+ ions. Given its excellent thermal and electrochemical stability, this study proposes the use of Nb12WO33 as a cathode material for thermal batteries for the first time. Electrochemical impedance spectroscopy (EIS) at room temperature was employed to investigate the variations in the material's internal electronic conductivity impedance. The EIS Nyquist plots of the Nb12WO33 electrode reveal a distinctive phenomenon of three semicircles in the high- and mid-frequency regions within the operating potential range. This behavior is primarily attributed to the electron conduction within the Nb12WO33 electrode. The resistance associated with electronic conduction (RE) exhibits a pattern of initial increase followed by a decrease. This phenomenon is explained by the valence transition of the Nb element from +5 to +4 occurring around 1.7 V. This step is more facile than the subsequent steps at 2.0 V and 1.2 V, resulting in the generation of a larger number of metastable electrons. Consequently, the internal channels become populated with electrons, leading to a significant increase in RE. The thermal battery constructed with Nb12WO33 as the cathode material was discharged at 500 ℃ and a current density of 500 mA·g−1 (with a cut-off voltage of 1.5 V), achieving a high specific capacity of 436.8 mAh·g−1 and an average polarized internal resistance of 0.52 Ω during pulse discharge. Therefore, Nb12WO33 holds great potential as a cathode material for high-capacity, thermally stable thermal batteries. This study paves the way for the use of other niobium-tungsten oxides as cathode materials for thermal batteries and establishes a precedent for in situ EIS testing and analysis of thermal battery systems. ![]()
As a primary energy storage device, the thermal battery offers advantages such as high specific energy and high-power density. However, developing new cathode materials with high specific capacity and thermal stability to meet the evolving needs of thermal batteries remains a significant challenge. Moreover, the high discharge temperatures of thermal batteries and the instability of the molten salt electrolyte system complicate the electrochemical in situ characterization of these systems. In this context, in situ electrochemical impedance spectroscopy (EIS) has become widely employed in electrochemistry and represents a promising technique for in situ monitoring of thermal battery systems. Niobium-tungsten oxides, which possess a Wadsley-Roth crystal shear structure, exhibit excellent rate capability and cyclic stability as anode materials for lithium-ion batteries. Among them, Nb12WO33 demonstrates remarkable lithium storage performance due to its unique 3D tunneling structure, which provides rapid de-intercalation channels for Li+ ions. Given its excellent thermal and electrochemical stability, this study proposes the use of Nb12WO33 as a cathode material for thermal batteries for the first time. Electrochemical impedance spectroscopy (EIS) at room temperature was employed to investigate the variations in the material's internal electronic conductivity impedance. The EIS Nyquist plots of the Nb12WO33 electrode reveal a distinctive phenomenon of three semicircles in the high- and mid-frequency regions within the operating potential range. This behavior is primarily attributed to the electron conduction within the Nb12WO33 electrode. The resistance associated with electronic conduction (RE) exhibits a pattern of initial increase followed by a decrease. This phenomenon is explained by the valence transition of the Nb element from +5 to +4 occurring around 1.7 V. This step is more facile than the subsequent steps at 2.0 V and 1.2 V, resulting in the generation of a larger number of metastable electrons. Consequently, the internal channels become populated with electrons, leading to a significant increase in RE. The thermal battery constructed with Nb12WO33 as the cathode material was discharged at 500 ℃ and a current density of 500 mA·g−1 (with a cut-off voltage of 1.5 V), achieving a high specific capacity of 436.8 mAh·g−1 and an average polarized internal resistance of 0.52 Ω during pulse discharge. Therefore, Nb12WO33 holds great potential as a cathode material for high-capacity, thermally stable thermal batteries. This study paves the way for the use of other niobium-tungsten oxides as cathode materials for thermal batteries and establishes a precedent for in situ EIS testing and analysis of thermal battery systems.
2025, 41(5): 100050
doi: 10.1016/j.actphy.2025.100050
Abstract:
Recently, the regulation of electronic spin polarization has attracted considerable interest as an effective strategy to mitigate the rapid recombination of photo-generated charges. However, current research predominantly targets individual photocatalysts, where the efficiency of charge separation still has significant room for improvement. Herein, a ZnFe1.2Co0.8O4 (ZFCO) and BiVO4 (BVO) S-scheme heterojunction was developed, which synergistically promoted charge separation through the S-scheme heterojunction and spin polarization, and further enhanced the photocatalytic performance in removing organic pollutants under an external magnetic field. Experimental results revealed that under sole light irradiation, ZB-1.5 (ZFCO : BVO = 3 : 2) demonstrated optimal performance, with a reaction rate constant (k) for tetracycline (TC) degradation of 0.0146 min−1. Under light irradiation and magnetic field conditions, the reaction rate constant (k) of ZB-1.5 for TC degradation increased to 0.0175 min−1, indicating enhanced photocatalytic performance. DFT calculations indicated that ZFCO exhibited the spin polarization. Photoluminescence measurements demonstrated that the S-scheme heterojunction structure improved the charge separation efficiency. In addition, possible degradation pathways and toxicity were assessed, indicating successful detoxification. This work provides some useful insights into utilizing S-scheme heterojunctions to develop photocatalysts with efficient separation of photo-generated charges. ![]()
Recently, the regulation of electronic spin polarization has attracted considerable interest as an effective strategy to mitigate the rapid recombination of photo-generated charges. However, current research predominantly targets individual photocatalysts, where the efficiency of charge separation still has significant room for improvement. Herein, a ZnFe1.2Co0.8O4 (ZFCO) and BiVO4 (BVO) S-scheme heterojunction was developed, which synergistically promoted charge separation through the S-scheme heterojunction and spin polarization, and further enhanced the photocatalytic performance in removing organic pollutants under an external magnetic field. Experimental results revealed that under sole light irradiation, ZB-1.5 (ZFCO : BVO = 3 : 2) demonstrated optimal performance, with a reaction rate constant (k) for tetracycline (TC) degradation of 0.0146 min−1. Under light irradiation and magnetic field conditions, the reaction rate constant (k) of ZB-1.5 for TC degradation increased to 0.0175 min−1, indicating enhanced photocatalytic performance. DFT calculations indicated that ZFCO exhibited the spin polarization. Photoluminescence measurements demonstrated that the S-scheme heterojunction structure improved the charge separation efficiency. In addition, possible degradation pathways and toxicity were assessed, indicating successful detoxification. This work provides some useful insights into utilizing S-scheme heterojunctions to develop photocatalysts with efficient separation of photo-generated charges.
2025, 41(5): 100042
doi: 10.1016/j.actphy.2024.100042
Abstract:
Metal halide perovskites have emerged as highly promising materials in optoelectronics, owing to their unique multidimensional crystal structures that impart exceptional optical and electronic properties. These materials exhibit remarkable fluorescence imaging and tracking capabilities, as well as efficient photoelectric conversion, making them suitable for a broad range of applications. Nevertheless, despite their significant potential, their poor water stability has posed a major challenge, particularly in biomedical fields such as drug delivery systems, biological imaging, and photoelectrocatalytic oncotherapy. This limitation has hindered their practical use in medical treatments and diagnostics. In this study, we address the water stability issue by successfully synthesizing CsSn0.5Pb0.5Br3 perovskite nanocrystals (PeNCs) and conjugating them with methotrexate-chitosan-folic acid (MTX-CS-FA), resulting in innovative green light-emitting PeNCs@MTX-CS-FA nanoparticles. These nanoparticles exhibited remarkable water stability, maintaining their structural and functional integrity for up to 228 d, a significant improvement that enables their application in complex biological environments. Under visible light illumination, the nanoparticles demonstrated a dual-action therapeutic mechanism. The perovskites effectively generated electrons and reactive oxygen species (ROS), inducing oxidative stress in tumor cells. At the same time, photogenerated holes oxidized glutathione (GSH), a molecule that is typically overexpressed in tumor cells to protect against oxidative damage. By depleting GSH, the nanoparticles weakened the tumor cells' efense mechanisms, thereby enhancing the oxidative damage caused by ROS. In addition, methotrexate (MTX), a chemotherapeutic agent integrated into the system, inhibited dihydrofolate reductase (DHFR) activity. This inhibition disrupted tumor cell metabolism, particularly nucleotide synthesis, leading to lipid peroxidation and subsequent cell death. Together, these mechanisms generated a potent, synergistic therapeutic effect. The therapeutic efficacy of the PeNCs@MTX-CS-FA nanoparticles was validated through in vivo antitumor experiments in mice. A total dose of 2.4 mg of nanoparticles resulted in a 63.68% reduction in tumor volume and a 63.26% decrease in tumor weight, demonstrating significant tumor growth suppression. Biological safety evaluations further confirmed the nanoparticles' biocompatibility. Notably, they were excreted from the mice in their fluorescent form without decomposition, ensuring minimal long-term toxicity. This safe excretion pathway underscores the feasibility of repeated use of these nanoparticles in clinical applications. Overall, this study highlights the transformative potential of metal halide perovskites in cancer treatment. By overcoming the water stability limitations that have previously constrained their biomedical applications, the PeNCs@MTX-CS-FA nanoparticles exhibited outstanding capabilities in real-time bioimaging and effective photoelectrocatalytic chemotherapy, thus paving the way for future innovations in biomedical science. ![]()
Metal halide perovskites have emerged as highly promising materials in optoelectronics, owing to their unique multidimensional crystal structures that impart exceptional optical and electronic properties. These materials exhibit remarkable fluorescence imaging and tracking capabilities, as well as efficient photoelectric conversion, making them suitable for a broad range of applications. Nevertheless, despite their significant potential, their poor water stability has posed a major challenge, particularly in biomedical fields such as drug delivery systems, biological imaging, and photoelectrocatalytic oncotherapy. This limitation has hindered their practical use in medical treatments and diagnostics. In this study, we address the water stability issue by successfully synthesizing CsSn0.5Pb0.5Br3 perovskite nanocrystals (PeNCs) and conjugating them with methotrexate-chitosan-folic acid (MTX-CS-FA), resulting in innovative green light-emitting PeNCs@MTX-CS-FA nanoparticles. These nanoparticles exhibited remarkable water stability, maintaining their structural and functional integrity for up to 228 d, a significant improvement that enables their application in complex biological environments. Under visible light illumination, the nanoparticles demonstrated a dual-action therapeutic mechanism. The perovskites effectively generated electrons and reactive oxygen species (ROS), inducing oxidative stress in tumor cells. At the same time, photogenerated holes oxidized glutathione (GSH), a molecule that is typically overexpressed in tumor cells to protect against oxidative damage. By depleting GSH, the nanoparticles weakened the tumor cells' efense mechanisms, thereby enhancing the oxidative damage caused by ROS. In addition, methotrexate (MTX), a chemotherapeutic agent integrated into the system, inhibited dihydrofolate reductase (DHFR) activity. This inhibition disrupted tumor cell metabolism, particularly nucleotide synthesis, leading to lipid peroxidation and subsequent cell death. Together, these mechanisms generated a potent, synergistic therapeutic effect. The therapeutic efficacy of the PeNCs@MTX-CS-FA nanoparticles was validated through in vivo antitumor experiments in mice. A total dose of 2.4 mg of nanoparticles resulted in a 63.68% reduction in tumor volume and a 63.26% decrease in tumor weight, demonstrating significant tumor growth suppression. Biological safety evaluations further confirmed the nanoparticles' biocompatibility. Notably, they were excreted from the mice in their fluorescent form without decomposition, ensuring minimal long-term toxicity. This safe excretion pathway underscores the feasibility of repeated use of these nanoparticles in clinical applications. Overall, this study highlights the transformative potential of metal halide perovskites in cancer treatment. By overcoming the water stability limitations that have previously constrained their biomedical applications, the PeNCs@MTX-CS-FA nanoparticles exhibited outstanding capabilities in real-time bioimaging and effective photoelectrocatalytic chemotherapy, thus paving the way for future innovations in biomedical science.
2025, 41(5): 100045
doi: 10.1016/j.actphy.2025.100045
Abstract:
The graphene film with high thermal conductivity has garnered considerable attention in recent years as an ideal material for dissipating heat in high-power electronic devices. Thermal conductivity is a crucial parameter for evaluating its fundamental performance. High-precision measurement holds significant importance for understanding its basic properties, fabrication optimization, and industrial applications. However, it is difficult to simultaneously achieve efficient, accurate, and reliable measurements with existing commercial thermal conductivity testing methods. The development of a convenient, high-precision, and reliable measurement approach remains a great challenge. Here, we introduce a thermal conductivity testing methodology with superior accuracy and excellent efficiency based on an improved steady-state electric heating method, refined through the optimization of heat transfer principles, experimental operation, and data analysis, supported by finite element simulation. The accuracy of measurements is affected by four factors: heat loss calibration, sample size, device design, and data treatment. The experimental results show that the heat loss caused by heat radiation and heat convection affects the temperature distribution and the measurements of the sample, which should be strictly controlled by sample size and temperature rise. Reasonable screening and preprocessing of data are also necessary to improve measurement accuracy. Through the comparative analysis of the temperature distribution and thermal conductivity measurements of samples under different conditions, we propose feasible operational guidance and a standardized testing protocol to minimize measurement error. The measurement error is less than 3.0%, and uncertainty is reduced to 0.5%. Simulation results confirm that the response time of this method is down to milliseconds, correlating well with the experiment, which can effectively improve test efficiency. Considering the combined merits of high accuracy, repeatability, and fast response, the improved steady-state electric heating method offers useful guidance for the accurate evaluation of the thermal conductivity of materials and crucial technical support for research and application in thermal management. ![]()
The graphene film with high thermal conductivity has garnered considerable attention in recent years as an ideal material for dissipating heat in high-power electronic devices. Thermal conductivity is a crucial parameter for evaluating its fundamental performance. High-precision measurement holds significant importance for understanding its basic properties, fabrication optimization, and industrial applications. However, it is difficult to simultaneously achieve efficient, accurate, and reliable measurements with existing commercial thermal conductivity testing methods. The development of a convenient, high-precision, and reliable measurement approach remains a great challenge. Here, we introduce a thermal conductivity testing methodology with superior accuracy and excellent efficiency based on an improved steady-state electric heating method, refined through the optimization of heat transfer principles, experimental operation, and data analysis, supported by finite element simulation. The accuracy of measurements is affected by four factors: heat loss calibration, sample size, device design, and data treatment. The experimental results show that the heat loss caused by heat radiation and heat convection affects the temperature distribution and the measurements of the sample, which should be strictly controlled by sample size and temperature rise. Reasonable screening and preprocessing of data are also necessary to improve measurement accuracy. Through the comparative analysis of the temperature distribution and thermal conductivity measurements of samples under different conditions, we propose feasible operational guidance and a standardized testing protocol to minimize measurement error. The measurement error is less than 3.0%, and uncertainty is reduced to 0.5%. Simulation results confirm that the response time of this method is down to milliseconds, correlating well with the experiment, which can effectively improve test efficiency. Considering the combined merits of high accuracy, repeatability, and fast response, the improved steady-state electric heating method offers useful guidance for the accurate evaluation of the thermal conductivity of materials and crucial technical support for research and application in thermal management.
2025, 41(5): 100046
doi: 10.1016/j.actphy.2025.100046
Abstract:
The pressing challenges posed by infectious diseases caused by pathogenic microbial infections have necessitated the development of advanced antimicrobial strategies. Among the promising avenues, photodynamic therapy (PDT) has emerged as a promising approach due to its non-invasive and targeted nature. Although it has been widely used in antibacterial therapy, there are still obstacles in precisely regulating the structure of photosensitizers to achieve satisfactory photodynamic performance. Herein, Pt single-atoms (SAs) are deposited on two-dimensional (2D) Al-TCPP metal-organic framework (MOF) nanosheets, creating Pt/Al-TCPP as the photosensitizer to boost reactive oxygen species (ROS) production for enhanced photodynamic antimicrobial therapy. By integrating Pt SAs onto 2D Al-TCPP MOF nanosheets, we not only improve the dispersion and stability of Pt atoms but also harness the synergistic effect between the MOF's crystal porous structure and Pt SAs, optimizing its light-trapping ability. This unique structure enhances the bridging unit between Pt SA and the porphyrin linker, facilitating efficient charge transfer and separation during illumination, ultimately boosting ROS production. In addition to the inherent photodynamic performance of Pt SAs, they can also increase the adsorption of oxygen, facilitate electron transfer, and improve charge separation, thus enhancing photodynamic ROS generation efficiency. Therefore, the Pt/Al-TCPP photosensitizer shows much greater efficacy in generating ROS under a 660 nm laser irradiation compared to Al-TCPP. Both in vitro and in vivo experiments demonstrate that the Pt/Al-TCPP nanosheets can effectively eliminate bacteria and promote wound healing in a short time at low doses under laser irradiation. This study underscores the advantages of integrating Pt SAs with Pt/Al-TCPP nanosheets and offers a highly effective photosensitizer for bacterial infections. The results pave the way for novel strategies in the antibacterial realm, highlighting the potential of Pt/Al-TCPP nanosheets as a promising therapeutic agent for efficient wound healing. ![]()
The pressing challenges posed by infectious diseases caused by pathogenic microbial infections have necessitated the development of advanced antimicrobial strategies. Among the promising avenues, photodynamic therapy (PDT) has emerged as a promising approach due to its non-invasive and targeted nature. Although it has been widely used in antibacterial therapy, there are still obstacles in precisely regulating the structure of photosensitizers to achieve satisfactory photodynamic performance. Herein, Pt single-atoms (SAs) are deposited on two-dimensional (2D) Al-TCPP metal-organic framework (MOF) nanosheets, creating Pt/Al-TCPP as the photosensitizer to boost reactive oxygen species (ROS) production for enhanced photodynamic antimicrobial therapy. By integrating Pt SAs onto 2D Al-TCPP MOF nanosheets, we not only improve the dispersion and stability of Pt atoms but also harness the synergistic effect between the MOF's crystal porous structure and Pt SAs, optimizing its light-trapping ability. This unique structure enhances the bridging unit between Pt SA and the porphyrin linker, facilitating efficient charge transfer and separation during illumination, ultimately boosting ROS production. In addition to the inherent photodynamic performance of Pt SAs, they can also increase the adsorption of oxygen, facilitate electron transfer, and improve charge separation, thus enhancing photodynamic ROS generation efficiency. Therefore, the Pt/Al-TCPP photosensitizer shows much greater efficacy in generating ROS under a 660 nm laser irradiation compared to Al-TCPP. Both in vitro and in vivo experiments demonstrate that the Pt/Al-TCPP nanosheets can effectively eliminate bacteria and promote wound healing in a short time at low doses under laser irradiation. This study underscores the advantages of integrating Pt SAs with Pt/Al-TCPP nanosheets and offers a highly effective photosensitizer for bacterial infections. The results pave the way for novel strategies in the antibacterial realm, highlighting the potential of Pt/Al-TCPP nanosheets as a promising therapeutic agent for efficient wound healing.
