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2025 Volume 44 Issue 6
2025, 44(6): 100527
doi: 10.1016/j.cjsc.2025.100527
Abstract:
2025, 44(6): 100574
doi: 10.1016/j.cjsc.2025.100574
Abstract:
2025, 44(6): 100575
doi: 10.1016/j.cjsc.2025.100575
Abstract:
Formaldehyde (HCHO), a significant indoor air pollutant, poses serious health risks to humans, making its removal a critical issue. Among the various methods for HCHO elimination, catalytic oxidation has emerged as one of the most efficient and practical approaches. In this study, hierarchical hollow nickel oxide nanofibers (NiO–HNF) are developed by using a semi-sacrificial template-assisted hydrothermal and calcination process. Platinum (Pt) nanoparticles are then loaded onto the NiO–HNF through an impregnation-chemical reduction process. The Pt/NiO–HNF nanocomposite demonstrates a marked improvement in HCHO decomposition activity at room temperature, which can be ascribed to its distinct structural features. The hierarchical structure of the nanocomposite, which provides a high specific surface area and abundant porosity, facilitates the uniform dispersion of Pt nanoparticles and increases the number of active sites available for catalysis. To further investigate the oxidation mechanism, in-situ diffuse reflectance infrared Fourier transform spectroscopy (in-situ DRIFTS) is utilized. The findings suggest that the main intermediates during the oxidation process are dioxymethylene and formate species. This study highlights the potential of hollow transition metal oxide composites as efficient materials for the removal of indoor air pollutants.
Formaldehyde (HCHO), a significant indoor air pollutant, poses serious health risks to humans, making its removal a critical issue. Among the various methods for HCHO elimination, catalytic oxidation has emerged as one of the most efficient and practical approaches. In this study, hierarchical hollow nickel oxide nanofibers (NiO–HNF) are developed by using a semi-sacrificial template-assisted hydrothermal and calcination process. Platinum (Pt) nanoparticles are then loaded onto the NiO–HNF through an impregnation-chemical reduction process. The Pt/NiO–HNF nanocomposite demonstrates a marked improvement in HCHO decomposition activity at room temperature, which can be ascribed to its distinct structural features. The hierarchical structure of the nanocomposite, which provides a high specific surface area and abundant porosity, facilitates the uniform dispersion of Pt nanoparticles and increases the number of active sites available for catalysis. To further investigate the oxidation mechanism, in-situ diffuse reflectance infrared Fourier transform spectroscopy (in-situ DRIFTS) is utilized. The findings suggest that the main intermediates during the oxidation process are dioxymethylene and formate species. This study highlights the potential of hollow transition metal oxide composites as efficient materials for the removal of indoor air pollutants.
2025, 44(6): 100576
doi: 10.1016/j.cjsc.2025.100576
Abstract:
Based upon the thiophene-2,5-dicarboxylic acid (H2Tdc), a novel [Sc3(μ2-OH)3(CO2)4O6]n inorganic chain-based Sc-MOF with decorated nitrate ions, {[Sc3(OH)2(Tdc)3(NO3)]⋅H2O}∞ (AEU-1; AEU for Army Engineering University of PLA), was synthesized, which shows good water and chemical stabilities. Significantly, due to channel constriction accompanied by the polar window caused by introducing nitrate ions, AEU-1 exhibits high C2H6/C2H4 adsorption selectivity comparable to many famous C2H6-selective MOFs, making it a promising candidate for the purification of methanol-to-olefin (MTO) products. Furthermore, theoretical investigations reveal that the introduced nitrate ions in AEU-1 as the main adsorption sites could provide strong interactions between the framework and C2H6/C3H6 in the full-contacting mode, leading to an increase in the adsorption enthalpies (Qst) of C2H6 and C3H6, and thus further improving the C2H6/C2H4 and C3H6/C2H4 adsorption selectivity. Our work could open up a new avenue for constructing MOFs with inorganic polar moieties as adsorption sites for one-step C2H4 purification and C3H6 recovery from MTO mixtures with high selectivity.
Based upon the thiophene-2,5-dicarboxylic acid (H2Tdc), a novel [Sc3(μ2-OH)3(CO2)4O6]n inorganic chain-based Sc-MOF with decorated nitrate ions, {[Sc3(OH)2(Tdc)3(NO3)]⋅H2O}∞ (AEU-1; AEU for Army Engineering University of PLA), was synthesized, which shows good water and chemical stabilities. Significantly, due to channel constriction accompanied by the polar window caused by introducing nitrate ions, AEU-1 exhibits high C2H6/C2H4 adsorption selectivity comparable to many famous C2H6-selective MOFs, making it a promising candidate for the purification of methanol-to-olefin (MTO) products. Furthermore, theoretical investigations reveal that the introduced nitrate ions in AEU-1 as the main adsorption sites could provide strong interactions between the framework and C2H6/C3H6 in the full-contacting mode, leading to an increase in the adsorption enthalpies (Qst) of C2H6 and C3H6, and thus further improving the C2H6/C2H4 and C3H6/C2H4 adsorption selectivity. Our work could open up a new avenue for constructing MOFs with inorganic polar moieties as adsorption sites for one-step C2H4 purification and C3H6 recovery from MTO mixtures with high selectivity.
2025, 44(6): 100591
doi: 10.1016/j.cjsc.2025.100591
Abstract:
Multifunctional semiconductors play an important role in developing advanced photoelectric technologies. In this work, based on an octahedral replacement strategy in chalcogenides, a new selenide semiconductor NaMn3Ga3Se₈ was rationally designed, and synthesized by the flux method. The compound crystallizes in the noncentrosymmetric (NCS) P6̄ space group, and is composed of unique prismatic [NaSe6], octahedral [MnSe6] and tetrahedral [GaSe4] motifs, inheriting the stable three-dimensional framework built by the octahedral and tetrahedral units in the AIMg3ᴵᴵC3ᴵᴵᴵQ₈ⱽᴵ family. NaMn3Ga3Se₈ shows the largest known secondary nonlinear optical (NLO) response of ∼2.1 × AgGaS2 (AGS) in the AIMg3ᴵᴵC3ᴵᴵᴵQ₈ⱽᴵ family, and a high laser-induced damage threshold of ∼3.0 × AGS. Meanwhile, the introduction of Mn2+ with unpaired 3d electrons induces a strong red emission band (685–805 nm) under the excitation source of 496 nm, as well as a paramagnetic to antiferromagnetic (AFM) transition at 7.3 K. The results confirm that NaMn3Ga3Se₈ possesses multifunctional features including significant NLO response, fluorescence emission and AFM properties, and illustrate that replacing octahedral units with approaching size and geometry (like [MgSe6] and [MnSe6]) could be a feasible way to develop multifunctional chalcogenides.
Multifunctional semiconductors play an important role in developing advanced photoelectric technologies. In this work, based on an octahedral replacement strategy in chalcogenides, a new selenide semiconductor NaMn3Ga3Se₈ was rationally designed, and synthesized by the flux method. The compound crystallizes in the noncentrosymmetric (NCS) P6̄ space group, and is composed of unique prismatic [NaSe6], octahedral [MnSe6] and tetrahedral [GaSe4] motifs, inheriting the stable three-dimensional framework built by the octahedral and tetrahedral units in the AIMg3ᴵᴵC3ᴵᴵᴵQ₈ⱽᴵ family. NaMn3Ga3Se₈ shows the largest known secondary nonlinear optical (NLO) response of ∼2.1 × AgGaS2 (AGS) in the AIMg3ᴵᴵC3ᴵᴵᴵQ₈ⱽᴵ family, and a high laser-induced damage threshold of ∼3.0 × AGS. Meanwhile, the introduction of Mn2+ with unpaired 3d electrons induces a strong red emission band (685–805 nm) under the excitation source of 496 nm, as well as a paramagnetic to antiferromagnetic (AFM) transition at 7.3 K. The results confirm that NaMn3Ga3Se₈ possesses multifunctional features including significant NLO response, fluorescence emission and AFM properties, and illustrate that replacing octahedral units with approaching size and geometry (like [MgSe6] and [MnSe6]) could be a feasible way to develop multifunctional chalcogenides.
2025, 44(6): 100592
doi: 10.1016/j.cjsc.2025.100592
Abstract:
The tightness of π-π stacking in supramolecular organic semiconductors plays a crucial role in governing the spatial separation and migration dynamics of photogenerated charge carriers, ultimately determining their photocatalytic performance. To achieve close π-π stacking, the suitable design of molecular structure is essential. Therefore, two isomers of pyridine carboxylic acid-modified perylene monoimide (PMI) were designed and synthesized, namely PM5A and PM6A. In aqueous solution, these molecules self-assemble into aggregates, which exhibit distinct stacking properties and optical characteristics. Upon photoexcitation, the loose π-π stacking of PM5A favors the generation of charge-transfer excitons (CTEs) over charge-separation excitons (CSEs). In contrast, PM6A, stabilized by intermolecular hydrogen bonds and possessing close π-π stacking, undergoes efficient charge separation (CS) to produce CSEs within 4.5 picoseconds. When incorporated into metal-insulator-semiconductor (MIS) photosystems with polyvinylpyrrolidone (PVP)-capped Pt, the Pt/PVP/PM6A system demonstrates a hydrogen evolution rate (HER) of 8100 μmol g-1 h-1, nearly five times higher than that of the Pt/PVP/PM5A system. Additionally, the maximum apparent quantum efficiency (AQE) reaches approximately 2.1% under irradiation with light of a single wavelength of λ = 425 nm.
The tightness of π-π stacking in supramolecular organic semiconductors plays a crucial role in governing the spatial separation and migration dynamics of photogenerated charge carriers, ultimately determining their photocatalytic performance. To achieve close π-π stacking, the suitable design of molecular structure is essential. Therefore, two isomers of pyridine carboxylic acid-modified perylene monoimide (PMI) were designed and synthesized, namely PM5A and PM6A. In aqueous solution, these molecules self-assemble into aggregates, which exhibit distinct stacking properties and optical characteristics. Upon photoexcitation, the loose π-π stacking of PM5A favors the generation of charge-transfer excitons (CTEs) over charge-separation excitons (CSEs). In contrast, PM6A, stabilized by intermolecular hydrogen bonds and possessing close π-π stacking, undergoes efficient charge separation (CS) to produce CSEs within 4.5 picoseconds. When incorporated into metal-insulator-semiconductor (MIS) photosystems with polyvinylpyrrolidone (PVP)-capped Pt, the Pt/PVP/PM6A system demonstrates a hydrogen evolution rate (HER) of 8100 μmol g-1 h-1, nearly five times higher than that of the Pt/PVP/PM5A system. Additionally, the maximum apparent quantum efficiency (AQE) reaches approximately 2.1% under irradiation with light of a single wavelength of λ = 425 nm.
2025, 44(6): 100593
doi: 10.1016/j.cjsc.2025.100593
Abstract:
2025, 44(6): 100596
doi: 10.1016/j.cjsc.2025.100596
Abstract:
The structure of water and proton transfer under nanoscale confinement has garnered significant attention due to its crucial role in elucidating various phenomena across multiple scientific disciplines. However, there remains a lack of consensus on fundamental properties such as diffusion behavior and the nature of hydrogen bonding in confined environments. In this work, we investigated the influence of confinement on proton transfer in water confined within graphene sheets at various spacings by ab initio molecule dynamic and multiscale analysis with time evolution of structural properties, graph theory and persistent homology. We found that reducing the graphene interlayer distance while maintaining water density close to that of bulk water leads to a decrease in proton transfer frequency. In contrast, reducing the interlayer distance without maintaining bulk-like water density results in an increase in proton transfer frequency. This difference is mainly due to the confinement conditions: when density is unchanged, the hydrogen bond network remains similar with significant layering, while compressive stress that increases density leads to a more planar hydrogen bond network, promoting faster proton transfer. Our findings elucidate the complex relationship between confinement and proton transfer dynamics, with implications for understanding proton transport in confined environments, relevant to energy storage and material design.
The structure of water and proton transfer under nanoscale confinement has garnered significant attention due to its crucial role in elucidating various phenomena across multiple scientific disciplines. However, there remains a lack of consensus on fundamental properties such as diffusion behavior and the nature of hydrogen bonding in confined environments. In this work, we investigated the influence of confinement on proton transfer in water confined within graphene sheets at various spacings by ab initio molecule dynamic and multiscale analysis with time evolution of structural properties, graph theory and persistent homology. We found that reducing the graphene interlayer distance while maintaining water density close to that of bulk water leads to a decrease in proton transfer frequency. In contrast, reducing the interlayer distance without maintaining bulk-like water density results in an increase in proton transfer frequency. This difference is mainly due to the confinement conditions: when density is unchanged, the hydrogen bond network remains similar with significant layering, while compressive stress that increases density leads to a more planar hydrogen bond network, promoting faster proton transfer. Our findings elucidate the complex relationship between confinement and proton transfer dynamics, with implications for understanding proton transport in confined environments, relevant to energy storage and material design.
2025, 44(6): 100597
doi: 10.1016/j.cjsc.2025.100597
Abstract:
2025, 44(6): 100598
doi: 10.1016/j.cjsc.2025.100598
Abstract:
In this work, we present an innovative method for fabricating high-performance proton-conductive fuel cells (PCFCs) by combining magnetron sputtering and flashlight sintering (FLS) techniques. BaZr0.8Y0.2O3–δ (BZY20) electrolyte thin-films are successfully prepared by improving the crystallinity while maintaining the stoichiometry. All components of PCFC, Ni-YSZ anode, BZY20 electrolyte and Pt-GDC cathode are fabricated by sequentially sputtering them onto an AAO substrate. Electrolytic sintering is performed at 550 and 650 V conditions using FLS, effectively solving the Ba evaporation problem encountered in conventional thermal sintering methods. XRD analysis confirms that the perovskite structure is retained, and crystallinity is improved in the FLS samples. Furthermore, FE-SEM and EDS analyses confirm the uniform elemental distribution and consistent thickness of the FLS-treated electrolyte. An optimized PCFC unit cell with FLS-treated electrolyte exhibits a peak power density of 200.0 mW cm-2 at 500 °C and an ohmic resistance of 376.0 mΩ cm-2. These results suggest that the combination of magnetron sputtering and FLS techniques is a promising approach for fabricating high-performance thin-film PCFCs.
In this work, we present an innovative method for fabricating high-performance proton-conductive fuel cells (PCFCs) by combining magnetron sputtering and flashlight sintering (FLS) techniques. BaZr0.8Y0.2O3–δ (BZY20) electrolyte thin-films are successfully prepared by improving the crystallinity while maintaining the stoichiometry. All components of PCFC, Ni-YSZ anode, BZY20 electrolyte and Pt-GDC cathode are fabricated by sequentially sputtering them onto an AAO substrate. Electrolytic sintering is performed at 550 and 650 V conditions using FLS, effectively solving the Ba evaporation problem encountered in conventional thermal sintering methods. XRD analysis confirms that the perovskite structure is retained, and crystallinity is improved in the FLS samples. Furthermore, FE-SEM and EDS analyses confirm the uniform elemental distribution and consistent thickness of the FLS-treated electrolyte. An optimized PCFC unit cell with FLS-treated electrolyte exhibits a peak power density of 200.0 mW cm-2 at 500 °C and an ohmic resistance of 376.0 mΩ cm-2. These results suggest that the combination of magnetron sputtering and FLS techniques is a promising approach for fabricating high-performance thin-film PCFCs.
2025, 44(6): 100599
doi: 10.1016/j.cjsc.2025.100599
Abstract:
The electrochemical nitrogen reduction reaction (eNRR) presents a sustainable alternative to the energy-intensive Haber-Bosch process for ammonia (NH3) production. This review examines the fundamental principles of eNRR, emphasizing the critical roles of proton-exchange membranes and electrolytes in facilitating efficient nitrogen (N2) reduction. Special attention is given to single-atom catalysts (SACs), highlighting their unique structural and electronic properties that contribute to enhanced catalytic performance. The discussions encompass SACs based on precious metals, non-precious metals, and non-metallic materials, delving into their synthesis methods, coordination environments, and activity in the eNRR. This review also elucidates current challenges in the field and proposes future research directions aimed at optimizing SACs design to enhance eNRR efficiency.
The electrochemical nitrogen reduction reaction (eNRR) presents a sustainable alternative to the energy-intensive Haber-Bosch process for ammonia (NH3) production. This review examines the fundamental principles of eNRR, emphasizing the critical roles of proton-exchange membranes and electrolytes in facilitating efficient nitrogen (N2) reduction. Special attention is given to single-atom catalysts (SACs), highlighting their unique structural and electronic properties that contribute to enhanced catalytic performance. The discussions encompass SACs based on precious metals, non-precious metals, and non-metallic materials, delving into their synthesis methods, coordination environments, and activity in the eNRR. This review also elucidates current challenges in the field and proposes future research directions aimed at optimizing SACs design to enhance eNRR efficiency.
