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2025 Volume 44 Issue 9
2025, 44(9): 100651
doi: 10.1016/j.cjsc.2025.100651
Abstract:
In recent years, the discharge of urea-containing wastewater from industrial and domestic sources has posed a continuing threat to aquatic ecosystems and human health. In this context, the urea oxidation reaction (UOR) has attracted significant attention due to its low thermodynamic potential of 0.37 V (vs. RHE). Compared with oxygen evolution reaction (OER), this reaction can significantly reduce the energy consumption of electrolysis while realizing wastewater treatment, and has the dual functions of hydrogen energy preparation and wastewater purification. However, UOR involves complex six-electron transfer and intermediate adsorption/desorption processes, resulting in slow reaction kinetics. Therefore, the development of economical and efficient catalysts has become a research focus, among which transition metal phosphides (TMPs) stand out due to their low cost, excellent activity and adjustable electronic structure. Compared with other non-noble metal systems, TMPs have unique electronic structure and surface properties that can adsorb and activate urea molecules more efficiently. However, there is still a lack of systematic reviews on TMP catalysts at present. Therefore, this review aims to deeply and systematically elaborate the design strategies of TMP catalysts and their applications in UOR, thoroughly discuss the current progress, challenges and future directions, and provide theoretical support and design ideas for the development of a new generation of efficient and stable UOR catalysts.
In recent years, the discharge of urea-containing wastewater from industrial and domestic sources has posed a continuing threat to aquatic ecosystems and human health. In this context, the urea oxidation reaction (UOR) has attracted significant attention due to its low thermodynamic potential of 0.37 V (vs. RHE). Compared with oxygen evolution reaction (OER), this reaction can significantly reduce the energy consumption of electrolysis while realizing wastewater treatment, and has the dual functions of hydrogen energy preparation and wastewater purification. However, UOR involves complex six-electron transfer and intermediate adsorption/desorption processes, resulting in slow reaction kinetics. Therefore, the development of economical and efficient catalysts has become a research focus, among which transition metal phosphides (TMPs) stand out due to their low cost, excellent activity and adjustable electronic structure. Compared with other non-noble metal systems, TMPs have unique electronic structure and surface properties that can adsorb and activate urea molecules more efficiently. However, there is still a lack of systematic reviews on TMP catalysts at present. Therefore, this review aims to deeply and systematically elaborate the design strategies of TMP catalysts and their applications in UOR, thoroughly discuss the current progress, challenges and future directions, and provide theoretical support and design ideas for the development of a new generation of efficient and stable UOR catalysts.
2025, 44(9): 100652
doi: 10.1016/j.cjsc.2025.100652
Abstract:
Per- and polyfluoroalkyl substances (PFAS) are persistent environmental contaminants that often show an adverse impact on human health. Rational design of porous adsorbents for selective and reversible removal of PFAS, such as perfluorooctane sulfonate (PFOS), is imperative and challenging. Herein, a Janus strategy based on an ionic covalent organic framework (iCOF-DGCl) composed of the alternately hydrophobic aromatic domains and hydrophilic guanidinium moieites has been proposed to meet the requirement of high-performance adsorbents. iCOF-DGCl shows fast adsorption kinetics (970.9 mg g-1 min-1) and ultrahigh uptake capacity (2491 mg g-1) toward PFOS, making it one of the most effective materials among the reported PFOS adsorbents. Moreover, the PFOS removal by iCOF-DGCl remains highly selective in the presence of disturbing anions, and the adsorbent could be well recovered for reuse. Mechanism studies have demonstrated that the Janus structure units of iCOF-DGCl form both hydrophobic and electrostatic interactions with the amphiphilic PFOS, thus achieving cooperative adsorption of PFOS. This work provides a facile approach based on Janus structure of COFs adsorbent for wastewater remediation.
Per- and polyfluoroalkyl substances (PFAS) are persistent environmental contaminants that often show an adverse impact on human health. Rational design of porous adsorbents for selective and reversible removal of PFAS, such as perfluorooctane sulfonate (PFOS), is imperative and challenging. Herein, a Janus strategy based on an ionic covalent organic framework (iCOF-DGCl) composed of the alternately hydrophobic aromatic domains and hydrophilic guanidinium moieites has been proposed to meet the requirement of high-performance adsorbents. iCOF-DGCl shows fast adsorption kinetics (970.9 mg g-1 min-1) and ultrahigh uptake capacity (2491 mg g-1) toward PFOS, making it one of the most effective materials among the reported PFOS adsorbents. Moreover, the PFOS removal by iCOF-DGCl remains highly selective in the presence of disturbing anions, and the adsorbent could be well recovered for reuse. Mechanism studies have demonstrated that the Janus structure units of iCOF-DGCl form both hydrophobic and electrostatic interactions with the amphiphilic PFOS, thus achieving cooperative adsorption of PFOS. This work provides a facile approach based on Janus structure of COFs adsorbent for wastewater remediation.
2025, 44(9): 100653
doi: 10.1016/j.cjsc.2025.100653
Abstract:
Six aryl- and pyridine-substituted nitronyl-nitroxide radicals were synthesized and characterized to investigate their optical anisotropic properties. Single-crystal X-ray diffraction analysis revealed molecular packing organized by either halogen and hydrogen bonding or hydrogen bonding alone. Single-crystal electronic absorption spectra in the visible region of three studied radicals exhibit pronounced linear dichroism, while single crystals of other radicals do not demonstrate this property. Time-dependent DFT and ab initio calculations were employed to determine the transition dipole moment (TDM) vectors corresponding to the long-wavelength absorption bands. For all radicals, these vectors are found to be practically parallel to the O⋯O direction of the nitronyl-nitroxide chromophore. Correlation between the dichroic properties and crystal structure was established through comprehensive analysis of TDM vector orientations relative to the crystal surface. The strongest dichroic effect was observed in crystals where all projections of the TDM vectors onto the illuminated face are parallel to each other, while weaker or absent effects correspond to non-parallel arrangements. This study constitutes the first systematic investigation of linear dichroism in paramagnetic organic crystals, thereby establishing new avenues for developing multifunctional materials that respond to both optical and magnetic stimuli.
Six aryl- and pyridine-substituted nitronyl-nitroxide radicals were synthesized and characterized to investigate their optical anisotropic properties. Single-crystal X-ray diffraction analysis revealed molecular packing organized by either halogen and hydrogen bonding or hydrogen bonding alone. Single-crystal electronic absorption spectra in the visible region of three studied radicals exhibit pronounced linear dichroism, while single crystals of other radicals do not demonstrate this property. Time-dependent DFT and ab initio calculations were employed to determine the transition dipole moment (TDM) vectors corresponding to the long-wavelength absorption bands. For all radicals, these vectors are found to be practically parallel to the O⋯O direction of the nitronyl-nitroxide chromophore. Correlation between the dichroic properties and crystal structure was established through comprehensive analysis of TDM vector orientations relative to the crystal surface. The strongest dichroic effect was observed in crystals where all projections of the TDM vectors onto the illuminated face are parallel to each other, while weaker or absent effects correspond to non-parallel arrangements. This study constitutes the first systematic investigation of linear dichroism in paramagnetic organic crystals, thereby establishing new avenues for developing multifunctional materials that respond to both optical and magnetic stimuli.
2025, 44(9): 100654
doi: 10.1016/j.cjsc.2025.100654
Abstract:
The Baeyer-Villiger (BV) oxidation of cyclohexanone is explored using IWV-type aluminosilicates with different Al sites as heterogeneous catalysts. The IWV framework exhibits a two-dimensional 12-membered ring (MR) pore system intersected by 14-MR supercages, resembling typical beta zeolite. To address the constraints associated with hydrothermal synthesis, IWV aluminosilicates were synthesized via interzeolite transformation of various FAU-type zeolites. HF-assisted transformation of dealuminated FAU zeolite resulted in the formation of a high-silica IWV aluminosilicate (Si/Al = 54.6), whereas the incorporation of aluminum isopropoxide enables the tuning of Si/Al ratio down to 18.7. The alkaline conversion of protonated FAU zeolites, utilizing Na+ ions as mineralizing agents, produces high-Al content IWV derivatives in just four days. Catalytic evaluation demonstrates that the high-silica IWV catalyst exhibits a higher turnover number than the other IWV catalysts, along with enhanced ε-caprolactone (CL) selectivity relative to that of high-silica beta zeolite. Facile modifications are performed to adjust Al sites, as characterized by pyridine-adsorbed infrared spectroscopy. Experimental evidence confirms that Al Brønsted acid sites improves the selective oxidation of cyclohexanone, while concurrently enhancing CL hydrolysis.
The Baeyer-Villiger (BV) oxidation of cyclohexanone is explored using IWV-type aluminosilicates with different Al sites as heterogeneous catalysts. The IWV framework exhibits a two-dimensional 12-membered ring (MR) pore system intersected by 14-MR supercages, resembling typical beta zeolite. To address the constraints associated with hydrothermal synthesis, IWV aluminosilicates were synthesized via interzeolite transformation of various FAU-type zeolites. HF-assisted transformation of dealuminated FAU zeolite resulted in the formation of a high-silica IWV aluminosilicate (Si/Al = 54.6), whereas the incorporation of aluminum isopropoxide enables the tuning of Si/Al ratio down to 18.7. The alkaline conversion of protonated FAU zeolites, utilizing Na+ ions as mineralizing agents, produces high-Al content IWV derivatives in just four days. Catalytic evaluation demonstrates that the high-silica IWV catalyst exhibits a higher turnover number than the other IWV catalysts, along with enhanced ε-caprolactone (CL) selectivity relative to that of high-silica beta zeolite. Facile modifications are performed to adjust Al sites, as characterized by pyridine-adsorbed infrared spectroscopy. Experimental evidence confirms that Al Brønsted acid sites improves the selective oxidation of cyclohexanone, while concurrently enhancing CL hydrolysis.
2025, 44(9): 100655
doi: 10.1016/j.cjsc.2025.100655
Abstract:
2025, 44(9): 100656
doi: 10.1016/j.cjsc.2025.100656
Abstract:
2025, 44(9): 100657
doi: 10.1016/j.cjsc.2025.100657
Abstract:
2025, 44(9): 100658
doi: 10.1016/j.cjsc.2025.100658
Abstract:
2025, 44(9): 100659
doi: 10.1016/j.cjsc.2025.100659
Abstract:
Odd-numbered and high-nuclearity coordination clusters are extremely rare, yet they represent an intriguing subclass lacking regular repeating building blocks and high structural symmetry for understanding self-assembled multiatomic systems. Herein, the largest cobalt and polydentate ligand based cluster featuring odd-nuclearity, namely [Co19(HL1)8(L1)12(L′)2(Ac)4]·10CH3CH2OH·6H2O (1, H2L1 = 1H-benzo[d]imidazole-2-yl)methanol, HL' = 1H-benzo[d]imidazole), was obtained with in-situ ligand transformation from H2L1 to L′. It features a hierarchical trilayer and void-cage inside structure, consisting of central disc-shaped [Co7L10] core with two [Co6] rings on both sides. ESI-MS of crystal 1 yields a series of more than sixteen fragments, all featuring an integrated [Co19] core, suggesting stability of the polynuclear cluster in solution. During increased in-source energy from 0 to 100 eV, all MS peaks shifted to a lower m/z range, but the [Co19] core remained intact, excepting for the stepwise elimination of up to three Ac- anions or three L1 linkers. PXRD tracking of the reaction sediments showed the formation of a key precursor of [Co4L4] cubane at 3 h, and its content decreased at 6 h and vanished at 12 h, followed by the appearance of crystals 1 by the generation of a clear solution at 18 h, suggesting an initial cluster assembly-disassembly process. ESI-MS spectra analysis of both reaction sediment and solution further identify the existence of other crucial higher-nuclearity reassembled fragments of [Co7L10] disk and its expansion of [Co13L12(L′)2]. A probable tandem assembly-disassembly-reassembly mechanism is put forward as [CoL2]→[Co4L4]→[Co7L10]→[Co13L12(L′)2]→[Co19L20(L′)2]. Their evolution also indicated the ingenious synergy of coexisting organic, inorganic and in-situ generated ligands, along with diverse coordination geometries of metal ions, plays a directional role in forming odd-numbered and high-nuclearity coordination clusters. Magnetism analysis revealed antiferromagnetic coupling plays dominated role in the cluster.
Odd-numbered and high-nuclearity coordination clusters are extremely rare, yet they represent an intriguing subclass lacking regular repeating building blocks and high structural symmetry for understanding self-assembled multiatomic systems. Herein, the largest cobalt and polydentate ligand based cluster featuring odd-nuclearity, namely [Co19(HL1)8(L1)12(L′)2(Ac)4]·10CH3CH2OH·6H2O (1, H2L1 = 1H-benzo[d]imidazole-2-yl)methanol, HL' = 1H-benzo[d]imidazole), was obtained with in-situ ligand transformation from H2L1 to L′. It features a hierarchical trilayer and void-cage inside structure, consisting of central disc-shaped [Co7L10] core with two [Co6] rings on both sides. ESI-MS of crystal 1 yields a series of more than sixteen fragments, all featuring an integrated [Co19] core, suggesting stability of the polynuclear cluster in solution. During increased in-source energy from 0 to 100 eV, all MS peaks shifted to a lower m/z range, but the [Co19] core remained intact, excepting for the stepwise elimination of up to three Ac- anions or three L1 linkers. PXRD tracking of the reaction sediments showed the formation of a key precursor of [Co4L4] cubane at 3 h, and its content decreased at 6 h and vanished at 12 h, followed by the appearance of crystals 1 by the generation of a clear solution at 18 h, suggesting an initial cluster assembly-disassembly process. ESI-MS spectra analysis of both reaction sediment and solution further identify the existence of other crucial higher-nuclearity reassembled fragments of [Co7L10] disk and its expansion of [Co13L12(L′)2]. A probable tandem assembly-disassembly-reassembly mechanism is put forward as [CoL2]→[Co4L4]→[Co7L10]→[Co13L12(L′)2]→[Co19L20(L′)2]. Their evolution also indicated the ingenious synergy of coexisting organic, inorganic and in-situ generated ligands, along with diverse coordination geometries of metal ions, plays a directional role in forming odd-numbered and high-nuclearity coordination clusters. Magnetism analysis revealed antiferromagnetic coupling plays dominated role in the cluster.
2025, 44(9): 100660
doi: 10.1016/j.cjsc.2025.100660
Abstract:
The synthesized molecular clusters featuring the cubic [4Fe–4S] core have been studied for several decades, as they serve as true analogs of the active components in ferritin within biological systems. Such a model cluster has been extensively investigated in various fields, including structural modulation, catalysis, and self-assembly under laboratory conditions, with the aim of gaining an in-depth understanding of their roles in biological functions. Herein, we revisited three well-known [Fe4S4(SR)4]2– molecules, namely [Me4N]2[Fe4S4(SR)4] (R = o-MBT, m-MBT, p-MBT), and successfully established their single crystal structures that remain unknown prior to this work. Interestingly, it is revealed that the position of the substituent methyl group has an obvious steric effect on the arrangement of the ligand around the [4Fe–4S] core, which further influences their overall packing patterns in single crystals. In addition, this work unveils two new structure transformation behaviors for the [Fe4S4(SR)4]2– system: i) the monomeric [Fe(SR)4]2– and tetrameric [Fe4S4(SR)4]2– can be interconverted, and ii) [Fe4S4(SR)4]2– can be transferred into an intriguing iron-oxide complex Na2Fe6O(OMe)18·6MeOH in a well-controlled oxidizing environment.
The synthesized molecular clusters featuring the cubic [4Fe–4S] core have been studied for several decades, as they serve as true analogs of the active components in ferritin within biological systems. Such a model cluster has been extensively investigated in various fields, including structural modulation, catalysis, and self-assembly under laboratory conditions, with the aim of gaining an in-depth understanding of their roles in biological functions. Herein, we revisited three well-known [Fe4S4(SR)4]2– molecules, namely [Me4N]2[Fe4S4(SR)4] (R = o-MBT, m-MBT, p-MBT), and successfully established their single crystal structures that remain unknown prior to this work. Interestingly, it is revealed that the position of the substituent methyl group has an obvious steric effect on the arrangement of the ligand around the [4Fe–4S] core, which further influences their overall packing patterns in single crystals. In addition, this work unveils two new structure transformation behaviors for the [Fe4S4(SR)4]2– system: i) the monomeric [Fe(SR)4]2– and tetrameric [Fe4S4(SR)4]2– can be interconverted, and ii) [Fe4S4(SR)4]2– can be transferred into an intriguing iron-oxide complex Na2Fe6O(OMe)18·6MeOH in a well-controlled oxidizing environment.
2025, 44(9): 100661
doi: 10.1016/j.cjsc.2025.100661
Abstract:
Defect engineering significantly enhances electrocatalytic performance by modulating electronic structures and interfacial coordination, yet the dynamic correlation between defect evolution and catalytic activity during reactions remains unclear. Herein, density functional theory (DFT) calculations first reveal the modulation of sulfur vacancy concentrations on Co9S8 electronic structures, predicting that optimized vacancy concentrations enable highly efficient electrocatalytic water splitting. Experimentally fabricated Co9S8 with appropriate sulfur vacancies exhibits superior bifunctional activity (HER: 164 mV@η10; OER: 297 mV@η100). The MCS-assembled overall water splitting system demonstrates stable operation at 1.57 V (10 mA cm-2) for over 60 h. Experimental studies illustrate that sulfur vacancies preferentially adsorb OH- during reactions, inducing the formation of CoOOH active phases. DFT analysis further indicates that OH- adsorption weakens d-p orbital hybridization, optimizing hydrogen/oxygen intermediate adsorption energy barriers and ultimately enhancing catalytic performance. This work establishes novel paradigms for systematic development of catalysts through synergistic analysis of defect dynamics, electronic structures and catalytic performance.
Defect engineering significantly enhances electrocatalytic performance by modulating electronic structures and interfacial coordination, yet the dynamic correlation between defect evolution and catalytic activity during reactions remains unclear. Herein, density functional theory (DFT) calculations first reveal the modulation of sulfur vacancy concentrations on Co9S8 electronic structures, predicting that optimized vacancy concentrations enable highly efficient electrocatalytic water splitting. Experimentally fabricated Co9S8 with appropriate sulfur vacancies exhibits superior bifunctional activity (HER: 164 mV@η10; OER: 297 mV@η100). The MCS-assembled overall water splitting system demonstrates stable operation at 1.57 V (10 mA cm-2) for over 60 h. Experimental studies illustrate that sulfur vacancies preferentially adsorb OH- during reactions, inducing the formation of CoOOH active phases. DFT analysis further indicates that OH- adsorption weakens d-p orbital hybridization, optimizing hydrogen/oxygen intermediate adsorption energy barriers and ultimately enhancing catalytic performance. This work establishes novel paradigms for systematic development of catalysts through synergistic analysis of defect dynamics, electronic structures and catalytic performance.
2025, 44(9): 100675
doi: 10.1016/j.cjsc.2025.100675
Abstract:
2025, 44(9): 100676
doi: 10.1016/j.cjsc.2025.100676
Abstract:
An expanding human population and technological progress demand clean and effective energy-storing systems. Within the realm of energy-storing devices, supercapacitors (SCs) have grabbed huge focus owing to their high-power density, unique cycling stability, and fast charging discharging capabilities. Electrode material has a prominent impact on the effectiveness of SCs. Several types of electrode materials have been used, encompassing varied metal oxides, activated carbon, conducting polymers, and MOFs. Metal organic frameworks (MOFs) are considered emerging electrode candidates, which could be ascribed to the tunable porosity, large surface areas, and designed morphology. This review shows a detailed analysis of various mono-, bi-, and tri-metallic MOFs along with derivatives in SC applications, their structural characteristics, and synthetic strategies. It also critically evaluates MOFs potential to boost the SC's energy density, power density, stability, and conductivity. Also, it underscores their significance in the establishment of future-oriented energy storage applications.
An expanding human population and technological progress demand clean and effective energy-storing systems. Within the realm of energy-storing devices, supercapacitors (SCs) have grabbed huge focus owing to their high-power density, unique cycling stability, and fast charging discharging capabilities. Electrode material has a prominent impact on the effectiveness of SCs. Several types of electrode materials have been used, encompassing varied metal oxides, activated carbon, conducting polymers, and MOFs. Metal organic frameworks (MOFs) are considered emerging electrode candidates, which could be ascribed to the tunable porosity, large surface areas, and designed morphology. This review shows a detailed analysis of various mono-, bi-, and tri-metallic MOFs along with derivatives in SC applications, their structural characteristics, and synthetic strategies. It also critically evaluates MOFs potential to boost the SC's energy density, power density, stability, and conductivity. Also, it underscores their significance in the establishment of future-oriented energy storage applications.
2025, 44(9): 100708
doi: 10.1016/j.cjsc.2025.100708
Abstract:
Short-wavelength nonlinear optical (NLO) crystals can convert a specific wavelength of light to ultraviolet (UV) and deep-UV region. To date, most of the commercialized UV and deep-UV NLO materials are borate crystals. By combining the merits of borates and silicates, borosilicates exhibit some unique advantages of rich structural types, moderate second harmonic generation (SHG) response, and high UV transmittance. This paper summarizes the known NLO borosilicates which can be grouped into two types according to the linkage modes of B–O and Si–O units: (1) borosilicates with B–O–Si covalent bond, and (2) borosilicates with isolated B–O and Si–O units. The structural features, SHG intensities, and UV cutoff edges of these borosilicates are discussed. Finally, future perspectives in this field are presented.
Short-wavelength nonlinear optical (NLO) crystals can convert a specific wavelength of light to ultraviolet (UV) and deep-UV region. To date, most of the commercialized UV and deep-UV NLO materials are borate crystals. By combining the merits of borates and silicates, borosilicates exhibit some unique advantages of rich structural types, moderate second harmonic generation (SHG) response, and high UV transmittance. This paper summarizes the known NLO borosilicates which can be grouped into two types according to the linkage modes of B–O and Si–O units: (1) borosilicates with B–O–Si covalent bond, and (2) borosilicates with isolated B–O and Si–O units. The structural features, SHG intensities, and UV cutoff edges of these borosilicates are discussed. Finally, future perspectives in this field are presented.
