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ArticleSelective Electrocatalytic Hydrogenation of 5-Hydroxymethyl-furfural to 2,5-Dihydroxymethylfuran on Bimetallic PdCu Alloy
Xu Yue, Weixing Zhao, Shuangyin Wang and Yuqin Zou*
Chin. J. Struct. Chem. 2022, 41, 2205063-2205069 DOI: 10.14102/j.cnki.0254-5861.2022-0074
May 20, 2022
biomass, 2,5-dihydroxymethylfuran, electrocatalyst, bimetallic alloy, hydrogenation
ABSTRACT
2,5-Dihydroxymethylfuran (DHMF), obtained from 5-hydroxymethylfurfural (HMF) by electrochemical method, is a promising building block for polymers. However, one challenge of this process is to reduce initial potential and improve catalytic selectivity. In this work, the PdCu bimetallic catalyst is prepared with an onset potential of -0.05 VRHE and a selectivity of 99%. Compared with the single Cu electrocatalyst, the adsorption of HMF and proton is improved by introducing of Pd, which is demonstrated by the electrochemical results and hydrogen production rate. This work provides an effective strategy to improve the selectivity of Cu-based electrocatalyst and builds a relationship between the adsorption capacity and the electrocatalytic performance. -
ArticleHighly Efficient Photocatalytic CO2 Methanation over Ru-Doped TiO2 with Tunable Oxygen Vacancies
Zheyue Li†, Di Wu†, Wanbing Gong*, Jiayi Li, Shuaikang Sang, Hengjie Liu, Ran Long and Yujie Xiong*
Chin. J. Struct. Chem. 2022, 41, 2212043-2212050 DOI: 10.14102/j.cnki.0254-5861.2022-0212
December 2, 2022
photocatalysis, CO2 methanation, metal doping, titanium oxide, oxygen vacancies
ABSTRACT
Solar-driven CO2 methanation is an imperative and promising approach to relieve the global warming and environmental crisis, yet remains a great challenge due to the low reaction efficiency, unsatisfactory selectivity and poor stability. In this work, we demonstrate a facile and efficient strategy to prepare Ru-doped TiO2 photocatalyst with tunable oxygen vacancies using the ascorbic acid as a reducing agent for the CO2 methanation reaction. The optimal Ru-TiO2-OV-50 exhibits a remarkable CH4 production rate of 81.7 mmol g-1 h-1 with a 100% CH4 selectivity under a 1.5 W cm-2 light illumination, which is significantly higher than commercial Ru/TiO2 and other reported catalysts. We reveal that the superior photocatalytic CO2 methanation performance is mainly due to the synergistic effect of Ru doping and TiO2 with tunable oxygen vacancies. Impressively, the light rather than thermal effect is confirmed as the main influencing factor by experimental studies. In addition, in situ spectroscopic technology is performed to investigate the CO2 methanation reaction pathway. This work will open an avenue to design and prepare highly efficient photocatalyst with tunable oxygen vacancies for CO2 conversion and other related applications. -
ArticleCoordination Assembly of Tetrahedral Ti4(embonate)6 Cages with Alkaline-Earth Metal IonsRuiyan Chen, Guanghui Chen, Yanping He* and Jian Zhang*
Chin. J. Struct. Chem. 2022, 41, 2201001-2201006 DOI: 10.14102/j.cnki.0254-5861.2021-0016
January 13, 2022
metal-organic cages, stepwise-assembly, alkaline-earth, structures, nonlinear optics
ABSTRACT
Recently, the tetrahedral Ti4L6 cage (L = embonate) has been applied as the starting material to realize coordination assembly with transition and rare-earth ornoble metal ions through a two-step reaction. In this work, by employing the Ti4L6 cages to assemble with alkaline-earth metal ions (such as Mg2+, Ca2+ and Ba2+) under different solvothermal conditions, a series of Ti4L6-based structures from simple cages to 1D chain, 2D layer and 3D framework have been synthesized and structurally characterized. In addition, thermal stability, phase purity, UV-vis absorption spectrum, the fluorescent and third-order nonlinear-optical properties are also investigated.
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ArticleLayer-by-Layer Grafting Dye on Chiral MOF Thin Films for Circularly Polarized Luminescence
Rui Zhai, Yindi Zhu, Limei Chang, Zhigang Gu* and Jian Zhang*
Chin. J. Struct. Chem. 2022, 41, 2209074-2209079 DOI: 10.14102/j.cnki.0254-5861.2022-0023
September 22, 2022
metal-organic frameworks, liquid-phase epitaxy, thin film, circularly polarized luminescence
ABSTRACT
Metal-organic frameworks with chiral feature (chirMOFs) are attracting great attention on circularly polarized luminescence (CPL). However, developing new efficient strategy to achieve or improve CPL properties is an urgent task. Herein, new chiral MOF thin films prepared by liquid-phase epitaxial layer by layer (lbl) growth method (SURchirMOF) are composed of D- or L-camphorate (D/Lcam) and aminopyrazine (Pr-NH2) by using liquid phase epitaxial layer by layer (lbl) method. The resulted Zn2(D/Lcam)2Pr-NH2 SURchirMOF shows strong chirality and luminescence but weak CPL emission at 390 nm. After lbl modifying a dye molecule FluoresceinIsothiocyanate (FITC), the chiroptical Zn2(D/Lcam)2Pr-NH-FITC SURchirMOFs with ~7 times CPL signal improvement and ~3 times glum value amplification are obtained. This work provides a new strategy to develop chiral MOF thin films for CPL improvement using lbl grafting approach. -
ReviewTransition Metal Boride-Based Materials for Electrocatalytic Water Splitting
Feng-Ge Wang, Xin Liu, Qian-Xi Lv, Bin Liu*, Yong-Ming Chai and Bin Dong*
Chin. J. Struct. Chem. 2022, 41, 2209008-2209044 DOI: 10.14102/j.cnki.0254-5861.2022-0117
September 22, 2022
transition metal borides/borates, electrocatalysts, hydrogen evolution reaction (HER), oxygen evolution reaction (OER), overall water splitting
ABSTRACT
Electrocatalytic water splitting to produce hydrogen is an eco-friendly way to achieve sustainable utilization of renewable energy. The industrial application of water electrolysis, which is severely limited by slow kinetic reactions on electrode surfaces, requires the development of highly reactive, low-cost and stable electrocatalytic materials. Transition metal borides/borates have recently emerged as promising electrocatalytic materials for catalyzing hydrogen/oxygen evolution reactions (HER/OER) in inexpensive electrolyzers. However, so far, there has been little comprehensive summary of transition metal borides/borates. Here, this review provides the latest research progress on transition metal borides/borates for electrocatalytic water splitting. The structural characteristics of transition metal borides/borates and their synthesis methods in recent years are discussed. Then, the theoretical and experimental progress of transition metal borides including single-metal borides, multi-metal borides, borate derived and other nanocomposites containing boron (boron-doped nanocomposites/substrate with boron) in electrocatalytic reaction and the role of boron in regulating electrocatalytic performance are further emphasized. Finally, the potential challenges and future prospects of transition metal borides/borates in electrocatalysis are presented. -
CommunicationStrong High Entropy Alloy-Support Interaction Enables Efficient Electrocatalytic Water Splitting at High Current DensityHongdong Li, Yue Pan, Jianping Lai*, Lei Wang* and Shouhua Feng
Chin. J. Struct. Chem. 2022, 41, 2208003-2208011 DOI: 10.14102/j.cnki.0254-5861.2022-0125
July 25, 2022
high entropy alloy, metal-support interactions, microwave heating, water splitting, activity and durability
ABSTRACT
In electrocatalysis, the stability issue between catalyst and support still needs great attention. Here, a series of high- entropy alloy nanoparticles (HEA-NPs) embedded in carbon cloth (CC) were synthesized by using the scalable strategy-microwave heating. Among them, PtRhCoNiCu/CC exhibits outstanding hydrogen evolution reaction (HER) activity (19 and 170 mV overpotential at 10 and 1000 mA cm-2) and stability (150 h), outperforming other recently reported HEAs catalysts. IrRuCoNiCu/CC displays superior oxygen evolution reaction (OER) activity (166 and 354 mV overpotential at 10 and 1000 mA cm-2) and stability (150 h), and shows a lower overpotential than recently reported HEA catalysts. In water splitting, IrRuCoNiCu/CC(+)//PtRhCoNiCu/CC(-) electrolyzer achieves 500 mA cm-2 (1000 mA cm-2) high current density at 1.76 V (1.88 V) and exhibits excellent stability, which is one of the best catalysts currently. Therefore, the novel supported HEA catalyst with high stability is expected to be a promising candidate material for industrialized water splitting. -
ArticleExplicating the Role of Metal Centers in Porphyrin-Based MOFs of PCN-222(M) for Electrochemical Reduction of CO2
Mengjie Liu, Mengting Peng, Baoxia Dong*, Yunlei Teng, Ligang Feng and Qiang Xu*
Chin. J. Struct. Chem. 2022, 41, 2207046-2207052 DOI: 10.14102/j.cnki.0254-5861.2022-0057
July 18, 2022
PCN-222, electrochemical reduction of CO2, DFT calculation, MOFs
ABSTRACT
The porphyrin-based MOFs formed by combining Zr6 clusters and porphyrin carboxylic acids with clear M-N4 active centers show unique advantages in electrocatalytic reduction of CO2 (CO2RR). However, its conductivity is still the bottleneck that limits its catalytic activity due to the electrical insulation of the Zr cluster. Therefore, the porphyrin-based MOFs of PCN-222(M) (M = Mn, Co, Ni, Zn) with explicit M-N4 coordination were combined with the highly conductive material carbon nanotube (CNT) for discussing the influence of metal centers on the CO2RR performance based on theoretical calculations and experimental observations. The results show that the PCN-222(Mn)/CNT, PCN-222(Co)/CNT, and PCN-222(Zn)/CNT all exhibit high selectivity to CO (FECO > 80%) in the range of -0.60 to -0.70 V vs. RHE. The FECOmax of PCN-222(Mn)/CNT (-0.60 V vs. RHE), PCN-222(Co)/CNT (-0.65 V vs. RHE), and PCN-222(Zn)/CNT (-0.70 V vs. RHE) are 88.5%, 89.3% and 92.5%, respectively. The high catalytic activity of PCN-222(Mn)/CNT and PCN-222(Co)/CNT comes from the excellent electron mobility of their porphyrin rings and their low ΔG*COOH (0.87 and 0.58 eV). It reveals that the strength of backbonding π of the transition metal and its influence on the electron mobility in the porphyrin ring can affect its CO2RR activity. -
ArticleCrystal Structure, Fe3+ Luminescence Sensing and Color Tuning of 2D Lanthanide-metal-organic Frameworks Constructed from Tricarboxylic Acid LigandPAN Meng-Qi, YANG Run-Qi, MUHAMMAD Yaseen, CAI Kun-Tong, HAN Feng, ZHANG Hao-Chen, NIU Yuan-Qing and WANG Hao*
Chin. J. Struct. Chem. 2022, 41, 2202023-2202033 DOI: 10.14102/j.cnki.0254-5861.2011-3243
February 15, 2022
lanthanide metal-organic frameworks, sensing, luminescence, Fe3+, color tuning
ABSTRACT
A new lanthanide metal-organic framework (MOF) [Eu(BTB)(phen)(DMF)]DMF (1, DMF = N,N-dimethylformamide) was synthesized using H3BTB (1,3,5-tri(4-carboxyphenyl)benzene) and phen (1,10-phenanthroline) under solvothermal conditions. The structure of the prepared MOF was characterized by single-crystal X-ray diffraction analyses, elemental analysis, fluorescence spectrum, FT-IR spectroscopy, powder X-ray diffraction and thermogravimetric analyses. The structure of 1 can be viewed as a 3-D supramolecular network, which is formed by the stacking of 2D layers through π-π interaction. The luminescence explorations revealed that 1 possesses favorable selectivity and sensitivity for testing Fe3+. Additionally, color tuning was achieved by varying Eu3+:Tb3+ ratios in the reaction mixtures. -
ArticleWO3@Fe2O3 Core-Shell Heterojunction Photoanodes for Efficient Photoelectrochemical Water SplittingGuobing Mao, Heng Wu, Tianyang Qiu, Dingjie Bao, Longjie Lai, Wenguang Tu* and Qi Liu*
Chin. J. Struct. Chem. 2022, 41, 2208025-2208030 DOI: 10.14102/j.cnki.0254-5861.2022-0086
July 25, 2022
host/guest photoelectrodes, WO3, a-Fe2O3, core-shell nanostructures, one-dimensional nanoarray
ABSTRACT
Photoelectrochemical (PEC) hydrogen production from water splitting is a green technology to convert solar energy into renewable hydrogen fuel. The construction of host/guest architecture in semiconductor photoanodes has been proven to be an effective strategy to improve solar-to-fuel conversion efficiency. In this study, WO3@Fe2O3 core-shell nanoarray heterojunction photoanodes are synthesized from the in-situ decomposition of WO3@Prussian blue (WO3@PB) and then used as host/guest photoanodes for photoelectrochemical water splitting, during which Fe2O3 serves as guest material to absorb visible solar light and WO3 can act as host scaffolds to collect electrons at the contact. The prepared WO3@Fe2O3 shows the enhanced photocurrent density of 1.26 mA cm-2 (under visible light) at 1.23 V vs RHE and a superior IPEC of 24.4% at 350 nm, which is higher than that of WO3@PB and pure WO3 (0.43 mA/cm-2 and 16.3%, 0.18 mA/cm-2 and 11.5%) respectively, owing to the efficient light-harvesting from Fe2O3 and the enhanced electron-hole pairs separation from the formation of type-II heterojunctions, and the direct and ordered charge transport channels from the one-dimensional (1D) WO3 nanoarray nanostructures. Therefore, this work provides an alternative insight into the construction of sustainable and cost-effective photoanodes to enhance the efficiency of the solar-driven water splitting. -
ArticleUltrathin ZnIn2S4 Nanosheets-Supported Metallic Ni3FeN for Photocatalytic Coupled Selective Alcohol Oxidation and H2 Evolution
Mengqing Li, Weiliang Qi, Jiuyang Yu, Lijuan Shen, Xuhui Yang, Siqi Liu* and Min-Quan Yang*
Chin. J. Struct. Chem. 2022, 41, 2212015-2212024 DOI: 10.14102/j.cnki.0254-5861.2022-0147
December 2, 2022
transition metal nitrides, cocatalyst, ultrathin 2D nanosheets, electrostatic self-assembly, interfacial contact, selective alcohol oxidation, H2 evolution
ABSTRACT
Photocatalytic anaerobic organic oxidation coupled with H2 evolution represents an advanced solar energy utilization strategy for the coproduction of clean fuel and fine chemicals. To achieve a high conversion efficiency, the smart design of efficient catalysts by the right combination of semiconductor light harvesters and cocatalyst is highly required. Herein, we report a composite photocatalyst composed of noble metal-free transition metal nitride Ni3FeN decorated on 2D ultrathin ZnIn2S4 (ZIS) nanosheets for selective oxidation of aromatic alcohols to aldehydes pairing with H2 production. In the composite, ultrathin ZIS serves as a light harvester that greatly shortens the diffusion length of photogenerated charges, while the metallic nitride Ni3FeN acts as an advanced cocatalyst which not only captures the photoelectrons generated from the ultrathin ZIS to promote the charge separation, but also provides active sites to lower the overpotential and accelerate the H2 reduction. The best photocatalytic performance is found on ZIS/1.5% M-Ni3FeN, which shows a H2 generation rate of 2427.9 μmol g-1 h−1 and a benzaldehyde (BAD) production rate of 2460 μmol g-1 h-1, about 7.8-fold as high as that of bare ZIS. This work is anticipated to endorse the exploration of transition metal nitrides as high-performance cocatalysts to promote the coupled photocatalytic organic transformation and H2 production. -
ArticleBoosting Stable and Fast Potassium Storage of Iron Sulfide through Rational Yolk-Shell Design and Ni Doping
Yanmei Gan, Jiajie Zhu, Qixin Zhang, Chaoying Wang, Lunhui Guan and Yi Zhao*
Chin. J. Struct. Chem. 2022, 41, 2205030-2205036 DOI: 10.14102/j.cnki.0254-5861.2022-0044
May 20, 2022
FeS2, Ni-doping, yolk-shell structure, anode, potassium-ion batteries
ABSTRACT
Metal sulfides have been regarded as promising anodes for potassium-ion batteries (PIBs) due to their high theoretical capacities, while the performance is limited by their intrinsic poor conductivity and large volume fluctuation during the insertion/extraction of large potassium ion. Herein, the battery performance of iron sulfide anode is significantly enhanced through yolk-shell (Y-S) structure design and nickel doping, aiming to realize good structure stability and superior electron/ion transportation. For potassium storage, as-prepared Y-S Ni-FeS2@C shows excellent cyclic performance and sustains high capacities of 328 mA h g-1 after 100 cycles at 0.2 A g-1 and 226 mA h g-1 after 1000 cycles at 1 A g-1. Especially, it displays a superior rate capacity of 200 mA h g-1 at 20 A g-1, higher than that of Y-S FeS2@C and most as-reported metal sulfide anodes for PIBs. The experimental analysis and theoretical calculation illuminate the effect of Ni-doping on decreasing the particle size of iron sulfide and enhancing the ion/electron transport ability, thus accounting for the exceptional rate capability of Y-S Ni-FeS2@C composite. -
ReviewRecent Progress in Covalent Organic Frameworks (COFs) for ElectrocatalysisCha Li, Zining Qiu, Hongming Sun*, Yijie Yang and Cheng-Peng Li*
Chin. J. Struct. Chem. 2022, 41, 2211084-2211099 DOI: 10.14102/j.cnki.0254-5861.2022-0162
October 31, 2022
covalent organic frameworks, electrocatalyst, catalytic performance, catalytic kinetics, energy conversion
ABSTRACT
Electrocatalysis provides various technologies for energy storage and conversion, which is an important part of realizing sustainable clean energy for the future. Covalent organic frameworks (COFs), as emerging porous crystalline polymers, possess high specific surface areas, tunable pore structures, high crystallinity and tailorable functionalization. These features endow COFs with abundant active sites and fast electron transport channels, making them potentially efficient electrocatalysts. In recent years, COF-based electrocatalysts have been widely developed for hydrogen evolution reaction (HER), hydrogen oxidation reaction (HOR), oxygen evolution reaction (OER), oxygen reduction reaction (ORR), nitrogen reduction reaction (NRR) and carbon dioxide reduction reaction (CO2RR). In this review, design strategies of COF-based electrocatalysts are briefly summarized, including applying COF as supports, introducing active metals in COF, constructing two-dimensional conductive COF, formation of COF-based hybrid and pyrolysis of COF to obtain carbon materials. Then, the recent research progress in COF-derived catalysts for specific electrocatalytic reactions is introduced systematically. Finally, the outlook and challenges of future applications of COFs in electrocatalysis are highlighted. -
ArticleCoupling of NiFe-Based Metal-Organic Framework Nanosheet Arrays with Embedded Fe-Ni3S2 Clusters as Efficient Bifunctional Electrocatalysts for Overall Water Splitting
Xianbiao Hou, Tianyuan Jiang, Xiujuan Xu, Xingkun Wang, Jian Zhou, Huimin Xie, Zhicheng Liu, Lei Chu* and Minghua Huang*
Chin. J. Struct. Chem. 2022, 41, 2207074-2207080 DOI: 10.14102/j.cnki.0254-5861.2022-0145
July 18, 2022
metal-organic frameworks, metal sulfides, nanosheet arrays, electrocatalysts, water splitting
ABSTRACT
Developing highly efficient, easy-to-make and cost-effective bifunctional electrocatalysts for water splitting with lower cell voltages is crucial to producing massive hydrogen fuel. In response, the coupled hierarchical Ni/Fe-based MOF nanosheet arrays with embedded metal sulfide nanoclusters onto nickel foam skeleton (denoted as Fe-Ni3S2 @NiFe-MOF/NF) are fabricated, in which the Fe-Ni3S2 clusters could effectively restrain the aggregation of the layer metal-organic frameworks (MOF) nanosheets and adjust the local electronic structures of MOFs nanosheets. Benefiting from the rapid charge transfer and the exposure of abundant active sites, the well-designed Fe-Ni3S2@NiFe-MOF/NF displays excellent oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) performance. More importantly, when equipped in the alkaline water electrolyzer, the Fe-Ni3S2@NiFe-MOF/NF enables the system with a mere 1.6 V for achieving the current density of 10 mA cm-2. This work offers a paradigm for designing efficient bifunctional HER/OER electrocatalysts based on the hybrid materials of nanostructured metal sulfide and MOF. -
ArticleOne-Pot Synthesis of Bismuth Basic Nitrate-Bi2MoO6 Photocatalyst for Selective Oxidation of TolueneTian-Qin Zeng, Lang Chen*, Bing-Hao Wang, Sheng Tian, Zhang-Jun Bai, Xiong Wang, Jun-Kang Guo* and Shuang-Feng Yin*
Chin. J. Struct. Chem. 2022, 41, 2212025-2212032 DOI: 10.14102/j.cnki.0254-5861.2022-0149
December 2, 2022
Bi2MoO6, basic bismuth nitrate, heterojunction, photocatalysis, selective oxidation of toluene
ABSTRACT
The key issues to improve the performance of photocatalysts for selective oxidation of toluene are promoting the migration and separation of charge carrier, and enhancing the generation of active oxygen species. It is known that the construction of compact heterojunction is an efficient protocol to inhibit photogenerated electron-hole recombination. In this work, a 2D-2D [Bi6O6(OH)3](NO3)3·1.5H2O-Bi2MoO6 (denoted as BBN-BMO) composite heterojunction has been prepared by one-step hydrothermal method for the first time. The tetragonal phase BBN in the composite plays the role of transferring electrons from the visible light activated orthorhombic phase BMO and promoting the generation of active •O2-, the holes left in BMO are used to activate toluene and produce benzyl radical, thus greatly improving the photocatalytic performance for selective oxidation of toluene. The toluene conversion rate of BBN-BMO is 3466 μmol·g-1·h-1, which is three times that of pure BMO. The selectivity to benzaldehyde is 94.2%. In addition, reasonable mechanism has been speculated based on a series of control experiments. -
ArticleIn-situ Synthesis of CQDs/BiOBr Material via Mechanical Ball Milling with Enhanced Photocatalytic PerformancesXingwang Yan, Bin Wang, Mengxia Ji, Qi Jiang, Gaopeng Liu, Pengjun Liu*, Sheng Yin, Huaming Li and Jiexiang Xia*
Chin. J. Struct. Chem. 2022, 41, 2208044-2208051 DOI: 10.14102/j.cnki.0254-5861.2022-0141
July 25, 2022
CQDs, BiOBr, photocatalysis, pollutant degradation
ABSTRACT
Designing simple, efficient, and environmentally friendly methods to construct high-efficient photocatalysts is an important strategy to promote the further development of the field of photocatalysis. Herein, flower-like carbon quantum dots (CQDs)/BiOBr composite photocatalysts have been prepared via in-situ synthesis by mechanical ball milling in the existence of ionic liquid. The CQDs/BiOBr composites exhibit higher photo-degradation performance for tetracycline (TC) than BiOBr monomer and the commercial Bi2O3 under visible light irradiation. For comparison, the different Br sources and synthetic methods are chosen to prepare BiOBr and CQDs/BiOBr composites. Photocatalysts prepared by ball milling and ionic liquid present significantly enhanced photocatalytic performance for removing TC. In addition, the introduction of CQDs could distinctly enhance the photocatalytic performances of pure BiOBr. The reason is that CQDs as electron acceptor effectively separate electrons and holes and inhibit their recombination. The intermediates during photocatalytic degradation were tested using liquid chromatography-mass spectrometry (LC-MS) and possible degradation pathways were given. During degradation, •OH, O2•- and h+ were identified to be the main active species based on electron spin resonance (ESR) spectra and free radical trapping experiments. A possible mechanism of CQDs/BiOBr with enhanced photocatalytic performances was further proposed.
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ArticleIn-Situ Construction of Sulfur-Doped g-C3N4/defective g-C3N4 Isotype Step-Scheme Heterojunction for Boosting Photocatalytic H2 EvolutionJing Zou, Guodong Liao, Jizhou Jiang*, Zhiguo Xiong, Saishuai Bai, Haitao Wang*, Pingxiu Wu, Peng Zhang and Xin Li*
Chin. J. Struct. Chem. 2022, 41, 2201025-2201033 DOI: 10.14102/j.cnki.0254-5861.2021-0039
January 13, 2022
sulfur-doping, defects, isotype step-scheme heterojunction, g-C3N4, photocatalytic H2
ABSTRACT
The rational construction of a high-efficiency step- scheme heterojunctions is an effective strategy to accelerate the photocatalytic H2. Unfortunately, the variant energy-level matching between two different semiconductor confers limited the photocatalytic performance. Herein, a newfangled graphitic-carbon nitride (g-C3N4) based isotype step-scheme heterojunction, which consists of sulfur-doped and defective active sites in one microstructural unit, is successfully developed by in-situ polymerizing N,N-dimethyl-formamide (DMF) and urea, accompanied by sulfur (S) powder. Therein, the polymerization between the amino groups of DMF and the amide group of urea endows the formation of rich defects. The propulsive integration of S-dopants contributes to the excellent fluffiness and dispersibility of lamellar g-C3N4. Moreover, the developed heterojunction exhibits a significantly enlarged surface area, thus leading to the more exposed catalytically active sites. Most importantly, the simultaneous introduction of S-doping and defects in the units of g-C3N4 also results in a significant improvement in the separation, transfer and recombination efficiency of photo-excited electron-hole pairs. Therefore, the resulting isotype step-scheme heterojunction possesses a superior photocatalytic H2 evolution activity in comparison with pristine g-C3N4. The newly afforded metal-free isotype step-scheme heterojunction in this work will supply a new insight into coupling strategies of heteroatoms doping and defect engineering for various photocatalytic systems. -
Short CommunicationFlexible Organic Single Crystal with Elastic Bending and Plastic Twisting Capabilities
Jiang Peng†*, Wanjun Zhao†, Jing Zhang, Chuchu Han, Junhui Jia, Tingting Feng and Jiawen Sun
Chin. J. Struct. Chem. 2022, 41, 2212004-2212006 DOI: 10.14102/j.cnki.0254-5861.2022-0217
December 2, 2022
flexible crystal, elastic bending, plastic twisting, elastoplastic deformation, waveguide
ABSTRACT
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ArticleMolecular Engineering of g-C3N4 with Dibenzothiophene Groups as Electron Donor for Enhanced Photocatalytic H2-ProductionShanren Tao, Sijie Wan, Qinyang Huang, Chengming Li, Jiaguo Yu and Shaowen Cao*
Chin. J. Struct. Chem. 2022, 41, 2206048-2206054 DOI: 10.14102/j.cnki.0254-5861.2022-0068
June 20, 2022
carbon nitride, donor-acceptor, photocatalysis, charge transfer
ABSTRACT
The construction of donor-acceptor (D-A) molecular structure is an attractive strategy to enhance the photocatalytic performance of polymeric semiconductors. Herein, dibenzothiophene (DBT)-4-carbaldehyde as the precursor is introduced into g-C3N4 (TCN) prepared by two-step thermal polymerization to construct an intramolecular D-A type copolymer (TCN-DBTx). DFT calculation and experimental results reveal that DBT plays the role of electron donor unit to modify g-C3N4. The incorporation of DBT not only adjusts the band gap to improve reduction ability, but also induces an internal electric field with extending π-conjugated system for effective charge transfer. As a result, TCN-DBTx exhibits much better photocatalytic performance with an optimal hydrogen production rate of 3334 μmol h-1 g-1, which is 2.5 times that of TCN. This work provides a protocol for preparing high-performance g-C3N4-based photocatalysts toward various applications. -
ArticleVersatile Inorganic Oligomer-Based Photochromic Spiropyrane GelsJiajia Song, Wei Duan, Yun Chen* and Xiangyang Liu*
Chin. J. Struct. Chem. 2022, 41, 2205037-2205047 DOI: 10.14102/j.cnki.0254-5861.2022-0061
May 20, 2022
inorganic oligomer, photochromic, gels, naked-eye detection of hydrazine
ABSTRACT
Here we report an example of a general strategy for the immobilization of various different photochromic spiropyran molecules on eco-friendly cheap nanomatrix. The spiropyrans are encapsulated in calcium salt oligomers-based gels by centrifugation, forming an inorganic oligomer-based gelatinous photoswitchable hybrid material. Ca2+ is also used to regulate the optical properties of spiropyrans through chelation. The oligomer-based gel can not only provide the space required for photoisomerization, but also reduce the interference of the surrounding environment on the photochromic properties. Moreover, a practical paper-based and colloidal flexible substrate platform is constructed for the removal and naked-eye detection of liquid and gaseous hydrazine at room temperature based on the reactivity of the formyl group on spiropyrans loaded in Ca3(PO4)2 oligomers. This general strategy can be used for other inorganic oligomer-based molecular switches and sensing systems. -
ArticleEnhanced Photocatalytic H2-production Activity of CdS Nanoflower using Single Atom Pt and Graphene Quantum Dot as Dual Cocatalysts
Yi Yang, Jinsong Wu, Bei Cheng*, Liuyang Zhang*, Ahmed Abdullah Al-Ghamdi, Swelm Wageh and Youji Li
Chin. J. Struct. Chem. 2022, 41, 2206006-2206014 DOI: 10.14102/j.cnki.0254-5861.2022-0124
June 20, 2022
hierarchical nanostructure, single-atom catalysts, graphene quantum dots, CdS nanosheets, hydrogen production
ABSTRACT
Single-atom catalysts have high catalytic activity due to their unique quantum size effects and optimal atom utilization. Herein, visible-light-responsive photocatalysts were designed by coupling CdS with graphene quantum dots (GQDs) and platinum single atoms (PtSAs). GQDs and PtSAs were successively loaded on ultrathin CdS nanosheets through freeze-drying and in-situ photocatalytic reduction. The synergistic effect between PtSAs and GQDs results in superior photocatalytic activity with a hydrogen production rate of 13488 μmol h-1 g-1 as well as the maximum apparent quantum efficiency (AQE) of 35.5% in lactic acid aqueous solution, which is 62 times higher than that of pristine CdS (213 μmol g-1 h-1). The energy conversion efficiency is ca. 13.05%. As a photosensitizer and an electron reservoir, GQDs can not only extend the light response of CdS to the visible-light region (400-800 nm), but also promotes the separation of photoinduced electron-hole pairs. Meanwhile, PtSAs, with unique electronic and geometric features, can provide more efficient proton reduction sites. This finding provides an effective strategy to remarkably improve photocatalytic H2 production performance.
- Address: Fuzhou High & New Technology Industrial Zone, Shangjie, Minhou, Fuzhou, Fujian 350108, China
- Tel: (86)-591-63173769, 63173770
- E-mail: cjsc@fjirsm.ac.cn