ACS Applied Energy Materials
·
2023
·
IF 6.4
Jianghua Yang,Zewen Ji,Shujuan Zhang
The identification of defects and their roles in photocatalytic production of hydrogen peroxide (H2O2) with carbon nitride (CN) is a challenging but important task. Here, a simple route was employed to generate defects in CN by tuning the ratio of the two synthesis precursors: acetylacetone (AcAc) and urea. In this way, a set of modified CNs (AxCN) with dual defects (C doping and surface −OH modification) were successfully fabricated. The one with an AcAc-to-urea ratio (x) of 0.05 showed a photocatalytic H2O2 production rate of 3.6 mmol·g–1·h–1, which was greater than most of the reported CNs. Moreover, the selectivity of H2O2 production was increased from 60% (CN) to 85% (A0.05CN). On the basis of density functional theory and the first-principles calculation, the high performance of A0.05CN was attributed to the synergistic roles of the dual defects in oxygen reduction reactions. The C doping enhanced the anchoring of dioxygen, while the −OH group facilitated the diffusion of charge carriers. The finding here provides an insight into the defect engineering for green generation of H2O2.
研究领域:
材料科学
·
环境科学
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产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2024
·
IF 20.2
Yandong Sun,Weiguang Han,Fangyuan Zhang,Hui Li,Ziqi Zhang,Xue Zhang,Boxiong Shen,Sheng-Qi Guo,Tianyi Ma
The generation of singlet oxygen ( 1 O 2 ) based on photocatalytic activation O 2 is considered to have important application prospects in purifying refractory organic pollutants in water. However, the uncertain dual pathway transformation of activated O 2 severely limits the generation of 1 O 2 . In this work, we show a robust BiOCl with dual defects (adjacent I-substitution defect and Cl vacancy) in halogen layer for the selective activation of O 2 to generate 1 O 2 . Combining experiments and theoretical calculations, we confirm that dual defects are beneficial in optimizing band structures, improving carrier separation efficiency, and promoting O 2 adsorption and activation. More importantly, it is confirmed that dual defects can directionally convert O 2 into 1 O 2 by increasing the thermodynamic conversion energy barrier of non- 1 O 2 conversion pathways and serving as a necessary site for 1 O 2 generation with dual functions of oxidation and reduction. Applying dual defect modified BiOCl to the removal of refractory aromatic pollutants in water, it is found that it has efficient and stable photocatalytic degradation efficiency and broad environmental adaptability. This work not only provides in-depth insights into the mechanism of photocatalytic activation of O 2 to selective produce 1 O 2 , but also lays the foundation for further development of highly active photocatalysts for environmental remediation and energy conversion.
研究领域:
环境科学
·
材料科学
·
化学
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DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2023
·
IF 8.4
Fengjia Xie,Huaping Jia,Ching Kit Tommy Wun,Xiaowen Huang,Yao Chai,Chi Chung Tsoi,Zhefei Pan,Shunni Zhu,Kangning Ren,Tsz Woon Benedict Lo,Yujiao Zhu,Xuming Zhang
Photocatalytic regeneration of valuable cofactors by using sunlight has emerged as a promising strategy for biosynthesis and pharmaceutical manufacturing. Graphitic carbon nitride (g-C3N4) is very suitable for photocatalytic nicotinamide cofactor regeneration since it is metal-free, visible-light responsive and has strong binding with nicotinamide cofactor. However, its great potential is hindered by some intrinsic drawbacks such as low visible absorption, fast electron/hole recombination, and limited active sites. Here, we demonstrate dual-defect g-C3N4 (DDCN) with controllable defects of nitrogen vacancies and cyano groups for efficient photocatalytic cofactor regeneration via a KOH-assisted thermal polymerization by using urea as a precursor. Although DDCN is widely used for other photocatalytic applications such as organic degradation and hydrogen peroxide production, this work is original in its application to photocatalytic cofactor regeneration. Material characterizations confirm the successful introduction of nitrogen vacancies and cyano groups. Measurements of nicotinamide-cofactor generation show that the DDCN samples assisted with 0.1 g and 0.01 g KOH are 3.0 and 2.5 times that of pristine g-C3N4 in terms of nicotinamide cofactor yield, respectively. The high yields are attributed to the synergetic effect of both enhanced light absorption and improved charge separation, achieved through the introduction of energy levels and trap states via dual defects. This work provides a green, energy-saving, and promising strategy for nicotinamide cofactor regeneration and would promote its application in biosynthesis and drug manufacturing.
研究领域:
材料科学
·
生物合成
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药物制造
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产品关联
DOI
高影响因子
Journal of Energy Storage
·
2023
·
IF 9.4
Xing Chen,Haijun Tao,Yinhua Jiang,Shishi Li,Yuxin Liu,Kun Xie,Yuqiao Wang
P-doped S vacancy-rich NiCo 2 S 4 hollow microspheres (P-NiCo 2 S 4-x HMSs) were prepared by hydrothermal, sulfuration, and phosphorization methods. P doping and S vacancy dual defects can be simultaneously obtained during the phosphorization process. The dual defects can modulate the electron structure and create abundant electrochemical sites, boosting electron transfer and reaction kinetics. Theoretical calculations illustrated that the dual defects could reduce the adsorption energy of OH − and Mulliken charges of Ni atoms, in favor of OH − adsorption. The hollow construction can increase the specific surface area, promote ion diffusion, and alleviate the volume variation during charge/discharge processes. The specific capacity and rate capability of the P-NiCo 2 S 4-x HMSs electrode can reach up to 1146.0 C g −1 at 1 A g −1 and 61.8 % at 30 A g −1 , respectively. The P-NiCo 2 S 4-x HMSs electrode exhibited remarkable cycling stability with a 79.5 % capacity retention after 20,000 consecutive charge/discharge cycles. The assembled P-NiCo 2 S 4-x //AC hybrid supercapacitor manifested an infusive energy density of 62.7 Wh kg −1 at 867 W kg −1 .
研究领域:
材料科学
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能源存储与转换
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产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2024
·
IF 9.4
Yucheng Wu,Yanli Yu,Wei Shen,Yimin Jiang,Rongxing He,Ming Li
Developing simple and energy-saving pathways to prepare high-efficient and robust non-noble metal based electrocatalysts remains a huge challenge to hydrogen production from seawater electrolysis. Here we demonstrate a facile hydrothermal-calcination-etching approach that simultaneously achieves the required surface N doping and Fe vacancies generation to activate the Ni-O-Fe active motifs in N -v Fe -NiFe 2 O 4 /NF. The unique localized environments (Ni- N -Fe structures and unsaturated O- and N -coordination) due to dual-defect strategy can effectively regulate the electronic structure of the Ni-O-Fe motif to make the motif more reactive. As a result, the N -v Fe -NiFe 2 O 4 /NF catalyst exhibits overpotentials of 210, 213 and 222 mV to deliver 100 mA cm −2 in 1.0 M KOH, simulated seawater and alkaline seawater environments, respectively. Theoretical calculations prove that the Ni-O-Fe structure is the active motif and that the presence of special localized environments can optimize the adsorption of key intermediates on the activated active motifs.
研究领域:
材料科学
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电化学
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可再生能源
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产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2020
·Vol. 11
·期 1
·78-86
·
IF 3.119
Jingxuan Zheng,Bo Zhang,Zhao Wang
g-C3N4/MoS2 composites were successfully prepared by an electron-assisted strategy in one step. Dielectric barrier discharge (DBD) plasma as an electron source, which has low bulk temperature and high electron energy, can etch and modify the surface of g-C3N4/MoS2. The abundant N and S vacancies were introduced in the composites by plasma. The dual defects promoted the recombination and formation of heterojunctions of the g-C3N4/MoS2 composite. It exhibited stronger light harvesting ability and higher charge separation efficiency than that of pure g-C3N4 and MoS2. Compared with the sample by traditional calcination method, the plasma-sample showed better performance for degrading rhodamine B (RhB) and methyl orange. RhB is completely degraded within 2 hours on g-C3N4/MoS2 by plasma. A mechanism for the photocatalytic degradation of organic pollutants via the composites was proposed. An electron-assisted strategy provides a green and effective platform to achieve catalysts with improved performance.
研究领域:
材料科学
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环境科学
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产品关联
DOI
PubMed
高影响因子
Materials Today Energy
·
2025
·
IF 8.6
Binghong Wu,Xinru Wu,Dong-Hau Kuo,Xiao Tang,Xin Mao,Baoqian Yang,Zhengjie Su,Pengkun Zhang,Longyan Chen,Minhao Liu,Jinguo Lin,Xiaoyun Chen
To reveal the role of bi-vacancy defects and heterovalent states in oxysulfide catalysts for enhancing the photocatalytic hydrogen evolution reaction (PHER), we demonstrate a Br/W co-doped Zn(O,S) catalyst (labeled as Br/W-ZnOS) featuring abundant anionic oxygen vacancies (V O )/cationic zinc vacancies (V Zn ) bi-defects and heterovalent W 5+ /W 6+ states via a facile hydrolysis method. The co-doping of Br and W induces lattice distortions that enable neighboring atoms to leave the lattice, creating surfaces enriched with anionic V O and cationic V Zn defects. The synergistic effect between dual defects forms an efficient electron-hole separation system, enhancing the efficiency of electron-hole pair separation. Density functional theory calculation (DFT) demonstrates that the combination of Br/W co-doping and vacancies significantly reduces the water dissociation barrier and optimizes the surface ∗H generation rate of the photocatalyst. Thus, Br/W-ZnOS exhibits a PHER rate of 3415.7 μmol h −1 , which is 12.5 times higher than the undoped Zn(O,S) catalyst, and achieves an apparent quantum yield (AQY) of 15.41 % at 365 nm, while maintaining good stability with a PHER activity of 3288.1 μmol h −1 after five repeated cycles. This research provides a promising strategy for designing oxysulfide catalysts with synergistically engineered defects for efficient PHER.
研究领域:
材料科学
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催化化学
·
理论计算化学
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产品关联
DOI
高影响因子
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY
·
2024
·
IF 4.1
Haiping Liu,Zhiwei Liu,Li Guo,Xinna Zhao,Jing Liang,Xinyue Zhang,Qiancheng Gao,Xuefei Tian,Xiaofeng Jia,Yu Sun,Jianguo Zhou,Haitao Liu
Antibiotics pollution may pose a great risk to ecosystem and human health. In this work, an innovative dual-defect AgBiO 3 /DCN S-scheme heterojunction was constructed to overcome the sluggish charge separation and transfer issue and showed exceptional photodegradation performance towards norfloxacin (NFL) pollution under the visible light. The degradation efficiency of NFL reached 95.30 % within 120 min respectively, the rate constant was 3.64 times higher than that of defective g-C 3 N 4 (DCN). The systematically characterizations proved that the enhanced photocatalytic activity was benefited from optimized band structures, improved carrier separation efficiency, due to dual defects and S-scheme heterojunction in AgBiO 3 /DCN. the intermediate degradation products and degradation pathway of NFL were speculated by UPLC-HRMS, and the environmental toxicity degree of degradation products was analyzed according to the T.E.S.T software. The charge transfer pathway was confirmed as an S-scheme mechanism through a combination of band structure analysis, alongside electron paramagnetic resonance (EPR) experiments.The quenching experiments and ESR analyses indicated that h + and O 2 •− radicals played predominant roles. The efficient and stable photocatalytic NFL degradation efficiency and broad environmental adaptability proved potential practical application. This work may shed light on designing new dual-defect heterojunction with photocatalytic antibiotic removal capability in the innovative water treatment process.
研究领域:
环境科学
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材料科学
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产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Binrong Li,Na Li,Zhiwei Guo,Chen Wang,Xuedong Wang,Zhi Zhu,Xu Tang,Pengwei Huo
Polymeric carbon nitride (PCN) is an environmentally friendly photocatalyst for solar-driven H 2 O 2 production, but the activity of original PCN is still not satisfactory. The main limitation is the sluggish exciton dissociation leading to slow generation and conversion of superoxide radical (•O 2 − ) intermediate. Herein, the PCN with dual defect sites and compact interlayer is rationally designed for H 2 O 2 photosynthesis with an ultrahigh rate of 3930.9 μmol g −1 h −1 and rapid •O 2 − yield rate of 1.92 min −1 . The enhanced activity is attributed to effective exciton dissociation during interlayer and intralayer process. Moreover, nitrogen vacancies change the oxygen adsorption configuration (formation of C − O − O − C bridge mode), thus promoting O 2 adsorption and activation. A well-matched linear relationship was established between the concentration of nitrogen vacancies and •O 2 − /H 2 O 2 production. This work not only provides in-depth insights for the photocatalytic H 2 O 2 generation mechanism, but also offers a new paradigm for designing efficient PCN-based photocatalysts for energy conversion.
研究领域:
材料科学
·
光催化
·
能源转换
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产品关联
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2024
·
IF 8.2
Xin Jiang,Kaiwei Li,Yimin Tang,Xiuwen Wang,Wei Kan,Libin Yang,Bing Zhao
High-performance flexible semiconductor material can be used as an excellent multifunctional matrix for in-situ ultrasensitive surface-enhanced Raman scattering (SERS) detection and synchronous photocatalytic degradation of antibiotic residues in aquatic ecosystem. Here, a calcium-doped TiO 2 flexible matrix with double defects (surface oxygen vacancy defect and Ti 3+ energy level defect) was developed by its “in-situ one-step” hydrothermal synthesis on cotton fabric for the above purposes. Due to the joint contribution of double defects, a multi-channel charge transfer mode and a high-efficiency carrier separation are achieved, which endows flexible cotton fabric/Ca-doped TiO 2 (Cot/Ca-TiO 2 ) substrate with the greatly boosted SERS effect for in-situ detection of antibiotic residues on fish body surface and in fishpond water by a simple wiping or dipping sampling method, even for simultaneous identification of multi-component residues. The detection limits of three antibiotic residues (enrofloxacin, ciprofloxacin and enoxacin) are as low as 10 −9 M, which are far lower than the EU standard. More meaningfully, the flexible Cot/Ca-TiO 2 can be used as a multifunctional filter-membrane type photocatalyst for efficient on-site degradation of antibiotic residues in flowing fishpond water by a multi-grade photocatalysis means. Moreover, the flexible matrix exhibits good recyclability in both actual detection and photocatalysis.
研究领域:
环境科学
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材料科学
·
分析化学
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产品关联
DOI
PubMed
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2025
·
IF 21.1
Wei Liao,Minghu Zhang,Jiangping Liu,Weikun Wang,Jichang Lu,Jin Zhang,Yumin Zhang,Wenjie Zhu,Yongming Luo
Previous studies have primarily focused on the role of single defects, particularly oxygen vacancies, in the catalytic oxidation of volatile organic compounds (VOCs). However, the mechanisms by which coexisting defects influence catalytic activity remain unclear. In this work, dual manganese and oxygen vacancies were introduced in Mn 3 O 4 via solvothermal synthesis and low-temperature H 2 treatment, and a comprehensive analysis of catalysts with varying defect configurations was performed. The introduction of dual vacancies in V Mn -100-1 resulted in a reduced MnO 4 /MnO 6 ratio, leading to significant structural modifications. These changes enhanced the redox properties and promoted the migration of oxygen species. Consequently, V Mn -100-1 exhibited superior catalytic performance, stability, and moisture resistance (15%) for the complete oxidation of styrene. Additionally, designed experiments and density functional theory (DFT) calculations revealed that the dual vacancies improved oxygen species mobility and O 2 dissociation, while the co-existing defects and surplus O 2 mitigated the adverse effects of moisture. In situ diffuse reflectance infrared spectroscopy and DFT results indicated that the dual vacancies enhanced styrene activation and maleic anhydride decomposition. Thus, the rate-limiting steps were modified and the reaction process was optimized. This study provides new insights into dual-defect systems and offers a novel approach for designing high-efficiency catalysts for VOC degradation.
研究领域:
材料化学
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环境催化
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表面科学
·
物理化学
·
纳米催化
·
理论计算化学
✓ 已验证
产品关联
DOI
高影响因子
Nano-Micro Letters
·
2024
·Vol. 16
·期 1
·1-13
·
IF 31.6
Chen Fuyu,Zhao Bai-Qing,Huang Kaifeng,Ma Xiu-Fen,Li Hong-Yi,Zhang Xie,Diao Jiang,Yue Jili,Huang Guangsheng,Wang Jingfeng,Pan Fusheng
MVOH/rGO cathode with dual defect of Mg 2+ pre-intercalation defect (P-Mg d ) and surface oxygen defect (O d ) is prepared.
The dual defect of O d and P-Mg d in MVOH/rGO lamellar structure effectively enhances Mg 2+ migration kinetics, structural stability, and electronic conductivity.
The Mg foil//MVOH/rGO full cell achieves an ultralong lifespan of 850 cycles at 0.1 A g −1 and powers an orange light-emitting diode.
研究领域:
材料科学
·
电化学
·
能源存储
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）