JOURNAL OF ALLOYS AND COMPOUNDS
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2022
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IF 6.371
Yan Wang,Guangshe Li,Chang Liu,Xinbo Li,Liping Li
Metal geometrical structure engineering of composite catalysts is powerful to boost their photocatalytic performance of hydrogen evolution . Herein, by rationally designing, transition metal phosphides (TMPs) have been loaded onto the P doped g-C 3 N 4 (PCN) to construct catalysts TMPs/PCN. For the first time, the effect of geometrical structure of TMPs on the photocatalytic activity is optimized and a geometrical-site-dependent photocatalytic hydrogen evolution is experimentally determined. Tri-metallic FeCoNiP/PCN, having 59.6% occupancy of tetrahedral cobalt sites, gives hydrogen production rate of 205 μmol/g/h, better than that of mono-metallic (FeP, CoP , NiP), bi-metallic (FeCoP, CoNiP, FeNiP) TMPs/PCN, and even much superior to that of Pt/b-g-C 3 N 4 and Pt/PCN. Trimetallic TMPs/PCN catalysts also show excellent OER performance. In addition to the efficient electron transfer between FeCoNiP and PCN, which can effectively improve the separation of photogenerated carriers, the high occupancy of tetrahedral cobalt sites of FeCoNiP as a co-catalyst promotes the formation of active intermediates, being the key to significantly improve the catalytic performance of ternary FeCoNiP/PCN. The findings in this work, especially about a link of the photocatalytic performance of TMPs/PCN composites and occupancy of tetrahedral cobalt site in co-catalysts TMPs, can open new occasion for creating novel composite catalysts and extending to other applications.
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高影响因子
MOLECULES
·
2022
·Vol. 27
·期 21
·7178
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IF 4.927
Yan Chen,Ao Li,Xiuli Fu,Zhijian Peng
The difficulty of exposing active sites and easy recombination of photogenerated carriers have always been two critical problems restricting the photocatalytic activity of g-C3N4. Herein, a simple (NH4)2MoO4-induced one-step calcination method was successfully introduced to transform bulk g-C3N4into g-C3N4/MoO2composites with a large specific surface area. During the calcination, with the assistance of NH3and water vapor produced by ammonium molybdate, the pyrolytical oxidation and depolymerization of a g-C3N4interlayer were accelerated, finally realizing the exfoliation of the g-C3N4. Furthermore, another pyrolytical product of ammonium molybdate was transformed into MoO2under an NH3atmosphere, which was in situ loaded on the surface of a g-C3N4nanosheet. Additionally, the results of photocatalytic hydrogen evolution under visible light show that the optimal g-C3N4/MoO2composite has a high specific surface area and much improved performance, which is 4.1 times that of pure bulk g-C3N4. Such performance improvement can be attributed to the full exposure of active sites and the formation of abundant heterojunctions. However, with an increasing feed amount of ammonium molybdate, the oxidation degree of g-C3N4was enhanced, which would widen the band gap of g-C3N4, leading to a weaker response ability to visible light. The present strategy will provide a new idea for the simple realization of exfoliation and constructing a heterojunction for g-C3N4simultaneously.Keywords:g-C3N4;MoO2;exfoliation;photocatalytic hydrogen evolution
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DIAMOND AND RELATED MATERIALS
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2023
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IF 4.1
Afzal Ali,Adeel Ahmed,Muhammad Usman,Tahir Raza,Muhammad Safdar Ali,Abdulhmeed Al-Nahari,Changbao Liu,Dong Li,Chunhu Li
Unintentional leakage of dyes into the aquatic environment has exacerbated global contamination of water resources in recent years, posing a serious danger to aquatic life and human health. As a result, highly adaptable and effective measures are required to address the worldwide environmental challenge posed by dye usage. Herein, we have adopted hydrothermal technique to synthesize a visible light-induced catalyst based on the Ce 0.2 Co 0.8 Fe 2 O 4 /g-C 3 N 4 composite. The catalysts were characterized in terms of their morphological, structural, and photoluminescence properties. The photocatalytic proficiency of the Ce 0.2 Co 0.8 Fe 2 O 4 /g-C 3 N 4 composite was determined by its ability to degrade rhodamine B (RhB) under visible light irradiation. Ce 0.2 Co 0.8 Fe 2 O 4 /g-C 3 N 4 exhibited superior degradation potential, degrading RhB to 90.27 % in 60 min, compared to CoFe 2 O 4 /g-C 3 N 4 (72.28 %), Ce 0.2 Co 0.8 Fe 2 O 4 (64.45 %) and CoFe 2 O 4 (56.63 %) under predetermined reaction conditions (catalyst dosage = 0.4 g/L, RhB concentration = 20 mg/L, pH = 7, T = 25 ± 1 °C). The substantial increase in photocatalytic potential was attributed mostly to the interfacial migration of photo-induced charge carriers from g-C 3 N 4 to Ce 0.2 Co 0.8 Fe 2 O 4 , which may facilitate electron migration. The as-synthesized catalyst demonstrated outstanding stability in four successive cycles. This study may provide a low-cost approach for fabricating visible-light responsive catalysts for use in environmental remediation applications.
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CARBON
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2022
·
IF 11.307
Xiang Yu,Yue Zhan,Tingting Fan,Yuqi Zhang,Shunqin Liang,Limin Sun,Xiaoli Hu,Weiping Fang,Zhou Chen,Xiaodong Yi
The stabilization and transport of the reactants, intermediates and products are significant to rational design of an industrial catalyst. In this work, we encapsulated the surface of Pd/g-C 3 N 4 catalyst with acrylic acid (AA) using a photo-induced grafting method to mimic the 3-dimensional nature of enzymes. A combined characterization and ab initio calculation revealed that AA ligands on the surface controlled the adsorption and diffusion behaviors of the reactants, rather than alter the electronic or geometric properties of Pd active centers. The optimized catalyst (Pd/CNA-4) significantly enhances isoprene partial hydrogenation activity without a decline in semi-hydrogenation selectivity. This approach can be further optimized by changing the types of the encapsulating ligands and can meet other specific catalytic reactions to regulate their conversion and selectivity and is therefore expected to extend to other areas of heterogeneous catalysis .
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SEPARATION AND PURIFICATION TECHNOLOGY
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2022
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IF 9.136
Jiangfu Zheng,Changzheng Fan,Xiaoming Li,Qi Yang,Dongbo Wang,Abing Duan,Shuaijun Pan,Baowei Zhang,Jinglin Ding,Shengxiang Rong,Haoyu Yin
Development of efficient nanomaterials for photocatalytic degradation is very important in the removal of organic pollutants from water. The oxygen vacancy-rich g-C 3 N 4 / LDH composites (g-C 3 N 4 /LDH-OVs) with a layered structure was prepared for the efficient photocatalysis degradation and mineralization of tetracycline hydrochloride (TC) under visible light irradiation. Oxygen vacancies in the composites achieved through structural induction strategy not only provide abundant active sites but also improve the separation efficiency of the photo-generated carriers, thereby enhancing the degradation and mineralization of TC, as revealed both by theories and experiments. The optimized g-C 3 N 4 /LDH-OVs have achieved excellent photocatalytic activity (i.e., 95 % degradation and 28 % mineralization of TC after 60 min of visible light irradiation), which was 2.3 and 3.5 times higher than that of the pristine g-C 3 N 4 and LDH-OVs, respectively. Furthermore, experimental results based on bio-acute toxicity show that the g-C 3 N 4 /LDH-OVs/Vis system can effectively detoxify the transformation products. This study provides an insight into the development of LDH-based photocatalysts, so as to realize photocatalytic mineralization and simultaneous detoxification through the new strategy of oxygen vacancy defect engineering.
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APPLIED SURFACE SCIENCE
·
2022
·
IF 7.392
Shuying Gao,Lingling Pan,Weiguo Kong,Li Zhou,Jian Wu,Shijian Zhou,Weilong Shi,Fu Yang,Yan Kong
In this study, an energetic materials (EM) deflagration process coupled with a gas-shocking exfoliation strategy was proposed for the in-situ introduction of a π-electron-conjugated structure into ultrathin g-C 3 N 4 nanosheets. The optimal 2C-CNS sample was endowed with a porous-ultrathin-nanosheets morphology (3–4 nm thickness), larger exposed surface area (144.1 m 2 /g), and significant pore volume (0.51 cm 3 /g). Using urotropin-deflagration and gas-shocking-driven processes, the precursors were dissociated and copolymerized in an aqueous solution into g-C 3 N 4 nanosheets chemically modified with conjugated carbon moieties. Most importantly, an expanded π-electron conjugated system was successfully constructed between the carbon moieties that interacted with the ultrathin g-C 3 N 4 (2C-CNS), which endowed its with a faster electron-hole separation efficiency and enhanced visible-light harvesting ability. The H 2 evolution rate and Cr 6+ reduction efficiency for 2C-CNS reached 2360 μmol h −1 g −1 for k = 0.0301 min −1 , which was almost 25.8/23 times higher than that of bulk g-C 3 N 4 (Bu-CN, 91.2 μmol h −1 g −1 , k = 0.0013 min −1 ). Also, 2C-CNS showed 2.8/2.4 times higher performance than the g-C 3 N 4 ultrathin nanosheets without a carbon-section modification (0C-CNS, 853 μmol h −1 g −1 , k = 0.0125 min −1 ).
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CERAMICS INTERNATIONAL
·
2022
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IF 5.532
Yisheng Xu,Yaoheng Liang,Zeng Yuai,Hangyu Long,Qizhi He,Kaijin Guo,Yuyuan Zhang,Dongchu Chen,Xuejun Xu,Huawen Hu
Although g-C 3 N 4 (CN) materials have been extensively explored for the photocatalytic degradation of organic pollutants, their weak response to visible light and fast recombination of photoexcited electron-hole pairs restrain their practical applications. Herein, we deeply mediated the CN's energy-band structure, morphology, and surface properties by non-metal (P) and metal (Mo) co-doping based on the thermal treatment of a phosphomolybdic acid hydrate and dicyandiamide mixture in a straightforward one-step manner. Meanwhile, cyano groups and nitrogen vacancies were generated as a result of the co-doping, and the resulting P, Mo co-doped CN (PM-CN) exhibited thinner layers, smaller sizes, and superior visible-light harvesting capacity and charge separation efficiency. Consequently, highly active PM-CN was obtained for photocatalytic tetracyclines (TC) degradation, and the rate was calculated to be 0.01 min −1 , 3.3 times greater than that of the pure CN, outstripping the single P- and Mo-doped counterparts. A free radical scavenging test demonstrated that the reactive species •O 2− and h + were critical in TC degradation. The present work is expected to shed light on co-doping CN with non-metal and metal elements to obtain high-performance, visible-light-responsive photocatalysts for practical environmental remediation.
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ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
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2022
·Vol. 29
·期 40
·61148-61160
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IF 5.19
Cao Yunmeng,Yue Lin,He Zhuang,Li Zaixing,Lian Jing,Zhou Shilei,Luo Xiao
In this study, the flower-shaped Bi 2 S 3 /g-C 3 N 4 -2.6 heterojunction obtained by solvothermal method and its photocatalytic degradation efficiency of rhodamine B (RhB) and tetracycline (TC) in aqueous solution within 40 min is as high as 98.8% and 94.6%. For RhB degradation, the photocatalytic reaction rate constant (k) of Bi 2 S 3 /g-C 3 N 4 -2.6 is approximately 1.8 and 45.5 times that of Bi 2 S 3 and g-C 3 N 4 . For TC, k is 3.1 and 2.4 times that of Bi 2 S 3 and g-C 3 N 4 , respectively. The key to determining the high catalytic activity of Bi 2 S 3 /g-C 3 N 4 lies in the formation of a good heterojunction between Bi 2 S 3 and g-C 3 N 4 , which accelerates the electron transfer rate between the heterojunction interface and effectively avoids electron–hole recombination. The effects of catalyst dosage, different pH values, inorganic anions, and capture agents on the photodegradation performance of RhB were investigated. The results show that the catalyst dosage is 1.33 g/L, and the solution pH is in the range of 5–9, which has the best removal effect on pollutants, and the isolation of holes ( h + ) with strong oxidizing ability promotes the collapse of pollutant molecules. Combined with electrochemical tests, a possible degradation mechanism was advised.
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高影响因子
Materials
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2022
·Vol. 15
·期 4
·1391
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IF 3.748
Jiajing Zhang,Yongjie Zheng,Heshan Zheng,Tao Jing,Yunpeng Zhao,Jingzhi Tian
Antibiotic contamination has received widespread attention globally. In this work, the oxygen-doped porous graphite carbonitride (g-C3N4) was prepared with urea and ammonium oxalate (CNUC) or urea and glycine (CNUG) as precursors by thermal polymerization. Using bisphenol A (BPA) as a probe and CNUC or CNUG as photocatalysts, the removal performance test was carried out. Meanwhile, all prepared photocatalysts were characterized by XRD, FT-IR, SEM, TEM, XPS, UV-Vis DRS, PL and EIS. Under visible light irradiation, both CNUC and CNUG exhibited about seven and five times greater photocatalytic activity than that of pure g-C3N4, respectively. The radical capture experiments verified that superoxide radicals (•O2−) and holes (h+) were the main active species in the photocatalytic degradation of BPA by CNUC, and the possible photocatalytic mechanism of CNUC was proposed. In addition, all these results indicate that CNUC catalyst can effectually inhibit the photocorrosion and keep superior stability. The proposed technique provides a prospective approach to develop nonmetal-modified photocatalysts for future applications.Keywords:copolymerization;g-C3N4;oxygen-doped;visible light degradation;photocatalysis
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Colloid and Interface Science Communications
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2022
·
IF 5.633
Zhiying Guo,Fangxu Dai,Huixiang Yin,Mingming Zhang,Jun Xing,Lei Wang
Gold nanoparticles (Au NPs) are widely utilized to broaden the light absorption of the photocatalysts due to their localized surface plasmon resonance (LSPR). However, the photocatalytic mechanism of Au/photocatalyst heterostructure involving charges transfer and reactive sites is still in dispute. Here, we synthesized a typical system Au/graphite carbon nitride (g-C 3 N 4 ) and demonstrate that the role of Au NPs in the LSPR enhanced photocatalysis . Under visible light, the photoexcited electrons of g-C 3 N 4 would transfer to Au NPs and reduce protons into hydrogen together with hot electrons of Au NPs. The hot holes of Au NPs would flow to g-C 3 N 4 and oxidize triethanolamine . Therefore, the Au NPs play a dual role, plasma, and cocatalyst, in the LSPR enhanced photocatalyst. When λ > 420 nm, Au /g-C 3 N 4 has hydrogen production of 159.9 μmol g −1 h −1 . Our findings confirm the significance of metal plasma in photocatalytic reaction and benefit designing photocatalysts with boosting performance.
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Journal of Environmental Chemical Engineering
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2022
·
IF 7.968
Hao Luo,Jiaxin Yan,Yiwei Shan,Jianwen Zhou,Jun Yu,Bruno Boury,Hui Wu,He Xiao,Liulian Huang,Zhanhui Yuan,Lihui Chen
Rational design of efficient semiconductors for photocatalytic nitrogen fixation is an urgent challenge for artificial ammonia (NH 3 ) production under mild condition. Recently, graphitic carbon nitride (g-C 3 N 4 , CN) shows fascinating potential in photocatalytic nitrogen fixation under visible light. However, compared with other catalysts, the low NH 3 production with pure CN leads to the restriction of practical application. Herein, we covalently coupled covalent organic frameworks (Tptta-COF) and carboxylated carbon nanotubes (CNT) onto CN with amido-linkage and imine-linkage, respectively, through the hydrothermal reaction. Compared with the pristine CN, the obtained COF/CN/CNT achieved larger specific surface area, more visible light absorption and more efficient separation of the photo-generated carriers. The optimal catalyst (COF/CN/CNT) exhibited enhanced photocatalytic activity with NH 3 conversion of 864 μmol·g −1 within 4 h under visible light illumination. Moreover, the introduction of COF and CNT results in a 6.20 times improved photocatalytic NH 3 conversion rate (211 μmol·g −1 ·h −1 ) under visible light in contrast to that of the pure CN. The boosting NH 3 production is due to the dual covalent decoration effect of COF and CNT. On the one hand, the COF introduction is favorable for the regulation of band gap, promoting specific surface area as well as N 2 adsorption ability. On the other hand, the CNT introduction not only enhances optical light harvesting, but also accelerates the transfer of photo-excited electron, maintaining high efficient separation of photo-generated carriers. This dual covalent decoration, therefore, shows a potential as a feasible strategy of combining light-harvesting and charge transfer for efficient NH 3 production.
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SYNTHETIC METALS
·
2022
·
IF 4
Afzal Ali,Tahir Raza,Adeel Ahmed,Muhammad Safdar Ali,Changbao Liu,Dong Li,Chunhu Li
The intentional discharge of polycyclic aromatic hydrocarbons (PAHs) into the aquatic system from different industrial units has posed a serious threat to human health. To address the concerns associated with PAHs misuse, an efficient approach for developing affordable photocatalyst materials for PAHs degradation is much needed. In this study, we have explored co-precipitation and hydrothermal methods to synthesize Fe 3 O 4 /GO/g-C 3 N 4 ternary composites and utilized them as photocatalyst materials for the degradation of naphthalene. Fe 3 O 4 /GO/g-C 3 N 4 nanocomposite demonstrated superior degradation performance, with 87.56% naphthalene degradation achieved in 140 min under visible light irradiation, far outperforming Fe 3 O 4 /GO (77.42%) and Fe 3 O 4 (69.42%). The enhanced degradation of naphthalene by the Fe 3 O 4 /GO/g-C 3 N 4 composite was credited to the effective charge carrier separation and increased visible-light absorption induced by GO and g-C 3 N 4 . The impact of operating parameters on the catalytic efficiency of the Fe 3 O 4 /GO/g-C 3 N 4 catalyst was also examined. The findings of this study revealed that lower naphthalene concentration (10 mg/L), higher catalyst dosage (40 mg), and moderate pH conditions (pH 5 to pH 9) were favorable for photocatalytic activity. The degradation of naphthalene followed pseudo-first-order kinetics with a rate constant value of 0.0137 min −1 . The generation of radicals ( • OH and O 2 •− ) liable for the degradation of naphthalene was corroborated through electron paramagnetic resonance analysis and quenching experiments. Furthermore, the Fe 3 O 4 /GO/g-C 3 N 4 photocatalyst exhibited promising reusability in five consecutive cyclic runs, validating its excellent stability.
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