APPLIED CATALYSIS B-ENVIRONMENTAL
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2020
·
IF 16.683
Zhi Liu,Minmin Wang,Shoujie Liu,Zheng Chen,Lingzhi Yang,Kaian Sun,Yanju Chen,Lingyou Zeng,Wenhong Wang,Jinchong Zhao,Guangxun Sun,Bin Liu,Yuan Pan,Yunqi Liu,Chenguang Liu
The biggest challenge for selective catalytic reduction (SCR) of NO by NH 3 at low temperatures is to develop robust catalysts with high resistance to SO 2 . Mn-based catalysts have attracted great attention for their excellent activity, but the poor SO 2 resistance limits their application. Herein, we report a novel assembled composite featuring Mn 3 O 4 nanoparticles embedded in defect-abundant graphitic carbon frame (Mn 3 O 4 @G-A) via a confinement–pyrolysis–oxidation strategy derived from MOF. The Mn 3 O 4 @G-A exhibits excellent activity (reaching over 90 % NO conversion in 100, 000 h −1 GHSV at 160 °C) and significantly improved SO 2 resistance in comparison to pristine Mn 3 O 4 , and all the performance tests were conducted with 5.6 vol.% water vapor. By combining synchrotron radiation-based X-ray absorption spectroscopy and density functional theory calculation, we further discovered the positive role and the origin of graphitic carbon for improving SO 2 resistance. Over the Mn 3 O 4 @G-A sample, the electrons can be transferred from graphitic carbon to Mn 3 O 4 nanoparticles, which can regulate the electronic properties and oxidizing ability of Mn 3 O 4 nanoparticles. The proper oxidizing ability of Mn 3 O 4 @G-A can inhibit the oxidation of SO 2 to SO 3 , thus further avoid the formation of NH 4 HSO 4 and improve the SO 2 resistance. Our work here not only solves the current problem of poor SO 2 resistance of Mn-based catalysts, but also provides new insights into the design and synthesis of MOF-derived graphitic carbon-containing catalysts for SCR applications.
研究领域:
催化化学
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环境科学
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材料科学
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
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2020
·
IF 6.182
Krishnamoorthy Rajavel,Shuyi Shen,Tao Ke,Daohui Lin
The present study addresses the establishment of a highly reactive catalyst derived from Ti 3 C 2 T x (MXene), which is a graphitic carbon-supported TiO 2 hybrid nanostructure for photocatalytic and bacteriostatic applications. The graphitic carbon-supported TiO 2 nanoparticles, which were placed onto a Ti 3 C 2 T x backbone as ternary hybrids under the controlled oxidation of isopropylamine delaminated Ti 3 C 2 T x , were demonstrated to be semiconducting nanostructures. Beneficially, the oxygen-related vacancies in TiO 2 along with graphitic carbon support in the metallic Ti 3 C 2 T x heterostructures exhibited distinct methylene blue dye degradation under UV irradiation at a rate constant of ( k ) of 0.035 ± 0.003 min −1 . The demonstrated superior catalytic performance of the assembled hybrid structure was attributed to the formation of multiple interfacial junctions formed by graphitic carbon, TiO 2 nanoparticles, and Ti 3 C 2 T x , which created distinct intermediate energy levels for electron-hole pair separation and improved the catalytic performance. The synthesized hybrid nanostructures also exhibited excellent antibacterial activity; approximately 97.4% of E. coli was killed by the nanostructures under light exposure due to the excessive radicals that caused oxidative stress on bacterial cells. The developed hybrid nanostructures from the controlled oxidation of delaminated Ti 3 C 2 T x are expected to be superior materials for photocatalytic and bacteriostatic applications.
研究领域:
材料科学
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环境科学
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微生物学
✓ 已验证
产品关联
DOI
高影响因子
CATALYSIS TODAY
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2024
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IF 5.2
Yang Gao,Shilin Fan,Bin Zhu,Soliman I. El-Hout,Jinghui Lyu,Jian Zhang,Chunlin Chen
Biomass energy has gained significant attention due to its renewability and clean, low-carbon characteristics. We prepared a Co@NC-a catalyst using the complexation-carbonation-acid etching method, which can catalyze both thermochemical and electrochemical HMF selective oxidation reactions. In thermocatalysis, it can achieve 100 % HMF conversion and 94.4 % FDCA yield at 65 °C and 0.2 MPa O 2 . In electrocatalysis , 100 % HMF conversion and 73 % FDCA yield were also realized. Significantly, graphitized carbon contributes to the aerobic oxidation of HMF due to its excellent electrical conductivity , which promotes electron transfer during the reaction. Additionally, a comparative study of the activation energy of this catalytic system in electrocatalysis and thermocatalysis showed that electrocatalysis is kinetically more favorable. The energy efficiency calculation also indicates electrocatalysis is more energy efficient than thermocatalysis.
研究领域:
生物质能
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催化化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
Crystals
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2020
·Vol. 10
·期 6
·490
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IF 2.404
Weiguang Zhong,Dan Wang,Congcong Jiang,Xiaolei Lu,Lina Zhang,Xin Cheng
Cement-based composite is one of the essential building materials that has been widely used in infrastructure and facilities. During the service of cement-based materials, the performance of cement-based materials will be affected after the cement surface is exposed to pollutants. Not only can the surface of cement treated with a photocatalyst degrade pollutants, but it can also protect the cement-based materials from being destroyed. In this study, graphite carbon nitride-silica composite materials were synthesized by thermal polymerization using nanosilica and urea as raw materials. The effect of nanosilica content and specific surface area were investigated with the optimal condition attained to be 0.15 g and 300 m2/g, respectively. An X-ray diffractometer, thermogravimetric analyzer, scanning electron microscope, a Brunauer–Emmett–Teller (BET) specific surface area analyzer and ultraviolet-visible spectrophotometer were utilized for the characterization of as-prepared graphite carbon nitride-silica composite materials. Subsequently, the surface of cement-based materials was treated with graphite carbon nitride-silica composite materials by the one-sided immersion and brushing methods for the study of photocatalytic performance. By comparing the degradation effect of Rhodamine B, it was found that the painting method is more suitable for the surface treatment of cement. In addition, through the reaction of calcium hydroxide and graphite carbon nitride-silica composite materials, it was found that the combination of graphite carbon nitride-silica composite materials and cement is through C-S-H gel.Keywords:graphite carbon nitride;silica;visible light catalysis;cement
研究领域:
材料科学
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环境工程
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
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2016
·Vol. 6
·期 114
·113570-113575
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IF 3.289
Wenyu Gao,Xiaofang Wang,Pei Li,Qiongtao Wu,Fang Qi,Songmei Wu,Yu Yu,Kejian Ding
A highly sensitive and selective electrochemical sensor is developed for the detection of cadmium with a nanosheet graphitic carbon nitride (g-C3N4) modified electrode. The g-C3N4 nanosheet modified glassy carbon electrode detects heavy metal not only by electrostatic interactions, but also by intercalating the holes during differential pulse anodic stripping voltammetry (DPASV) measurements for Cd2+ in aqueous solution. The calibration curves for Cd2+ covered two ranges varying from 1 nM to 1 μM and 1 μM to 100 μM. The limitation of detection (LOD) is estimated to be 0.5 nM for Cd2+, which is 53 times lower than the guideline values of drinking water given by the World Health Organization (WHO). In addition, the good repeatability and stability of the modified electrode is feasible for heavy metal detection in this study.
研究领域:
环境科学
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分析化学
✓ 已验证
产品关联
DOI
高影响因子
CHINESE JOURNAL OF CATALYSIS
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2016
·
IF 2.628
Cheng Wang,Liya Hu,Meiyin Wang,Yuanhang Ren,Bin Yue,Heyong He
A series of graphitic carbon nitride supported vanadium catalysts ( x V/g-C 3 N 4 ) with different vanadium contents ( x /%) were prepared by impregnation. XRD, FT-IR, TEM, TG-DTG, nitrogen adsorption and XPS characterizations were conducted which revealed a strong interaction between the vanadium species and g-C 3 N 4 support. 8V/g-C 3 N 4 exhibited the highest activity and showed stable recyclability in the benzene hydroxylation reaction with a benzene conversion of 24.6% and phenol selectivity of 99.2% under the optimized conditions. The excellent catalytic performance of x V/g-C 3 N 4 was due to the integration of vanadium species with high catalytic activity and the g-C 3 N 4 support in their interaction with the benzene substrate
研究领域:
催化化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
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2022
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IF 7.968
Xiangyu Wang,Yiming Wang,Jun Ma,Ping Ning
The wide band gap of g-C 3 N 4 and severe aggregation of Fe 0 adequately limit their applications. To address these two critical issues, novel ternary phosphorus-doped g-C 3 N 4 /Fe 0 @expanded graphite carbon layer (P-CN/Fe 0 @EGC) photocatalyst with extremely narrow band gap and significantly enhanced catalytic activity was in-situ synthesized. P-CN/Fe 0 @EGC hybrid composite exhibited excellent photodegradation performance of tetracycline (TC) removal, which is 5.18 and 1.92 times higher than that of pristine g-C 3 N 4 and Fe 0 , respectively. Enhancement in photocatalytic activity is evaluated via photoluminescence (PL), UV–vis DRS, XRD and electron spin resonance (ESR). A reasonable catalytic mechanism of P-CN/Fe 0 @EGC is proposed. The multiply synergistic mechanisms of phosphorus-doped g-C 3 N 4 (P-CN), Fe 0 and expanded graphite carbon layer (EGC), as well as the strong reducibility of Fe 0 were accounted for the expanded visible light absorption range. The even dispersion of Fe 0 on porous and worm-like structured P-CN/EGC effectively and successfully avoided the decline in photocatalytic activity caused by aggregation of Fe 0 nanoparticles . Compared with g-C 3 N 4 , the band gap of phosphorus-doped g-C 3 N 4 was narrowed from 2.79 to 2.60 eV. It is worth noting that Fe 0 plays an important role in accelerating electron transfer speed and efficiency between P-CN and EGC. The·O 2 − and h + were the dominant active substances for TC degradation . Moreover, P-CN/Fe 0 @EGC catalyst could be used repeatedly for at least 7 cycles with high TC removal efficiency. This study may pave a new way on designing high efficient ternary hybrid photocatalyst for antibiotic degradation.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
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2016
·
IF 3.205
Yunfeng Zhan,Xiang Yu,Linmin Cao,Bodong Zhang,Xiaoxian Wu,Fangyan Xie,Weihong Zhang,Jian Chen,Weiguang Xie,Wenjie Mai,Hui Meng
The nitrogen doping effect on a kind of graphitic carbon as non noble metal catalyst for the oxygen reduction reaction is studied. Glycine and NH 3 are chosen as different nitrogen source and different doping sequences are applied. The structural defect of graphitic carbon, total nitrogen content, types of nitrogen species and surface area are different from different treatment. Glycine will not influence the structure of graphitic carbon but NH 3 introduces defects. Glycine introduces high content of nitrogen to graphitic carbon but NH 3 introduces no nitrogen. The best catalyst is prepared by doping graphitic carbon with glycine first then heat treated with NH 3 . Some of the nitrogen species can be removed by further NH 3 treatment, but the relative content of graphitic nitrogen increases, together with increased surface area result in higher activity.
研究领域:
材料科学
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电化学
✓ 已验证
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2024
·
IF 7.1
Dong Zhang,Dafeng Zhang,Dong Fan,Junchang Liu,Hengshuai Li,Xipeng Pu,Haiquan Hu,Feng Guo,Peiqing Cai
Photocatalytic hydrogen production technology has emerged as one of the most promising technologies to address the future energy crisis. Cd0.9Zn0.1S (CZS) is a promising photocatalyst for visible light activation but is limited by the slow kinetics of photoexcited carrier separation. Density functional theory (DFT) calculations based on first-principles showed that the introduction of a cocatalyst, N-doped graphite carbon (FC@NC), could effectively reduce the adsorption free energy of hydrogen, thus accelerating the hydrogen reaction kinetics of CZS. Supported by theoretical predictions, magnetic FC@NC nanoparticles were successfully prepared by precipitation and calcination and then combined with tetrapod CZS by ultrasonic self-assembly and calcination to form the FC@NC/CZS composite photocatalyst with Schottky contact. The FC@NC/CZS composite photocatalyst with the best mass ratio of FC@NC proved a considerable photocatalytic hydrogen evolution rate up to 79.9 ± 0.1 mmol g–1 h–1 under visible light exposure, which was 4.4 ± 0.1 times that of pristine CZS, and the apparent quantum efficiency (AQE) at 450 nm was as high as 52%. Finally, based on the experimental results and DFT calculations, a possible mechanism for the enhanced photocatalytic activity of FC@NC/CZS composites with the Schottky heterojunction was first proposed. In general, we attribute the boosted and stable photocatalytic property of FC@NC/CZS photocatalytic performance to the following three aspects: (1) the bimetallic alloy cocatalyst easily acts as an electron collector, (2) the graphite carbon layer protects the alloy from oxidation, and (3) the nitrogen-doped carbon layer provides more active sites for the reaction. This work provided a green and economical technique for an efficient hydrogen evolution reaction using light energy in the environment.
研究领域:
材料科学
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能源科学
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理论计算
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2021
·
IF 6.609
Jin Zhong,Qiang Deng,Taimei Cai,Xiang Li,Rui Gao,Jun Wang,Zheling Zeng,Guiping Dai,Shuguang Deng
Upgrading fatty acids to hydrocarbons via deoxygenation is significant for the synthesis of high-grade biofuels. Developing economic reaction conditions without using noble metal-based catalysts in the absence of hydrogen and solvent has promising application prospects. Herein, carbon-coated bimetallic FeNi nanoparticles were prepared via an in-situ carbonization-reduction strategy using double-metal cyanide at different temperatures for the deoxygenation of stearic acid. The size of the alloy core and the thickness of the carbon shell were found to be easily adjusted by varying temperature. Compared with monometallic Fe/C and Ni/C catalysts, the alloy catalyst exhibits an obvious improvement in both the conversion of stearic acid and the selectivity of heptadecane. ATR-IR spectra show that the insertion of the inert Fe element into Ni nanoparticles can promote carboxylic acid group adsorption but restrain hydrocarbon group adsorption. The synergistic effect of Fe and Ni elements leads to the promotion of direct decarboxylation of stearic acid and suppression of the C–C cracking reaction. Among different alloy catalysts studied, FeNi@C-800 exhibits the greatest catalytic performance with a 99.9% conversion of stearic acid and 76.8% selectivity for heptadecane. Furthermore, the catalyst can still maintain a stable catalytic performance against the leaching and ripening of metal through the protection afforded by the carbon shell. This work not only provides a powerful reaction system for the decarboxylation of stearic acid but also demonstrates an alternative catalyst to noble metals based on a convenient carbonization-reduction strategy.
研究领域:
化学工程
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催化科学
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能源材料
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
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2019
·
IF 14.229
Guiming Ba,Zhiwei Liang,Haiping Li,Na Du,Jianqiang Liu,Wanguo Hou
Graphite carbon nitride (CN) is considered as a promising photocatalyst for solving current energy and environmental crises, but its practical application is still restricted by fast recombination of photogenerated charge carriers, low specific surface area, and narrow visible light absorption range. Herein, oxygen-modified CN (MCN) with simultaneous formation of massive mesopores and homojunctions was successfully synthesized by calcining the precursor, a cyanuric acid (CYA)-loaded melamine (MA) hierarchical structure composed of nanobelts, which was prepared for the first time. MCN exhibits accelerated charge separation, increased specific surface areas, and enhanced visible light absorption, compared with CN, and these jointly render the photocatalytic hydrogen evolution rate of MCN (934 μmol h −1 g −1 ) be about five times higher than that of CN (163 μmol h −1 g −1 ). MCN also exhibits much faster singlet oxygen generation and higher photoactivity in organic degradation. The MA hierarchical structure and CYA synergistically formed the new mesopores and C O C bonds in MCN, which cause prominent upper shift of the Fermi level and enhanced photoabsorption of MCN. Besides, electronic microscopy images distinctly show two different sorts of regions in MCN, i.e. those with massive and few mesopores (marked as MPCN and NPCN), respectively. Therefore, MPCN/NPCN homojunctions were probably constructed in MCN, which leads to the accelerated charge separation. This work gives a way to form simultaneously mesopores and homojunctions in CN and illustrates the formation mechanism, which can effectively direct synthesis of similar photocatalysts.
研究领域:
材料科学
·
环境科学
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
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2018
·
IF 4.229
Xinran Zhao,Xiaobo He,Fengxiang Yin,Biaohua Chen,Guoru Li,Huaqiang Yin
In this work, a series of metallic cobalt-molybdenum carbide@graphitic carbon (CoMo(x:y)-T@GC) nanocomposites for the electrochemical hydrogen evolution reaction (HER) were synthesized by a sol-gel method. In the as-prepared nanocomposites, β-Mo 2 C and metallic Co coexisted and were encapsulated by graphitic carbon . The presence of metallic Co effectively enhanced the crystallinity of β-Mo 2 C, charge transfer efficiency and electrochemical active surface area (ECSA), thus resulting in the improved HER catalytic activities of the CoMo(x:y)-T@GC nanocomposites. The optimized electrocatalyst CoMo(0.5:0.5)-800@GC required the lowest overpotential of ∼165 mV to deliver a current density of 10 mA cm −2 in 0.1 M KOH, which was at the forefront compared with recently reported Mo 2 C-based electrocatalysts.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）