ChemistrySelect
·
2022
·Vol. 7
·期 40
·e202203024
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IF 2.307
Xuehui You,Fang Liu,Guofei Jiang,Shuhua Chen,Beiya An,Rongli Cui
Graphical Degradation experiments of TC suggested that SCN/NT-2@PTFE composites showed the best photocatalytic performance under the optimal conditions, the degradation rate of tetracycline reached 99 % after 120 min of irradiation. The preparation of SCN/NT-2@PTFE composite membrane can solve the problem of difficult recovery and secondary contamination of powder catalysts. Herein we synthesized S-g-C 3 N 4 and N−TiO 2 catalysts by hydrothermal and calcination technologies and SCN/NT@PTFE membrane by a vacuum filtration method. The morphology and composition of the synthesized materials were analyzed by different characterization methods (SEM/HRTEM/XRD/XPS/UV-vis et.). The effects of different catalysts, pollutant concentrations, mass of catalyst and pH on the photo-degradation of tetracycline were investigated. The degradation rate of tetracycline by SCN/NT-2@PTFE membrane was as high as 99.9 % after 2 h of illumination. This was mainly because heterogeneous structure between S-g-C 3 N 4 and N−TiO 2 broadened the light absorption range and suppressed the carrier complex. Superoxide radicals (⋅O 2 − ) were proved to play a dominant role in the degradation reaction. After 20 days of stirring in water, the photocatalytic performance of membrane decreased slightly, demonstrating its good stability. The study of SCN/NT-2@PTFE membrane provides a new direction for the development of photocatalysis and membrane.
研究领域:
环境科学
·
材料科学
·
化学
·
水处理
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产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2024
·
IF 7.4
Chuanhao Li,Yi Tian,Shuangyu Wang,Ping Yang,Xiao Zhang
To improve the stability of Ag based co-catalysts and to increase the photocatalytic performance of graphitic carbon nitride (g-C 3 N 4 ), Ag 2 Se nanoparticles were grown onto superior thin sulfur-doped g-C 3 N 4 nanosheets which was fabricated via two-step thermal polymerization at high temperature. Ultrathin S-doped g-C 3 N 4 nanosheets were prepared via two-step thermal polymerization using melamine and thiourea. The ratios of Ag 2 Se were adjusted to fabricate a series of Ag 2 Se/S-g-C 3 N 4 (Ag 2 Se/SCN) composite samples by controlled solvothermal synthesis. S-doping plays an important role in mono-dispersion of Ag 2 Se nanoparticles on S-g-C 3 N 4 nanosheets because of the control of growth sites. The photocatalytic removal of tetracycline hydrochloride test indicates that sample Ag 2 Se/SCN-3 with Ag 2 Se loading of 3 % reveals the best removal effect, in which tetracycline hydrochloride of 60 % is removed within 60 min. Photocatalytic hydrogen generation test results without co-catalyst addition demonstrate that sample Ag 2 Se/SCN-3 exhibits the best H 2 evolution rate of 2116.35 μmol·g −1 ·h −1 , which is 3.8 times of that of pure carbon nitride. The photocatalytic mechanism tests suggest that Schottky heterojunctions are formed in the Ag 2 Se/S-g-C 3 N 4 composites. The formation of Schottky heterojunctions improved the separation efficiency of photogenerated charge carriers. The incorporation of Ag 2 Se nanoparticles (as the co-catalyst) on S-g-C 3 N 4 nanosheets is the key for drastically improving the photocatalytic performance and eliminating the use of Pt co-catalyst during the photocatalytic processes.
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
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2024
·Vol. 31
·期 43
·55836-55849
·
IF 0
Kang Lu,Wang Ying,Du Ruihan,Zhang Jinpu,Kang Chunli
In this paper, a modification of g-C 3 N 4 was carried out by combining non-metal doping with the construction of heterojunctions, and a type II heterojunction composite, S/g-C 3 N 4 @β-Bi 2 O 3 , was prepared. The phase structure, morphology, elemental composition, valence band structure, and light absorption performance of the photocatalyst were analyzed using characterization techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and UV–vis diffuse reflectance spectroscopy (UV–vis DRS). The performance of the composite photocatalyst in the photocatalytic degradation of gaseous toluene, one of the typical volatile organic compounds (VOCs), under simulated solar light was studied. The effects of preparation conditions, toluene concentration, and recycling on the photocatalytic performance of the composite photocatalyst were investigated. The results show that under the optimal preparation conditions, S/g-C 3 N 4 @β-Bi 2 O 3 achieved a degradation efficiency of 74.0% for 5 ppm toluene after 5 h of light irradiation. Although the degradation efficiency decreased to 61.2% after five cycles, it maintained 83% of its initial activity, indicating good stability of the composite photocatalyst. Free radical quenching experiments demonstrated that h + was the main active species in the photocatalytic degradation of toluene, followed by ·O 2 − . Based on all experimental results, the migration law of photo-generated charges was analyzed, and a possible photocatalytic mechanism was proposed. In this study, a new material was obtained for the photocatalytic removal of VOCs by improving the photocatalytic properties of g-C 3 N 4 .
研究领域:
材料科学
·
环境科学
·
光催化技术
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DOI
PubMed
CHEMICAL ENGINEERING JOURNAL
·
2019
·
IF 8.355
Shizong Wang,Yong Liu,Jianlong Wang
In this study, the iron and sulfur co-doped graphite carbon nitride (FeO y /S-g-C 3 N 4 ) was easily prepared by one-step pyrolysis using thiourea and ferric chloride hexahydrate as precursors and applied to activate peroxymonosulfate (PMS) for the degradation of sulfamethoxazole (SMX). The characterization results showed that iron existed as Fe 2 O 3 and Fe 3 O 4 . Partial nitrogen atoms in the frame of g-C 3 N 4 were substituted by sulfur atoms. FeO y /S-g-C 3 N 4 can effectively activate PMS to produce sulfate radicals, hydroxyl radicals and singlet oxygen contributing to the SMX degradation. According to the density functional theory (DFT) calculation, the co-doping of iron and sulfur altered the charge density and its distribution of g-C 3 N 4 surface, which enhanced the PMS activation. The effect of initial concentrations of SMX and PMS, pH, temperature and inorganic ion concentrations on SMX degradation was investigated. 0.8 mM of PMS could degrade up to 10 mg/L of SMX. The initial pH had no obvious effect on the SMX degradation. Higher temperature accelerated the SMX degradation, and the activation energy was calculated to be 43.7 kJ/mol. The effect of inorganic ions was dependent on their initial concentration. Based on the comparison of XPS spectrum before and after reaction, the decreased catalytic activity of FeO y /S-g-C 3 N 4 after five cycle reuse was due to the breakdown of surface functional groups. Seven intermediate products were identified, and the possible degradation pathway was proposed. This study could provide a facile and cost-effective method to synthesize the efficient activator of PMS, and a mechanistic insight into PMS activation by FeO y /S-g-C 3 N 4 for the degradation of emerging pollutants in water and wastewater.
研究领域:
环境科学
·
材料科学
·
化学工程
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）