Desalination and Water Treatment
·
2024
·
IF 1
Wen An,Shaomang Wang,Yang Fu,Yuan Guan,Zhongyu Li,Tao Xu,Haoran Wang
Bi 2 WO 6 nanosheets with gradient oxygen vacancies were synthesized by acetic acid solvothermal and subsequent calcination. The photocatalytic activity of the calcined Bi 2 WO 6 was significantly enhanced. The calcination regulated the oxygen vacancy in Bi 2 WO 6 . Oxygen vacancy defects helped to adjust the band structure and change the surface chemical state. At the same time, the electrons were the main charge carriers of the n-type semiconductor Bi 2 WO 6 . Part of the electrons was captured by the oxygen vacancies to promote the separation of the holes. Some of the electrons reacted with oxygen to generate • O 2 – . The h + and • O 2 – were the main active species that degraded rhodamine B. Among them, Bi 2 WO 6 with 1 h of calcination at 315°C (Bi 2 WO 6 -315°C 1 h) exhibited the optimal photocatalytic activity. The degradation velocity of rhodamine B over Bi 2 WO 6 was 21.4 times that of Bi 2 WO 6 under the same reaction condition.
研究领域:
材料科学
·
化学
✓ 已验证
DOI
高影响因子
Polymers
·
2023
·Vol. 15
·期 4
·850
·
IF 5
Linlin Liu,Yue Zhang,Youliang Cheng,Jing Chen,Fengjuan Li
The photocatalytic degradation of organic dyes in waste water using carbon quantum dots (CQDs) remains a hot topic due to the importance of environmental protection. However, identifying suitable carbon resources and successful surface modification are still challenging. Herein, the hydrothermal method and surface modification of ammonia and thionyl chloride were applied to synthesize CQDs with different surface groups using PEO106PPO70PEO106(Pluronic F127) as a carbon source. The average particle size of the as-prepared CQDs was in the range of 2.3–3.5 nm. The unmodified CQDs had the highest relative photoluminescence intensity, while all as-prepared CQDs exhibited abnormal photoluminescence located outside the scope of the visible spectrum. Interestingly, CQDs modified with ammonia achieved a degradation rate of 99.13% (15 d) for 50 mg/L indigo carmine solution, while CQDs modified with thionyl chloride reached a degradation rate of 97.59% (15 d) for light green SF yellowish solution. Therefore, in this work, two typical organic dyes can be effectively photocatalytically degraded by as-prepared CQDs, with suitable surface modification.Keywords:carbon quantum dots;hydrothermal method;photocatalytic activity
研究领域:
环境科学
·
材料科学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2024
·
IF 5.8
Yaqi Wu,Jianhua Qian,Jinjuan Xing,Junhua Li,He Huang,Yanan Wang,Jiasheng Xu
Toluene is one of the most toxic contaminants in industrial waste gases, it can enter the body through the respiratory system and skin. Long-term exposure to it can lead to skin inflammation and neurasthenia, and even cause lesions in organs. Over the years, catalytic oxidation technology has been extensively employed to the remove of toluene, and oxides, especially copper oxide, is considered to be an effective catalyst technology and has been extensively studied. In this work, we introduced CuO as an active species to investigate the impact of Cu content in TiO 2 @CuO (TC-x, x=1, 2, 3, and 5) catalyst on the activity, reusability, and stability of toluene oxidation. The result demonstrated that the addition of Cu species, facilitating the generation of active oxygen obviously reduced the complete oxidation temperature of toluene. Among them, TC-3 catalyst exhibited the highest activity (T 50 = 234 ℃, T 90 = 289 ℃, and T 100 = 310 ℃, with C toluene =1000 ppm, WHSV=20,000 mL/ (g h)), great reusability, and stability for toluene degradation. According to the in-situ DRIFTS, the ultimate degradation products of toluene were CO 2 and H 2 O, which were clean and free of secondary pollution.
研究领域:
环境科学
·
催化化学
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产品关联
DOI
高影响因子
Green Energy & Environment
·
2019
·
IF 0
Ge Li,Baodong Wang,Qi Sun,Wayne Qiang Xu,Ziran Ma,Hongyan Wang,Daojun Zhang,Jiali Zhou
A combined acid–alkali hydrothermal method was used to prepare fly ash –derived SAPO-34 molecular sieves from a thermal power plant in Inner Mongolia (China). The specific surface area of the prepared fly-ash-derived SAPO-34 molecular sieves was 579 m 2 g −1 , the total pore volume was about 0.27 cm 3 g −1 , and the pore size was 0.56 nm; the molar ratios of Al 2 O 3 :P 2 O 5 :SiO 2 were 1:0.86:0.45. Cu/SAPO-34 catalysts were prepared by impregnation of low-cost fly-ash-derived SAPO-34 molecular sieves as a support and tested in selective catalytic reduction with NH 3 (NH 3 -SCR). Powder X-ray diffraction (XRD), N 2 adsorption–desorption, X-ray photoelectron spectroscopy (XPS), H 2 temperature-programmed reduction (H 2 -TPR), NH 3 temperature-programmed desorption (NH 3 -TPD), electron paramagnetic resonance (EPR), nuclear magnetic resonance (NMR), X-ray fluorescence analysis (XRF) and scanning electron microscopy (SEM) were used for catalyst characterization and investigation of the relationships between the catalyst structure and the catalytic activity. The actual silica:alumina ratio of the molecular sieves did not increase with increasing Cu loading, indicating that increasing the Cu loading does not change the original structure of the SAPO-34 molecular sieves. The XRF and NMR results showed that replacement by Cu results in more Si islands. The molecular sieve acidity decreased because of the increased number of Si islands. The NH 3 -TPD results showed that for the Cu/SAPO-34 catalysts there was a low correlation between the low-temperature activity and the amount of acidic sites. SCR activity is closely related to the location of Cu. The 4.47Cu/SAPO-34 catalyst has the highest isolated Cu 2+ showed the highest NH 3 -SCR activities (> 90%) at 250–350 °C. This work opens up new avenues for recycling fly ash formed in coal-fired power plants (reducing environmental pollution) and developing low-cost SCR catalysts for NO x pollution control.
研究领域:
环境科学
·
材料科学
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产品关联
DOI
Catalysts
·
2020
·Vol. 10
·期 10
·1126
·
IF 3.52
Jun Liu,Xuli Li,Haobo Hou,Min Zhou
To further boost the charge separation and photocatalytic activity of TiO2under visible light, the anatase–rutile mixed-phase nitrogen-doped (N-doped) TiO2nanoparticles were successfully synthesized through a facile one-step calcining procedure using TiN as raw materials. The crystal phases, morphologies, chemical compositions, textural structures, and optical properties of as-obtained N-doped TiO2were characterized by the corresponding analytical techniques. The photocatalytic activities of as-fabricated samples were evaluated by degrading 4-chlorophenol (4-CP) and methylene blue (MB) aqueous solution under visible light irradiation. The results revealed that the ratio of rutile to anatase increased with the improvement of sintering temperature, and the sample prepared at 500 °C had the best photocatalytic activity. This might be because it possessed the most appropriate rutile/anatase proportion as well as the nitrogen doping. The transient photocurrent responses, photoluminescence spectra (PL) measurements, and active species trapping experiments were implemented to disclose the photocatalytic mechanism. This work will provide a further insight into the synthesis of highly efficient N-doped TiO2photocatalysts for organic contaminant removal.Keywords:N-doped TiO2;charge separation;photocatalytic activity
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
DIAMOND AND RELATED MATERIALS
·
2021
·
IF 3.315
Yan Hua Gao,Wen Li Zhao,Ying Chen
In this paper, g-C 3 N 4 was modified by the synergistic effect of double salt KCl-(NH 4 ) 2 CO 3 , and porous g-C 3 N 4 with hydroxylated surface was prepared. Combined with a series of characterization (XRD, SEM , BET, FTIR, UV–vis DRS and XPS) and density functional theory (DFT) analysis, it is confirmed that KCl can cooperate with ammonium salt (NH 4 ) 2 CO 3 to produce rich pore structure , and (NH 4 ) 2 CO 3 , as an alkaline slow-release agent, can assist KCl to further enhance hydroxylation . KCl-(NH 4 ) 2 CO 3 not only plays a synergistic role in pore formation, but also introduces hydroxyl and cyano groups, which improves the hydrophilicity of g-C 3 N 4 , promotes the separation efficiency of photo-generated carriers, and is beneficial to enhance the photocatalytic activity . Taking methyl orange (MO) as the model of pollutant degradation, and proposed the possible degradation mechanism . This study provides a simple, efficient and widely applicable method for modifying g-C 3 N 4 to improve its activity.
研究领域:
材料科学
·
环境科学
·
化学
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产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2023
·
IF 7.2
Shikai Wang,Xiaoli Su,Wei Han,Guangfan Xu,Dafeng Zhang,Changhua Su,Xipeng Pu,Peiqing Cai
The problems of low activity, high cost and difficulty in recycle of photocatalysts limit their practical application. Coupling photocatalyst with abundant and natural organic material is one of feasible strategies to achieve high photoactivity and low cost of photocatalysts. Herein, one-dimensional (1D) cotton fiber@ZnIn 2 S 4 (CF@ZIS)·composites with a novel core-shell structure were synthesized by coupling ZIS with inexpensive and natural abundance CF via a simple one-pot hydrothermal process. The microstructure, crystalline structures, optical properties and electrochemical property of CF@ZIS were investigated. ZIS nanosheets were in-situ attached on the CF surface, obtaining the CF@ZIS core-shell structure. This core-shell structure significantly suppressed the self-assembly of ZIS nanosheets made almost all ZIS nanosheets exposed to visible light, improving the utilization of light and meanwhile affording more reactive sites. The as-synthesized CF@ZIS showed improved photoactivity for efficient hydrogen production under visible-light irradiation. By replacing the half ZIS by cheap CF, the CF@ZIS-50 photocatalyst exhibited the optimal visible-light photocatalytic activity , which is 2 times than pure ZIS in hydrogen production. The enhanced photoactivity of CF@ZIS photocatalyst should be attributed to the uniform in-situ growth of ZIS nanosheets on the CF surface, the reduction of CF, and the intimate interface between ZIS and CF, resulting in the boosted separation and transfer of photogenerated charges. Additionally, due to the fibrous morphology of CF, the CF@ZIS photocatalyst showed excellent recoverability and photostability. This work provides a promising approach for designing highly efficient and low cost photocatalysts by using natural organic materials.
研究领域:
材料科学
·
能源科学
✓ 已验证
DOI
高影响因子
Desalination and Water Treatment
·
2015
·
IF 1.173
Shuguang Shen,Binbin Li,Meina Li,Jimin Fan,Zhijun Zhao
In order to find an effective method for urea removal from wastewater, a number of experiments were conducted in a batch reactor with α-Al2O3 and η-Al2O3 as catalysts, respectively. The results indicate that η-Al2O3 catalyst shows significantly higher urea removal rate than α-Al2O3 catalyst or the thermal hydrolysis, and the removal rate increases with increasing temperature, catalyst dosage and reaction time. Using η-Al2O3 catalyst, the urea concentration in wastewater is reduced to less than 1 mg/L at 165°C after 150 min. The reaction kinetics study shows that the hydrolysis of urea behaves as a pseudo-first-order reaction. From the calculated rate constants, η-Al2O3 exhibits an excellent catalytic activity for urea hydrolysis, whereas the activity of α-Al2O3 is considerably weak. In addition, the η-Al2O3 catalyst possesses good recycling ability. The slight loss of activity of η-Al2O3 should be attributed to the generation of a small amount of hydrated aluminas, and the activity can be recovered by calcination.
研究领域:
环境科学
·
化学工程
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DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2018
·Vol. 25
·期 32
·32466-32477
·
IF 2.8
Cui Peipei,Hu Yun,Zheng Mengmeng,Wei Chaohai
Graphitic-like carbon nitride (g-C 3 N 4 ) photocatalyst was synthesized by a facile chemical pyrolysis method, which was built on the self-condensation of different precursors to generate g-C 3 N 4 , e.g., melamine, urea, and thiocarbamide. And the different precursors produced a great influence on the photocatalytic activities of g-C 3 N 4 . Heterojunctions of g-C 3 N 4 and BiVO 4 were synthesized using a facile solvent evaporation method. The formation of BiVO 4 /g-C 3 N 4 composites were confirmed by XRD, FT-IR, SEM, XPS, and UV-Vis DRS. The photocatalytic activities for RhB degradation were evaluated under visible-light irradiation. The photocatalytic activity of g-C 3 N 4 prepared by urea was higher than that of g-C 3 N 4 prepared by melamine and thiocarbamide, which was attributed to its favorable dispersibility, larger specific surface area, and higher oxidation capacity. The heterojunction composites exhibited higher photocatalytic activity than pure g-C 3 N 4 or BiVO 4 . The results showed obvious removal efficiency for RhB, and the optimal sample with a BiVO 4 content of 10% exhibited higher efficiency than pure g-C 3 N 4 and BiVO 4 , and 10 wt%BiVO 4 /CN-U showed the highest photocatalytic activity. The enhanced photocatalytic activity of BiVO 4 /g-C 3 N 4 composite can be attributed to the intimate coupling between the two host substrates, resulting in an efficient charge separation.
研究领域:
材料科学
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环境科学
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DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2017
·Vol. 42
·期 1
·489-496
·
IF 3.269
Zengyu You,Qianhong Shen,Yuxuan Su,Yang Yu,Hui Wang,Tian Qin,Fang Zhang,Di Cheng,Hui Yang
A novel Z-scheme core–shell g-C3N4/MCNTs/BiOI heterojunction was successfully designed and fabricated through filling multi-walled carbon nanotubes (MCNTs) with g-C3N4, followed by the loading of BiOI on the outer surface of the MCNTs. The structure–property relationship was analyzed by X-ray diffraction (XRD), Fourier transform infrared spectra (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-vis diffuse reflectance spectra (DRS), photoluminescence spectra (PL), ESR probe tests and reactive species trapping measurements. The results show that the BiOI nanoparticles are uniformly loaded on the surface of the MCNTs which are fully filled by g-C3N4. The MCNTs connect the two semiconductors of g-C3N4 and BiOI, and serve as electron mediating conductors to promote the transfer of the photo-generated electrons, thereby constructing a Z-scheme heterojunction between g-C3N4 and BiOI. With this unique structure, enhanced visible-light photocatalytic activities are achieved because of the synergistic effect of light harvesting and improved separation efficiency of photo-generated carriers.
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
ADVANCED POWDER TECHNOLOGY
·
2024
·
IF 4.2
Min Qiu,Xue-Li Yang,Zi-Xuan Zhao,Qiu-Ping Luo,Ling Chen,Jun Du,Xing Fan,Bing-Xin Lei
The separation and transfer of photogenerated charges are limited by the deep energy defects and high exciton binding energy of Cs 2 AgBiBr 6 (CABB). The creation of heterostructure is a great promising path to solve this obstacle. In this paper, BiOBr (BOB) nanosheets epitaxially grew on the surface of CABB octahedrons through immersing CABB into in water-solution with the assistance of ethanol, thereby creating an interesting CABB/BOB heterojunction. The CABB/BOB heterostructure markedly enhances water stability, preserving its structure and morphology even after being submerged in a mixture of ethanol and water for 100 h. The CABB/BOB photocatalyst exhibited significantly enhanced photocatalytic activity towards the degradation of Rhodamine B in comparison to its individual pristine components, namely CABB and BOB. Specifically, the advanced CABB/BOB−90 photocatalyst attains a degradation efficiency of 98 % within 40 min, significantly surpassing the initial CABB and BOB photocatalysts by approximately 1.3 and 4.1 times, respectively. The heightened photocatalytic activity is attributable to the formation of a tightly integrated heterojunction interface, which promotes the efficient separation of charge carriers.
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
JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY
·
2013
·
IF 2.145
Wei-guo Pan,Jie-nan Hong,Rui-tang Guo,Wen-long Zhen,Hong-lei Ding,Qiang Jin,Cheng-gang Ding,Shi-yi Guo
MnO x –CuO x /TiO 2 and MnO x –CuO x /Al 2 O 3 catalysts were prepared by sol–gel method and used for low temperature selective catalytic reduction of NO with NH 3 . The results showed that MnO x –CuO x /TiO 2 had better catalytic activity and SO 2 resistance than MnO x –CuO x /Al 2 O 3 in the temperature range of 100–250 °C. The properties of the catalysts were characterized by using XRD, N 2 adsorption, temperature programmed reduction (H 2 -TPR) and temperature programmed desorption (NH 3 -TPD). It was found that the support has a great impact on the acidity of catalyst; TiO 2 and Al 2 O 3 can promote the formation of Lewis acid sites and Brönsted acid sites respectively.
研究领域:
环境科学
·
催化化学
✓ 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）