Reaction Kinetics Mechanisms and Catalysis
·
2022
·Vol. 135
·期 2
·1099-1111
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IF 1.843
Zhang Hewei,Duan Congcong,Xu Zhen,Yin Jiahang
Herein, the C 60 /Cd 0.5 Zn 0.5 S (C 60 /CZS) photocatalysts with excellent photocatalytic performance were prepared using facile one-pot hydrothermal method. The crystal structure, morphology, photoelectric performance and photocatalytic activity of the samples were characterized by XRD, XPS, UV–Vis and electrochemistry. The catalytic degradation of pollutants under the irradiation of visible light was simulated using Rhodamine B (Rh B). The content of C 60 was changed from 0.5 to 5 wt%, and the optimal value for the photocatalytic activity was determined to be 2 wt%. The apparent degradation rate and degradation efficiency of Rh B were 0.024 min −1 and 97.5% within 140 min, which is 3.4 times that of pure CZS. C 60 /CZS exhibited excellent catalytic performance, and its photocatalytic activity was sustained even after three cycles. Moreover, electrochemical test results demonstrated that the separation and transfer of photocarriers on CZS surface were effectively improved by C 60 , thus enhancing its activity. In this study, we innovatively prepared a novel photocatalyst by combining fullerenes with sulfide solid solution for the first time, which has rarely been studied in the past. The synthetic method is simple, efficient and pollution-free. Subsequently, the catalytic degradation of Rh B experiment confirmed that the catalyst has high catalytic efficiency and stability. This experiment has practical significance not only for the catalytic degradation of Rh B but also for the application of fullerene in photocatalysis.
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
ENERGY & FUELS
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2024
·
IF 5.2
Xin Huang,Guangchuan Tang,Lei Tang,Chuan Ma,Yunlin Shao,Jingyu Ran
Bio-based platform chemicals are of great significance to future green fine and commodity chemicals. This study reports the performances and mechanisms of solvothermal dehydration of levoglucosan (LGA), the main precursor from noncatalytic pyrolysis of cellulose with a yield up to 80 wt %, to levoglucosenone (LGO) using cesium heteropolyacid salts at the catalyst in DMSO solvent. Catalyst characterizations revealed that cesium was well doped in the cubic of heteropolyacids, and the cesium doping ratio substantially influenced the catalytic performances toward LGO. LGO yield first increased and then decreased with the increase of cesium doping ratios, which is consistent with the change trends of pore structures and Brønsted/Lewis acid site ratios of the cesium heteropolyacid salts. LGO was obtained with the maximum yield at 41.2% over Cs2H2SiW12O40 compared to 39.2% over Cs2.5H0.5PW12O40. The catalyst can be regenerated by calcination without losing its catalytic performances. In addition, density functional theory calculation was used to reveal the mechanism for LGO formation, and the rate-determining step was the first step of the dehydration reaction with the energy barrier of 166 kJ/mol.
研究领域:
化学工程
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可再生资源与环境科学
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DOI
高影响因子
MODERN PHYSICS LETTERS B
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2020
·
IF 1.224
Hetian Xia,Yu Zhao,Weili Li,Ruixuan Song,Yulei Zhang,Weidong Fei
Herein, we report the fabrication of UV-active NaNbO 3 /Al 2 O 3 (30 wt.%) ferroelectric heterojunction photocatalyst with enhanced photoelectrochemical activity to Methylene Blue (MB). Pure NaNbO 3 nanorods (NRs) were synthesized by a facile hydrothermal process and NaNbO 3 /Al 2 O 3 composite was prepared by an ultrasonic vibration method. The heterostructures showed a remarkable increase in photocurrent density and the MB degradation ratio reached 88% in the initial 15 min and eventually reached 98.6% in 75 min. The high photocatalytic efficiency is attributed to the ferroelectric polarization of NaNbO 3 with the forming of heterojunction electric fields assisted by Al 2 O 3 . These properties demonstrate that NaNbO 3 /Al 2 O 3 ferroelectric heterojunction photocatalyst shows promising photoactivity and provides an effective method to improve the photocatalytic properties of other ferroelectrics.
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
SEPARATION AND PURIFICATION TECHNOLOGY
·
2025
·
IF 9
Xiaolong Deng,Maolin Tian,Jian Cui,Hongtao Liu,Wenjie Zhang,Zhen Shang,Jiawei Wen,Guoyong Huang,Shengming Xu
The sustainable recovery and value-added utilisation of active metals, Pt and Re, from spent reforming catalysts represents a significant challenge in the context of industrial catalyst recycling.This study proposes an enhanced method for the selective separation and high-value utilisation of Pt and Re through the implementation of sodium roasting and weak base leaching processes.The integration of these two processes resulted in phase separation, whereby Re and Al were preferentially dissolved, while Pt was concentrated in the slag phase. Subsequent adsorption on an ion exchange resin exhibited excellent selectivity for Re/Al separation, with adsorption and desorption efficiencies of 99.67 % and 99.82 % for Re, respectively.The residual Pt was effectively recovered by oxidative acid leaching, with a combined recovery of 98.89 %.In view of the presence of trace Fe in the leach solution, the potential synergistic effect of Pt utilisation was further explored in this study. The prepared Pt/Fe@C-M intermetallic catalysts exhibited excellent electrocatalytic performance for HER, with an overpotential of 28 mV at 10 mA⋅cm −2 , which exceeded that of commercially available Pt/C catalysts.The improved performance is attributed to the beneficial electronic effect of iron in the catalyst structure. A cost-benefit analysis of the integrated recovery and value-added process was conducted, demonstrating significant commercial viability, with a net profit of $549.89 per kilogram of spent catalyst.
研究领域:
化学工程
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材料科学
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环境科学
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DOI
高影响因子
CATALYSIS LETTERS
·
2024
·
IF 2.3
Yan Xiaoxu,Zhao Xianfeng,Shao Xinxin,Li Kangpeng,Sun Minghong,Ji Xinpeng,Lu Huidan,Liu Yongping
Platinum-group metal ruthenium (Ru) is considered an ideal substitute for platinum (Pt) in the hydrogen evolution reaction (HER) due to its excellent electrocatalytic performance and cost that is 20 times lower than Pt. Herein, we prepared Ru-doped WO 3 nanosheets array on carbon cloth (CC) using the hydrothermal method, followed by successful high-temperature nitridation to obtain Ru-WN/CC nanoarray electrocatalysts. As prepared Ru-doped WN nanosheets exhibit a highly porous structure, providing abundant active sites for HER. Electrochemical performance tests demonstrate that compared to pristine WN/CC, 7% Ru-WN/CC exhibits a reduced overpotential of 94 mV at a current density of 10 mA cm -2 , with a Tafel slope of only 51.4 mV dec -1 and an Rct of 6.08 Ω. Moreover, it maintains high catalytic activity for at least 24 hours under acidic conditions. The superior electrocatalytic activity of Ru-WN/CC is attributed to the significant acceleration of the kinetic rate of WN electrocatalysts by Ru doping, the reduction of electronic transfer resistance in WN, and the enlargement of the electrochemically active surface area of WN. This study provides an important reference for the development of novel low noble metal-doped electrocatalytic materials and has guiding significance for the application of metal nitrides in water splitting for hydrogen production. Graphical Abstract
研究领域:
材料科学
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电化学
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DOI
高影响因子
Journal of Environmental Chemical Engineering
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2024
·
IF 7.4
Kang Li,Jiaoqun Zhu,Weibing Zhou,Lilong Sun,Shouqin Tian
To improve the photocatalytic performance of single-phase Bi 2 WO 6 , the heterojunction construction is usually employed to effectively separate and transport photo-induced carriers. Herein, MXene/Bi 2 WO 6 heterojunction (NB2 and VB2) with face-to-face contact and hierarchical structure was constructed by growing ultrafine Bi 2 WO 6 nanosheets on the surface of two-dimensional MXene (Nb 2 C and V 2 C) materials. Compared with the original Bi 2 WO 6 , the hybrids exhibited a larger specific surface area (42.17 m 2 ∙g −1 for NB2, 50.15 m 2 ∙g −1 for VB2), and displayed significant enhancements in the photodegradation of anionic MO (13.8-fold, 6.5-fold), cationic RhB (9.1-fold, 4.5-fold), and neutral phenol (8.5-fold, 6.1-fold), respectively. This is mainly attributed to the heterostructures via face-to-face coupling which can facilitate the tuning of the photoresponsive properties and internal energy level structure, as well as the generation of free radicals ( • O 2 - , • OH, and h + ) for the stepwise redox process in photodegradation. Therefore, this work is expected to expand the diverse use of Non-Ti 3 C 2 MXene in photocatalysis, meanwhile provide important guidance for the harmless treatment of organic pollutants.
研究领域:
材料科学
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环境科学
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化学
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DOI
高影响因子
Catalysis Science & Technology
·
2018
·Vol. 8
·期 24
·6384-6395
·
IF 5.365
Zhiyang Zhang,Yanle Li,Jing Gu,Liping Ding,Nianhua Xue,Luming Peng,Xuefeng Guo,Yan Zhu,Jing Ma,Weiping Ding
The electrostatic field of a dielectric cavity is powerful for modulating many aspects of confined metal clusters. Here we report that the catalytic properties of Ptn clusters confined in X-zeolite cages are strongly tuned by altering the zeolitic field, which is achieved by using different cations (Na+, Cs+, Ca2+ or La3+) to balance the negative framework of the zeolite. Compared with Ptn@LaX, for example, Ptn@CsX shows a surprising ∼5500% enhancement in TOF value for phenol hydrogenation to cyclohexanol. Electrostatic field modulation leads to gradual changes of electronic properties such as the Fermi levels/d-band centers of the Ptn clusters, as revealed by DFT calculations and experimental characterizations. The decreases in Fermi levels of the Ptn clusters benefit the hydrogenation of –CCH groups (phenylacetylene and acetylene) and –NO2 groups (nitrobenzene, o-nitroanisole and o-chloronitrobenzene) but are detrimental for aromatic ring hydrogenation (phenol). These findings are important for the design of high performance catalysts.
研究领域:
化学
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材料科学
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DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
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2021
·
IF 5.316
Xisong Mao,Xuewen Xia,Junqi Li,Chaoyi Chen,Xiaoying Gu,Song Li,Yuan-Pei Lan
In this work, various new-observed structured CeCO 3 OH were synthesized by a self-assembly hydrothermal method , and a novel tactic to produce CeO 2- x with excellent photocatalytic activity by decomposing CeCO 3 OH in H 2 was proposed and identified. By controlling the synthetic conditions, almond-like, subglobose shape and hollow-sphere of CeCO 3 OH, 3D-broom-like of Ce 2 O 3 · 2CO 2 · nH 2 O (n = (1–2)), and sheet-like of Ce 2 (CO 3 ) 3 · 6H 2 O were synthesized. The crystal growth and formation of the cerium carbonate compounds were carefully studied using XRD , SEM and TEM. TG, thermodynamic calculation and in-situ XRD were employed to reveal the decomposition behavior of almond-like CeCO 3 OH in air, Ar and H 2 . The results show that the decomposition temperatures of CeCO 3 OH in Ar and H 2 are higher than that of in air, and suggest that Ce 2 O 3 has a low thermodynamic stability during the decomposition of CeCO 3 OH in Ar and H 2 , and Ce 3+ will be mostly oxidized by H 2 O firstly and then by both of H 2 O and CO 2 . The ceria samples obtained by decomposing from CeCO 3 OH in different atmosphere maintain indistinguishable shape and particle size. The XPS , Raman spectra and ESR results indicate that the one obtained in H 2 has the richest surface oxygen vacancies (OVs), narrowest band gap of 3.12 eV, lowest intensity in PL spectra and a significantly enhanced photodegradation ratio of methylene blue. The MB photodegradation ratio after 120 min reaction with the catalysts of CeO 2 -Air, CeO 2 -Ar and CeO 2 -H 2 is 43.14%, 54.43% and 73.41%, with a calculated reaction rate constant of 0.00539, 0.00652 and 0.01097 min -1 , respectively. The offered novel tactic of decomposing CeCO 3 OH in H 2 is an efficient and facile technique for active CeO 2- x production.
研究领域:
材料科学
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化学
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DOI
高影响因子
COMPOSITE INTERFACES
·
2019
·
IF 2.025
Xueyi Zhu,Shuling Shen,Zhihong Tang,Junhe Yang
Ti3+-doped TiO2@C nanorods were prepared through a facile hydrothermal process. Na2Ti3O7 ultralong nanotubes and glucose were used as TiO2 precursor and carbon (C) source, respectively. During hydrothermal treatment, the hydrolysis of Na2Ti3O7 and polymerization of glucose induced the formation of TiO2 nanorods with a coating of carbon complex. At the same time, a part of Ti4+ was reduced to Ti3+ due to the rich hydroxyl groups in glucose. After calcination, an ultrathin carbon shell was formed on the surface of TiO2 nanorods. In this prepared composite, Ti3+ self-doped TiO2 nanorods work as photosensitizer to harvest solar energy to generate electron-hole pairs, the tight-binding interface between TiO2 nanorods and carbon shell works as electron transportation path, and the ultrathin carbon shell acts as electrons trapped and accumulated site. Photocatalytic test results indicate that Ti3+-doped TiO2@C nanorods exhibit higher activity and stability than TiO2 for photodegradation of methylene blue under visible light.
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
Catalysts
·
2020
·Vol. 11
·期 1
·24
·
IF 3.52
Juan Du,Jiaxin Zhang,Tingyu Yang,Renming Liu,Zhiyi Li,Dandan Wang,Tong Zhou,Yucun Liu,Chunbo Liu,Guangbo Che
The BiOI/NH2-MIL-125(Ti) composite photocatalyst with excellent photocatalytic performance was prepared by the solvothermal method. For the BiOI/NH2-MIL-125(Ti) (BNMT) system, the contents of NH2-MIL-125(Ti) in BNMT-4, BNMT-5, BNMT-7, BNMT-9, and BNMT-10 were 4 wt %, 5 wt %, 7 wt %, 9 wt %, and 10 wt %, respectively. XRD, XPS, SEM, and TEM characterizations indicated that BiOI/NH2-MIL-125(Ti) was successfully prepared. Brunauer, Emmett, and Teller (BET) and UV–vis diffuse reflectance spectra photoelectrochemical analysis indicated that BNMT-9 can make the specific surface area and photo absorption region larger than BiOI. In addition, the separation efficiency of photogenerated carriers was improved, and the recombination efficiency was reduced. The degradation percentages of Rhodamine B (RhB) and p-chlorophenol (P-CP) reached 99% and 90% over BNMT-9 under visible light irradiation. Additionally, the catalysts had high stability. The results of the active spices trapping experiments test indicated that h+was the main active species. The possible degradation mechanism was proposed.Keywords:photocatalysis;BiOI;NH2-MIL-125(Ti);organic pollutants
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
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
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2020
·
IF 16.683
Dandan Zhu,Qixing Zhou
In this work, nitrogen doped g-C 3 N 4 (NCN) with the extremely narrow band gap was prepared and applied for the photodegradation of phenols. Experiments and DFT (the density functional theory) computation identified that N-doping introduced in the g-C 3 N 4 matrix by substituting C atoms. DFT, PL (photoluminescence) spectra, optical property characteristic and PEC (photoelectrochemical) indicated that NCN possess extremely narrow band gap, efficient photogenerated carrier separation and the charge transfer, which enhanced the absorption of visible light and further promoted the photocatalytic activity. As a result, NCN(2:2) showed about twice higher photodegradation efficiencies and 3 times rate constant than pristine g-C 3 N 4 . The radical trapping experiments showed that •O 2 - radical and h + served as crucial active species during the whole photodegradation reaction. This work can provide a strategy to enhance the photocatalytic activity of photocatalysts via introduce foreign atoms in matrix.
研究领域:
材料科学
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环境科学
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理论化学
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产品关联
DOI
高影响因子
CATALYSIS LETTERS
·
2020
·Vol. 151
·期 3
·698-712
·
IF 2.482
Yu Shanqing,Yan Jiasong,Lin Wei,Long Jun,Liu Shang-Bin
Abstract A better understanding of the roles of rare earth (RE) in heterogeneous catalysts is crucial for improving the properties of catalysts in petro-chemical industry. Fluid catalytic cracking (FCC) catalysts containing RE-incorporated Y zeolites with excellent stability and activity are continuously used to improve the conversion of heavy oil into transportation fuels. In this paper, the effect mechanism of Lanthanum (La) on stability and acidity of Y zeolites are elucidated in conjunction with their influences on catalytic performance. The improvement on stability of La-incorporated Y zeolites can be attributed to the La incorporation which bonds strongly with framework O2 and O3 atoms and strengthens the interaction between framework Al and its neighbouring O atoms. It is the enhanced stability restrains the release of framework Al and the formation of extra-framework Al, hence leads to a decrease of total L acid amount and an increase of total B acid amount, especially a clear increase in medium strength B acid amount (with 31 P NMR/TMPO chemical shifts at 62 and 58) and a significant decrease in strong B acid amount (with 31 P NMR/TMPO chemical shifts at 70 and 65) with the incorporation of La into Y zeolites. However, the total acid amount decreases significantly when La 2 O 3 content is high. The increase of B acid amount and improved stability of LaHY zeolites, boost the conversion ability and isomerization ability of heavy oil, while resulting in poor olefins selectivity and coke selectivity caused by the enhancement of hydrogen transfer reactions. Therefore, Y zeolite containing appropriate La 2 O 3 content should be considered to enhance heavy oil cracking ability while boosting light olefins production and optimizing coke selectivity. Graphic Abstract
研究领域:
石油化工
·
催化材料
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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）