Reaction Kinetics Mechanisms and Catalysis
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2024
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IF 1.7
Lin Guangqiang,Mao Chunfeng,Li Menghua,Wang Ziyi,Li Qinyi,Zhan Jiaqing,Liu Junsheng
In this study, Zn–W–Bi–O catalysts with a sandwich structure were prepared by mixing zinc tungstate and bismuth nitrate to form bismuth tungstate at the interface. The catalyst was composed of bismuth nitrate as the upper layer, zinc tungstate as the lower layer, and phase interface (bismuth tungstate) as the core. The generation of phase interfaces provides a new reaction mechanism for catalytic processes. Based on the different intermediate state changes in the reaction process, the Zn–W–Bi–O catalysis system can be divided into H-S Mechanism, B-R Mechanism, and P-G Mechanism. These reaction mechanisms will simultaneously react with H 2 O 2 to generate various transition states, which will cooperatively oxidize sulfur atoms to remove them. The structural characteristics and stability of Zn–W–Bi–O catalysts were determined. There are strong stability and catalytic efficiency for Zn–W–Bi–O catalysts. The desulfurization rate can be close to 100% under optimal conditions (Catalyst of 0.02 g, ionic liquids of 0.5 mL, H 2 O 2 of 0.2 mL, model oil of 5 mL, 80 °C). Zn-W-Bi-O-2 catalysts lead to 3 times improvement in ODS activity for the upper layer and 1.25 times improvement in ODS activity for the lower layer. The catalytic reaction mechanism was obtained by the structure-activity relationship.
研究领域:
化学工程
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催化材料
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能源化学
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DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
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2024
·Vol. 35
·期 6
·1-12
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IF 2.8
Tang Lanxin,Li Shuangchi,Wang Fang,Chen Yu
The binary perovskite-type compound (1 − x )BiFeO 3 – x BaTiO 3 (BF-BT) is considered as a promising high-temperature lead-free piezoelectric material due to its high Curie temperature ( T C > 400 °C) and better electromechanical properties. In this work, ternary lead-free piezoelectric ceramics with a chemical formula of (0.67 − x )BiFeO3–0.33BaTiO3– x Bi(Zn0.5Ti0.5)O 3 + 1 mol% MnO 2 (where x = 0–0.05) were prepared by the conventional solid-state reaction route. The effects of Bi(Zn 0.5 Ti 0.5 )O 3 introduction on the phase structures and microstructures, piezoelectric and dielectric properties, as well as impedance characteristics of BF-BT ceramics were investigated in detail. Firstly, all the samples synthesized exhibit a pure perovskite structure with the coexistence of rhombohedral ( R ) and tetragonal ( T ) phases, and the T phase content increases with increase in x . A small amount of Bi(Zn 0.5 Ti 0.5 )O 3 ( x ≤ 0.03) that were incorporated into the perovskite lattice of BF-BT can promote the grain growth of ceramics. Secondly, all samples were found with a notable relaxed phase transition behavior, T C of the system decreases with increase in x . The AC impedance spectra of the samples were fitted and analyzed according to the R-CPE equivalent circuit model, the electric impedance of the ceramics at high temperatures was mainly contributed by grain boundaries. Moreover, the dielectric relaxation activation energy of the samples firstly decreases and then increases with increase in x . Finally, the composition with x = 0.02 shows the optimized electrical properties among these samples, including T C = 454 °C, d 33 = 117 pC/N, k p = 23%, tan δ = 0.11, which are mainly benefited from the bismuth content compensation and the substitution of (Zn 0.5 Ti 0.5 ) 3+ for Fe 3+ at B-site reducing the valence change of Fe 3+ in BF-BT.
研究领域:
材料科学
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物理学
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DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
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2017
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IF 9.446
Jun Xiao,Weiyi Yang,Qi Li
Bi quantum dots were deposited onto rutile TiO 2 nanoparticles by a one-pot, solvent-thermal process to create the Bi/TiO 2 (rutile) heterojunction photocatalyst. Due to the specific semimetal property of Bi, a metal to semiconductor transition occurred for Bi quantum dots, which endowed them with the hole trapping capability to enhance the charge carrier separation in rutile TiO 2 and eliminate the need of sacrificial agents for the consumption of photogenerated holes in photocatalytic reduction process. The Bi/TiO 2 (rutile) heterojunction photocatalyst demonstrated an efficient photocatalytic bromate reduction under visible light illumination without the addition of sacrificial agents in the reaction solution, and it could be easily regenerated for reuse. Different with previously reported noble/transition metal modifications as the electron trapping center, this study demonstrated a novel material design strategy of the introduction of hole trapping centers to create photocatalysts with strong photocatalytic reduction capabilities, which could be readily adopted for a broad range of technical applications.
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
Journal of Environmental Chemical Engineering
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2024
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IF 7.4
Beijia Yuan,Liang Bao,Huaiwei zhang,Yong-jun Yuan
In this paper, carbon supported Bi 2 O 3 -BiOCl-Bi heterostructures were successfully synthesized via a facile and simple hydrothermal method. A series of structure and morphology testing clearly showed that carbon and metallic Bi were deposited on the surface margin of Bi 2 O 3 -BiOCl, which benefited the rapid transfer of internal photogenerated electrons. Photophysical experiments including electron paramagnetic resonance (EPR) and X-ray photoelectron spectroscopy (XPS) indicated that the amount of surface oxygen vacancies (OVs) was significantly increased, which act as reactive active sites and therefore effectively enhance the photocatalytic performance. The photocatalytic N 2 reduction yield of C@Bi 2 O 3 -BiOCl-Bi was remarkably improved to 400 μg·L −1 , which was 3.63 times higher than that of BiOCl. This research demonstrated a feasible strategy to construct advanced photocatalyst by incorporating defect-rich structures and surface engineering.
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
WATER SCIENCE AND TECHNOLOGY
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2024
·Vol. 90
·期 4
·1132-1148
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IF 2.5
Wang Rui,Dai Zhineng,Zhang Wenqi,Ma Chao
View large Download slide View large Download slide Close modal Efficient degradation of industrial organic wastewater has become a significant environmental concern. Electrochemical oxidation technology is promising due to its high catalytic degradation ability. In this study, Co–Bi/GAC particle electrodes were prepared and characterized for degradation of 1,4-dioxane. The electrochemical process parameters were optimized by response surface methodology (RSM), and the influence of water quality factors on the removal rate of 1,4-dioxane was investigated. The results showed that the main influencing factors were the Co/Bi mass ratio and calcination temperature. The carrier metals, Co and Bi, existed mainly on the GAC surface as Co 3 O 4 and Bi 2 O 3 . The removal of 1,4-dioxane was predominantly achieved through the synergistic reaction of electrode adsorption, anodic oxidation, and particle electrode oxidation, with ·OH playing a significant role as the main active free radical. Furthermore, the particle electrode was demonstrated in different acid–base conditions (pH = 3, 5, 7, 9, and 11). However, high concentrations of Cl − and NO 3 - hindered the degradation process, potentially participating in competitive reactions. Despite this, the particle electrode exhibited good stability after five cycles. The results provide a new perspective for constructing efficient and stable three-dimensional (3D) electrocatalytic particle electrodes to remove complex industrial wastewater. A Co–Bi/GAC particle electrode for the 3D/E system was prepared by the one-step method. The production of ·OH was increased significantly by adding a 3D particle electrode. Fast and effective removal was achieved in the high range of initial 1,4-dioxane concentration. The Co–Bi/GAC particle electrode has a high catalytic activity. The 1,4-dioxane was removed via electrode adsorption and oxidation synergy.
研究领域:
环境科学
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电化学工程
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DOI
PubMed
高影响因子
JOURNAL OF MATERIALS PROCESSING TECHNOLOGY
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2019
·
IF 4.178
Qin Sun,Wanchun Yang,Yihan Liu,Yufeng Li,Mingyu Li
Soda lime tempered glass was successfully joined by a Bi-B-Zn lead-free low-melting glass with a composition of 35Bi 2 O 3 -50H 3 BO 3 -15ZnO (mol%). The Bi-B-Zn glass exhibited a glass transition temperature (T g ), softening point (T d ) and crystallization temperature (T c ) of 346 ℃, 364 ℃and 448 ℃ respectively. The wettability of the glass on tempered glass substrate was investigated, and a contact angle of less than 13.94° was obtained when the temperature was raised to above 470 ℃ in open atmosphere. The microstructural evolution, interfacial bonding mechanism and mechanical properties of the joint at different joining temperatures were investigated. The diffusion bonding between Bi-B-Zn glass solder and tempered glass was achieved. The crystals of Bi 4 B 2 O 9 were detected in the joint when the joining temperature was higher than 450 ℃. The shear strength and Vickers hardness of the joint reached 35.14 ± 1.89 MPa and 191.55 ± 13.93 MPa, respectively. The effects of the fractions and size of Bi 4 B 2 O 9 on the shear strength were evaluated, and the fracture mechanism at the interface was also clarified.
研究领域:
材料科学
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工程学
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DOI
高影响因子
ENVIRONMENTAL ENGINEERING SCIENCE
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2020
·Vol. 37
·期 1
·64-77
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IF 1.681
Yuxiang Yan,Hua Yang,Zao Yi,Xiangxian Wang,Ruishan Li,Tao Xian
In this work, we have adopted a coprecipitation method to synthesize BiOBr nanoplates with diameter of 150–450 nm and thickness of 40–80 nm, and then created Bi nanowires (diameter: 6 nm) on their surface through a NaBH4 reduction method. Evolution of Bi nanowires was systematically investigated by varying the concentration of NaBH4 solution and reaction time. It is demonstrated that with increasing the NaBH4 concentration (2 h reaction), Bi nanowires are gradually evolved from BiOBr crystals, and in particular treatment by 110 mM NaBH4 solution leads to the complete evolution of BiOBr nanoplates to Bi nanowires. At a low-concentration NaBH4 solution (30 mM), BiOBr crystals are partially reduced to Bi nanowires with increasing reaction time, and then the Bi nanowires are recrystallized into BiOBr nanowires/nanoparticles on the surface of BiOBr nanoplates. At a high-concentration NaBH4 solution (110 mM), BiOBr nanoplates are easily reduced to Bi nanowires with a short reaction time, and further prolonging the reaction time leads to the gradual transformation of Bi nanowires into Bi4O5Br2 nanoparticles/nanowires. Photocatalytic performances of the samples were evaluated by eliminating rhodamine B from aqueous solution under simulated sunlight illumination. It is demonstrated that the creation of Bi nanowires (an appropriate content) on the surface of BiOBr nanoplates can produce excellent Bi@BiOBr composite photocatalysts with enhanced photodegradation performances. The underlying enhanced photocatalytic mechanism was investigated and discussed.
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
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2018
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IF 3.927
Hui Xu,Yunfang Huang,Dan Luo,Xiaomin Yang,Shao Jin,Qiyao Guo,Yuezhu Zhao,Yu Fang,Yuelin Wei,Jihuai Wu
In this work, multiple heterojunction Ag/Bi/BiOCl 0.8 Br 0.2 photocatalysts with novel porous micro-flower structure were fabricated via a facile one-step solvothermal route and characterized systematically. The TEM and HRTEM images clearly showed the heterogeneous nanostructures at the interface between Ag/Bi and BiOCl 0.8 Br 0.2 . The as-prepared Ag/Bi/BiOCl 0.8 Br 0.2 composites displayed a strong optical absorption in the region of 250–1500 nm, especially in the unexploited near infrared region which accounts for most of the sunlight. The multiple heterojunction photocatalyst exhibited an outstanding photocatalytic activity for the degradation of Rhodamine B under the UV, visible and NIR light irradiation, respectively. The highly enhanced photocatalytic activity was attributed to the synergistic effects, including the reduced band gap, the surface plasmon resonance effect, efficient charge separation of photo-generated electron-holes. On the basis of the radical species trapping experiments, the holes and superoxide radicals were confirmed to be the mainly active species involved in the degradation of Rhodamine B under the NIR light irradiation. This study provides a novel strategy for designing highly performance plasmonic photocatalysts under the whole solar light irradiation.
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
CHEMICAL RESEARCH IN CHINESE UNIVERSITIES
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2015
·Vol. 31
·期 5
·761-765
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IF 0.875
Sun Weizhi,Yu Shitao,Xian Mo
To investigate the green trinitration method of aromatic compounds, with Lewis acid/ionic liquid as catalyst and HNO 3 /Ac 2 O as nitration reagent, a Lewis acid/ionic liquid/HNO 3 /Ac 2 O system was established. In various combinations of Lewis acids and ionic liquids, Bi(NO 3 ) 3 ·5H 2 O/[HMIM]ClO 4 proved to be a very efficient catalyst for the trinitration of activated aromatic compounds and reusable for 3 times. Reaction conditions for the trinitration were optimized and yields of the trinitro products were from mild to excellent. This sulfuric acid-free system has the advantages of strong trinitration ability, low environment pollution, low toxicity, low cost and high potential for industrial application.
研究领域:
有机化学
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环境化学
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DOI
高影响因子
Journal of CO2 Utilization
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2018
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IF 5.503
Qian Li,Zhuxing Sun,Haiqiang Wang,Zhongbiao Wu
In this study, hollow-structured Bi decorated g-C 3 N 4 hybrids were successfully fabricated by a simple solvothermal method and applied for the first time to the photocatalytic reduction of CO 2 . Remarkably, the composites exhibited excellent CO 2 conversion efficiencies in the presence of H 2 O under visible light irradiation compared to unmodified g-C 3 N 4 , especially for the production of CH 4 . The optimum photocatalyst 30-Bi/g-C 3 N 4 presented the best production of CO and CH 4 , approximately 3 times and 9 times as high as those of unmodified g-C 3 N 4 , respectively. A series of characterizations were conducted to explore the essence behind such an enhancement; we found that enhanced light harvesting, quick separation of photoinduced carriers and more negative conduction band, due to the formation of a Schottky junction between g-C 3 N 4 and Bi metal and the solvothermal process, co-contributed for the enhanced CO 2 conversion; A more important finding was that the surprising improvement of CH 4 yield stem primarily from the introduction of the hollow-structured Bi, which enabled the accumulation of electrons on its surface exhibiting the metal-like property. The CO 2 photocatalytic conversion process was also investigated by in-situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFT) spectroscopy and we found that HCO 3 − and CO 2 − were active intermediates over 30-Bi/g-C 3 N 4 and Bi doping could promote the activation of CO 2 . In summary, this work presented hollow-structured Bi decorated g-C 3 N 4 composites as new materials for energy applications, proving once more the meta-like nature of bismuth, and laying the groundwork for the utilization of Bi in CO 2 photocatalytic reduction processes.
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
SOLID STATE SCIENCES
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2022
·
IF 3.752
Peijie Weng,Qing Cai,Linfeng Zhang,Huadong Wu,Kun Wu,Jia Guo
In this study, the Mo -doped hollow hierarchical Bi/BiOBr microspheres are prepared by the solvothermal method with the Sn 2+ as reductant. The prepared composites show a good degradation effect for ciprofloxacin (CIP) under visible light. Especially, the BSM-22 composite show the best photocatalytic activity, with the apparent rate constant k as high as 0.03014 min −1 , which is 26.9 times that of the pure BiOBr. It is assumed that the introduction of Sn 2+ facilitate the formation of hollow hierarchical microspheres structure of BiOBr microspheres and the appearance of metallic Bi on the surfaces. Therefore, the transfer and separation efficiency of photogenerated charges is increased in the composites. Impressive, benefit from the microtopography of the hollow structure, the specific surface area of the BSM-22 (53.476 m 2 /g) is 21.76 times than that of the BiOBr (2.458 m 2 /g). The doping of Mo reduces the band gap of BiOBr (exactly from 2.61 to 1.96 eV) and broaden the photoabsorption region. Therefore, the photocatalytic activity of the Mo -doped Bi/BiOBr microspheres are heavily improved in dealing with different kinds of antibiotic molecules. More importantly, these results show that the design strategies of heteroatom doping, metal bismuth production, and morphology control of the bismuth oxybromide composite can greatly improve the visible-light catalytic activity.
研究领域:
环境科学
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材料科学
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DOI
高影响因子
SURFACE REVIEW AND LETTERS
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2019
·
IF 0.748
XIANGRUI MENG,MEIFENG HAO,YIWEI JIANG,XIANGZHENYUE SUN,YAN WANG,YUQING MIAO
A simple wet-explosion method was employed to synthesize the Ni–Bi–P composite microspheres. The hollow structure was obtained possibly due to the violent evolution of gas bubbles when the reaction reagents were mixed. The hollow microspheres of Ni–Bi–P exhibited outstanding high catalytic activity for the reduction of p -nitrophenol ( p -NP) to form p -aminophenol in the presence of NaBH 4 within only 1 s. Due to the space limitation, the hollow structure of Ni–Bi–P microspheres helps to accommodate and confine the molecules of NaBH 4 and p -NP within the small space where NaBH 4 and p -NP contact closely at Ni–Bi–P catalysts. The synergetic action of Ni, Bi and P elements also contributes the enhanced catalytic activity.
研究领域:
材料科学
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环境科学
·
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）