JOURNAL OF HAZARDOUS MATERIALS
·
2019
·
IF 7.65
Xingyun Hu,Xianjia Peng,Linghao Kong,Feng Zhu
The most toxic and mobile form of vanadium (V) is V(V). Thus, the oxidation of V is a subject of considerable importance since the process may increase environmental risks of V. V(IV) is known to be stable when pH < 4.5. However, in this study, stable V(IV) was oxidized almost completely in goethite suspension within 60 min at pH 2.0 and pH 4.0, correspondingly, only 25%–30% and 15%–20% of V(IV) were oxidized in equimolar Fe 3+ solution and the blank solution, respectively. The promoted oxidation of V(IV) by FeOOH is attributed to the formation of the complex, VO(OFe<) + or VO(OFe<) 2 . On the one hand, the formation of the complex caused higher pH in the interface of solid FeOOH and corresponding lower conditional potential of V(V)/V(IV) than those in bulk solutions, which facilitates the oxidation of V(IV). On the other hand, the surface group OFe < may serve as a medium that facilitating the electron transfer from V(IV) ions to dissolved oxygen molecules, also favoring the oxidation of V(IV). This study not only deepens our understanding of the transfer, transformation, and risk of V in environments, but also provides a reference to speculate the fate of similar elements in environments.
研究领域:
环境化学
·
地球化学
·
水污染控制
·
金属形态转化
·
界面过程
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2019
·
IF 3.45
Zhiwei Wang,Hongfeng Yin,Yun Tang,Qin Hou,Chen He,Hudie Yuan
Herein, we constructed an ordered nanoporous embedding nanoparticles composite by anodic oxidation of Ti 3 SiC 2 in fluorine containing organic electrolyte. Compared to anodized Ti which resulted in TiO 2 nanotubes , the anodized Ti 3 SiC 2 (ATSC) led to the formation of nanostructured TiO 2 /C/SiO 2 composite. The morphologies of oxides in the composite also varied with different anodization parameters. The ATSC could be directly used as an electrode without further processes, which possessed a superior structure and composition with a visible-light photocurrent density of 7.56 μA cm −2 , initial reversible area capacity of 6.18 F cm −2 , which were respectively 1.32 and 6.87 times higher than those of the anodized Ti (AT), respectively. The ATSC synthesized by such a feasible fabricating strategy shows favorable photoelectrochemical properties and remarkable stability, and may broaden the bifunctional material prospects of anodized MAX phases.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 128
·105747-105752
·
IF 3.84
Yuanyuan Zheng,Xiaoming Zhang,Yi Yao,Xiaohong Chen,Qihua Yang
Ultra-small Au nanoparticles (<2 nm) supported on hollow silica nanospheres were successfully fabricated with the aid of chemical modification (–SH groups) or through simple immersion method, leading to supported catalysts Au/SH-HNS and Au/HNS. The resulting solid catalysts showed good thermal stability and the small particle sizes could be remained even at high temperature of 350 °C. Such catalysts were catalytically active in the oxidation of styrene using O2 as oxidant under 1 atm pressure. The catalytic results showed that the activity strongly depends on the Au loading amount, and the loading of 4–5 wt% led to the highest activity. Significant rate enhancement was observed with gold nanoparticles supported on pure silica in comparison with thiol modified silica nanospheres, suggesting the negative effects of thiol groups. The solid catalyst could be reused at least 8 reaction cycles without significant decrease in activity and selectivity. This study not only supplies an active, recoverable catalyst for the green transformation of styrene, but also demonstrates that the hollow silica nanosphere material has a superior ability in stabilizing metal nanoparticles against growth.
研究领域:
纳米催化
·
材料化学
·
绿色化学
·
有机氧化反应
·
多相催化
✓ 已验证
DOI
高影响因子
Journal of Environmental Sciences
·
2024
·
IF 5.9
Xixian Huang,Bing Yang,Ye Dou,Yang Ding
The abiotic oxidation of divalent manganese (Mn(II)) and the formation of Mn oxides are important geochemical processes, which control the mobility and availability of Mn as well as element cycling and pollutant behavior in soils. It was found that iron (oxyhydr)oxides can catalyze Mn(II) oxidation , but the effects of the coexisting dissolved organic matter (DOM) molecules on the catalysis of different iron (oxyhydr)oxides for Mn(II) oxidation are poorly understood. Herein, we investigated Mn(II) oxidation under the impacts of the interactions between iron (oxyhydr)oxides (i.e., ferrihydrite, goethite and hematite) and DOM molecules. Simultaneously, we elucidated the variations of DOM composition and properties. Our results indicated that the catalysis of iron (oxyhydr)oxides for Mn(II) oxidation was significantly inhibited by DOM. Moreover, DOM had less inhibiting effect on the catalysis of ferrihydrite for Mn(II) oxidation and the formation of Mn oxides (e.g., hausmannite and buserite) relative to goethite and hematite, which was partially because of the higher electron transfer capacities of ferrihydrite. Meanwhile, DOM molecules with high nominal oxidation state of carbon (NOSC), molecular weight, unsaturation and aromaticity were selectively adsorbed and oxidized by Mn oxides , including the oxygenated phenols and polyphenols. The newly formed molecules mainly belonged to phenols depleted of oxygen and aliphatics. Furthermore, NOSC was a key molecular characteristic for controlling DOM composition during DOM adsorption and oxidation by Mn oxides when iron minerals were present. Overall, our research contributes to understanding Mn(II) oxidation mechanisms under heterogeneous systems and behaviors of DOM molecules in the environment.
研究领域:
环境地球化学
·
土壤化学
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水文地球化学
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有机-矿物相互作用
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元素生物地球化学循环
✓ 已验证
DOI
高影响因子
Journal of Energy Chemistry
·
2021
·
IF 9.676
Yu Kang,Yujia Han,Cong Wei,Kuo Liu,Ming Tian,Chuande Huang,Chaojie Wang,Jian Lin,Baolin Hou,Xiaoli Pan,Yang Su,Lin Li,Riguang Zhang,Yong Hao,Xiaodong Wang
Thermochemical two-step CO 2 splitting is a potential approach that fixes the sustainable resource into transportable liquid fuels. However, the harsh CO 2 splitting conditions, the limited oxygen release kinetics and capacity of metal oxides block further promoted the CO yield and solar-to-fuel energy efficiency. Here, we propose a different carbon cycle assisted by Ni/La 2 O 3 via coupling methane decomposition with thermochemical CO 2 splitting, replacing conventional metal oxides cycle. Superior performance was demonstrated with methane conversion reached around 94% with almost pure H 2 generation. Encouragingly, CO 2 conversion of 98% and CO yield of 6.9 mmol g −1 derived from CO 2 were achieved, with peak CO evolution rate (402 mL min −1 g −1 ) of orders of magnitude higher than that in metal oxide process and outstanding thermodynamic solar-to-fuel energy efficiency (55.5% vs. 18.5%). This was relevant to the synergistic activation of La 2 O 3 and Ni for CO 2 in carbon cycle, thus improving CO 2 splitting reaction with carbon species.
研究领域:
能源化学
·
催化化学
·
可持续能源
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热化学转化
·
二氧化碳利用
✓ 已验证
DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2023
·Vol. 30
·期 18
·53492-53504
·
IF 5.8
Tang Hao,Liu Xiaolong,Li Yiren,Tian Jinglei,Hou Changjiang,Tian Mengkui,Zhu Tingyu
Based on the unique technique property of grate–kiln pellet production process and its demand of ultra-low emission of NO x , a low energy-consumed embedded selective catalytic reduction (SCR) denitration technology was proposed. The temperature of the NO x -containing tributary flue gas was 350–500 °C, which basically accorded with the temperature range of SCR by V 2 O 5 -based catalyst. Considering the potential inhibition effect of high SO 2 concentration (8000–10000 mg/m 3 ) and metal-containing dust in the pelletizing flue gas, the catalyst compositions were optimized to V 2 O 5 (0.5%) and WO 3 (5%), giving NO conversion over 90% with low yield of N 2 O by-product. Compared with the low-medium temperature SCR technology, it was no longer necessary to reheat the flue gas, showing a remarkable CO 2 emission reduction effect. The CO 2 emission reduction ratios were 94% and 66% contributed by the decrease of fuel and electricity consumption for the embedded SCR technology, respectively. The operating cost was also greatly reduced from 11.4 CNY/t-pellet to 3.1 CNY/t-pellet (Chinese Yuan).
研究领域:
环境工程
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大气污染控制
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化学工程
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能源与环境科学
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工业生态学
✓ 已验证
DOI
高影响因子
CHEMOSPHERE
·
2020
·
IF 5.778
Kexin Chen,Xi Wang,Pengfei Xia,Jinxin Xie,Jing Wang,Xukai Li,Yiming Tang,Laisheng Li
Z-scheme Cu 2 O-(rGO-TiO 2 ) photocatalyst was successfully synthesized via a simple three-step approach for 2,2′,4,4′-tretrabromodiphenyl ether (BDE47) reductive removal under simulated solar irradiation. Unlike the traditional heterojunction , the addition of reduced graphene oxide (rGO) enhanced the redox ability of Cu 2 O-TiO 2 by increasing charge transfer. When modifying Cu 2 O films by adding 1% rGO and coating with 70% TiO 2 , the resulting Cu 2 O-(rGO-TiO 2 ) exhibited the best photocatalytic activity for BDE47 removal. The charge transfers of Cu 2 O-(rGO-TiO 2 ) were proven to follow a Z-scheme pathway through the electron paramagnetic resonance analysis. The degradation pathways of BDE47 were elucidated by identifying intermediate products via gas chromatography-mass spectrometry (GC-MS) and gas chromatography (GC). Photo-electrons (e − ) generated from the conduction band of Cu 2 O and hydrogen protons (H 0 ) reduced from H + in water were the main contributing elements for the removal of BDE47, which response to the ortho and para debromination . Ortho-Br of BDE47 was attacked by e − and BDE28 was the dominant debromination product on the first stage. Then e − and H 0 attacked ortho-Br and para-Br of BDE28 to form BDE15 and BDE8, respectively. The concentration of BDE8 was higher than that of BDE15, suggesting that H 0 played the most important role on the second debromination stage. An effective Cu 2 O-(rGO-TiO 2 )-based Z-scheme system for BDE47 debromination was proposed in this study, which may contribute to the development of novel green technologies.
研究领域:
环境科学
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光催化化学
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环境污染与控制
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材料科学
·
绿色技术
·
有机污染物降解
✓ 已验证
DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 81
·77358-77365
·
IF 3.289
Ting-Ting Li,Jinjie Qian,Yue-Qing Zheng
Metal–organic frameworks (MOFs) have been demonstrated as suitable metal sources and sacrificial templates for the preparation of porous transition-metal oxide nanomaterials. Herein, porous CuO micro-polyhedra assembled from numerous nanoparticles are synthesized simply by employing a Cu-based MOF as a precursor via a one-step calcination process under an air atmosphere. Benefitting from their high porosity and large specific surface area, porous CuO materials exhibit excellent electrocatalytic performances toward water oxidation in pH 9.2 KBi solution. A low catalytic onset potential at 1.05 V vs. NHE (NHE = normal hydrogen electrode) is obtained based on electrochemical measurements. A faradaic efficiency of nearly 98% and a stable catalytic current density of 2.2 mA cm−2 are achieved under an applied potential of 1.30 V vs. NHE over an electrolysis period of 10 h. In addition, based on the Tafel plot, the required overpotentials are only ∼410 mV and ∼510 mV for achieving the catalytic current densities of 0.1 mA cm−2 and 1.0 mA cm−2, respectively. The excellent performances make it an appealing candidate as a potential catalyst for green energy applications.
研究领域:
材料化学
·
电化学
·
纳米材料
·
能源催化
·
无机功能材料
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2014
·Vol. 2
·期 29
·11065-11072
·
IF 0
Qian Zhang,Ying Zhou,Fang Wang,Fan Dong,Wei Li,Haimin Li,Greta R. Patzke
Elemental photocatalysts have recently been proposed as interesting materials to be used as alternatives to conventional semiconductor compounds. In this study, we demonstrate that not only elements with semiconducting properties are photocatalytically active by introducing semimetallic bismuth for the photooxidation of NO. Black Bi films were prepared via an electrochemical deposition approach. Both density functional theory (DFT) calculations and temperature dependence electrical resistivity measurements pointed out that the obtained films exhibited semimetallic behavior. The Bi films were easily oxidized upon exposure to air. However, electrochemical reduction of the surface amorphous oxide layer led to a more than 4-fold enhancement of the photocurrent density of the Bi films. The detection of hydroxyl radicals with electron spin resonance (ESR) investigations further confirmed the photogeneration of electrons and holes. A 37.7% removal ratio of NO over Bi films was observed under UV light irradiation with no significant reduction of photocatalytic activity after five cycles. Given that the conduction and valence bands of semimetallic Bi overlap, the associated excitation processes are more complex in comparison with semiconductor photocatalysts, thereby indicating a different photocatalytic mechanism. The present study points out new directions for developing semimetallic photocatalysts.
研究领域:
材料科学
·
环境催化
·
物理化学
·
表面科学
·
无机功能材料
✓ 已验证
DOI
PROCEEDINGS OF THE COMBUSTION INSTITUTE
·
2018
·Vol. 37
·期 1
·565-573
·
IF 5.336
Xiaoyuan Zhang,Yuyang Li,Chuangchuang Cao,Jiabiao Zou,Yan Zhang,Wei Li,Tianyu Li,Jiuzhong Yang,Philippe Dagaut
The kinetics of propanal oxidation was studied in a jet-stirred reactor (JSR) at atmospheric pressure. The investigated temperature range is from 450 to 800 K at two different equivalence ratios (0.35 and 4.0). Thanks to the synchrotron vacuum ultraviolet photoionization mass spectrometry (SVUV-PIMS), critical intermediates were identified, including methylperoxy, methyl hydroperoxide , ethylperoxy, ethyl hydroperoxide, α-lactone, β-propiolactone and ketohydroperoxides. A kinetic model for propanal oxidation was also developed and validated against the present experimental results, as well as those available from the literature. Main chain-branching pathways under the investigated conditions were analyzed based on present experimental data and kinetic model . The O 2 addition reaction to the propanoyl radical and subsequent oxidation reactions play an important role in determining the oxidation rate of propanal under fuel-lean conditions, especially in the low-temperature oxidation region. Under fuel-rich conditions, the decomposition of the propanoyl radical is predominant and C 2 H 5 relevant reactions consequently determine the kinetics of oxidation of propanal.
研究领域:
物理化学
·
燃烧化学
·
反应动力学
·
分析化学
·
能源化学
✓ 已验证
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2021
·
IF 6.901
Na Li,Yaru Peng,Zeng Chen,Wenjuan Xiong,Jiaqi Sun,Yiming Chen,Putao Zhang,Meiyue Liu,Shengjun Li
The electro-deoxidation of MgO does not proceed efficiently due to the electrical insulation properties of MgO and large molar volume of metallic magnesium. In this experiment, an attempt was done to prepare Mg-Zr alloy from their oxides using the method of electro-deoxidation. The electrochemical mechanism of the deoxidation process of MgO, ZrO 2 and MgO-ZrO 2 composite was studied through cyclic voltammetry using metallic cavity electrode (MCE). There was an intermediate phase (Zr 3 O) in the reduction process of ZrO 2 . The electro-deoxidation of MgO occurred for MgO-ZrO 2 composite in CaCl 2 -NaCl molten salt. Moreover, the electro-deoxidation of MgO was promoted by the addition of polyvinyl butyral (PVB). The formation of metal phase Mg was confirmed by XRD, EDS, Raman spectroscopy, and inductively-coupled plasma spectroscopy. The electro-deoxidation products showed significant differences with the concentration of PVB and the ratio between MgO and ZrO 2 . The electro-deoxidation of MgO and ZrO 2 was favorable when the PVB concentration was 5.0% (wt.%). Pure metal phase of Mg-Zr alloys was formed when the molar ratio of MgO and ZrO 2 was 1:2. The atomic fraction of Mg in the electrolytic product was ca. 28.0 mol.%. This work shows that MgO could be directly electro-deoxidized to Mg without the formation of intermediate phase oxide.
研究领域:
材料科学
·
冶金工程
·
无机化学
·
电化学
·
金属合金制备
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2021
·Vol. 47
·期 19
·26869-26876
·
IF 4.527
Shao-Min Lin,Ya-Ling Yu,Ming-Feng Zhong,Huan Yang,Chen-Yang Zhang,Zhi-Jie Zhang,Wei Xu,Jiong-Yan Xie,Yu-Chun Qiu
Converting the γ phase into the α phase completely is necessary in the presintering stage of industrial alumina (Al 2 O 3 ), which requires high temperature and energy consumption. To reduce the presintering temperature, γ-Al 2 O 3 was activated by oxalic acid . XRD , 27 Al-MAS-NMR and TG-DSC were used to characterize the γ - alumina before and after activation, and the phase transformation was studied. The formation temperature of α-Al 2 O 3 decreased to 1029 °C for oxalic acid activated γ-Al 2 O 3 , and the α-fraction was 100% for activated γ-Al 2 O 3 at 1300 °C. After oxalic acid activation , the diffraction peak intensity of γ-Al 2 O 3 decreased significantly; the results of 27 Al-MAS-NMR suggested that octahedral [AlO 6 ] in γ-Al 2 O 3 was easier than tetrahedral [AlO 4 ] to be attacked by oxalic acid , and the formation of pentavalent [AlO 5 ] with higher reaction activity, which was in favour of the lowering formation temperature of α-Al 2 O 3 . The dissolution concentration of Al increased after oxalic acid activation, and the dissolution process was controlled by surface reactions. Oxalic acid mainly attacked the octahedral aluminium in γ-Al 2 O 3 and extracted Al as three complexes of [Al(C 2 O 4 )] + , [Al(C 2 O 4 ) 2 ] - and [Al(C 2 O 4 ) 3 ] 3- . Oxalic acid activated γ - Al 2 O 3 with a lower phase transformation temperature has broad application prospects in the alumina industry.
研究领域:
材料化学
·
无机化学
·
固态化学
·
工业催化
·
陶瓷材料
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）