Catalysts
·
2018
·Vol. 8
·期 2
·53
·
IF 3.465
Yuanyuan Zhao,Ya Chu,Xiuping Ju,Jinsheng Zhao,Lingqian Kong,Yan Zhang
In this work, a nitrogen-containing bidentate ligand named 5,5′-(9-octyl-9H-carbazole-2,7-diyl)bis(1,10-phenanthroline) (OCBP) was synthesized as a nitrogen precursor for making an oxygen reduction catalyst. The 1,10-phenanthroline unit provides a coordination site for copper ions, and the resulting Cu-Nxunit may be responsible for the catalytic activities of the catalyst. Carbon black was selected as a support to improve the electroconductibility of the resulting catalyst. The metallo-supramolecule (Cu-SOCBP) was dispersed on the surface of Vulcan XC-72 carbon and was used as a catalyst (designated as Cu-SOCBP/C) for the oxygen reduction reaction (ORR). The microscope structure and surface components of the catalyst were acquired via scanning electron microscopy and X-ray photoelectron spectroscopy, as well as X-ray powder diffraction. The electrochemical property and ORR mechanism of Cu-SOCBP/C were analyzed using a variety of electroanalytical methods including cyclic voltammetry, electrochemical impedance spectroscopy, and linear sweep voltammetry. These results show that Cu-SOCBP/C was successfully synthesized and that ORR was achieved mainly via a four-electron transfer process to water. Thus, Cu-SOCBP/C was an effective catalyst and might have potential application as a cathodic catalyst in microbial fuel cells, which operate in an aqueous medium.Keywords:supramolecule;ORR activity;kinetics study
研究领域:
电化学
·
材料科学
✓ 已验证
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2021
·
IF 7.312
Libin Fu,Xueqin Peng,Qi Chen,Yaobin Ding,Jizhou Jiang
Photolysis and debromination of bromophenols were widely investigated previously. However, the role of reactive species especially hydrated electrons (e aq − ) in their degradation was overlooked. Therefore, in the study, generation and role of the reactive species generated during the photolysis of bromophenols were identified and evaluated by using 2,4,6-tribromophenol (TBP) as a model at different pH values from 4 to 11 under anaerobic condition. It was found that photolysis of TBP solution under UV irradiation (254 nm) yielded organic radicals (C•), hydrogen radicals (H•) and e aq − . By using nitrite and monochloroacetic acid (MCAA) as scavengers of H•/e aq − , the role of UV direct photolysis, H• and e aq − in degradation of TBP was quantitatively assessed at different initial pH (pH 0 ) values. UV irradiation induced direct photolysis of TBP was mainly dependent on its molar absorbance coefficient (ε) at 254 nm. Contribution rate of UV irradiation to degradation of TBP was about 60% at pH 0 4, 7 and 11. Interestingly, the contribution rate of e aq − was high as 35.8%-40% at pH 0 4–11, while the contribution rate of H• was negligible (<2.5%) at these pH values. Accordingly, UV and e aq − induced degradation and debromination pathways of TBP under UV irradiation were proposed. This work gains deep insight into the photolysis process of bromophenols, and clarifies the important role of e aq − in photo-degradation of bromophenols.
研究领域:
环境科学
·
化学
✓ 已验证
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2022
·
IF 14.224
Peng Wang,Jian Hu,Yidong Wang,Tingyi Liu
The ball-milling technology , a highly efficient and cost-effective method, had excellent application prospects for overcoming passivation issues of normal zero-valent iron (ZVI) to enhance the decontamination efficiency. In this work, we investigated the effects and mechanisms of pH, process control agents (PCA), and main process parameters on the removal of V 5+ using ball-milled zero-valent iron (ZVI bm ). The results showed that ZVI was successfully activated due to mechanochemical action. The enhanced proton conductivity of ZVI bm leaded to the rapid production of more Fe 2+ , thereby resulting in an order of magnitude higher elimination of V 5+ by ZVI bm than by ZVI under near-neutral conditions. In addition, the introduction of NaCl in the ball milling process could not only effectively alleviate the agglomeration phenomenon of ZVI bm , but also effectively enhance its activity. Unexpectedly, due to over-compaction and small size effects, excessive energy input weakened the reactivity of ZVI bm on V 5+ elimination. Various characterization results confirmed that the removal of V 5+ by ZVI bm was dominated by reduction and supplemented by adsorption. This work updated the basic understanding of the critical effects of process parameters and NaCl on ZVI bm in the remediation of vanadium-containing wastewater.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2019
·
IF 4.561
Huiling Zheng,Xuemei Ren,Xiaodong Zhang,Gang Song,Diyun Chen,Changlun Chen
Nanoscale zero-valent iron (nZVI) has been widely considered as a promising permeable barrier material for remediating U(VI)-contaminated waters. Little information is available regarding co-removal of U(VI) and oxyanion contaminants by nZVI, yet in the majority of areas polluted by U(VI), co-existence of phosphate is found to be common especially in eutrophic water. Herein, the mutual influence of U(VI) and phosphate on the effectiveness of nZVI in co-removing U(VI) and phosphate is investigated by macroscopic and microscopic approach. The results indicate that nZVI can effectively co-remove U(VI) and phosphate and the processes intensively depend on the solution pH and the additional order due to the formation of nZVI-U(VI)-phosphate complexes and will change the morphology of nZVI through the formation of a new phase. Furthermore, the maximum removal capacity of nZVI increases by 21.63% at pH 6.0 for U(VI) ions and by 34.28% at pH 7.0 for phosphate when both U(VI) and phosphate are present simultaneously. In short, the co-presence of U(VI) and phosphate has a great impact on the reactivity and morphology of nZVI. The findings will be beneficial to broaden the potential feasibility of nZVI in simultaneous radionuclide and phosphate pollution cleanup.
研究领域:
环境科学
·
放射生物学
✓ 已验证
DOI
高影响因子
CRYSTENGCOMM
·
2021
·Vol. 23
·期 43
·7602-7614
·
IF 3.545
Chao Feng,Gaoyan Xiong,Yaping Li,Qianqian Gao,Yuan Pan,Zhaoyang Fei,Yanpeng Li,Yukun Lu,Chenguang Liu,Yunqi Liu
Determining the effect of crystal facets on reaction performance is essential for designing an efficient propane oxidation catalyst. Herein, α-MnO2 nanowires with exposed (110), (211), (310) and (200) facets were proposed, and their crystal facet-dependent reactivity to propane oxidation was investigated. The resultant α-MnO2 nanowires with predominantly exposed (110) facets showed the maximum propane oxidation activity (T90 = 262.1 °C), oxidation rate, and turnover frequency (at 230 °C), and high stability during the oxidation of propane. In situ diffuse reflectance infrared Fourier transform spectroscopy revealed that the oxidation to form carboxylates is the decisive step; therefore, the production of reactive oxygen species is very important. The results from density of states computations revealed that the lowest electron energy was present in the (110) facet, which helps in the generation of reactive oxygen species and the regulation of the surface valence of Mn. The characterization and calculation results indicated that the (110) facets are conducive to forming oxygen vacancies, which allowed the activation and adsorption of O2 and propane, resulting in significantly enhanced propane oxidation activity. Apart from offering new insights about the structure–activity relationship of α-MnO2 with different facets exposed for short-chain volatile oxidation reactions, this study proposes a technique that can be used for improving other manganese-based catalyst oxidation systems.
研究领域:
材料科学
·
催化化学
✓ 已验证
DOI
高影响因子
Journal of Energy Chemistry
·
2024
·
IF 14
Hao Wang,Chun Yang,Xiaoyan Yu,Mingrui Wang,Runze Yang,Xiaowa Nie,Ben Hang Yin,Alex C.K. Yip,Chunshan Song,Guanghui Zhang,Xinwen Guo
Indium oxide (In 2 O 3 ), as a promising candidate for CO 2 hydrogenation to C 1 products, often suffers from sintering and activity decline, closely related to the undesirable structural evolution under reaction conditions. Based on the comprehension of the dynamic evolution, this study presents an efficient strategy to alleviate the agglomeration of In 2 O 3 nanoparticles by the surface decoration with highly dispersed silica species (SiO x ). Various structural characterizations combined with density functional theory calculations demonstrated that the sintering resulted from the over-reduction, while the enhanced stability originated from the anchoring effect of highly stable In–OSi bonds, which hinders the substantial formation of metallic In (In 0 ) and the subsequent agglomeration. 0.6Si/In 2 O 3 exhibited CO 2 conversion rate of 10.0 mmol g −1 h −1 at steady state vs. 3.5 mmol g −1 h −1 on In 2 O 3 in CO 2 hydrogenation. Enhanced steady-state activity was also achieved on Pd-modified catalysts. Compared to the traditional Pd/In 2 O 3 catalyst, the methanol production rate of Pd catalyst supported on 0.6Si/In 2 O 3 was enhanced by 23%, showing the potential of In 2 O 3 modified by SiO x in serving as a platform material. This work provides a promising method to design new In 2 O 3 -based catalysts with improved activity and stability in CO 2 hydrogenation.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2023
·
IF 13.6
Kangfu Wang,Meiru Lv,Tian Si,Xiaoning Tang,Hao Wang,Yuanyuan Chen,Tian Zhou
The effects of exposing crystal planes and vacancy defect engineering can induce unique surface atom arrangements that strongly influence the physicochemical properties of semiconductor materials . This paper used Cu 2 O with different surface structures as a research model. A liquid-phase method was chosen for surface structure regulation to prepare Cu 2 O semiconductors (Vo-(111)Cu 2 O, Vo-(100)Cu 2 O, Vo-(110)Cu 2 O) with different exposed crystalline surfaces analyze the antibacterial mechanisms of other faceted models in the photodynamic antibacterial process. The bactericidal effect of Vo-(111)Cu 2 O (40 μg/mL, 100%) was better than that of Vo-(100)Cu 2 O and Vo-(110)Cu 2 O. DFT simulations show that the photocatalytic antimicrobial performance of Vo-(111)Cu 2 O is improved due to surface defect structures caused by unsaturated coordination bonds and suspension bonds on its exposed crystalline surfaces. The suspension bonds act as active centres for trapping electrons, leading to a lower carrier complexation rate on the material surface. The antibacterial mechanism of Vo-(111)Cu 2 O showed that oxidative sterilization by reactive oxygen species (ROS) was the dominant factor (61.98%) in the antibacterial process. The most potent depolarizing effect on E. coli , the highest copper ion solubilization , and the highest ROS yield. Therefore, ROS oxidative sterilization, copper ion leaching sterilization, and contact damage synergistically affect E. coli from the inside out.
研究领域:
材料科学
·
微生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Green Chemical Engineering
·
2022
·
IF 0
Yumei Liu,Shengxin Chen,Ran An,Xingsheng Wang,Ruixia Liu
The sustainable synthesis of dimethyl maleate via diesterification through the utilization of ionic liquid (IL) is of great importance. However, the relationship between the ILs nature and the reactivity of diesterification is still unclear. Herein, a series of ILs with different structures were selected for the comprehensive investigation of diesterification. The acidity (H 0 ) and Kamlet-Taft solvent parameters (hydrogen bond donor ability (α), hydrogen bond acceptor ability (β), and polarizability (π∗)) of ILs were measured by UV–Visible spectroscopy, and the effects of them on the diesterification of maleic anhydride were also studied in detail. The results indicated that not only H 0 of the IL-based catalysis system, but also its α, β, and π∗ influenced the reaction activity of diesterification. Furthermore, a quantifiable correlation was fitted between the natural logarithm of the rate constant and multiple parameters of ILs, indicating that the diesterification rate had a positive correlation with the H 0 , α, and π∗, and inverse correlation with the β of the IL. A plausible synergetic reaction mechanism for the excellent performance of [(HSO 3 )PMim][HSO 4 ] has been proposed. Overall, this work thoroughly explored the relationship between the nature of ILs on diesterification in-depth, which will reveal the nature of diesterification in detail.
研究领域:
化学工程
·
催化化学
✓ 已验证
DOI
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2021
·
IF 19.503
Xixi Chen,Shujuan Zhan,Dingsheng Chen,Chun He,Shuanghong Tian,Ya Xiong
Grey Fe doped CeO 2-σ with tunable surface and bulk oxygen vacancies (OVs) were facilely prepared by a hydrothermal method. The light absorption, charge transfer efficiency, and catalytic activity and mechanism closely depended on the OVs. By tailoring the surface and bulk OVs, the catalytic activity of grey ceria was boosted due to the enhanced production of reactive oxygen species (i.e. OH, surface O). Density functional theory calculations show that the OVs, especially the bulk OVs, modulate the electronic structure for narrowing the bandgap and accelerating the charge transfer. Meanwhile, the surface OVs more promote the adsorption of ozone and the bulk OVs more induces the dissociation of ozone into reactive surface O. The calculation results agree well with the experimental observations. This study provides a simple method for engineering the surface and bulk OVs of ceria and gains insight into their roles in photocatalytic ozonation .
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2022
·
IF 11.357
Fanxu Meng,Jiang Xu,Huiwang Dai,Yunlong Yu,Daohui Lin
Surface modification of microscale Fe powder with nitrogen has emerged recently to improve the reactivity of Fe0 for dechlorination. However, it is unclear how an even incorporation of a crystalline iron nitride phase into Fe0 nanoparticles affects their physicochemical properties and performance, or if Fe0 nanoparticles with a varied nitridation degree will act differently. Here, we synthesized nitridated Fe0 nanoparticles with an even distribution of N via a sol–gel and pyrolysis method. Nitridation expanded the Fe0 lattice and provided the Fe4N species, making the materials more hydrophobic and accelerating the electron transfer, compared to un-nitridated Fe0. These properties well explain their reactivity and selectivity toward trichloroethylene (TCE). The TCE degradation rate by nitridated Fe0 (up to 4.8 × 10–2 L m–2 h–1) was much higher (up to 27-fold) than that by un-nitridated Fe0, depending on the nitridation degree. The materials maintained a high electron efficiency (87–95%) due to the greatly suppressed water reactivity (109–127 times lower than un-nitridated Fe0). Acetylene was accumulated as the major product of TCE dechlorination via β-elimination. These findings suggest that the nitridation of Fe0 nanoparticles can change the materials’ physicochemical properties, providing high reactivity and selectivity toward chlorinated contaminants for in situ groundwater remediation.
研究领域:
环境科学
·
纳米材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF ENVIRONMENTAL MANAGEMENT
·
2022
·
IF 8.91
Jing Feng,Gang Lang,Tingting Li,Jing Zhang,Tengyue Li,Zhenju Jiang
Heavy metals (HMs) pose serious threats to both human and environmental health and therefore, effective and low-cost techniques to remove HMs are urgently required. Here we report a facile Fe-tannin coating method for zero-valent iron (ZVI) including nanoparticles (nZVI) and foam (Fe foam ), and demonstrate that the generated Fe-tannin coating would remove the inherent passive iron oxide shell of ZVI and provide channels for the galvanic replacement reaction between ZVI and HM ions . Electrochemical characterizations demonstrate that the Fe core of the modified ZVI materials could be easily oxidized and transfer electrons to HM ions owing to the facile mass transport and charge transfer. In 40 min, nZVI@Fe-TA exhibits excellent performances for Cd(II), Ni(II), Pb(II), Hg(II), Cu(II) and Cr(VI) removal, with the apparent removal rate constants of 0.083, 0.085, 0.083, 0.073, 0.092 and 0.078 min −1 , respectively. It is found that the surface area normalized rate constants of nZVI@Fe-TA are 4–7 times higher than that of nZVI@Fe 2 O 3 counterpart, suggesting that the improved HM removal reactivity of nZVI@Fe-TA is derived from the surface modification. Moreover, nZVI@Fe-TA has advantages in resisting interference and in the simultaneous removal of different HM ions. Under a 30 min hydraulic retention time , Fe foam @Fe-TA could remove 98% HMs in the successive process. For real electroplating wastewater, Fe foam @Fe-TA exhibits excellent performance for Cr(VI) and Ni(II) removal, producing effluent of stable quality that meets local emission regulation. This study provides a facile strategy to remove the inherent passive iron oxide shell and enhance the HM removal reactivity for ZVI materials.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2024
·
IF 12.2
Yanshi Zheng,Jinyan Yang,Mei Li,Yingshi Zhu,Jiayu Liang,Dehai Yu,Ziyao Wang,Jianchuan Pei
Sulfadiazine (SDZ), a widely used effective antibiotic , is resistant to conventional biological treatment, which is concerning since untreated SDZ discharge can pose a significant environmental risk. Electro-Fenton (EF) technology is a promising advanced oxidation technology for efficiently removing SDZ. However, due to the limitations of traditional experimental methods, there is a lack of in-depth study on the mechanism of ·OH-dominated SDZ degradation in EF process. In this study, an EF system was established for SDZ degradation and the transformation products (TPs) were detected by mass spectrometry . Dynamic thermodynamic, kinetic and wave function analysis of reactants, transition states and intermediates were proposed by density functional theory calculations, which was applied to elucidate the underlying mechanism of SDZ degradation. Experimental results showed that amino, benzene, and pyrimidine sites in SDZ were oxidized by ·OH, producing TPs through hydrogen abstraction and addition reactions. ·OH was kinetically more likely to attack SDZ - than SDZ. Fe(IV) dominated the single-electron transfer oxidation reaction of SDZ, and the formed organic radicals can spontaneously generate the de-SO 2 product via Smiles rearrangement . Toxicity experiments showed the toxicity of SDZ and TPs can be greatly reduced. The results of this study promote the understanding of SDZ degradation mechanism in-depth. Environmental Implication Sulfadiazine (SDZ) is one of the antibiotics widely used around the world. However, it has posed a significant environmental risk due to its overuse and cannot be efficiently removed by traditional treatment methods. The lack of in-depth study on SDZ degradation mechanism under reactive species limits the improvement of SDZ degradation efficiency. Therefore, this work focused on SDZ degradation mechanism in-depth under electro-Fenton system through reactive species investigation, mass spectrometry analysis , and theoretical calculation. The results in this study can provide a theoretical basis for improving the SDZ degradation efficiency which will contribute to solving SDZ pollution problems.
研究领域:
环境科学
·
化学
·
生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）