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Dynamic evolution of nitrogen and oxygen dual-coordinated single atomic copper catalyst during partial oxidation of benzene to phenol

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Nano Research 2022年第4期15卷 3017-3025页

作者： Weiming Chen Hongqiang Jin Feng He Peixin Cui Changyan Cao Weiguo Song beijing National laboratory for Molecular Sciences CAS Research/Education Center for Excellence in Molecular SciencesLaboratory of Molecular Nanostructures and NanotechnologyInstitute of ChemistryChinese Academy of SciencesBeijing 100190China beijing National laboratory for Molecular Sciences CAS Research/Education Center for Excellence in Molecular SciencesLaboratory of Organic SolidsInstitute of ChemistryChinese Academy of SciencesBeijing 100190China School of Chemical Sciences University of Chinese Academy of SciencesBeijing 100049China key laboratory of Soil Environment and pollution remediation Institute of Soil ScienceChinese Academy of SciencesNanjing 210008China

Single atom catalysts(SACs)with metal_(1)-N_(x)sites have shown promising activity and selectivity in direct catalytic oxidation of benzene to phenol.The reaction pathway is considered to be involving two steps,including a H_(2)O_(2)molecule dissociated on the metal single site to form the(metal_(1)-N_(x))=O active site,and followed by the dissociation of another H_(2)O_(2)on the other side of metal atom to form O=(metal_(1)-N_(x))=O intermediate center,which is active for the adsorption of benzene molecule via the formation of a C-O bond to form phenol.In this manuscript,we report a Cu SAC with nitrogen and oxygen dual-coordination(Cu1-N3O1 moiety)that doesn’t need the first H_(2)O_(2)activation process,as verified by both experimental and density function theory(DFT)calculations results.Compared with the counterpart nitrogen-coordinated Cu SAC(denoted as Cu1/NC),Cu SAC with nitrogen and oxygen dual-coordination(denoted as Cu1/NOC)exhibits 2.5 times higher turnover frequency(TOF)and 1.6 times higher utilization efficiency of H_(2)O_(2).Particularly,the coordination number(CN)of Cu atom in Cu1/NOC maintains four even after H_(2)O_(2)treatment and reaction.Combining DFT calculations,the dynamic evolution of single atomic Cu with nitrogen and oxygen dualcoordination in hydroxylation of benzene is proposed.These findings provide an efficient route to improve the catalytic performance through regulating the coordination environments of SACs and demonstrate a new reaction mechanism in hydroxylation of benzene to phenol reaction.

关键词： single atom catalyst coordination dynamic evolution benzene oxidation phenol

PM_(2.5)and water-soluble inorganic ion concentrations decreased faster in urban than rural areas in China

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Journal of Environmental Sciences 2022年第12期34卷 83-91页

作者： Yangyang Zhang Aohan Tang Chen Wang Xin Ma Yunzhe Li Wen Xu Xiaoping Xia Aihua Zheng Wenqing Li Zengguo Fang Xiufen Zhao Xianlong Peng Yuping Zhang Jian Han Lijuan Zhang Jeffrey L.Collett Jr Xuejun Liu beijing key laboratory of Farmland Soil pollution Prevention and remediation College of Resources and Environmental SciencesNational Academy of Agriculture Green DevelopmentChina Agricultural UniversityBeijing 100193China Analysis and Testing Center Beijing Normal UniversityBeijing 100875China Fujian Institute of Tobacco Agricultural Sciences Fuzhou 350003China College of Resources and Environment Qingdao Agricultural UniversityQingdao 266109China College of Resources and Environment Northeast Agricultural UniversityHaerbin 150030China College of Resources and Environment Hunan Provincial Key Laboratory of Farmland Pollution Control and Agricultural Resources UseHunan Agricultural UniversityChangsha 410128China College of Resources and Environment Hebei Agricultural UniversityBaoding 071001China Department of Atmospheric Science Colorado State UniversityFort CollinsCO 80523USA

We investigated variations of PM_(2.5)and water-soluble inorganic ions chemical characteristics at nine urban and rural sites in China using ground-based observations.From 2015 to 2019,mean PM_(2.5)concentration across all sites decreased by 41.9μg/m~3with a decline of 46%at urban sites and 28%at rural sites,where secondary inorganic aerosol(SIAs)contributed to 21%(urban sites)and 17%(rural sites)of the decreased PM_(2.5).SIAs concentrations underwent a decline at urban locations,while sulfate(SO_(4)^(2–)),nitrate(NO_(3)^(–)),and ammonium(NH_(4)^(+))decreased by 49.5%,31.3%and 31.6%,respectively.However,only SO_(4)^(2–)decreased at rural sites,NO_(3)^(–)increased by 21%and NH_(4)^(+)decreased slightly.Those changes contributed to an overall SIAs increase in 2019.Higher molar ratios of NO_(3)^(–)to SO_(4)^(2–)and NH_(4)^(+)to SO_(4)^(2–)were observed at urban sites than rural sites,being highest in the heavily polluted days.Mean molar ratios of NH_(3)/NH_xwere higher in 2019 than 2015 at both urban and rural sites,implying increasing NH_xremained as free NH_(3).Our observations indicated a slower transition from sulfate-driven to nitrate-driven aerosol pollution and less efficient control of NO_(x)than SO_(2)related aerosol formation in rural regions than urban regions.Moreover,the common factor at urban and rural sites appears to be a combination of lower SO_(4)^(2–)levels and an increasing fraction of NO_(3)^(–)to PM_(2.5)under NH_(4)^(+)-rich conditions.Our findings imply that synchronous reduction in NO_(x)and NH_(3)emissions especially rural areas would be effective to mitigate NO_(3)^(–)-driven aerosol pollution.

关键词： PM_(2.5) Nitrate Ammonium Sulfate Air pollutant emission pollution mitigation

Photocatalytic fuel cell for simultaneous antibiotic wastewater treatment and electricity production by anatase TiO_(2) nanoparticles anchored on Ni foam

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Chinese Chemical Letters 2023年第2期34卷 311-316页

作者： Jinhan Li Xicheng Li Shaobin Yu Shuai Gao Yang Zhang Yan Li Changzheng Wang Qiang Wang beijing key laboratory of Functional Materials for Building Structure and Environment remediation Beijing University of Civil Engineering and ArchitectureBeijing 100044China College of Chemistry Beijing Normal UniversityBeijing 100875China laboratory for Micro-sized Functional Materials&College of Elementary Education Capital Normal UniversityBeijing 100048China

Photocatalytic fuel cell (PFC) holds great potential for the sustainable production of electricity and degradation of organic pollutants for solving global energy and environmental problems.However,the efficient photodegradation of organic dyes and antibiotic drugs,such as ciprofloxacin (CIP) and methylene blue(MB),remains challenging.Aiming at improving the separation efficiency of hole and electron for electricity generation in the PFC system,TiO_(2)-NPs@NF-x photoanode was fabricated by a cost-effective and laborsaving hydrothermal approach.The as-fabricated photoanode demonstrated abundant active sites,enhanced light harvesting capacity and photogenerated charge carrier separation.At a CIP-HCl concentration of 10 mg/L and p H value of about 7,85%of CIP-HCl can be efficiently removed after 3 h irradiation by 300 W Xe lamp.TiO_(2)-NPs@NF-20 photoelectrode based PFC system exhibited an impressed ability to simultaneously degrade ciprofloxacin and generate electricity under light irradiation with an open circuit voltage of 1.021 V,short circuit current density and maximum power density of 2.4 mA/cm^(2),0.357 mW/cm^(2),respectively.This work provided a cost-effective method for the treatment of organic waste and generation of electrical power.

关键词： Photocatalytic fuel cell TiO_(2) Ni foam Electricity production Antibiotic wastewater treatment

Robust route to H_(2)O_(2)and H_(2)via intermediate water splitting enabled by capitalizing on minimum vanadium-doped piezocatalysts

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Nano Research 2022年第9期15卷 7986-7993页

作者： Yuekun Li Li Li Fangyan Liu Biao Wang Feng Gao Chuan Liu Jingyun Fang Feng Huang Zhang Lin Mengye Wang School of Materials Sun Yat-Sen UniversityShenzhen 518107.State Key Laboratory of Optoelectronic Materials and TechnologiesSun Yat-Sen UniversityGuangzhou 510275China School of Environment and Energy Guangdong Provincial Key Laboratory of Solid Wastes Pollution Control and RecyclingSouth China University of TechnologyGuangzhou 510006China School of Metallurgy and Environment Central South UniversityChangsha 410083China Guangdong Provincial key laboratory of Environmental pollution Control and remediation Technology School of Environmental Science and EngineeringSun Yat-Sen UniversityGuangzhou 510275China The Guangdong Province key laboratory of Display Material and Technology School of Electronics and Information TechnologySun Yat-Sen UniversityGuangzhou 510275China

H_(2)O_(2)is an environmentally friendly chemical for a wide range of water treatments.The industrial production of H_(2)O_(2)is an anthraquinone oxidation process,which,however,consumes extensive energy and produces pollution.Here we report a green and sustainable piezocatalytic intermediate water splitting process to simultaneously obtain H_(2)O_(2)and H_(2)using single crystal vanadium(V)-doped NaNbO_(3)(V-NaNbO_(3))nanocubes as catalysts.The introduction of V improves the specific surface area and active sites of NaNbO_(3).Notably,V-NaNbO_(3)piezocatalysts of 10 mg exhibit 3.1-fold higher piezocatalytic efficiency than the same catalysts of 50 mg,as more piezocatalysts lead to higher probability of aggregation.The aggregation causes reducing active sites and decreased built-in electric field due to the neutralization between different nano-catalysts.Remarkably,piezocatalytic H_(2)O_(2)and H_(2)production rates of V-NaNbO_(3)(10 mol%)nanocubes(102.6 and 346.2μmol·g^(−1)·h^(−1),respectively)are increased by 2.2 and 4.6 times compared to the as-prepared pristine NaNbO_(3)counterparts,respectively.This improved catalytic efficiency is attributed to the promoted piezo-response and more active sites of NaNbO_(3)catalysts after V doping,as uncovered by piezoresponse force microscopy(PFM)and density functional theory(DFT)simulation.More importantly,our DFT results illustrate that inducing V could reduce the dynamic barrier of water dissociation over NaNbO_(3),thus enhancing the yield of H_(2)O_(2)and H_(2).This facile yet robust piezocatalytic route using minimal amounts of catalysts to obtain H_(2)O_(2)and H_(2)may stand out as a promising candidate for environmental applications and water splitting.

关键词： water splitting H_(2)evolution H_(2)O_(2)production piezocatalysis vanadium-doped NaNbO_(3)

Fe(Ⅱ)-mediated transformation of schwertmannite associated with calcium from acid mine drainage treatment

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Journal of Environmental Sciences 2023年第4期126卷 612-620页

作者： Cong Fan Chuling Guo Wei Chen Guining Lu Yu Shen Zhi Dang National Research Base of Intelligent Manufacturing Service Chongqing Technology and Business UniversityChongqing 400067China School of Environment and Energy South China University of TechnologyGuangzhou 510006China The key laboratory of pollution Control and Ecosystem Restoration in Industry Clusters Ministry of EducationSouth China University of TechnologyGuangzhou 510006China Chongqing key laboratory of Environmental Materials and remediation Technologies Chongqing University of Arts and SciencesChongqing 402160China

Schwertmannite is an important Fe(Ⅲ)-oxyhydroxysulfate in acid mine drainage (AMD) polluted areas and its stability depends on surrounding environmental factors and previously bound elements.The treatment and neutralization of AMD normally involve the use of lime,which leads to the discharge of abundant Ca in the mining area.Such an environmental disturbance brings up an important and less considered problem of how the reductive transformation of schwertmannite associated with coexisting Ca occurred.Here,the Fe(Ⅱ)-mediated transformation of Ca-adsorbed schwertmannite and subsequent Ca repartitioning behaviors were investigated.Results showed that adsorbed Ca had a weak inhibitory effect on Fe(Ⅱ)-mediated schwertmannite transformation.Release of SO_(4)2-and SEM images both indicated that transformation rates of schwertmannite decreased under the influence of adsorbed Ca.XRD patterns indicated that adsorbed Ca altered schwertmannite transformation pathways and product compositions upon treatment with 0.4 mmol/L Fe(Ⅱ).The end products of Sch notably contained both goethite and lepidocrocite;however,transformation products of SchCa only contained goethite all along.Approximately 33.5%of the surface adsorbed-Ca was released into solution within 6 hr after Fe(Ⅱ) injection.Aqueous Ca behaved in a“first release and then im-mobilization”manner,which indicated dissolution and secondary mineralization drove Ca migration during the Fe(Ⅱ)-mediated transformation of SchCa.Adsorbed Ca blocked the surface sites for subsequent Fe(Ⅱ) adsorption,limited the Fe(Ⅱ)-Fe(Ⅲ) ETAE,and decreased the transformation rates.This work sheds light on the complex geochemical behavior of schwertmannite under the influences of environmental perturbations in AMD environments.

关键词： Acid mine drainage Schwertmannite Calcium Fe(II) Transformation

Toxicity of the xenoestrogen nonylphenol and its biodegradation by the alga Cyclotella caspia

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Journal of Environmental Sciences 2013年第8期25卷 1662-1671页

作者： Yu Liu Xiaokang Dai Jie Wei School of Environmental Science and Engineering Sun Yat-Sen University Guangdong Provincial key laboratory of Environmental pollution Control and remediation Technology

Alkylphenols （APs）, the breakdown products of alkylphenol polyethoxylates that are widely used as surfactants, have been proven to exert estrogenic effects. With industrial development, higher concentrations of APs are discharged into aquatic environments. Nonylphenol （NP）, the most noxious AP, is included in the blacklist of several countries. The toxicity of NP to the alga Cyclotella caspia and the biodegradation of NP by C. caspia were studied in the laboratory. The median effective concentration at 96 hr （96 hr EC50 ） of NP for C. caspia was found to be 0.18 mg/L. Five toxicity and three degradation indices were selected for toxicity and biodegradation experiments, respectively, in five or three concentrations of NP set by the 96 hr EC50 of NP. The algal growth rate and chlorophyll a contents decreased as NP concentration increased. The main manifestations of morphological deformity of the cells included volume expansion and the presence of cytoplasmic inclusions （lipid droplets）. The abnormality rate of the cells increased with NP concentration and time, and was 100% at 0.22 and 0.26 mg/L of NP after 192 hr of culture. Superoxide dismutase activity initially increased and then declined at a higher NP toxicity of greater than 0.18 mg/L. After 192 hr of culture, the biodegradation rates of NP by C. caspia with initial concentrations of 0.14, 0.18, and 0.22 mg/L were 37.7%, 31.7%, and 6.5%, respectively. The kinetic equation of C. caspia biodegradation on NP was correlated with algal growth rate and initial NP concentration.

关键词： alkylphenol nonylphenol Cyclotella caspia toxicity biodegradation

Thermal stability of soil organic carbon subjected to water erosion as a function of edaphic factors

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International Journal of Sediment Research 2022年第1期37卷 26-36页

作者： Zhongwu Li Linhui Xiao Chuxiong Deng Zaijian Yuan Chen Liang Qian Xiong Zeting Li Xiaodong Nie College of Resources and Environmental Science Hunan Normal University Guangdong Engineering Center of Non-point Source pollution Control Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management Guangdong Institute of Eco-environmental Science & Technology Guangdong Academy of Sciences National-Regional Joint Engineering Research Center for Soil pollution Control and remediation in South China

The stability of soil organic carbon (SOC),as it relates to resistance to decomposition,is important for greenhouse gas emission and climate change.However,the SOC stabilization and its related influencing factors subjected to water erosion remain uncertain.The objective of the current study was to determine the SOC stability under long-term water erosion and to investigate the link between SOC stability and edaphic factors.Soil samples from eroded,depositional,and control sites in a closed watershed in subtropical China were collected.The SOC concentration,carbon functional groups,soil physicochemical properties,and thermal stability of SOC were determined.The study results showed that the primary component of the SOC functional groups was O-alkyl carbon (reached 40%),and its proportion has no significant difference among different sites.The TG-T50(the temperature at which 50%of the soil organic matter is lost) values indicated that the SOC thermal stability in the eroded topsoil was higher than that of the deposited topsoil.The carbon functional groups were lack of relation with SOC thermal stability(p>0.05).However,the TG-T50was significantly positively correlated with the cation exchange capacity and silt,but remarkably negatively correlated with SOC,dissolved organic carbon,total nitrogen,sand,clay,p H,aluminum,specific surface area,and iron oxides.These results indicated that the edaphic factors,which were strongly affected by micro-environment,are the main factors affecting thermal stability of organic carbon.The SOC stabilization under the effects of long-term water erosion should be addressed from the perspective of the ecosystem.

关键词： Soil erosion Soil organic matter Thermogravimetry Preservation Stability

土壤和地下水中重金属污染物迁移模型:以某有色金属冶炼厂为例

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Journal of Central South University 2024年第4期31卷 1092-1106页

作者：张海丽赵鹏高文艳肖保华杨雪枫宋磊冯翔郭林陆永平李海峰孙静 State key laboratory of Environmental Geochemistry Institute of GeochemistryChinese Academy of SciencesGuiyang 550081China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 101408China School of Metallurgy and Environment Central South UniversityChangsha 410083China Henan Academy of Geology Zhengzhou 450001China China Railway Seventh Bureau Group Nanjing Engineering Co. Ltd.Nanjing 210000China

冶炼厂表层土壤重金属污染严重。由于数据采集和计算量的限制,大多数数值模拟将土壤和地下水分开,这与实际情况不符。本文以某冶炼厂为研究对象,将土壤和地下水视为一个整体系统,建立了土壤-地下水反应性溶质迁移三维耦合数值模型,以定... 详细信息

冶炼厂表层土壤重金属污染严重。由于数据采集和计算量的限制,大多数数值模拟将土壤和地下水分开,这与实际情况不符。本文以某冶炼厂为研究对象,将土壤和地下水视为一个整体系统,建立了土壤-地下水反应性溶质迁移三维耦合数值模型,以定量表征重金属在土壤和地下水中的迁移规律。模型采用反应系数(λ)和滞留系数(R)来描述重金属的释放和吸附能力。模型结果与现场实际污染分布一致,表明土壤-地下水修复技术对严重污染土壤和局部污染地下水均有良好的修复效果。所构建的土壤-地下水反应性溶质迁移三维耦合模型很好地描述和预测研究地点重金属的分布和迁移扩散行为。

关键词：有色金属冶炼场重金属污染迁移和转化机制扩散通量预测修复技术模拟

0D/3D direct Z-scheme heterojunctions hybridizing by MoS2 quantum dots and honeycomb conjugated triazine polymers (CTPs) for enhanced photocatalytic performance

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Journal of Environmental Sciences 2023年第2期124卷 602-616页

作者： Shuqi Li Weishun Lai Xinming Jiang Yashuang Wang Xinyi Cai Da Wang Shuang Song Min Liu Tao Zeng key laboratory of Microbial Technology for industrial pollution Control of Zhejiang Province College of EnvironmentZhejiang University of TechnologyZhejiang 310032China College of Architecture and Environment Sichuan UniversitySichuan 610065China Shaoxing Research Institute Zhejiang University of TechnologyZhejiang 312000China

Herein,a novel direct Z-scheme photocatalyst was accomplished by hybridization of 0D MoS2 quantum dots(MSQDs)and 3D honeycomb-like conjugated triazine polymers(CTP)(namely,CTP-MSQD).The unique 0D/3D hierarchical structure significantly enhanced the exposure of active sites and light harvesting property,while the formed p-n junction enabled the direct strong interface coupling without the necessity of any mediators.The optimized CTP-MSQD3 exhibited continuously increased visible-light-driven photocatalytic activity and strong durability both in Cr(VI)reduction and H2 evolution,featured a rate of 0.069 min^(-1) and 1070μmol/(hr•g),respectively,which were 8 times than those of pure 3D-CTP(0.009 min^(−1) and 129μmol/(hr•g)).We believe that this work provides a promising photocatalyst system that combines a 0D/3D hierarchical structure and a Z-scheme charge flow for efficient and stable photocatalytic conversion.

关键词： 0D/3D structure Conjugated triazine polymers MoS2 quantum dots Direct Z-scheme mechanism Cr(VI)reduction and H2 production