作者机构:
[Guo, Furong; Gao, Tingjuan] Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, Institute of Environmental & Applied Chemistry, College of Chemistry, Central China Normal University, Wuhan 430079, China;School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China;[Li, Jiangshan] State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan 430071, China;[Cao, Shiyu] Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, Institute of Environmental & Applied Chemistry, College of Chemistry, Central China Normal University, Wuhan 430079, China<&wdkj&>State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan 430071, China;[Shi, Yanbiao; Zhang, Lizhi] Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, Institute of Environmental & Applied Chemistry, College of Chemistry, Central China Normal University, Wuhan 430079, China<&wdkj&>School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
通讯机构:
[Tingjuan Gao; Lizhi Zhang] K;Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, Institute of Environmental & Applied Chemistry, College of Chemistry, Central China Normal University, Wuhan 430079, China<&wdkj&>School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China<&wdkj&>Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, Institute of Environmental & Applied Chemistry, College of Chemistry, Central China Normal University, Wuhan 430079, China
摘要:
Nano zero-valent iron (nZVI) is a promising phosphate adsorbent for advanced phosphate removal. However, the rapid passivation of nZVI and the low activity of adsorption sites seriously limit its phosphate removal performance, accounting for its inapplicability to meet the emission criteria of 0.1 mg P/L phosphate. In this study, we report that the oxalate modification can inhibit the passivation of nZVI and alter the multi-stage phosphate adsorption mechanism by changing the adsorption sites. As expected, the stronger anti-passivation ability of oxalate modified nZVI (OX-nZVI) strongly favored its phosphate adsorption. Interestingly, the oxalate modification endowed the surface Fe(III) sites with the lowest chemisorption energy and the fastest phosphate adsorption ability than the other adsorption sites, by in situ forming a Fe(III)-phosphate-oxalate ternary complex, therefore enabling an advanced phosphate removal process. At an initial phosphate concentration of 1.00 mg P/L, pH of 6.0 and a dosage of 0.3 g/L of adsorbents, OX-nZVI exhibited faster phosphate removal rate (0.11 g/mg/min) and lower residual phosphate level (0.02 mg P/L) than nZVI (0.055 g/mg/min and 0.19 mg P/L). This study sheds light on the importance of site manipulation in the development of high-performance adsorbents, and offers a facile surface modification strategy to prepare superior iron-based materials for advanced phosphate removal.
摘要:
As one of the most widely used disinfectants, active chlorine is synthesized predominantly through electrolysis of saturated sodium chloride solutions, an industrial process known as the chlor-alkali process, with high energy consumption. Seawater is an abundant source of chloride and thus an ideal alternative electrolyte. However, substantial challenges are to be addressed, notably the competing oxygen evolution reaction and progressive anode passivation due to the presence of rich cations in seawater. Here, we show durable and efficient active chlorine electrosynthesis directly from natural seawater with intrinsic turnover frequency and mass activity two orders of magnitude higher than the state of the art. The essential chemistry is an Fe-doped Ti4O7 anode that strengthens the electrophilicity of lattice oxygen to allow for site-selective chloride activation at remarkably lowered kinetic overpotentials relative to the oxygen evolution reaction, while also impeding the precipitation of alkaline earth metal cations on the Ti4O7 surface. A seawater splitting device with an integrated commercial silicon photovoltaic cell delivers an impressive active chlorine production rate of 3.15 mg min-1 for effective simulated ballast water disinfection. This work suggests the possibility to substantially improve the sustainability of the chlor-alkali process without compromising the synthetic performance for the mass production of disinfectants. This work shows a delicate titanium suboxide-based anode design for electrolysis of seawater, delivering selective production of active chlorine for on-site disinfection.
作者机构:
[凌灿灿; 李浩; 占光明] School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China;[凌灿灿; 占光明] Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, Institute of Environmental & Applied Chemistry, Central China Normal University, Wuhan 430079, China;[梁川; 刘修凡; 孙红卫; 赵进才; 周兵; 李亚玲; 李美琪] Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, Institute of Environmental & Applied Chemistry, Central China Normal University, Wuhan 430079, China;[Li, Hao] School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China. Electronic address: hao_li@sjtu.edu.cn;[李浩] Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, Institute of Environmental & Applied Chemistry, Central China Normal University, Wuhan 430079, China. Electronic address: zhanglizhi@sjtu.edu.cn
通讯机构:
[Hao Li; Lizhi Zhang] S;School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China<&wdkj&>Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, Institute of Environmental & Applied Chemistry, Central China Normal University, Wuhan 430079, China<&wdkj&>School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
摘要:
Heterogeneous peroxysulfates-based advanced oxidation pro-cesses(AOPs)have garnered significant attention for purifying organic wastewater since they offer many advantages like low cost,safe storage,facile activation and reactive species participation[1].
作者机构:
[Lin Zhang; Furong Guo; Chuan Liang; Jundi Cheng; Hongwei Sun] Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, Institute of Environmental & Applied Chemistry, College of Chemistry, Central China Normal University, Wuhan 430079, P. R. China;School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, P. R. China;State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan 430071, P. R. China;[Shiyu Cao] Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, Institute of Environmental & Applied Chemistry, College of Chemistry, Central China Normal University, Wuhan 430079, P. R. China<&wdkj&>State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan 430071, P. R. China;[Cancan Ling; Meiqi Li; Yanbiao Shi; Lizhi Zhang] Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, Institute of Environmental & Applied Chemistry, College of Chemistry, Central China Normal University, Wuhan 430079, P. R. China<&wdkj&>School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, P. R. China
通讯机构:
[Hongwei Sun] K;Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, Institute of Environmental & Applied Chemistry, College of Chemistry, Central China Normal University, Wuhan 430079, P. R. China
摘要:
Mackinawite (FeS) is an excellent Cd(II) removal material but suffers from rapid reactivity loss. Herein, we demonstrate that rational surface preoxidation could enhance the single maximum adsorption capacity of mackinawite from 625.0 to 666.7 mg g–1 and also promote its air stability and reusability for long-term application. The Cd(II) removal processes were carefully characterized with a multifunctional in situ electrochemical device, theoretical calculation, and extended X-ray absorption fine structure (EXAFS) spectroscopy. Characterization results revealed that surface preoxidation treatment changed the Cd(II) removal mechanism from ion exchange to ion-exchange coupled surface adsorption because surface preoxidized FeS possessed abundant surface −OH sites. This extra surface adsorption process offered surface preoxidized FeS a superior long-term Cd(II) removal performance of 1290.5 mg g–1 in 5 successive cycles, much higher than that of pristine FeS (842.4 mg g–1). This study highlights the importance of surface oxidation on the Cd(II) removal performance of mackinawite and also opens a new strategy to design and produce high-performance mackinawite nanocrystals for pollutant control and environmental remediation.
作者机构:
[Liu, Lijuan; Zhang, Lizhi; Gong, JM; Meng, Mingxia; Gong, Jingming; Yao, Qingfeng; Cai, Zheng; Sun, Hongwei; Jiang, Fang] Cent China Normal Univ, Int Joint Res Ctr Intelligent Biosensing Technol &, Key Lab Pesticide & Chem Biol, Coll Chem,Minist Educ, Wuhan 430079, Peoples R China.
通讯机构:
[Gong, JM ] C;Cent China Normal Univ, Int Joint Res Ctr Intelligent Biosensing Technol &, Key Lab Pesticide & Chem Biol, Coll Chem,Minist Educ, Wuhan 430079, Peoples R China.
摘要:
As emerging contaminants in the environment, antibiotic resistance genes (ARGs) have aroused a global health crisis and posed a serious threat to ecological safety and human health. Thus, efficient and accurate onsite detection of ARGs is crucial for environmental surveillance. Here, we presented a colorimetric-photoelectrochemical (PEC) dual-mode bioassay for simultaneous detection of multiple ARGs by smartly incorporating rolling circle amplification (RCA) into a stimuli-responsive DNA nanoassembly, using the tetracycline resistance genes tetA and tetC as models. The tailored DNA nanoassembly containing RCA amplicons hybridized with specific signal probes: CuO nanoflowers-anchored signal DNA1 and HgO nanoparticles-anchored signal DNA2, respectively. Upon exposure to an acidic stimulus, numerous Cu2+ and Hg2+ were released, serving as the reporting agent of colorimetric/PEC dual-mode assay. The released Cu2+ and Hg2+ induced localized surface plasmon resonance shifts in Au nanorods and triangular Ag nanoplates through an etching process, respectively, enabling visual analysis of ARGs with distinguishing color changes. Meanwhile, numerous Cu2+ and Hg2+ triggered the amplified PEC variations via reacting with the photoactive layers of CuS/CdS and ZnS, respectively. Thus, a rapid and ultrasensitive colorimetric/PEC dual-mode detection of multiple ARGs was achieved with the detection limit down to 17.2 aM. Furthermore, such dual-mode bioassay could discriminate single-base mismatch and successfully determine ARGs in E. coli plasmids and sludge samples, holding great promise for point-of-care genetic diagnostics.
通讯机构:
[Liu, W ] W;Wuhan Inst Technol, Sch Chem Engn & Pharm, Hubei Key Lab Novel Reactor & Green Chem Technol, Wuhan 430205, Peoples R China.
关键词:
L-cysteine;Zero-valent iron (ZVI);Ni(II)-EDTA;Decomplexation
摘要:
The remarkable stability and detrimental environmental impacts of nickel(II)-ethylenediaminetetraacetic acid (Ni(II)-EDTA) complexes originated from electroplating effluents have sparked a growing curiosity about their efficient remediation. In this study, L -cysteine functionalized zero -valent iron (C-ZVI bm ) was synthesized via a ball-milling method and employed as a heterogeneous Fenton-like catalyst to decomplex Ni(II)-EDTA and immobilize Ni(II) from wastewater. The results demonstrated that the pseudo-second-order kinetic rate constant (2.096 L center dot mol - 1 center dot min - 1 ) for EDTA degradation in the C-ZVI bm /H 2 O 2 system was 123.3 times that in the ZVI bm / H 2 O 2 system (0.017 L center dot mol - 1 center dot min - 1 ). The incorporation of L -cysteine onto the surface of ZVI significantly enhanced the H 2 O 2 activation, reactive oxygen species ( center dot OH, center dot O 2 - , and 1 O 2 ) generation, and the sequential Ni(II)EDTA decomplexation and EDTA degradation. The results of capture experiments revealed that 1 O 2 played a crucial role in the degradation of EDTA in the C-ZVI bm /H 2 O 2 system. The optimization of the experimental variables indicated that the degradation of EDTA and the reduction/adsorption of Ni(II) were antagonistic in the C-ZVI bm /H 2 O 2 system, resulting in an efficient reduction/immobilization of Ni(II) and an inhibition of EDTA degradation at a higher dosage of C-ZVI bm . Our findings provide new insights into the promising heterogeneous Fenton-like process that enables the decomplexation of Ni(II)-EDTA, the degradation of EDTA, and the synchronous immobilization of Ni(II).
关键词:
ammonia recovery;atomic hydrogen;electrocatalytic nitrate reduction;fluorine modification;neutral media
摘要:
Electrocatalytic nitrate reduction to ammonia (NITRR) offers an attractive solution for alleviating environmental concerns, yet in neutral media, it is challenging as a result of the reliance on the atomic hydrogen (H*) supply by breaking the stubborn HO-H bond (similar to 492 kJ/mol) of H2O. Herein, we demonstrate that fluorine modification on a Cu electrode (F-NFs/CF) favors the formation of an O-H center dot center dot center dot F hydrogen bond at the Cu-H2O interface, remarkably stretching the O-H bond of H2O from 0.98 to 1.01 & Aring; and lowering the energy barrier of water dissociation into H* from 0.64 to 0.35 eV at neutral pH. As a benefit from these advantages, F-NFs/CF could rapidly reduce NO3- to NH3 with a rate constant of 0.055 min(-1) and a NH3 selectivity of similar to 100%, far higher than those (0.004 min(-1) and 9.2%) of the Cu counterpart. More importantly, we constructed a flow-through coupled device consisting of a NITRR electrolyzer and a NH3 recovery unit, realizing 98.1% of total nitrogen removal with 99.3% of NH3 recovery and reducing the denitrification cost to $5.1/kg of N. This study offers an effective strategy to manipulate the generation of H* from water dissociation for efficient NO3--to-NH3 conversion and sheds light on the importance of surface modification on a Cu electrode toward electrochemical reactions.
摘要:
<jats:title>Abstract</jats:title><jats:p>Capturing gaseous mercury (Hg<jats:sup>0</jats:sup>) from sulfur dioxide (SO<jats:sub>2</jats:sub>)-containing flue gases remains a common yet persistently challenge. Here we introduce a low-temperature sulfur chemical vapor deposition (S-CVD) technique that effectively converts SO<jats:sub>2</jats:sub>, with intermittently introduced H<jats:sub>2</jats:sub>S, into deposited sulfur (S<jats:sub>d</jats:sub><jats:sup>0</jats:sup>) on metal sulfides (MS), facilitating self-sustained adsorption of Hg<jats:sup>0</jats:sup>. ZnS, as a representative MS model, undergoes a decrease in the coordination number of Zn–S from 3.9 to 3.5 after S<jats:sub>d</jats:sub><jats:sup>0</jats:sup> deposition, accompanied by the generation of unsaturated-coordinated polysulfide species (S<jats:sub>n</jats:sub><jats:sup>2–</jats:sup>, named S<jats:sub>d</jats:sub><jats:sup>*</jats:sup>) with significantly enhanced Hg<jats:sup>0</jats:sup> adsorption performance. Surprisingly, the adsorption product, HgS (ZnS@HgS), can serve as a fresh interface for the activation of S<jats:sub>d</jats:sub><jats:sup>0</jats:sup> to S<jats:sub>d</jats:sub><jats:sup>*</jats:sup> through the S-CVD method, thereby achieving a self-sustained Hg<jats:sup>0</jats:sup> adsorption capacity exceeding 300 mg g<jats:sup>−1</jats:sup> without saturation limitations. Theoretical calculations substantiate the self-sustained adsorption mechanism that S<jats:sub>8</jats:sub> ring on both ZnS and ZnS@HgS can be activated to chemical bond S<jats:sub>4</jats:sub> chain, exhibiting a stronger Hg<jats:sup>0</jats:sup> adsorption energy than pristine ones. Importantly, this S-CVD strategy is applicable to the in-situ activation of synthetic or natural MS containing chalcophile metal elements for Hg<jats:sup>0</jats:sup> removal and also holds potential applications for various purposes requiring MS adsorbents.</jats:p>
摘要:
K species is confined in the natural 2*2 channel of α‐MnO2 by hydrothermal treatment coupled with molten salt strategy and exhibits special electron‐rich state. Compared with surface K modification, channel K confinement lowers the activation energy barrier of H2O dissociation to generate hydroxyl species with more nucleophilic oxygen atoms, contributing to the more excellent HCHO oxidation performances. Abstract Water molecules are actively involved in many catalytic oxidation processes, which require the construction of highly active sites for their activation to accelerate the reaction rate, especially over non‐noble metal catalysts. Herein, K species is embeded into the natural 2*2 channel of α‐MnO2 by a hydrothermal coupled molten salt method, which would make these K species behave in an electron‐rich state and provide more electrons for the activation of water molecules. Compared with surface K modification (namely, the electron‐deficient K species), channel K confinement can lower the activation energy barrier of H2O dissociation on α‐MnO2 to generate hydroxyl species with more nucleophilic oxygen atoms, contributing to the superior HCHO catalytic oxidation activity with a fourfold enhancement. The internal relationship among the confined channel, K species, and catalytic performance is systematically elucidated at the molecular level. This work offers a new ion confinement method and opens up new avenues to construct electron‐rich metal sites with channel structures for the activation of water molecules.
期刊:
Journal of Hazardous Materials,2024年465:133009 ISSN:0304-3894
通讯作者:
Jia, FL
作者机构:
[Zhang, Lizhi; Jia, Falong; Guo, Furong; Li, Donglei; Zhang, Yuhang; She, Liang; Ai, Zhihui; Liu, Xiao] Cent China Normal Univ, Coll Chem, Wuhan 430079, Peoples R China.
通讯机构:
[Jia, FL ] C;Cent China Normal Univ, Coll Chem, Wuhan 430079, Peoples R China.
关键词:
Cu(II)-EDTA;Decomplexation;Ferrous formate shell;Oxidative degradation;Zero-valent iron
摘要:
Heavy metal complexes in industrial wastewater are challenging to be removed by conventional methods arising from their stable chelating structure. In this study, zero-valent iron (ZVI) was ball-milled with tiny formic acid (FA), and the as-prepared sample (FA-ZVI(bm)) was attempted to eliminate a model heavy metal complex of Cu(II)-ethylenediaminetetraacetic acid (Cu(II)-EDTA). The addition of FA to ball-milling could dramatically enhance the performance of ball-milled ZVI (ZVI(bm)) towards Cu(II)-EDTA removal and increase the removal rate constant by 80 times. This conspicuous improvement of Cu(II)-EDTA elimination was attributed to the ferrous formate (Fe(HCOO)(2)) shell formed on the surface of FA-ZVI(bm). Results revealed that the Fe(HCOO)(2) shell facilitated the activation of O(2) to reactive oxygen species (ROS) and the leaching of Fe(3+). Cu(II)-EDTA was decomplexed through both oxidative destruction and Fe(3+) replacement, and the released Cu(2+) was reduced by FA-ZVI(bm) and immobilized synchronously. Meanwhile, the ligands underwent oxidative degradation by ROS, thus avoiding the re-chelation ecological risk. Impressively, FA-ZVI(bm) could achieve cyclic treatment of actual copper complex wastewater and possessed promising advantage in treatment cost. This study would offer a promising approach for eliminating Cu(II)-EDTA through EDTA ligands degradation and synchronous Cu(II) removal, moreover to shed light on the decomplexation mechanism.
通讯机构:
[Huang, Y; Ai, ZH ] C;[Zhang, LZ ] S;Cent China Normal Univ, Coll Chem, Engn Res Ctr Photoenergy Utilizat Pollut Control, Inst Environm & Appl Chem,Minist Educ,Key Lab Pes, Wuhan 430079, Peoples R China.;Shanghai Jiao Tong Univ, Sch Environm Sci & Engn, Shanghai 200240, Peoples R China.
关键词:
Ammonia Recovery;Dual sites;Nitrate Electroreduction;Nitrate-pollution Treatment;Single Atom Copper
摘要:
The electrochemical nitrate reduction reaction (NO(3)RR) is able to convert nitrate (NO(3) (-)) into reusable ammonia (NH(3)), offering a green treatment and resource utilization strategy of nitrate wastewater and ammonia synthesis. The conversion of NO(3) (-) to NH(3) undergoes water dissociation to generate active hydrogen atoms and nitrogen-containing intermediates hydrogenation tandemly. The two relay processes compete for the same active sites, especially under pH-neutral condition, resulting in the suboptimal efficiency and selectivity in the electrosynthesis of NH(3) from NO(3) (-). Herein, we constructed a Cu(1)-Fe dual-site catalyst by anchoring Cu single atoms on amorphous iron oxide shell of nanoscale zero-valent iron (nZVI) for the electrochemical NO(3)RR, achieving an impressive NO(3) (-) removal efficiency of 94.8 % and NH(3) selectivity of 99.2 % under neutral pH and nitrate concentration of 50 mg L(-1) NO(3) (-)-N conditions, greatly surpassing the performance of nZVI counterpart. This superior performance can be attributed to the synergistic effect of enhanced NO(3) (-) adsorption on Fe sites and strengthened water activation on single-atom Cu sites, decreasing the energy barrier for the rate-determining step of *NO-to-*NOH. This work develops a novel strategy of fabricating dual-site catalysts to enhance the electrosynthesis of NH(3) from NO(3) (-), and presents an environmentally sustainable approach for neutral nitrate wastewater treatment.
期刊:
Proceedings of the National Academy of Sciences of the United States of America,2024年121(37):e2405236121 ISSN:0027-8424
作者机构:
[Zhang, Weixing; Zhang, Lizhi; Zhou, Bing] Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, Institute of Environmental & Applied Chemistry, Central China Normal University, Wuhan 430079, People's Republic of China;[Zhang, Lizhi; Hou, Wei; Yao, Yancai; Zheng, Qian; Zhou, Bing; Zhan, Guangming] School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China;[Gu, Xiang-Kui; Tong, Yawen] School of Power and Mechanical Engineering, Wuhan University, Wuhan 430072, People's Republic of China
关键词:
ammonia synthesis;electrocatalytic nitrate reduction;nonmetal single atom;proton-coupled electron transfer mechanism;reversed single-atom configuration
摘要:
Electrochemical ammonia (NH(3)) synthesis from nitrate reduction (NITRR) offers an appealing solution for addressing environmental concerns and the energy crisis. However, most of the developed electrocatalysts reduce NO(3)(-) to NH(3) via a hydrogen (H*)-mediated reduction mechanism, which suffers from undesired H*-H* dimerization to H(2), resulting in unsatisfactory NH(3) yields. Herein, we demonstrate that reversed I(1)Cu(4) single-atom sites, prepared by anchoring iodine single atoms on the Cu surface, realized superior NITRR with a superior ammonia yield rate of 4.36 mg h(-1) cm(-2) and a Faradaic efficiency of 98.5% under neutral conditions via a proton-coupled electron transfer (PCET) mechanism, far beyond those of traditional Cu sites (NH(3) yield rate of 0.082 mg h(-1) cm(-2) and Faradaic efficiency of 36.5%) and most of H*-mediated NITRR electrocatalysts. Theoretical calculations revealed that I single atoms can regulate the local electronic structures of adjacent Cu sites in favor of stronger O-end-bidentate NO(3)(-) adsorption with dual electron transfer channels and suppress the H* formation from the H(2)O dissociation, thus switching the NITRR mechanism from H*-mediated reduction to PCET. By integrating the monolithic I(1)Cu(4) single-atom electrode into a flow-through device for continuous NITRR and in situ ammonia recovery, an industrial-level current density of 1 A cm(-2) was achieved along with a NH(3) yield rate of 69.4 mg h(-1) cm(-2). This study offers reversed single-atom sites for electrochemical ammonia synthesis with nitrate wastewater and sheds light on the importance of switching catalytic mechanisms in improving the performance of electrochemical reactions.
摘要:
Trichloroethylene (TCE) with trace concentrations is often detected in soils and groundwater, posing potential damages to public health. The elimination of TCE can be achieved through reductive dechlorination using zero-valent iron (ZVI). However, ZVI usually suffers from the presence of passive iron (hydro)oxides layer and low electron transfer rate, thus leading to the unsatisfactory reactivity. Herein, we fabricated oxalated ZVI (Ox-ZVI(bm)) by mechanical ball-milling of micro-scale ZVI and H2C2O4 center dot 2H(2)O to modify the ZVI surface composition. To be specific, the modification of the iron oxide shell by oxalic acid facilitated the generation of unsaturated coordination Fe(II), enhancing TCE adsorption. Furthermore, the formed FeC2O4 on the iron oxide shell improved electron transfer efficiency, contributing to the enhanced TCE reductive dechlorination. Impressively, the rate of TCE degradation by Ox-ZVI(bm) was 10-fold higher than that of ZVI(bm) without oxalate modification. Moreover, Ox-ZVI(bm) samples were filled in a laboratory Permeable Reactive Barriers (PRB) column to treat actual underground wastewater containing TCE pollutants. The effluent concentration of TCE maintained steadily below 0.21 mg/L for over 10 days, complying with the National Groundwater Class IV standard (GBT 14848-2017). This marks a significant step toward practical groundwater treatment.
摘要:
Enrichment of OVs on oxide semiconductors is an effective strategy to promote their photocatalytic performances but limited by the maximum concentration allowed by lattice thermodynamics. Herein, we report that an In(I) doping strategy, realized by an UV light-induced reduction of a sluggish In(III) precursor, can promote OVs-laden BiOCl by up to 6.5 times for the visible-light sodium pentachlorophenate (PCPNa) degradation. The photocatalysis mechanism study highlighted the In(I) site as an electron transfer site could reduce PCPNa directly, related to the In(I) induced more negative conduction band and faster transfer of electron. Moreover, several monocyclic aromatic organic compounds (AOC) exhibited degradation selectivity over In(I) doped OVs-laden BiOCl (BOVs-In) by an electron reduction path, PCPNa with the lowest negative charge density on the benzene ring has been degraded fastest. Differently, the doped In(I) in BOVs-In mainly triggered the multiring Rhodamine B degradation by promoting the O-center dot(2)- generation not the directly electron reduction path. The electron transfer ability, band structure, and the free energy of O-2 activation over BOVs-In were confirmed by TPV spectra, EPR spectra and DFT calculation. This study illustrates an In(I) doping strategy to couple with OVs engineering for champion photoactivity of BiOCl for AOC degradation under visible light irradiation.
摘要:
The comprehensive understanding of contaminant interfacial behavior strongly depends on the in situ characterization technique, which is still a great challenge. In this study, we constructed a device integrated with open-circuit potentialand attenuated total reflectance Fourier transform infrared (OCP-ATR-FTIR) spectroscopy to simultaneously monitor the electrochemical and infrared spectral information on the interfacial reaction for the process analysis, taking the competitive adsorption of hexavalent chromium (Cr(VI)) and oxalate on hematite nanocubes (HNC) as an example. The synchronous OCP and infrared results revealed that Cr(VI) interacted with HNC via bidentate binuclear inner-sphere coordination, accompanied by electron transfer from HNC to Cr(VI), while oxalate was adsorbed on HNC through bidentate mononuclear side-on inner-sphere coordination with electron transfer from HNC to oxalate, and also outer-sphere coordination with negative charge accumulation. When oxalate was added to HNC with preadsorbed Cr(VI), oxalate would occupy the inner-sphere adsorption sites and thus cause the detaching of preadsorbed Cr(VI) from HNC. This study provides a promising in situ characterization technique for real-time interfacial reaction monitoring and also sheds light on the competitive adsorption mechanism of oxalate and Cr(VI) on the mineral surface.
摘要:
Catalytic oxidation technology is currently considered as a feasible approach to degrade and mineralize volatile organic compounds (VOCs). However, it is still challenging to realize efficient removal of VOCs through catalytic oxidation at room temperature. In our study, a novel flow-through electrocatalytic reactor was designed, composed of porous solid-electrolyte, gas-permeable titanium sub-oxides/titanium-foam (TiSO/Ti-foam) as anode and platinum coated titanium foam (Pt/Ti-foam) as cathode. This device could oxidize nearly 100% of benzene (10 ppm) to carbon dioxide at a current density of 1.2 mA/cm2 under room temperature. More importantly, the device maintained excellent stability over 1000 h. Mechanism of benzene mineralization was discussed. Hydroxyl radicals generated on the TiSO/Ti-foam anode played a crucial role in the oxidation of benzene. This study provides a promising prototype of the electrochemical air purifier, and may find its application in domestic and industrial air pollution control.
通讯机构:
[Hongwei Sun; Zhihui Ai] K;Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, Institute of Environmental Chemistry, Central China Normal University, Wuhan 430079, PR China
关键词:
Heterogeneous fenton reaction;Oxalic acid;Proton transfer;Thiamphenicol;Zero-valent iron
摘要:
Heterogeneous Fenton reactions of zero-valent iron (ZVI) requires the sufficient release of Fe(II) to catalyze the H(2)O(2) decomposition. However, the rate-limiting step of proton transfer through the passivation layer of ZVI restricted the Fe(II) release via Fe(0) core corrosion. Herein we modified the shell of ZVI with highly proton-conductive FeC(2)O(4)·2H(2)O by ball-milling (OA-ZVI(bm)), and demonstrated its high heterogeneous Fenton performance of thiamphenicol (TAP) removal, with 500 times enhancement of the rate constant. More importantly, the OA-ZVI(bm)/H(2)O(2) showed little attenuation of the Fenton activity during 13 successive cycles, and was applicable across a wide pH range of 3.5-9.5. Interestingly, the OA-ZVI(bm)/H(2)O(2) reaction showed pH self-adapting ability, which initially reduced and then sustained the solution pH in the range of 3.5-5.2. The abundant intrinsic surface Fe(II) of OA-ZVI(bm) (45.54% vs. 27.52% in ZVI(bm), according to Fe 2p XPS profiles) was oxidized by H(2)O(2) and hydrolyzed to generate protons, and the FeC(2)O(4)·2H(2)O shell favored the fast transfer of protons to inner Fe(0), therefore, the consumption-regeneration cycle of protons were accelerated to drove the production of Fe(II) for Fenton reactions, demonstrated by the more prominent H(2) evolution and nearly 100% H(2)O(2) decomposition by OA-ZVI(bm). Furthermore, the FeC(2)O(4)·2H(2)O shell was stable and slightly decreased from 1.9% to 1.7% after the Fenton reaction. This study clarified the significance of proton transfer on the reactivity of ZVI, and provided an efficient strategy to achieve the highly efficient and robust heterogeneous Fenton reaction of ZVI for pollution control.
通讯机构:
[Gong, JM ] C;Cent China Normal Univ, Inst Environm & Appl Chem, Coll Chem, Key Lab Pesticide & Chem Biol,Minist Educ, Wuhan 430079, Peoples R China.
关键词:
Ammonia nitrogen;6-Trichlorophenol;Peroxymonosulfate;Dechlorination;Active chlorine species
摘要:
Halogenated phenol and ammonia nitrogen (NH4+-N) are typical composite pollutions in wastewater. It is still unclear how the transformation of halogenated phenol affects the fate of co-existing NH4+-N. In this study, the removal performance of the NH4+-N containing the co-existed halogenated organic, using 2, 4, 6-trichlorophenol (TCP) as the model pollutant was firstly investigated in the waste lithium-ion batteries (LIBs) material-derived catalysts activating peroxymonosulfate system (LIBs/PMS). The rapid degradation of TCP and the selective transformation of NH4+-N to N2 were simultaneously achieved. TCP could be degraded rapidly (within 2 min) whether with or without NH4+-N. Interestingly, the NH4+-N removal was initiated by the co-present TCP, strongly dependent on TCP dechlorination. And NH4+-N removal displayed a thermally accelerated process in the temperature range of 25 to 60 degrees C. With the co-present TCP (60 mg/L), 93.7% of NH4+-N could be removed at 50 degrees C. Based on the capture and the electron spin resonance (ESR) experiments, the generated reactive oxygen species (& BULL;OH, SO4 & BULL; and 1O2) participated in the TCP dechlorination, particularly 1O2 with dominant roles, whereas ClO & BULL; played an important role on NH4+-N removal. Theoretical calculations were used not only to predict the possible reactive site of TCP, but also evaluate the difficulty of reaction between NH4+-N and different active species. Moreover, NH4+-N could be removed 80% in outdoor simulated experiment (in Wuhan) and 100% for chlorobenzene and nitrogen-containing wastewater. This study unveiled the influence of the co-existed halogenated phenol toward the fate of NH4+-N in LIBs/PMS system and enriched the treatment of NH4+-N wastewater strategies.
摘要:
Oxygen vacancies (O(V)), as the sites of molecular oxygen adsorption and activation, play an important role in the catalytic combustion process of volatile organic compounds (VOCs). Revealing the relationship between O(V) concentration and molecular oxygen activation behavior is of significance to construct the efficient catalysts. Herein, α-MnO(2) with different O(V) concentrations was prepared to investigate the molecular oxygen activation for C(3)H(8) combustion. It is disclosed that the enhanced O(V) concentration in α-MnO(2) induced the reconfiguration of surface metal atoms, resulting in the transformation of oxygen activation configuration from end-on mode to side-on mode. Oxygen molecules in side-on mode possessed more localized electron density and weaker coordination bond strength with surrounding Mn atoms, which were more favorable to adsorb C(3)H(8) molecules and activate C-H bond for the improved combustion performance. This work provides a new understanding to reveal that the increased O(V) concentration contributes to more efficient VOCs combustion.