In order to better understand the specific substituent effects on the electrochemical oxidation process of β-O-4 bond, a series of methoxyphenyl type β-O-4 dimer model compounds with different localized methoxyl gro...In order to better understand the specific substituent effects on the electrochemical oxidation process of β-O-4 bond, a series of methoxyphenyl type β-O-4 dimer model compounds with different localized methoxyl groups, including 2-(2-methoxyphenoxy)-1-phenylethanone, 2-(2-methoxyphenoxy)-1-phenylethanol, 2-(2-methoxyphenoxy)-1-(4-methoxyphenyl)ethanone, 2-(2-methoxyphenoxy)-1-(4-methoxyphenyl)ethanol, 2-(2,6-dimethoxyphenoxy)-1-(4-methoxyphenyl)ethanone, 2-(2,6-dimethoxyphenoxy)-1-(4-methoxyphenyl)ethanol have been selected and their electrochemical properties have been studied experimentally by cyclic voltammetry, and FT-IR spectroelectrochemistry. Combining with electrolysis products distribution analysis and density functional theory calculations, oxidation mechanisms of all six model dimers have been explored. In particular, a total effect from substituents of both para-methoxy(on the aryl ring closing to Cα) and Cα-OH on the oxidation mechanisms has been clearly observed, showing a significant selectivity on the Cα-Cβbond cleavage induced by electrochemical oxidations.展开更多
As a general problem in the field of batteries,materials produced on a large industrial scale usually possess unsatisfactory electrochemical performances.Among them,manganese-based aqueous rechargeable zinc-ion batter...As a general problem in the field of batteries,materials produced on a large industrial scale usually possess unsatisfactory electrochemical performances.Among them,manganese-based aqueous rechargeable zinc-ion batteries(ARZBs)have been emerging as promising large-scale energy storage systems owing to their high energy densities,low manufacturing cost and intrinsic high safety.However,the direct application of industrial-scale Mn2O3(MO)cathode exhibits poor electrochemical performance especially at high current rates.Herein,a highly reversible Mn-based cathode is developed from the industrial-scale MO by nitridation and following electrochemical oxidation,which triples the ion diffusion rate and greatly promotes the charge transfer.Notably,the cathode delivers a capacity of 161 m Ah g^(-1) at a high current density of 10 A g^(-1),nearly-three times the capacity of pristine MO(60 m Ah g^(-1)).Impressive specific capacity(243.4 m Ah g^(-1))is obtained without Mn^(2+) additive added in the electrolyte,much superior to the pristine MO(124.5 m Ah g^(-1)),suggesting its enhanced reaction kinetics and structural stability.In addition,it possesses an outstanding energy output of 368.4 Wh kg^(-1) at 387.8 W kg^(-1),which exceeds many of reported cathodes in ARZBs,providing new opportunities for the large-scale application of highperformance and low-cost ARZBs.展开更多
The generation and transformation of radicals on the cathode of indirect electrochemical oxidation were studied by chemilumines- cence(CL)and UV-Visible spectra in the reactor with a salt bridge that connected the sep...The generation and transformation of radicals on the cathode of indirect electrochemical oxidation were studied by chemilumines- cence(CL)and UV-Visible spectra in the reactor with a salt bridge that connected the separated chambers.The CL intensity of 4×10^(-9)mol/L luminol on the cathode with bubbling oxygen was about seven times that of the intensity without it,which was because of the generation of reactive oxygen species(ROS).The existence of ROS,especially the generation of the superoxide radical,c...展开更多
The mineralization of phenol in aerated electrochemical oxidation has been investigated.The results show that a cathodic Fenton process can occur when the Ti-0.3Mo-0.8Ni alloy material is used as cathode in solution c...The mineralization of phenol in aerated electrochemical oxidation has been investigated.The results show that a cathodic Fenton process can occur when the Ti-0.3Mo-0.8Ni alloy material is used as cathode in solution containing ferric or ferrous ions; moreover,the reinforcement of cathodic Fenton process on the total organic carbon (TOC) removal rate of phenol is quite distinct.Among the metallic ions investigated,the ferric ion is the best catalyst for the electrochemical mineralization of phenol at initial pH 2.0,and the optimal concentration range is from 50 to 200 mg/L.The favorable pH range and supporting electrolyte (Na2SO4) concentration for mineralization of phenol in solution containing ferrous ions are 1.8-2.3 and below 0.10 mol/L,respectively.UV radiation can improve the TOC removal rate of phenol,but the enhanced effect varies in different solutions.In the solution containing ferric ions,an equal sum or synergetic effect can be observed.The optimal effect of electrolysis system under UV radiation is achieved in the solution containing 50 mg/L Fe3+ with a final removal percentage of 81.3%.展开更多
The surface of dry-jet wet spun carbon fibers(CFs)is relatively smooth compared with those of wet spun CFs,which results in weak interfacial interactions between the fiber and the polymer resin.A surface functionaliza...The surface of dry-jet wet spun carbon fibers(CFs)is relatively smooth compared with those of wet spun CFs,which results in weak interfacial interactions between the fiber and the polymer resin.A surface functionalization treatment is particularly important to unleash the full potential of the superior mechanical properties of dry-jet wet spun CFs.In this study,the effects of electrochemical oxidation treatment time and current density on the surface structures and the mechanical properties of dry-jet wet spun CFs were investigated.The interlaminar shear strength of the CFs improves significantly from 69 to 84 MPa after 120 s of treatment.Further structural analysis reveals that the improvements are due to the addition of oxygen-containing functional groups and the optimization of the morphology on the surface of the CFs.展开更多
The electrochemical oxidation of paper mill wastewater was studied using a dimensionally stable anode of composition Ti/RuPb(40%)Ox. The oxidation process was analyzed as a function of electrolysis time and with respe...The electrochemical oxidation of paper mill wastewater was studied using a dimensionally stable anode of composition Ti/RuPb(40%)Ox. The oxidation process was analyzed as a function of electrolysis time and with respect to the cell potential difference, electrolyte (NaCl) concentration, and pH of the sample. The purification of the effluent was evaluated through measurements of the removal of chemical oxygen demand (COD), color, and total polyphenols, and using UV-Vis spectroscopy. The results showed that the presence of NaCl is a determining factor in the purification process. Electrolysis of wastewater containing 5 g/L NaCl at a cell potential difference of 6 V for 120 min, removed 99% of COD and the percent removal values of color and polyphenols were 95% after 15 min of electrolysis. The UV-Vis spectrum showed evidence of the formation of hypochlorite ions (ClO-) during the electrolysis process, indicating that the electrochemical oxidation proceeds via an indirect mechanism with the participation of hypochlorite ions.展开更多
In order to further reduce the sulfur content in gasoline, a new desulfurization process was proposed by using catalytic oxidation and extraction realized in an electrochemical fluidized reactor. The fluidized layer o...In order to further reduce the sulfur content in gasoline, a new desulfurization process was proposed by using catalytic oxidation and extraction realized in an electrochemical fluidized reactor. The fluidized layer of loaded catalyst particles consisted of lead dioxide (PbO2) supported on activated carbon particles (PbO2/C) and the electrolyte was aqueous NaOH solution. The PbO2/C particle anodes could remarkably accelerate the electrochemical reaction rate and promote the electrochemical catalysis of sulfur compounds. The sulfur compounds were at first oxidized to sulfones or sulfoxides, which were then re- moved after extraction. The experimental results indicated that the optimal desulfurization conditions were as follows: The cell voltage was 3.2 V, the concentration of hydroxyl ions in electrolyte was 0.12 mol/L, and the feed rate was 300 mL/min. Under these conditions the concentration of sulfur in gasoline was reduced from 310 ppm to 70 ppm. Based on these experimental results, a mechanism of indirect electrochemically catalytic oxidation was proposed.展开更多
The treatment of biologically treated wastewater of coffee-curing industry by the electrochemical oxidation using steel anode was investigated. Bench-scale experiments were conducted for activated sludge process on ra...The treatment of biologically treated wastewater of coffee-curing industry by the electrochemical oxidation using steel anode was investigated. Bench-scale experiments were conducted for activated sludge process on raw wastewater and the treated effluents were further treated by electrochemical oxidation method for its colour and organic content removal. The efficiency of the process was determined in terms of removal percentage of COD, BOD and colour during the course of reaction. Several operating parameters like time, pH and current density were examined to ascertain their effects on the treatment efficiency. Steel anode was found to be effective for the COD and colour removal with anode efficiency of 0.118 kgCOD\5h -1\5A -1\5m -2 and energy consumption 20.61 kWh\5kg -1 of COD at pH 9. The decrease in pH from 9 to 3 found to increase the anode efficiency from 0.118 kgCOD\5h -1\5A -1\5m -2 to 0.144 kWh\5kg -1 of COD while decrease the energy consumption from 20.61 kWh\5kg -1 of COD to 12.86 kWh\5kg -1 of COD. The pH of 5 was considered an ideal from the present treatment process as it avoids the addition of chemicals for neutralization of treated effluents and also economical with respect to energy consumption. An empirical relation developed for relationship between applied current density and COD removal efficiency showed strong predictive capability with coefficient of determination of 96.5%.展开更多
The electrochemical oxidation of L-cysteine in an SDS/BA/H2O microemulsion system was studied with the methods of ultramicroelectrode cyclic voltammetry and AC impedance. The catalytic efficiency of the microemulsion ...The electrochemical oxidation of L-cysteine in an SDS/BA/H2O microemulsion system was studied with the methods of ultramicroelectrode cyclic voltammetry and AC impedance. The catalytic efficiency of the microemulsion on the electrochemical oxidation increases with the increase of BA or SDS content, but decreases with the increase of the water content because of the effects of BA, SDS and water on the solubilization of L-cysteine in the microemulsion. Furthermore, the catalytic efficiency of the bicontinuous structure is greater than that of an O/W microemulsion system. The results derived from both the rate constant k0 and Gibbs free energy ΔG≠ accord with those from the catalytic efficiency.展开更多
The indirect electrochemical oxidation of 4-amino-dimethyl-aniline hydrochloride containing wastewater generated from vanillin production is presented. Experiments were conducted at a constant current density of 30 mA...The indirect electrochemical oxidation of 4-amino-dimethyl-aniline hydrochloride containing wastewater generated from vanillin production is presented. Experiments were conducted at a constant current density of 30 mA/cm 2 via a Ti/Ru-Ti-Sn ternary oxide coated anode and an undivided reactor. During the various stages of the electrolysis, parameters such as the values of chemical oxygen demand(COD) and total organic carbon(TOC) were determined in order to evaluate the feasibility of the electrochemical treatment. The energy consumption and the current efficiency during the electrolysis were calculated. The present study proves the effectiveness of the electrochemical treatment for wastewater resulted from vanillin production.展开更多
By using a self-made carbon/polytetrafluoroethylene(C/PTFE) O2-fed as cathode and Ti/IrO2/RuO2 as anode, the effects of electrochemical oxidation of phenol and the coal-gas wastewater containing phenol were studied. T...By using a self-made carbon/polytetrafluoroethylene(C/PTFE) O2-fed as cathode and Ti/IrO2/RuO2 as anode, the effects of electrochemical oxidation of phenol and the coal-gas wastewater containing phenol were studied. The terylene diaphragm which kept pH>12 in cathodic compartment and pH<1 in the anodic compartment was selected in the experiment in comparison with the other types of diaphragm. Furthermore, hydroxyl radical(HO·) was determined in the cathodic compartment of the diaphragm cell by ele- ctron spin resonance spectrum(ESR) and the fluorescence spectra. Compared with pH, the accumulated H2O2 and the COD removal of the no-diaphragm cell, the mechanism of electrochemical oxidation in the terylene diaphragm cell was supposed. The degradation of phenol was supposed to be cooperative oxidation by direct or indirect electrochemical oxidation at the anode and H2O2, HO· produced by oxygen reduction at the cathode. The mineralization of phenol in the diaphragm cell was better than that in the no-diaphragm cell. When the coal-gas wastewater was treated by the electrolysis system with terylene diaphragm, the average removal efficiency of the volatile phenol and COD were 100% and 79.6%, respectively.展开更多
The electrochemical oxidation degradation processes for artificial and actual wastewater containing ammonia were carried out with a Ti/RuO2-Pt anode and a Ti plate cathode.We studied the effects of different current d...The electrochemical oxidation degradation processes for artificial and actual wastewater containing ammonia were carried out with a Ti/RuO2-Pt anode and a Ti plate cathode.We studied the effects of different current densities,space sizes between the two electrodes,and amounts of added NaCl on ammonia-containing wastewater treatment.It was shown that,after a 30-min treatment under the optimal conditions,which were a current density of 20mA/cm2,a space size between the two electrodes of 1cm,and an added amount of 0.5g/L of NaCl,the COD concentration in municipal wastewater was 40 mg/L,a removal rate of 90%;and the NH3-N concentration was 7mg/L,a removal rate of 88.3%.The effluent of municipal wastewater qualified for Class A of the Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant(GB18918-2002).展开更多
The electrochemical oxidation of 1, 3-benzenedithiol was investigated in a 0. 100 mol/L tetrabutylammonium perchlorate/acetonitrile electrolyte. The electrochemical techniques used were potential sweep, bulk electroly...The electrochemical oxidation of 1, 3-benzenedithiol was investigated in a 0. 100 mol/L tetrabutylammonium perchlorate/acetonitrile electrolyte. The electrochemical techniques used were potential sweep, bulk electrolysis, rotating disc and the potential step method. The combination of the techniques yielded the number of electrons transferred per molecule, the reaction order, the transfer coefficient, the diffusion coefficient and concentration of dithiol anions, the standard heterogeneous rate constant as well as the formal potential and equilibrium constant of the preceeding dissociation reaction. This paper also illustrates the methods for studying the electrode kinetics of reactions which (a) involve a chemical reaction preceeding the electron-transfer process, (b) have insoluble polymer products, and (c) are totally irreversible.展开更多
The characteristic of electrochemical oxidation of aniline on SnO 2/Ti electrode is studied. The results indicate that SnO 2/Ti electrode doped F plays a wonderful role in the oxidation of aniline comparing with Pt el...The characteristic of electrochemical oxidation of aniline on SnO 2/Ti electrode is studied. The results indicate that SnO 2/Ti electrode doped F plays a wonderful role in the oxidation of aniline comparing with Pt electrode. The kinetics factors that influence the oxidation rate of aniline on the SnO 2/Ti electrode are determined by the dissolving of the film on the electrode. The dissolving of the film consisted of intermediate products on the electrode is the slow step. The effects of aniline concentration, pH in aniline solution and the current density( i )on the rate of aniline oxidation, the complexity of intermediate products and the basic category of the intermediate products consisted of the film are introduced.展开更多
Regulation of the electronic structure and interface property becomes a major strategy in the preparation of electrocatalyst.This paper reports the synthesis of cerium(Ce)and sodium dodecyl benzene sulfonate(SDBS)como...Regulation of the electronic structure and interface property becomes a major strategy in the preparation of electrocatalyst.This paper reports the synthesis of cerium(Ce)and sodium dodecyl benzene sulfonate(SDBS)comodified Ti/PbO_(2)electrodes(Ti/PbO2CeSDBS).Ce and SDBS could greatly change the electronic structure and interface property of PbO2.Ti/PbO_(2)CeSDBS exhibited excellent electrocatalytic activity and stability in Rhodamine B(RhB)electrocatalytic oxidation reaction.The improved electrocatalytic activity associates with the synergistic effect of electronic and interface factors.In the electrochemical degradation of RhB,the removal efficiencies of RhB and COD are about 0.880 and 0.694 respectively after the electrolysis of 220 min with Ti/PbO_(2)Ce4SDBS40,which are higher than the contrast Ti/PbO_(2)electrodes.In the meantime,the accelerated lifetime of Ti/PbO_(2)Ce4SDBS40 is more than 6.2 times than that of Ti/PbO_(2).展开更多
The increasing occurrence of cyanobacterial blooms in water bodies is a serious threat to the environment. Efficient in-lake treatment methods for the control of cyanobacteria proliferation are needed, their in-vivo d...The increasing occurrence of cyanobacterial blooms in water bodies is a serious threat to the environment. Efficient in-lake treatment methods for the control of cyanobacteria proliferation are needed, their in-vivo detection to obtain a real-time response to their presence, as well as the information about their physiological state after the applied treatment. In-vivo fluorescence measurements of photosynthetic pigments have proved to be effective for quantitative and qualitative detection of phytoplankton in a water environment. In the experiment, chlorophyll and phycocyanin fluorescence sensors were used concurrently to detect stress caused by electrochemical oxidation applying an electrolytic cell equipped with borondoped diamond electrodes on a laboratory culture of cyanobacteria Microcystis aeruginosa PCC 7806. The inflicted injuries were reflected in a clear transient increase in the phycocyanin fluorescence signal(for 104 %? 43%) 24 h after the treatment, which was not the case for the chlorophyll fluorescence signal. In the next 72 h of observation, the fluorescence signals decreased(on 40% of the starting signal) indicating a reduction of cell number, which was confirmed by cell count(24% reduction of the starting concentration) and analysis of extracted chlorophyll and phycocyanin pigment. These results demonstrate the viability of the combined application of two sensors as a useful tool for in-vivo detection of induced stress, providing real-time information needed for the evaluation of the efficiency of the in-lake treatment and decision upon the necessity of its repetition. The electrochemical treatment also resulted in a lower free microcystins concentration compared to control.展开更多
Surface of polyacrylonitrile (PAN)-based carbon fibers was modified by electrochemical oxidation. The modification effect on carbon fibers surface was explored using atomic force microscopy (AFM), X-ray photoelectron ...Surface of polyacrylonitrile (PAN)-based carbon fibers was modified by electrochemical oxidation. The modification effect on carbon fibers surface was explored using atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). Results showed that on the modified surface of carbon fibers, the carbon contents decreased by 9.7% and the oxygen and nitrogen contents increased by 53.8% and 7.5 times, respectively. The surface roughness and the hydroxyl and carbonyl contents also increased. The surface orientation index was reduced by 1.5%which decreased tensile strength of carbon fibers by 8.1%, and the microcrystalline dimension also decreased which increased the active sites of carbon fiber surface by 78%. The physical and chemical properties of carbon fibers surface were modified through the electrochemical oxidative method, which improved the cohesiveness between the fibers and resin matrix and increased the interlaminar shear strength (ILSS) of carbon fibers reinforced epoxy composite (CFRP) over 20%.展开更多
A rotating ring (Pt) disc (Pt) electrode was employed to investigate the oxidation process of sodium sulfide (Na 2S). It was reported that the oxidation intermediates and product of HS - were formed on the disc electr...A rotating ring (Pt) disc (Pt) electrode was employed to investigate the oxidation process of sodium sulfide (Na 2S). It was reported that the oxidation intermediates and product of HS - were formed on the disc electrode and then reduced on the ring electrode. The results indicate that at a rotation rate of 20 Hz, when the disc electrode potential was -0.15 V (vs SHE) and higher, more extensive oxidation process took place via a series of electrochemical steps to produce sulfur (S). The products of oxidation intermediates (S 2- x , S 2- 2) and sulfur (S) reduced either on the ring electrode with a set potential of -0.8 V (vs SHE), or on disc electrode with negative going potential sweep at about -0.5～ 0.55 V (vs SHE). The experimental results of voltammogram of ring disc electrode at sodium sulfide solution demonstrated that the first step was the oxidation of HS - and produce S 2- x , and then the S 2- x adsorbed integrated itself and formed sulfur (S).展开更多
The preparation of nanometer γ-Fe2O3 through an electrochemical process was studied at room temperature, using a metal iron plate as sacrificing anode and a sheet of stainless steel as cathode, in non-aqueous mediate...The preparation of nanometer γ-Fe2O3 through an electrochemical process was studied at room temperature, using a metal iron plate as sacrificing anode and a sheet of stainless steel as cathode, in non-aqueous mediate containing （Bu）4NBr as support electrolyte and 2%（vol%） water. The powdery particles obtained were then calcined at 300 °C. The products were characterized by IR, XRD, SEM, TEM and laser particle size analyser, indicating the fine particle is a pure nanometer γ-Fe2O3. The morphology is like cone-shaped and their average size is 22.0 nm. Furthermore the VSM spectrum shows that the particle’s coercivity （3.9×103 A/m） is rather small, presenting the excellent super-paramagnetism.展开更多
基金The authors gratefully acknowledge the financial support of the Natural Science Foundation of China,China(Grant No.21975082 and 21736003)the Guangdong Basic and Applied Basic Research Foundation(Grant Number:2019A1515011472 and 2022A1515011341)the Science and Technology Program of Guangzhou(Grant Number:202102080479).
文摘In order to better understand the specific substituent effects on the electrochemical oxidation process of β-O-4 bond, a series of methoxyphenyl type β-O-4 dimer model compounds with different localized methoxyl groups, including 2-(2-methoxyphenoxy)-1-phenylethanone, 2-(2-methoxyphenoxy)-1-phenylethanol, 2-(2-methoxyphenoxy)-1-(4-methoxyphenyl)ethanone, 2-(2-methoxyphenoxy)-1-(4-methoxyphenyl)ethanol, 2-(2,6-dimethoxyphenoxy)-1-(4-methoxyphenyl)ethanone, 2-(2,6-dimethoxyphenoxy)-1-(4-methoxyphenyl)ethanol have been selected and their electrochemical properties have been studied experimentally by cyclic voltammetry, and FT-IR spectroelectrochemistry. Combining with electrolysis products distribution analysis and density functional theory calculations, oxidation mechanisms of all six model dimers have been explored. In particular, a total effect from substituents of both para-methoxy(on the aryl ring closing to Cα) and Cα-OH on the oxidation mechanisms has been clearly observed, showing a significant selectivity on the Cα-Cβbond cleavage induced by electrochemical oxidations.
基金supports from the National Natural Science Foundation of China(No.21805063)the Natural Science Foundation of Guangdong Province for Distinguished Young Scholars(No.2018B030306022)+2 种基金the Project of International Science and Technology Cooperation in Guangdong Province(No.2020A0505100016)the Shenzhen Sauvage Nobel Laureate Laboratory for Smart Materialsthe Shenzhen Science and Technology Program(Nos.KQTD20200820113045083,ZDSYS20190902093220279)。
文摘As a general problem in the field of batteries,materials produced on a large industrial scale usually possess unsatisfactory electrochemical performances.Among them,manganese-based aqueous rechargeable zinc-ion batteries(ARZBs)have been emerging as promising large-scale energy storage systems owing to their high energy densities,low manufacturing cost and intrinsic high safety.However,the direct application of industrial-scale Mn2O3(MO)cathode exhibits poor electrochemical performance especially at high current rates.Herein,a highly reversible Mn-based cathode is developed from the industrial-scale MO by nitridation and following electrochemical oxidation,which triples the ion diffusion rate and greatly promotes the charge transfer.Notably,the cathode delivers a capacity of 161 m Ah g^(-1) at a high current density of 10 A g^(-1),nearly-three times the capacity of pristine MO(60 m Ah g^(-1)).Impressive specific capacity(243.4 m Ah g^(-1))is obtained without Mn^(2+) additive added in the electrolyte,much superior to the pristine MO(124.5 m Ah g^(-1)),suggesting its enhanced reaction kinetics and structural stability.In addition,it possesses an outstanding energy output of 368.4 Wh kg^(-1) at 387.8 W kg^(-1),which exceeds many of reported cathodes in ARZBs,providing new opportunities for the large-scale application of highperformance and low-cost ARZBs.
文摘The generation and transformation of radicals on the cathode of indirect electrochemical oxidation were studied by chemilumines- cence(CL)and UV-Visible spectra in the reactor with a salt bridge that connected the separated chambers.The CL intensity of 4×10^(-9)mol/L luminol on the cathode with bubbling oxygen was about seven times that of the intensity without it,which was because of the generation of reactive oxygen species(ROS).The existence of ROS,especially the generation of the superoxide radical,c...
基金the Hi-Tech Research and Development Program (863) of China (No.2005AA601010-02-2)the Science Pilot Plan of the Science and Technology Bureau of Wuhan City (No.20066009138-02).
文摘The mineralization of phenol in aerated electrochemical oxidation has been investigated.The results show that a cathodic Fenton process can occur when the Ti-0.3Mo-0.8Ni alloy material is used as cathode in solution containing ferric or ferrous ions; moreover,the reinforcement of cathodic Fenton process on the total organic carbon (TOC) removal rate of phenol is quite distinct.Among the metallic ions investigated,the ferric ion is the best catalyst for the electrochemical mineralization of phenol at initial pH 2.0,and the optimal concentration range is from 50 to 200 mg/L.The favorable pH range and supporting electrolyte (Na2SO4) concentration for mineralization of phenol in solution containing ferrous ions are 1.8-2.3 and below 0.10 mol/L,respectively.UV radiation can improve the TOC removal rate of phenol,but the enhanced effect varies in different solutions.In the solution containing ferric ions,an equal sum or synergetic effect can be observed.The optimal effect of electrolysis system under UV radiation is achieved in the solution containing 50 mg/L Fe3+ with a final removal percentage of 81.3%.
基金Jiangsu Province for the Transformation of Scientific and Technological Achievements(BA2019043)Jiangsu Provincial Key Research and Development Program(BE2021014-2)。
文摘The surface of dry-jet wet spun carbon fibers(CFs)is relatively smooth compared with those of wet spun CFs,which results in weak interfacial interactions between the fiber and the polymer resin.A surface functionalization treatment is particularly important to unleash the full potential of the superior mechanical properties of dry-jet wet spun CFs.In this study,the effects of electrochemical oxidation treatment time and current density on the surface structures and the mechanical properties of dry-jet wet spun CFs were investigated.The interlaminar shear strength of the CFs improves significantly from 69 to 84 MPa after 120 s of treatment.Further structural analysis reveals that the improvements are due to the addition of oxygen-containing functional groups and the optimization of the morphology on the surface of the CFs.
文摘The electrochemical oxidation of paper mill wastewater was studied using a dimensionally stable anode of composition Ti/RuPb(40%)Ox. The oxidation process was analyzed as a function of electrolysis time and with respect to the cell potential difference, electrolyte (NaCl) concentration, and pH of the sample. The purification of the effluent was evaluated through measurements of the removal of chemical oxygen demand (COD), color, and total polyphenols, and using UV-Vis spectroscopy. The results showed that the presence of NaCl is a determining factor in the purification process. Electrolysis of wastewater containing 5 g/L NaCl at a cell potential difference of 6 V for 120 min, removed 99% of COD and the percent removal values of color and polyphenols were 95% after 15 min of electrolysis. The UV-Vis spectrum showed evidence of the formation of hypochlorite ions (ClO-) during the electrolysis process, indicating that the electrochemical oxidation proceeds via an indirect mechanism with the participation of hypochlorite ions.
文摘In order to further reduce the sulfur content in gasoline, a new desulfurization process was proposed by using catalytic oxidation and extraction realized in an electrochemical fluidized reactor. The fluidized layer of loaded catalyst particles consisted of lead dioxide (PbO2) supported on activated carbon particles (PbO2/C) and the electrolyte was aqueous NaOH solution. The PbO2/C particle anodes could remarkably accelerate the electrochemical reaction rate and promote the electrochemical catalysis of sulfur compounds. The sulfur compounds were at first oxidized to sulfones or sulfoxides, which were then re- moved after extraction. The experimental results indicated that the optimal desulfurization conditions were as follows: The cell voltage was 3.2 V, the concentration of hydroxyl ions in electrolyte was 0.12 mol/L, and the feed rate was 300 mL/min. Under these conditions the concentration of sulfur in gasoline was reduced from 310 ppm to 70 ppm. Based on these experimental results, a mechanism of indirect electrochemically catalytic oxidation was proposed.
文摘The treatment of biologically treated wastewater of coffee-curing industry by the electrochemical oxidation using steel anode was investigated. Bench-scale experiments were conducted for activated sludge process on raw wastewater and the treated effluents were further treated by electrochemical oxidation method for its colour and organic content removal. The efficiency of the process was determined in terms of removal percentage of COD, BOD and colour during the course of reaction. Several operating parameters like time, pH and current density were examined to ascertain their effects on the treatment efficiency. Steel anode was found to be effective for the COD and colour removal with anode efficiency of 0.118 kgCOD\5h -1\5A -1\5m -2 and energy consumption 20.61 kWh\5kg -1 of COD at pH 9. The decrease in pH from 9 to 3 found to increase the anode efficiency from 0.118 kgCOD\5h -1\5A -1\5m -2 to 0.144 kWh\5kg -1 of COD while decrease the energy consumption from 20.61 kWh\5kg -1 of COD to 12.86 kWh\5kg -1 of COD. The pH of 5 was considered an ideal from the present treatment process as it avoids the addition of chemicals for neutralization of treated effluents and also economical with respect to energy consumption. An empirical relation developed for relationship between applied current density and COD removal efficiency showed strong predictive capability with coefficient of determination of 96.5%.
文摘The electrochemical oxidation of L-cysteine in an SDS/BA/H2O microemulsion system was studied with the methods of ultramicroelectrode cyclic voltammetry and AC impedance. The catalytic efficiency of the microemulsion on the electrochemical oxidation increases with the increase of BA or SDS content, but decreases with the increase of the water content because of the effects of BA, SDS and water on the solubilization of L-cysteine in the microemulsion. Furthermore, the catalytic efficiency of the bicontinuous structure is greater than that of an O/W microemulsion system. The results derived from both the rate constant k0 and Gibbs free energy ΔG≠ accord with those from the catalytic efficiency.
文摘The indirect electrochemical oxidation of 4-amino-dimethyl-aniline hydrochloride containing wastewater generated from vanillin production is presented. Experiments were conducted at a constant current density of 30 mA/cm 2 via a Ti/Ru-Ti-Sn ternary oxide coated anode and an undivided reactor. During the various stages of the electrolysis, parameters such as the values of chemical oxygen demand(COD) and total organic carbon(TOC) were determined in order to evaluate the feasibility of the electrochemical treatment. The energy consumption and the current efficiency during the electrolysis were calculated. The present study proves the effectiveness of the electrochemical treatment for wastewater resulted from vanillin production.
文摘By using a self-made carbon/polytetrafluoroethylene(C/PTFE) O2-fed as cathode and Ti/IrO2/RuO2 as anode, the effects of electrochemical oxidation of phenol and the coal-gas wastewater containing phenol were studied. The terylene diaphragm which kept pH>12 in cathodic compartment and pH<1 in the anodic compartment was selected in the experiment in comparison with the other types of diaphragm. Furthermore, hydroxyl radical(HO·) was determined in the cathodic compartment of the diaphragm cell by ele- ctron spin resonance spectrum(ESR) and the fluorescence spectra. Compared with pH, the accumulated H2O2 and the COD removal of the no-diaphragm cell, the mechanism of electrochemical oxidation in the terylene diaphragm cell was supposed. The degradation of phenol was supposed to be cooperative oxidation by direct or indirect electrochemical oxidation at the anode and H2O2, HO· produced by oxygen reduction at the cathode. The mineralization of phenol in the diaphragm cell was better than that in the no-diaphragm cell. When the coal-gas wastewater was treated by the electrolysis system with terylene diaphragm, the average removal efficiency of the volatile phenol and COD were 100% and 79.6%, respectively.
基金supported by the Eleventh Five-Year Key Technology Research and Development Program in China (Grant No. 2006BAJ08B04)
文摘The electrochemical oxidation degradation processes for artificial and actual wastewater containing ammonia were carried out with a Ti/RuO2-Pt anode and a Ti plate cathode.We studied the effects of different current densities,space sizes between the two electrodes,and amounts of added NaCl on ammonia-containing wastewater treatment.It was shown that,after a 30-min treatment under the optimal conditions,which were a current density of 20mA/cm2,a space size between the two electrodes of 1cm,and an added amount of 0.5g/L of NaCl,the COD concentration in municipal wastewater was 40 mg/L,a removal rate of 90%;and the NH3-N concentration was 7mg/L,a removal rate of 88.3%.The effluent of municipal wastewater qualified for Class A of the Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant(GB18918-2002).
文摘The electrochemical oxidation of 1, 3-benzenedithiol was investigated in a 0. 100 mol/L tetrabutylammonium perchlorate/acetonitrile electrolyte. The electrochemical techniques used were potential sweep, bulk electrolysis, rotating disc and the potential step method. The combination of the techniques yielded the number of electrons transferred per molecule, the reaction order, the transfer coefficient, the diffusion coefficient and concentration of dithiol anions, the standard heterogeneous rate constant as well as the formal potential and equilibrium constant of the preceeding dissociation reaction. This paper also illustrates the methods for studying the electrode kinetics of reactions which (a) involve a chemical reaction preceeding the electron-transfer process, (b) have insoluble polymer products, and (c) are totally irreversible.
基金Supported by the National Natural Science Foundation of PRC( 10 9710 2 3)
文摘The characteristic of electrochemical oxidation of aniline on SnO 2/Ti electrode is studied. The results indicate that SnO 2/Ti electrode doped F plays a wonderful role in the oxidation of aniline comparing with Pt electrode. The kinetics factors that influence the oxidation rate of aniline on the SnO 2/Ti electrode are determined by the dissolving of the film on the electrode. The dissolving of the film consisted of intermediate products on the electrode is the slow step. The effects of aniline concentration, pH in aniline solution and the current density( i )on the rate of aniline oxidation, the complexity of intermediate products and the basic category of the intermediate products consisted of the film are introduced.
基金Thanks to the financial support from the Science and technology project of Shaanxi Province(2017ZDXM-GY-041).
文摘Regulation of the electronic structure and interface property becomes a major strategy in the preparation of electrocatalyst.This paper reports the synthesis of cerium(Ce)and sodium dodecyl benzene sulfonate(SDBS)comodified Ti/PbO_(2)electrodes(Ti/PbO2CeSDBS).Ce and SDBS could greatly change the electronic structure and interface property of PbO2.Ti/PbO_(2)CeSDBS exhibited excellent electrocatalytic activity and stability in Rhodamine B(RhB)electrocatalytic oxidation reaction.The improved electrocatalytic activity associates with the synergistic effect of electronic and interface factors.In the electrochemical degradation of RhB,the removal efficiencies of RhB and COD are about 0.880 and 0.694 respectively after the electrolysis of 220 min with Ti/PbO_(2)Ce4SDBS40,which are higher than the contrast Ti/PbO_(2)electrodes.In the meantime,the accelerated lifetime of Ti/PbO_(2)Ce4SDBS40 is more than 6.2 times than that of Ti/PbO_(2).
基金Supported by the ARRS Project L1-5456(Control of Harmful Cyanobacteria Bloom in Fresh-Water Bodies)LIFE+Project:LIFE12 ENV/SI/00083 LIFE Stop CyanoBloom
文摘The increasing occurrence of cyanobacterial blooms in water bodies is a serious threat to the environment. Efficient in-lake treatment methods for the control of cyanobacteria proliferation are needed, their in-vivo detection to obtain a real-time response to their presence, as well as the information about their physiological state after the applied treatment. In-vivo fluorescence measurements of photosynthetic pigments have proved to be effective for quantitative and qualitative detection of phytoplankton in a water environment. In the experiment, chlorophyll and phycocyanin fluorescence sensors were used concurrently to detect stress caused by electrochemical oxidation applying an electrolytic cell equipped with borondoped diamond electrodes on a laboratory culture of cyanobacteria Microcystis aeruginosa PCC 7806. The inflicted injuries were reflected in a clear transient increase in the phycocyanin fluorescence signal(for 104 %? 43%) 24 h after the treatment, which was not the case for the chlorophyll fluorescence signal. In the next 72 h of observation, the fluorescence signals decreased(on 40% of the starting signal) indicating a reduction of cell number, which was confirmed by cell count(24% reduction of the starting concentration) and analysis of extracted chlorophyll and phycocyanin pigment. These results demonstrate the viability of the combined application of two sensors as a useful tool for in-vivo detection of induced stress, providing real-time information needed for the evaluation of the efficiency of the in-lake treatment and decision upon the necessity of its repetition. The electrochemical treatment also resulted in a lower free microcystins concentration compared to control.
基金This work was financially supported by the National Nat-ural Science Foundation of China(Grant No.50172004 and 50333070).
文摘Surface of polyacrylonitrile (PAN)-based carbon fibers was modified by electrochemical oxidation. The modification effect on carbon fibers surface was explored using atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). Results showed that on the modified surface of carbon fibers, the carbon contents decreased by 9.7% and the oxygen and nitrogen contents increased by 53.8% and 7.5 times, respectively. The surface roughness and the hydroxyl and carbonyl contents also increased. The surface orientation index was reduced by 1.5%which decreased tensile strength of carbon fibers by 8.1%, and the microcrystalline dimension also decreased which increased the active sites of carbon fiber surface by 78%. The physical and chemical properties of carbon fibers surface were modified through the electrochemical oxidative method, which improved the cohesiveness between the fibers and resin matrix and increased the interlaminar shear strength (ILSS) of carbon fibers reinforced epoxy composite (CFRP) over 20%.
文摘A rotating ring (Pt) disc (Pt) electrode was employed to investigate the oxidation process of sodium sulfide (Na 2S). It was reported that the oxidation intermediates and product of HS - were formed on the disc electrode and then reduced on the ring electrode. The results indicate that at a rotation rate of 20 Hz, when the disc electrode potential was -0.15 V (vs SHE) and higher, more extensive oxidation process took place via a series of electrochemical steps to produce sulfur (S). The products of oxidation intermediates (S 2- x , S 2- 2) and sulfur (S) reduced either on the ring electrode with a set potential of -0.8 V (vs SHE), or on disc electrode with negative going potential sweep at about -0.5～ 0.55 V (vs SHE). The experimental results of voltammogram of ring disc electrode at sodium sulfide solution demonstrated that the first step was the oxidation of HS - and produce S 2- x , and then the S 2- x adsorbed integrated itself and formed sulfur (S).
文摘The preparation of nanometer γ-Fe2O3 through an electrochemical process was studied at room temperature, using a metal iron plate as sacrificing anode and a sheet of stainless steel as cathode, in non-aqueous mediate containing （Bu）4NBr as support electrolyte and 2%（vol%） water. The powdery particles obtained were then calcined at 300 °C. The products were characterized by IR, XRD, SEM, TEM and laser particle size analyser, indicating the fine particle is a pure nanometer γ-Fe2O3. The morphology is like cone-shaped and their average size is 22.0 nm. Furthermore the VSM spectrum shows that the particle’s coercivity （3.9×103 A/m） is rather small, presenting the excellent super-paramagnetism.
