| Water is the source of life,it is of great significance to protect the limited water resources on the earth.However,with the development of modern industry,water pollution become a serious problem.It is urgent to explore efficient sewage treatment methods to improve water environment.Photocatalytic fuel cell?PFC?is an economical and energy-saving pollutant treatment technology developed on the basis of microbial fuel cell?MFC?.It utilizes the photocatalytic ability and self-produced ability of semiconductor to mineralize and decompose pollutants,making it possible for the degradation of various organic wastewater.However,due to the limitation of the catalytic electrode material,PFC generally has the problems of high preparation cost,slow degradation rate and incomplete degradation,and it is difficult to obtain good effects in practical applications.In order to solve the above problems,the paper proposed the following two methods:?1?finding a new catalyst with excellent electrochemical performance and catalytic performance and low cost as the catalytic electrode material and?2?combining PFC with a metal activated persulfate process.The specific research process and the results obtained by expanding the types of active particles and improving battery performance are as follows:?1?BiOCl/BiOI visible light catalyst was prepared by hydrothermal method and copper-cobalt oxide composite catalyst was synthesized by coprecipitation method.The catalytic electrode was prepared by using silica sol as the binder and stainless steel mesh as the carrier.The prepared catalysts and catalytic electrodes were characterized by SEM,XPS,XRD,UV-Vis and CV.It was found that BiOCl/BiOI and copper cobalt oxide catalysts have small nanometer,scalegood crystallinity and good photoelectrochemical performance.?2?Two different photocatalytic fuel cells,BiOCl/BiOI//carbon rod and BiOCl/BiOI//ZnIn2S4,were constructed,and the influencing factors in the degradation process were studied and analyzed.The degradation of RhB by BiOCl/BiOI//carbon rod single catalytic electrode PFC system achieved the best degradation rate and electricity generation under the condition of aeration of 0.5 min/L and pH=3,and the NaHSO3 also promoted the performance of the system.In the degradation test of RhB and tetracycline,the degradation performance of BiOCl/BiOI//ZnIn2S4 two-electrode system is significantly higher than that of BiOCl/BiOI//carbon rod single catalytic electrode PFC,but the current density and voltage generated by the system were very low which cannot meet the requirements.?3?A PFC system consisting of an anode with BiOI/BiOCl and a cathode with copper cobalt oxide was investigated to treat tetracycline and coking wastewater.When 20mM PS was added to the PFC system,the removal efficiency of 100 mg/L tetracycline increased from64%in 1 h to 95%in 10 min,and the kinetic constant increased from 0.021/min to0.296/min.The open circuit voltage was increased from 0.15 V to 0.36 V,and the current density was increased from 1.7×10-3 mA/cm2 to 1.4×10-2 mA/cm2.Treating coking wastewater,the PFC/PS removed 90%TOC?initial 162 mg/L,pH 5?in 1 h,generating a current density of 1.2×10-2 mA/cm2 and open circuit voltage 0.42 V.The synergistic performance of PFC/PS was stable.The effects of persulfate concentration,initial pH and pollutant concentration on the kinetics and PFC performance were investigated and the synergy mechanism in PFC/PS was discussed.In summary,three different photocatalytic fuel cell systems with BiOCl/BiOI as anodes were constructed in this paper,which effectively removed Rhodamine B,tetracycline and coking wastewater.The influence of reaction conditions on the performance of PFC was measured,and the reaction mechanism during the operation was explored,which provided a new idea for the construction of new high-efficiency PFC. |
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