Study On The Performance Of Photo-electric Synergistic Catalytic Degradation Of Dyes And Antibiotics Based On MoS₂/WO₃/CF

Photocatalysis is a technique that uses a catalyst to convert light energy into chemical energy.Traditional photocatalytic techniques suffer from low light energy conversion rates and slow reaction rates.However,photoelectrocatalysis can lower the recombination of photo-generated carriers by introducing an external electric field,thus improving energy utilization and reaction rates.Moreover,most photocatalysts exist in powder form,which makes them difficult to recover and reuse,and can cause secondary pollution.To address this problem,catalysts can be fixed onto substrates to prepare supported catalysts,such as carbon felt（CF）,sand,or stainless steel.Among these substrates,CF is an ideal substrate material due to its good conductivity,high temperature resistance,mechanical stability,and low cost.Thus,the development of photocatalytic materials based on CF should be investigated,which can be couple photocatalysis with electrocatalysis.The mechanisms of photo-electric synergistic catalysis should be investigated,which has practical significance for large-scale industrial applications.MoS₂/WO₃/CF was selected as the photocatalysts in this study.Furhermore,methylene blue（MB）and enrofloxacin（EFA）solutions were used to simulate dye and antibiotic wastewater.The performance and mechanism of MoS₂/WO₃/CF photo-electric synergistic catalysis,and application of photo-electric synergistic catalytic reactor based on MoS₂/WO₃/CF were investigated.The main conclusions of this study are as follows:（1）Different composite ratios of Mo S₂/WO₃ powder were prepared using a hydrothermal method.The specific surface area tests showed that Mo S₂/WO₃-5%had the largest specific surface area（23.67 m²/g）.Thus,Mo S₂/WO₃-5%was loaded onto CF by the dipping-desposition method.The excellent photochemical performance of composite material（MoS₂/WO₃/CF-5%）was demonstrated by multiple-scale characterization techniques,including SEM,XRD,DRS,and XPS,which also proved the successful preparation of MoS₂/WO₃/CF-5%.Furthermore,the electrochemical performance tests proved that both Mo S₂ and WO₃ were n-type semiconductors.MoS₂/WO₃/CF-5%had the smallest charge transfer resistance,which was conducive to improve the migration rate of charge carriers and enhance the photoelectrocatalytic performance.Thus,MoS₂/WO₃/CF-5%was selected for the photo-electric synergistic catalytic degradation experiments.（2）The influence factors in the photo-electric synergistic degradation of MB and EFA by MoS₂/WO₃/CF-5%were investigated.The results showed that alkaline conditions,lower initial pollutant concentrations,higher electrolyte concentrations and bias voltage were more favorable for the removal of MB and EFA.The degradation performance of MoS₂/WO₃/CF-5%on MB and EFA was compared under three modes:Photocatalysis,electro-oxidation,and photo-electric synergistic degradation.The results showed that the removal of MB and EFA by MoS₂/WO₃/CF-5%were 83.6%and 63.1%,respectively,which were much higher than those of photocatalysis and electro-oxidation.Free radical capture experiments demonstrated that the contribution of reactive species to pollutant degradation in the photo-electric synergistic process was in the order of·OH>h⁺>·O₂^–.14 intermediate products were detected by LC-MS,and the degradation pathway of EFA was proposed during the degradation process of EFA.Furthermore,the photo-electric synergistic catalytic degradation mechanism of MoS₂/WO₃/CF-5%was explored,and the existence of applied bias voltage could promote the separation of e^––h⁺pairs,which can improve the photocatalytic performance.（3）Based on MoS₂/WO₃/CF-5%,A solar-powered photovoltaic system was used to construct a continuous-flow photo-electric synergistic catalytic reactor system for all-weather operation.The optimal operating conditions for the all-weather continuous-flow photo-electric synergistic catalytic reactor system were determined under simulated conditions.The hydraulic retention time was 8 h and the current density was 0.1 m A/cm².Under the optimal operating conditions,the average removal of MB and EFA in the real environment by the all-weather continuous-flow photo-electric synergistic catalytic reactor were 91.7%and 55.0%,respectively,with corresponding treatment loads of 1542.59 mg/（m²·d）and 478.13 mg/（m²·d）.Additionally,MoS₂/WO₃/CF-5%exhibited good stability in the photoelectrochemical reactor.Economic evaluation showed that this reactor does not require subsequent investment and can achieve energy self-sufficiency,which has significant economic benefits.