Treatment Of Sulfonamides In Water Environment By Photocatalytic Fuel Cell Based On TiO₂ Composite Nanotube Arrays

Antibiotic pollutants are a kind of persistent organic pollutants that cannot be ignored,which have a significant impact on ecological stability and human health.Sulfonamides,as a kind of antibiotics,are widely used and difficult to degrade.The residual sulfonamides in water have hidden dangers to human life and health.However,the conventional methods used in water treatment are not effective in degradation of sulfonamides.Among the organic degradation methods,photocatalytic fuel cell system derived from advanced oxidation technology is a good choice to deal with pollution and solve energy problems.This technology can not only treat wastewater,but also recycle the chemical energy in wastewater.It is of great significance to explore the ability of photocatalytic fuel cell system to degrade sulfanilamide pollutants in water.The performance of photoanode is an important factor affecting the degradation performance and power generation efficiency of photocatalytic fuel cell system.As an important photocatalyst,TiO₂ is also the preferred anode material for photocatalytic fuel cells.However,the band structure of TiO₂ is difficult to respond to visible light,and the electron-hole pair is easy to reorganize,which makes it difficult for TiO₂ to be used as the anode of photocatalytic fuel cell directly in practical water treatment.Therefore,the traditional TiO₂nanotube array photoanode was optimized by adjusting the phase combination and semiconductor recombination,so as to solve the light response range,enhance the separation effect of electron-hole pairs,construct the photocatalytic fuel cell system,and improve the ability of photocatalytic fuel cell system to degrade sulfonamide pollutants in water.TiO₂ nanotube arrays were prepared by anodic oxidation method.The phase composition of TiO₂ nanotube arrays was controlled by controlling the calcination temperature.It was found that the microstructure of the samples calcined at different temperatures was similar,and the calcination temperature was 600℃,the TiO₂ nanotube arrays have anatase rutile self-doping structure,which shows more excellent photoelectric performance,and can be used as the photoanode of photocatalytic fuel cell and the substrate of subsequent experiments.By comparing the degradation performance between the fuel cell system and the traditional photocatalysis system,it is found that the photocatalysis fuel cell system has higher treatment efficiency,which may be due to the self-bias between the two electrodes after forming the loop,which reduces the carrier recombination efficiency.BiOBr/TiO₂ composite with type II heterojunction was designed and prepared as photoanode based on TiO₂ nanotube array.The results show that the composite photoanode has better light response performance and more significant electron-hole pair separation efficiency,and its voltage density is 1.47 times that of the substrate.The degradation rate of sulfanilamide can reach 78%in 180 min.the degradation rate of sulfanilamide can still reach 76%in simulated wastewater using tap water as solvent.BiOBr/UiO-66/TiO₂ ternary composite was prepared by two-step method with metal organic framework introduced by impregnation drying method as photoanode,which successfully solved the problems of easy agglomeration of BiOBr and easy falling off of coated photoanode material from the substrate.The degradation performance of the ternary composite has good stability and can be recycled.In conclusion,the TiO₂ nanotube arrays can be used as the photoanode in the photocatalytic fuel cell system by doping and modifying the TiO₂ nanotube arrays through phase control,semiconductor composite and other methods.The composite nanotube arrays have good degradation ability to sulfonamide,which provides theoretical and data support for the future development and practical application of the photocatalytic fuel cell system.