TiO₂ Photocatalytic Membrane Electrode Coupled With Biological Anode For The Treatment Of VOCs And Electricity Generation

Volatile organic compounds?VOCs?,one of the most primary air pollutants in chemical and petrochemical industrial emissions,can lead to the deterioration of air quality and endanger human health.In recent years,photocatalysis for VOCs degradation has become a very attractive and promising technology,the problem of easy recombination of electrons and holes in photocatalytic processes can be solved by coupling with other technologies.Therefore,this experiment proposes a device that coupled photocatalytic membrane electrode with bioanode to improve the efficiency of VOCs degradation.The main results of this paper are as follows:?1?Four TiO₂ photocatalysts with different morphologies were compared.The results of various characterization methods?UV-vis,SEM,BET,XRD,and CV?showed that the TiO₂nanosheets have the narrowest band gap of 3.0 eV and square platelet structure exposed to the?001?crystal surface.The result indicated that TiO₂ nanosheets had the highest activity in the anatase TiO₂,and the maximum redox peak area of the TiO₂ nanosheets in the CV curve also manifested its superior catalysis performance.?2?the homogeneous mixture involved TiO₂ catalyst and water were coated onto a conductive substrate to test the photocatalytic activity of the electrode on the model VOC?Ethyl acetate?.At the same time,the conditions for the photocatalytic degradation of ethyl acetate were optimized(conductive substrates,Catalysts loading,substrate concentration,ambient humidity and external electricity.The experimental results showed that 0.1 g TiO₂ nanosheets are loaded on a 3 cm×10 cm carbon fiber cloth to degrade 250 ppm Ethyl acetate in the ambient humidity of 50%,which can achieved the degradation rate of 98%in 20 minutes.?3?A bio-photoelectrochemical cell?BPEC?was configured to remove ethyl acetate and produce electricity simultaneously.A cost-effectively separator?PVDF membrane?was designed to replace the proton exchange membrane.PVDF membrane can effectively promote the diffusion of VOCs from cathode to the bioanode and reduce the cost of the device.The experimental results showed that BPEC with PVDF membrane has a higher EA degradation rate and electricity yield than that with PEM.?4?The degradation mechanism of ethyl acetate on BPEC system was studied.The kinetic constants indicated that there is a synergy between the bioanode and photocathode.In addition,system performance is affected by the external resistance.When the external resistance is 50?,system has the highest EA degradation rate that achieved 100%within 40min.