Photo-electrocatalytic oxidation of atrazine using sputtured deposited TiO2: WN photoanodes under uv/visible light

Publication date: Available online 19 April 2019Source: Catalysis TodayAuthor(s): Simon Komtchou, Nazar Delegan, Ahmad Dirany, Patrick Drogui, Didier Robert, My Ali El KhakaniAbstractHerein were report on the UV/visible light driven photo-electrocatalytic (PEC) degradation of Atrazine (ATZ) and its major degradation by-products (DEA, DIA, DEDIA and ATZ-OH) in synthetic and real agricultural surface waters. For this purpose, sub-stoichiometric TiO2-x, and tungsten-nitrogen codoped TiO2:WN photoanodes were prepared by means of a radio frequency magnetron sputtering (RF-MS) deposition process. The codoping’s objective was to shift the material’s optical absorption from the UV towards the visible light, while minimizing defect formation. This was achieved, and directly demonstrated via UV-Vis transmittance spectra analysis. Tauc plot extrapolation was used to determine the values of the band gaps of the films. We found that the band gap of TiO2-x is 3.0 eV and narrows to reach 2.3 eV for TiO2:WN. TiO2-x photoanodes crystallised in a predominantly rutile phase, whereas codoped TiO2:WN photoanodes crystallised in a predominantly anatase phase. Prior to PEC oxidation, agricultural surface water (ASW) containing ATZ was first treated by coagulation using metal salts (FeCl3 and Al2(SO4)3, respectively) as to reduce turbidity and colloidal particles. Optimal jar tests conditions allowed 52.9% and 39.7% DOC removal with FeCl3 and Al2(SO4)3, respectively. Subsequently, our TiO2:W...

Source: Catalysis Today - April 20, 2019 Category: Chemistry Source Type: research