Turning carbon dioxide into fuel concomitantly to the photoanode-driven process of organic pollutant degradation by photoelectrocatalysis

TiO2 nanotubes (TiO(2)Nt) were modified with zirconium oxide and used as photoanode-driven to oxidize benzyl alcohol concomitantly to the reduction of carbon dioxide using a gas diffusion layer modified with cuprous oxide (GDL-Cu2O) as cathode. ZrO2 was deposited by a simple wet chemical method onto TiO(2)Nt and presented higher photocurrents when irradiated by UV-Vis irradiation. Under optimized conditions, 0.1 mol L-1 Na2SO4 pH 7 and 0.1 mol L-1 KHCO3 pH 7 supporting electrolytes in the anodic and cathodic compartments, respectively, the degradation of benzyl alcohol reached 41% at the TiO(2)Nt electrode and 68% at TiO(2)Nt-ZrO2 under UV-Vis irradiation and bias potential of 1.5 V vs. Ag/AgCl. Concomitantly, the electrons driven to the cathode side saturated with CO2 promoted generation of around 3.8 mmol L-1 of methanol and 0.96 mmol L-1 of ethanol under TiO(2)Nt-ZrO2. So, our finding shows for the first time the performance of a hybrid reactor in which is possible to promote photooxidation of an organic compound concomitantly to CO2 reduction to alcohol using a simple photoanode-driven and a cathode separated by a proton exchange membrane. (c) 2019 Elsevier Ltd. All rights reserved.