Photo-electrochemical study of TiO2/Co3O4 thin films in polluted electrolyte: A promising route for coupling hydrogen production with water remediation

The use of a photo-electrochemical cell (PEC) to produce hydrogen from wastewater is a promising innovation. In this context, this study investigates the impact of a pollutant on the photo-electrochemical properties of sol-gel synthesized TiO 2 and TiO 2 –Co 3 O 4 thin films for hydrogen production in a polluted electrolyte. Combining the photocatalytic properties of TiO 2 with the electronic properties of Co 3 O 4 offers an effective solution for achieving effective photo-electrochemical properties in polluted environments. Nevertheless, despite the lowest photocatalytic activity, the hybrid thin film TiO 2 –Co 3 O 4 with the highest Ti/Co ratio (1:0.5) shows the most promising performance with simultaneous 11.4 μmol cm −2 h −1 H 2 production and 12% acid orange 7 degradation after 3 h irradiation under xenon light without the use of any sacrificial agent. This indicates that the electronic conductivity provided by the presence of Co 3 O 4 is a critical property for achieving optimal performance in PEC coupling for hydrogen production and wastewater treatment. • Sol-gel TiO 2 –Co 3 O 4 films enabled coupling of water splitting and remediation. • 11 μmol cm −2 h −1 H 2 was produced after 3h Xe irradiation without sacrificial agent. • Simultaneous 12% acid orange 7 degradation was measured.