Simultaneous H₂ production and water purification with surface-modified nanostructured TiO₂ photoelectrodes

The removal of emerging contaminants from water and production of green energy are some of the pressing needs of today's world. The use of water pollutants for the production of H₂ can be a powerful strategy for solving both these problems. Several approaches have been proposed for this purpose, such as photocatalysis, electrocatalysis and photoelectrocatalysis. In this context, TiO₂ is the most commonly used material, but it has several performance limitations. However, they can be improved with appropriate surface modifications. In this work, the inner surfaces of nanostructured TiO₂-based films were modified to improve their photoelectrocatalytic and photocatalytic performances, with an aim to simultaneously remove a water pollutant (rhodamine B dye) and generate H₂ in a custom-designed dual-chamber reactor. For this purpose, the TiO₂ nanostructure, which can be used as a photoanode in photocatalytic and photoelectrocatalytic experiments, was functionalized by introducing a zirconium phosphate monolayer (ZP modification). The excellent performances of the ZP-modified photoanodes in simultaneously achieving photoelectrocatalytic dye removal and H₂ evolution indicate that they are interesting candidates for attaining sustainable and circular solutions for environmental protection.