Thermal decomposition synthesis of CuO on TiO₂ NTs as promising photocatalysts for effective photoelectrocatalytic hydrogen evolution and pollutant removal

The preparation strategy is the important factor to obtain the effective photocatalyst, and the thermal decomposition could be used to prepare photocatalysts with high crystallinity and photoactivity. In this paper, thermal decomposition method was used to deposit CuO nanoparticles on TiO₂ nanotube arrays (TiO₂ NTs), and the TiO₂ NTs/CuO exhibited remarkably high visible light absorption and photoelectrocatalytic performances toward dye degradation and Cr(VI) reduction. The potential degradation pathway and toxicities of rhodamine B (RhB) dyes and intermediates were investigated. Moreover, the high photoelectric conversion with visible light photocurrent of 25.94 μA/cm² and interface photovoltage of -0.12 V was produced, and the visible light-induced photoelectrocatalytic water splitting performance was outstanding. The mechanisms of hybrid photocatalyst preparation and photocatalytic progress were analyzed, and the p-n heterojunction was the decisive factor of the excellent photocatalytic property. The preparation strategy of TiO₂ NTs/CuO provides the reference and guidance for the effective photocatalysts used in industrial waste water remediation and new energy generation.