TiO2 Nanotubes/Ag/MoS2 Meshy Photoelectrode with Excellent Photoelectrocatalytic Degradation Activity for Tetracycline Hydrochloride

Abstract

A novel type of TiO2 nanotubes (NTs)/Ag/MoS2 meshy photoelectrode was fabricated with highly oriented TiO2 nanotube arrays grown from a Ti mesh supporting Ag nanoparticles and three-dimensional MoS2 nanosheets. In this structure, Ag nanoparticles act as bridges to connect MoS2 and TiO2 and pathways for electron transfer, ensuring the abundant production of active electrons, which are the source of •O2−. The TiO2 NTs/Ag/MoS2 mesh can be used as both photocatalyst and electrode, exhibiting enhanced photoelectrocatalytic efficiency in degrading tetracycline hydrochloride under visible light irradiation (λ ≥ 420 nm). Compared to unmodified TiO2 NTs, the improved photoelectrocatalytic activity of the TiO2 NTs/Ag/MoS2 arise from the formation of Z-scheme heterojunctions, which facilitate the efficient separation of photogenerated electron-hole pairs through the Schottky barriers at the interfaces of TiO2 NTs–Ag and Ag–MoS2.