Fabrication and enhanced photocatalytic properties of dual S-scheme heterojunction TiO2/MoS2/C3N4 nanotube arrays

A novel (MoS2/C3N4)-sensitized TiO2 nanotube array (NTA) photoelectrode has been prepared by a simple hydrothermal synthesis and high-temperature calcination. When petal-like MoS2 nanosheets are uniformly distributed on the surface of TiO2 nanotubes coated with layered C3N4, a notable red-shift and high absorption are observed in the visible light region. The photocurrent density (mA cm−2) systematically increases from TiO2 NTAs (0.97), C3N4/TiO2 (1.25), MoS2/TiO2 (1.50), to TiO2/MoS2/C3N4 (1.97) under visible light irradiation, due to the dual S-scheme semiconductor heterostructures comprising multiple components with a staggered band offset. Such a heterostructure exhibits an enhanced photocatalytic performance towards the degradation of organic contaminants, e.g. P-nitrophenol (PNP) and rhodamine B (RhB).