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

Abstract

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).