Construction of 2D/2D NH2-TiO2/ReS2 molecular-connected heterojunction to achieve selective carrier transport for photocatalytic hydrogen production

Abstract

The 2D/2D heterojunction photocatalyst demonstrates a broad range of applications owing to its large interface contact area. At present, most of the current 2D/2D structures are constructed by self-assembly, which mainly forms a relatively weak van der Waals force at the interface. This poses a challenge to achieving effective carrier separation. Here, we proposed an innovative strategy of molecular-connected heterojunctions to address this challenge. The strategy uses (3-aminopropyl) trimethoxysilane (APTMS) to modify the surface of TiO2 and construct NH2-TiO2/ReS2 heterojunction, which not only alters the material’s Zeta potential but also uses molecular chains connecting TiO2 and ReS2. Simultaneously, the design of molecular-connected heterojunction changes the work function of TiO2, leading to the transformation of the TiO2/ReS2 heterojunction from type-Ⅰ to S-scheme, thereby achieving a selective carrier separation. The constructed NH2-TiO2/ReS2 photocatalytic heterojunction composite has a hydrogen production rate of 451.3 μmol g-1 h−1, which is over 11 and 3 times than TiO2 and TiO2/ReS2, respectively, and exhibits excellent long-term photocatalytic stability. This study presents a novel approach for achieving strong interface bonding and introduces an innovative approach for constructing 2D/2D photocatalytic heterojunctions.