Controlled Loading of MoS₂ on Hierarchical Porous TiO₂ for Enhanced Photocatalytic Hydrogen Evolution

Abstract

In this study, we garnered three important factors simultaneously, namely, wormhole mesoporosity of TiO2 with well-designed interfaces for effective charge transfers, precise loading of MoS2 for plasmon induction, and increased surface area with exposed surface atoms and active sites. The controlled loading of MoS2 on porous TiO2 (MPT) forms a heterojunction that effectively modulates the interface engineering and thereby greatly enhances hydrogen evolution. The synthesis of a photocatalyst is based on a simple hydrothermal process that is well characterized. The resulting composite materials were tested for hydrogen evolution reactions. At optimum loading, MPT10 induced a maximum hydrogen evolution rate of 1376 μmol h–1 g–1 with 2.28% apparent quantum yield (AQY), which was 10-fold higher compared to the MCT10 (MoS2-commercial TiO2) H2 evolution rate of 138 μmol h–1 g–1 with 0.23% AQY under similar reaction conditions. The shorter decay component, lower emission intensity, and higher estimated lifetime of MPT10 suggest its superiority over other materials. Density functional theory (DFT) calculations have further revealed the active sites of MPT and hierarchical porous TiO2 (HPT) to support the experimental hydrogen evolution reaction (HER). This study suggests an avenue to design an efficient noble-metal-free photocatalyst for solar fuel productions.