MoS2 quantum dot-modified Ag/polyaniline composites with enhanced photogenerated carrier separation for highly efficient visible light photocatalytic H2 evolution performance

Abstract

Designing photocatalysts with multiple active materials based on composites is essential for the creation of a photocatalytic hydrogen evolution reaction (HER) system. Here, we report the design and preparation of novel MoS₂ quantum dot-modified Ag nanoparticle/polyaniline (MoS₂ QDs–Ag/PANI) composites through a green liquid probe sonication route and hydrothermal synthesis for the first time. The composite photocatalysts exhibit significantly enhanced photocatalytic activity for H₂ production from water splitting under visible light irradiation. The optimal photocatalytic activity of H₂ evolution reaches 420.1 μmol over 4 wt% MoS₂ QDs–Ag/PANI in the first 3 hours, which is 262.6 times higher than that of Ag/PANI composites and 4.0 times better than that of MoS₂ QDs. The apparent quantum efficiency (AQE) is 30.5% at 430 nm. The composites have a large amount of reaction active sites and outstanding visible light utilization upon the introduction of MoS₂ QDs. In addition, the synergistic effect of MoS₂ QDs, PANI and Ag NPs promotes the spatial separation and transport efficiency of photogenerated charge carriers. These positive factors ultimately contribute to the superior photocatalytic activity for hydrogen production. Meanwhile, the photocatalyst exhibits high stability and reusability. This idea of composite design will be useful for the development of both hydrogen generation and multifunctional composite materials.