Facile in situ fabrication of rGO/MoS2 heterostructure decorated with gold nanoparticles with enhanced photoelectrochemical performance

Abstract

Two-dimensional materials offer a promising visible light-driven photoelectrochemical (PEC) application thanks to their high electrical conductivity and tunable bandgap. However, the high recombination rate of photogenerated carriers significantly limits their photoelectrochemical efficiency. Here, a reduced graphene oxide/molybdenum disulfide/gold nanoparticles (rGO/MoS2/Au NPs) heterostructure is introduced based on a simple and high-throughput method to efficiently convert light into electricity. For this purpose, MoS2 dispersion is cast on GO few layers followed by sputtering 5 nm thin film of gold. With a thermal-assisted method not only GO is reduced to rGO but also Au is converted into Au NPs. The introduced heterostructure is thoroughly studied by SEM, TEM, Raman, UV–Visible, and AFM analyses. The rGO/MoS2/Au NPs heterostructure demonstrates about 240% improvement in photocurrent density compared with GO/MoS2 hybrid which is due to the efficient transfer of electrons to Au NPs and a significant reduction in the recombination rate of photogenerated carriers. Straightforward fabrication of such a high-performance PEC heterostructure is very promising for photoelectrochemical and energy generation applications. Finally, using numerical simulations, the mechanism of the photogenerated carriers is well elucidated in the suggested heterostructure, which shows complete agreement with the experimental results.