Exfoliated Molybdenum Disulfide-Wrapped CdS Nanoparticles as a Nano-Heterojunction for Photo-Electrochemical Water Splitting

We developed a heterojunction photocathode, MoS2@CdS, based on the wrapping of CdS nanoparticles by the MoS2 nanocrystals. The liquid-phase exfoliation method was adopted for preparing few-layer MoS2 nanocrystals of a layer thickness of similar to 7.9 nm, whereas CdS nanoparticles of an average diameter of similar to 17 nm were synthesized by the one-step hydrothermal process. The synthesized nanocrystals and nanoparticles were characterized by AFM, FESEM, HRTEM, STEM, XRD, GIXRD, UV-vis absorption, fluorescence emission, and Raman 4 spectroscopy. The difference between two modes in the Raman spectrum of MoS2 indicates the formation of few-layer MoS2. The photoelectrochemical performance of the heterojunction photocathode was excellent. The MoS2 pCdS heterostructure photocathode increased the photocurrent density (J(Ph)) under 100 mW/cm(2) illumination. We obtained the maximum applied biased photoconversion efficiency (PE) of similar to 1.2% of the MoS2@CdS heterojunction photocathode in optimum device configuration. The production of H-2 was measured as similar to 72 mu mol/h for the MoS2@CdS heterostructure with a cyclic stability of up to 7500 s.

Automated summary

A heterojunction photocathode, MoS2@CdS, was developed by wrapping CdS nanoparticles with MoS2 nanocrystals. The photocathode showed excellent photoelectrochemical performance with a maximum applied biased photoconversion efficiency of approximately 1.2% and a hydrogen production rate of around 72 µmol/h, demonstrating cyclic stability up to 7500 seconds.