MoS decorated CdS hybrid heterojunction for enhanced photoelectrocatalytic performance under visible light irradiation.

Pervious photocatalysis application of nanostructured suspensions reveals high recombination rates of photogenerated electron-hole pairs, low recycling efficiency and secondary pollution problems. Herein, MoS@CdS nanocomposites thin films on FTO (fluorine-doped tin oxide) substrates are fabricated using facile electrodeposition by decorating a layer of highly-active MoS cocatalyst on CdS film to optimize the interface modification. The hybrid film exhibits enhanced photoelectrocatalytic activity compared to pristine CdS film. The synthesized CdS exhibits a bandgap of 2.42 eV with the conduct band at ca. -0.25 V vs. RHE, while MoS reveals a bandgap of 1.73 eV with the valance band at ca. 1.59 V vs. RHE. The appropriate band alignment between the hybrid films favours the electrons transfer thus the charge recombination are suppressed. The MoS@CdS film yields a highest photocurrent of 15.2 mA/cm at 0 V vs. Ag/AgCl under visible light illumination (λ ≧ 420 nm), exhibiting a 5.2 times enhancement as compared to that of CdS film (2.9 mA/cm). The structural integration of MoS with CdS will be a promising strategy to develop a high-efficient and low-cost non-noble metal cocatalyst for solar energy conversion.