Tuning size of MoS2 in MoS2/graphene oxide heterostructures for enhanced photocatalytic hydrogen evolution

Nano-sized materials have attracted tremendous attentions because of their promising practical applications and theoretical values. The nano-sized materials are able to not only enhance the intrinsic properties of their bulk counterparts but also give birth to new promising properties. Herein, heterojunctions consisted of graphene oxide (GO) and three different MoS 2 nanostructures, including nanoflowers, nanoparticles, and quantum dots, were constructed and used as photocatalysts in water splitting. The electrochemical behavior and photocatalytic performance of MoS 2 /GO composites were found closely related to the particle size and morphology of MoS 2 . Compared to bulk MoS 2 /GO photocatalyst, nano-sized MoS 2 /GO heterostructures exhibited obviously enhanced performance in photocatalytic hydrogen generation. Benefitting from the surface effect and the quantum confinement in MoS 2 quantum dots, MoS 2 quantum dots/GO displayed the highest photocatalytic activities. This study indicates that the decrease in the dimension of MoS 2 can effectively increase the photocatalytic hydrogen evolution performance of MoS 2 /GO heterostructures, and thus suggests preferred strategy to design other HER photocatalysts based on MoS 2 .