Interfacial engineering of heterostructured carbon-supported molybdenum cobalt sulfides for efficient overall water splitting

Constructing hetero-structured catalyst is promising but still challenging to achieve overall water splitting for hydrogen production with high efficiency.Herein,we developed a sulfide-based MoS2/Col-xS@C hetero-structure for highly efficient electrochemical hydrogen evolution reaction(HER) and oxygen evolution reaction(OER).The carbon derived from the filter paper acts as a conducting carrier to ensure adequate exposure of the active sites guaranteed with improved catalytic stability.The unique hierarchical nano-sheets facilitate the charge and ion transfer by shortening the diffusion path during electro-catalysis.Meanwhile,the robust hetero-interfaces in MoS2/Co1-xS@C can expose rich electrochemical active sites and facilitate the charge transfer,which further cooperates synergistically toward electro-catalytic reactions.Consequently,the optimal MoS2/Co1-xS@C hetero-structures present small over-potentials toward HER(135 mV@10 mA·cm-2) and OER(230 mV@10 mA·cm-2).The MoS2/Co1-xS@C electrolyzer requires an ultralow voltage of 1.6 V at the current density of 10 mA·cm-2with excellent durability,outperforming the state-of-the-art electro-catalysts.This work sheds light on the design of the hetero-structured catalysts with interfacial engineering toward large-scale water splitting.