Synthesis of Mo-based nanostructures from organic-inorganic hybrid with enhanced electrochemical for water splitting

Abstract

scarcity and high cost of Pt severely hinder their practical application. Recently, various molybdenum-based com-pounds, such as MoS 2 , MoSe 2 , Mo 2 C, and MoP, are prom-ising non-noble-metal candidates due to their comparable HER activity to Pt-based catalysts [15–17]. Among them, Mo 2 C, as a typical interstitial alloys material, has similar metallic structures and possesses Pt-like catalytic behav-iors. The traditional synthesis method usually involves the mix of metals with carbon and subsequent carbonization under high temperature to form Mo 2 C structure, which results in serious aggregation and compromises their per-formance. Recently, various morphologies of Mo 2 C nano-structure with excellent HER performance have been developed through various methods [18–23]. Sun and co-workers [24] synthesized closely interconnected network of molybdenum phosphide nanostructure with highly ef-ficient electrocatalyst for HER. Tang's group reported that nanoporous Mo 2 C can be obtained by thermal decompo-sition process under an inert atmosphere, which was used as a very effective electrocatalyst for generating hydrogen from water [25,26]. In addition, Sasaki's group demonstra-ted that small Mo 2 C nanoparticles loaded on carbon nano-tubes showed highly active and durable electrocatalyst for HER [27]. Evidently, these results suggest that Mo 2 C can be used as an effective electrocatalyst for water splitting. Recently, the formation of MoO 2 with carbon materials such as graphene was used to further improve the perfor-mance of MoO 2 [28–31]. For example, Mai's group [32] synthesized ultrathin MoO 2 nanosheets encapsulated car-bon matrix with a facile thermal reduction method, which showed high specific capacities and enhanced cycling sta-bility. Li and co-workers [33] fabricated flawed MoO 2 na-nobelts on graphene with enhanced HER performance. However, few reports focus on constructing heterocompos-ite Mo 2 C with MoO 2 . Compared with those of the corre-sponding homogeneous materials, these heterostructured A simple method to fabricate Mo-based nanostructures were developed by the thermal decomposition of MoOx-based or-ganic–inorganic hybrid nanowires. Well-defined Mo-based nanostructures, including MoO2 and MoO3 nanowires, can be prepared by changing the hybrid precursor. More importantly, Mo2C/MoO2 heterostructures with porous structure were suc-cessfully synthesized under an inert atmosphere. The resultant Mo2C/ MoO2 heterostructures show enhanced electrocatalytic activity and superior stability for electrochemical hydrogen evolution from water. The enhanced performance might be as-cribed to the high electrical conductivity and porous structures with one-dimensional structure. Indeed, our result described here provides a new way to synthesize other Mo-based nano-structures for various applications.