Triple Ni-Co-Mo metal sulfides with one-dimensional and hierarchical nanostructures towards highly efficient hydrogen evolution reaction

Abstract

Designing multi-transition metal-based sulfides holds promising in alkaline water electrolysis, whereas selecting proper candidates and facile building strategy remain challengeable. Herein, based on previous theory of combining 3d-transition metal (NiCo) with non-3d-transition metal (Mo) to lower hydrogen-adsorption energy barriers, we develop an indirect access to NiCoMo sulfides supported by nickel foam (CoMoO-S/NF) with one dimensional (1 D) and hierarchical nanostructures. In the first step, the metal oxides as precursor frameworks are designed as one-dimensional (1 D) nanostructures comprising interwoven nanosheets. The unique structure not only provides the large surface areas for exposing abundant active sites, but also improves the contact between catalyst/interface and facilitates the mass or charge transportation. Besides, the ternary metals are supposed to generate synergistic effect to boost hydrogen evolution reaction (HER) properties of CoMoO-S/NF via sulfurization in the second step. Furthermore, CoMoO-S/NF demonstrates high electrocatalytic performances with structural stability in long-term HER process. Therefore, the two-step building of ternary transition metal sulfides may be provide applications for various transition metal materials with unique architecture and high efficiency in alkaline HER.