Sintered Ni metal as a matrix of robust self-supporting electrode for ultra-stable hydrogen evolution.

A novel porous sintered Ni metal as the matrix for supporting MoS 2 /Ni 3 S 2 hierarchical nanorods is successfully prepared by powder metallurgy and hydrothermal sulfurization. The porous sintered Ni-metal matrix supported with the MoS 2 /Ni 3 S 2 displays more advantages over Ni foam, including enhanced catalytic activity and stability, as well as the sufficient mechanical properties, which can be beneficial for the industrial service. [Display omitted] • The porous Ni metal substrate is fabricated via powder metallurgy. • The catalyst of MoS 2 /Ni 3 S 2 with hierarchical structures is confirmed. • The catalytic activity, conductivity and stability for HER are improved. • The self-supporting electrode exhibits sufficient mechanical properties. • NiO controlled by the annealing temperature determines the morphology. For the self-supporting catalysts of Hydrogen evolution reaction (HER), the rational design and fabrication of substrate with porous structure and sufficient mechanical strength are critical to promoting the industrial HER application. In this work, a novel porous sintered Ni metal as the matrix for supporting catalysts was successfully prepared by powder metallurgy, and a self-supporting electrode for HER was fabricated via a simple sulfurization process on this sintered Ni metal matrix. For instance, MoS 2 /Ni 3 S 2 nanorods (NRs) were vertically grown on the as-sintered porous Ni matrix, and the morphology of the sintered Ni matrix significantly affected the growth of MoS 2 /Ni 3 S 2 NRs. The NRs@Sintered Ni electrode shows a low overpotential of η10 = 56 mV and Tafel slope of 82 mV dec−1. Compared with NRs@Ni foam, the NRs@Sintered Ni exhibits superior stability, where no exfoliation and cracks are observed on the surface of the electrode after 5000 CV cycles. Ultra-high stability and long-term durability are obtained over 100 h even at high potentials of 200 and 300 mV. Moreover, the tensile strength of the as-obtained electrode based on the sintered Ni manifests nearly 260 times higher than that of NRs@Ni foam, evidencing an excellent mechanical property. This work provides an idea for the preparation of self-supporting metal-based catalytic electrodes in large-scale hydrogen production. [ABSTRACT FROM AUTHOR]