Ultralow-Pt-loading assisted by reconstruction of cobalt molybdate nanoarrays for enhanced hydrogen evolution reaction

Abstract

The utilization of Pt nanoparticles as catalysts in hydrogen evolution reaction (HER) is a widely adopted strategy for hydrogen production. Nonetheless, the reduction of Pt usage costs and enhancement of its durability are crucial factors that need to be addressed in order to facilitate the commercialization of these catalysts. In this study, Pt–Co(OH)2@CoMoO4/NF has been developed and synthesized on nickel foam (NF) through the implementation of hydrothermal and electrodeposition techniques. Cobalt molybdate is subjected to surface reconstruction of the precatalyst by anion etching under electrodeposition conditions to form hydroxides nanosheets, and the ultra-low content of Pt nanoparticles (0.25 wt%) was uniformly dispersed on the CoMoO4 nanoarrays and Co(OH)2 nanosheets subsequently. Detailed experimental characterization showed that low Pt loading promoted charge transfer, accelerated the Heyrovsky step of HER, and surface reconstruction increased oxygen vacancies. Pt–Co(OH)2@CoMoO4/NF exhibited an overpotential of 100 mV at current densities of 100 mA cm−2, while lasting this current density for a duration of 100 h. At higher current densities, the electrocatalytic activity of Pt–Co(OH)2@CoMoO4/NF surpassed that of the commercially accessible 20 wt% Pt/C. Our work offers a viable approach towards designing efficient electrocatalysts for hydrogen production base on platinum.