Selenium-inducing activates molybdenum phosphide/nitrogen-doped porous carbon nanoparticles for boosting hydrogen generation

Abstract

Transition metal phosphide has recently become a research hotspot of electrocatalysis because of its low price and excellent performance. Furthermore, nonmetal heteroatom incorporation into materials is a good way to regulate the surface electronic structure of electrocatalysts to boost their electrocatalytic performance. Based on this, the molybdenum phosphide (MoP) nanoparticles were firstly anchored on nitrogen-doped the porous carbon (NC) substrate by a simple annealing process, and then doped with nonmetal heteroatom selenium (Se) by hydrothermal method. By adjusting the content of selenium, x Se-doped MoP/NC nanoparticle electrocatalysts were successfully synthesized. Among them, the 0.25 Se-MoP/NC electrocatalyst exhibited the best HER catalytic performance, which presented a low overpotential of 141 and 166 mV at 10 mA cm−2 in a 1.0 M KOH and 0.5 M H2SO4 and Tafel slope of 69.91 and 62.93 mV dec−1 for HER, respectively. Benefiting from the doping of selenium, the electronic structure and surface composition of MoP can be effectively regulated, which is conducive to expose abundant active sites and enhance the inherent activity of MoP. Additionally, the N-doped porous carbon substrate also facilitates the diffusion of electrolyte/bubbles and good charge/mass-transfer ability. Furthermore, the electrocatalyst had good stability both in an acidic and alkaline media. This work provides an idea for the synthesis of nonmetal doped-transition metal phosphide as HER electrocatalyst with high efficiency and stability.