In situ N-, P- and Ca-codoped biochar derived from animal bones to boost the electrocatalytic hydrogen evolution reaction

Abstract

Abstract The development of highly efficient and inexpensive carbon-based catalysts for the production of hydrogen from water electrolysis is a considerable challenge in the field of sustainable energy transformation. Herein, an in situ N-, P- and Ca-codoped biochar was successfully fabricated from animal bone by thermal treatment at 800\xa0°C. This in situ N-, P- and Ca-codoped catalyst exhibits high atomic contents with synergistic effects of N, P and Ca, a large electrochemically active surface area, a low charge-transfer resistance, high conductivity, and a large specific area. These characteristics lead to an outstanding hydrogen evolution reaction (HER) activity and good stability in a H2SO4 acidic solution, with an onset potential of 80±3\xa0mV, an overpotential of 162±3\xa0mV at a current density of 10\xa0mA/cm2, a Tafel slope of 80\xa0mV/dec, and an exchange current density of 52.5 µA/cm2, which are comparable to or even better than those of synthetic heteroatom-doped or transition metal-doped carbon-based catalysts. These findings demonstrate that animal bone is a useful material for the preparation of N-, P- and Ca-codoped carbon materials as effective electrocatalysts for the HER.