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

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 degrees 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 mV, an overpotential of 162 +/- 3 mV at a current density of 10 mA/cm(2), a Tafel slope of 80 mV/dec, and an exchange current density of 52.5 mu A/cm(2), which are comparable to or even better than those of synthetic hetematom-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.

Automated summary

An in situ N-, P- and Ca-codoped biochar catalyst was successfully prepared from animal bone, showing high atomic contents and synergistic effects. The catalyst exhibited outstanding performance and stability in hydrogen production from water electrolysis, surpassing synthetic materials in catalytic activity.