B, N-co-doped and C-coated Co2P composite derived from phytate derivatives as a high-efficiency HER electrocatalyst

Abstract

The investigation of efficient, durable, and highly stable non-noble metal multifunctional electrocatalysts is of great importance for the hydrogen evolution reaction (HER) and has great potential to alleviate energy issues. Herein, cobalt phosphides were fabricated by pyrolyzing melamine, H₃BO₃ and self-assembled phytic acid (PA) cross-linked metal complexes under an Ar atmosphere. Finally, B, N-co-doped C-coated Co₂P (Co₂P@BNC) was obtained. Co₂P@BNC showed excellent HER activity under the condition of acidic electrolyte. Co₂P@BNC shows an overpotential of 75 mV in 0.5 M H₂SO₄ with the Tafel value of 56 mV dec⁻¹ at a current density of 10 mA cm⁻². Particularly, the B-dopant could efficiently rearrange the electronic structure of the Co₂P@BNC catalyst, finally enhancing its electrocatalytic activity. The N-doped C coating effectively prevented the corrosion of Co₂P@BNC, and thus it showed stable catalytic activity after 10 h of testing in an acidic electrolyte.