Electronic modulation on allotropic Co2P/CoP heterojunctions with N, P co-doped porous carbon matrix through metal-injection toward high-efficiency water splitting

The interfacial electron modulation of electrocatalysts is a useful technique for promoting catalyst performance for the water-related dissociation reactions. Herein, a high-efficient Fe-doped allotropic Co 2 P/CoP heterojunction nanoparticles embedded in N, P co-doped carbon matrix was constructed. The intense electrical interfacial contacts between the allotropic heterojunction optimized the reaction kinetics by boosting efficient charged active centers, regulating the intermediate adsorption/desorption. The incorporation of Fe atoms further enhancing the heterointerface contact between CoP and Co 2 P by providing favorable electronic properties and special coordination environment, causing the interfacial coupling enhancement. Therefore, Fe-Co 2 P/CoP possesses outstanding performance in both hydrogen evolution reaction and oxygen evolution reaction, with small overpotentials of 174 mV and 286 mV at 10 mA·cm −2 in alkaline medium, respectively. And only 1.71 V battery voltage is needed for the Fe-Co 2 P/CoP (+, −) cell device with satisfactory durability. This finding provides valuable insights into the engineering of electronic structures of well-designed metal phosphides for water electrolysis.