Interface and cation dual-engineering promoting Ce-Co(OH)2/CoP/NF as bifunctional electrocatalyst toward overall water splitting coupling with oxidation of organic compounds

Transition metal-based electrocatalysts are the promising candidates to substitute noble metal-based catalysts for water electrolysis, owing to its abundant earth reserves and inexpensive fabrication costs. Interface engineering and cation doping engineering are verified as the effective methods to improve the sluggish electrocatalytic performance of transition metal-based electrocatalysts. Here, we synthesized a self-supported heterostructure of Ce doped Co(OH)2 nanosheets/CoP nanowires on the support of nickel foam (Ce-Co(OH)2/CoP/NF) by simple hydrothermal method, low-temperature phosphorization method. The Ce atom doping can lead to lattice distortion and abundant superficial defects on crystal surface, which will generate more active sites and faster charges transformation. The heterointerface between Ce-Co(OH)2 and CoP also can lead to electronic structure modulation at interface domain, which not can induce much fresh active sites in this area, but can optimize the active sites to the optimal state for superior catalytic activity. Benefitting from these, it only needs the overpotentials of 253 and 56 mV to realize 10 mA/cm2 for OER and HER under 1 M KOH solution, which is much enhance than single-phased samples. As the bifunctional electrocatalyst for two-electrode system, it merely requires 1.53 V to attain 10 mA/cm2 in 1 M KOH, and it also exhibits outstanding overall water splitting performance in alkaline natural electrolyte, along with excellent catalytic long-time durability. In addition, the Ce-Co(OH)2/CoP/NF-based electrolyzer also could achieve energy-saving hydrogen production, and simultaneously oxidative degradation of organic materials or biomass upgrading at anode under lower voltages. This work paves a novel idea to fabricate high-efficient bifunctional electrocatalysts for energy-saving H2 production.