Bifunctional heterostructured nitrogen and phosphorus co-doped carbon-layer-encapsulated Co2P electrocatalyst for efficient water splitting
Hua Zhang, Hongyi Li, Shuai Niu, Yao Zhou, Zitao Ni, Qianwen Wei, Anran Chen, Shusheng Zhang, Tao Sun, Ruijie Dai, Yu Yang, Guangzhi Hu
Abstract
Highly efficient and robust non-noble bifunctional electrocatalysts with excellent stability are essential for practical large-scale application of hydrogen energy. Here, we design a hybrid nanostructure of Co2P nanoparticles encapsulated uniformly within N, P co-doped carbon layers that are then integrated into conductive carbon cloth (N-Co2P/NPC). As expected, the developed electrode exhibits very low overpotentials of 68 and 230 mV at 10 mA cm−2 for the hydrogen evolution reaction and oxygen evolution reaction, respectively. Density functional theory calculations reveal that the electronic structure of Co2P can be tailored effectively via the N-doping effect, with the d-band center shifting to a negative position compared with that at the Fermi level, leading to optimized adsorption interaction with hydrogen evolution reaction (HER)/oxygen evolution reaction (OER) intermediates. Furthermore, a stable solar-to-hydrogen conversion efficiency of 17.9% is achieved with a solar-driven water splitting electrolyzer.