One-pot synthesis of N and P Co-doped carbon layer stabilized cobalt-doped MoP 3D porous structure for enhanced overall water splitting

• Published in: Journal of alloys and compounds 2022-02, Vol.895, p.162595, Article 162595
• Main Authors: Sun, Dongfeng, Lin, Songmin, Yu, Yuan, Liu, Shengwei, Meng, Fangyou, Du, Gaohui, Xu, Bingshe
• Format: Article
• Language: English
• Subjects: Alkaline medium; Carbon; Catalytic activity; Cobalt; Electrical resistivity; Electrocatalysts; Full water splitting; Hydrogen evolution reactions; Hydrogen production; Nanoparticles; Noble metals; Oxygen evolution reactions; Phosphides; Transition metals; Water splitting
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2021.162595

•3D porous structure CoMoP@N,P-C was prepared by a one-step pyrolysis method.•N and P-doped carbon matrix improved the conductivity and active sites.•Cobalt doping regulates the electronic structure of MoP.•3D porous structure offered more permeability to electrolyte and ions transport.•CoMoP@N,P-C exhibits excellent HER and OER activity and stability in alkaline media. [Display omitted] Transition metal phosphides are novel electrocatalysts that can be used to replace noble metals for the electrochemical production of hydrogen. In this work, N and P co-doped carbon-coated cobalt-doped molybdenum phosphide (CoMoP@N,P-C) nanoparticles are explored as electrocatalyst for overall water splitting. The presence of a unique three-dimensional (3D) porous structure in CoMoP@N,P-C offers abundant catalytic active sites for the penetration of the electrolyte solution, thereby facilitating the transfer of ions. In addition, cobalt doped into MoP increases the catalytic activity, and N and P co-doped carbon improves the electrical conductivity of the carbon matrix. Subsequently, the synergy between CoMoP cores and N, P-C shells enhances the total hydrolysis performance of the electrocatalyst in hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) processes. At a current density of 10 mA/cm2 in 1 M KOH, HER and OER overpotential of the CoMoP@N, P-C are 152 mV and 296 mV, respectively. Moreover, the cell voltage of CoMoP@N, P-C as a bifunctional electrode for overall water splitting is 1.62 V (at 10 mA/cm2), which is close to that of the full noble-metal electrode (RuO2 || Pt/C, 1.58 V). Overall, the CoMoP@N, P-C bifunctional catalyst shows great potential for replacing noble-metal electrodes in water splitting applications.