In-situ phosphating Co@Nitrogen-doping graphene boosts overall water splitting under alkaline condition

• Published in: Journal of electroanalytical chemistry (Lausanne, Switzerland) Vol. 904; p. 115882
• Main Authors: Sun, Dongfeng, Lin, Songmin, Yu, Yuan, Meng, Fangyou, Du, Gaohui, Xu, Bingshe
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.01.2022; Elsevier Science Ltd
• Subjects: Alkaline medium; Catalysts; Cobalt; Doping; Electrocatalysts; Full water splitting; Graphene; Nanoparticles; Nitrogen; Noble metals; Oxygen evolution reactions; Phosphating (coating); Phosphide; Phosphides; Water splitting; Wettability; Nanoparticles; Alkaline medium; Full water splitting; Electrocatalysts; Phosphide
• ISSN: 1572-6657; 1873-2569
• DOI: 10.1016/j.jelechem.2021.115882

[Display omitted] •3D porous structure CoP@N,PC was prepared by a one-step pyrolysis method.•The N and P-doped carbon matrix improved the conductivity and also enhanced active sites.•The 3D porous structure offered more permeability to electrolyte and facilitated ions transport.•CoP@N,PC exhibits excellent HER and OER activity and stability in alkaline media. It is still challenging to design and synthesize highly efficient and noble-metal-free electrocatalysts for hydrogen/oxygen evolution reaction (HER/OER). Herein, we developed an in-situ phosphating Co@nitrogen-doping graphene to obtain N and P co-doped carbon-coated cobalt phosphide (CoP@N,PC) that could be used for overall water splitting. The unique 3D porous structure of CoP@N,PC is characterized by a large number of active catalytic sites. High wettability of catalyst in electrolyte solution facilitates the transfer of ions. The synergism between the CoP cores and N, PC shells improves the total hydrolysis performance of the electrocatalyst during the HER and OER. At the current densities of 10 mA/cm2 (1 M of KOH), the HER overpotential recorded for the CoP@N,PC is 113 mV, and the OER overpotential is 320 mV. The cell voltage of the CoP@N,PC as bifunctional electrode for overall water splitting is 1.67 V (at 10 mA/cm2), which is close to that of the full noble-metal electrode (RuO2 || Pt/C, 1.58 V). The CoP@N, PC bifunctional catalyst can be potentially used to replace noble-metal electrodes to realize water splitting.