Nitrogen and phosphorus Co-doped non stoichiometric cobalt selenides (Co0.85Se) ultrathin nanosheets as highly efficient electrocatalysts for the hydrogen evolution reaction

• Published in: Materials chemistry and physics 2022-02, Vol.278, p.125693, Article 125693
• Main Authors: Liang, Wenjing, Gao, Jiajia, Wang, Xinyi, Meng, Xiuyan, Xiong, Shuangsheng, Ji, Kexin, Wang, Xuan, Hou, Li, Chen, Rongna, Gao, Faming
• Format: Article
• Language: English
• Subjects: Catalytic activity; Co-doping; Cobalt; Cobalt selenide; Electrocatalysts; Hydrogen evolution reaction; Hydrogen evolution reactions; Nanosheets; Nitrogen; Phosphorus; Selenides; Stoichiometry
• ISSN: 0254-0584; 1879-3312
• DOI: 10.1016/j.matchemphys.2021.125693

Two-dimensional (2D) non-stoichiometric cobalt selenide (Co0.85Se) has the specific electrochemical performances of exposing more active sites and the high conductivity, which makes it a unique advantage as promising candidates for hydrogen evolution reaction (HER). Hence, we used the one-step hydrothermal method to synthesize nitrogen-phosphorus co-doped Co0.85Se (N,P–Co0.85Se) ultrathin nanosheets for catalyzing HER. Due to the co-doping of N and P, more active sites were generated, thus making N,P–Co0.85Se ultrathin nanosheets have excellent HER performance. The LSV test results in 1 M KOH showed that the overpotential of N,P–Co0.85Se ultrathin nanosheets was 210 mV under the current density of 10 mA cm−2, 130 mV lower than that of the un-doped Co0.85Se nanosheets (340 mV). The N,P–Co0.85Se ultrathin nanosheets also had excellent stability that the overpotential merely increased by 12 mV after 1000 cycles, much lower than that of the un-doped Co0.85Se nanosheets (48 mV). This one-step hydrothermal method can provide an efficient and facile idea for fabrication of various co-doped metal selenide nanocatalysts with high electrocatalytic performance. •Develop nitrogen and phosphorus co-doped Co0.85Se ultrathin nanosheet catalysts via a gentle one-pot method.•Synergistic effect of N and P co-doping improves the HER performance of the catalyst.•N,P–Co0.85Se ultrathin nanosheets exhibit high catalytic activity and excellent stability.•Significant potential in poly-atoms doping material design.