Hetero-interfacial nickel nitride/vanadium oxynitride porous nanosheets as trifunctional electrodes for HER, OER and sodium ion batteries
Tuzhi Xiong, Jingting Li, Jagadish Chandra Roy, Malcolm Koroma, Zhixiao Zhu, Hao Yang, Lei Zhang, Ting Ouyang, Muhammad‐Sadeeq Balogun, Mohammad Al‐Mamun
Abstract
The development of single electrode with multifunctional purposes for electrochemical devices remains a symbolic challenge in recent technology. This work explores interfacially-rich transition metal nitride hybrid that consist of nickel nitride and vanadium oxynitride (VO0.26N0.52) on robust carbon fiber (denoted CF/Ni3N/VON) as trifunctional electrode for hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and sodium ion batteries (SIBs). The as-prepared CF/Ni3N/VON exhibits low HER overpotential of 48 [email protected] mA cm−2, OER overpotential of 287 [email protected] mA cm−2, and sodium-ion anode storage reversible capacity of 555 mA h g−[email protected] C. Theoretical analyses reveal that the Ni3N effectively facilitates hydrogen desorption for HER, increases the electrical conductivity for OER, and promotes the Na-ion storage intercalation process, while the VON substantially elevates the water dissociation kinetics for HER, accelerates the adsorption of OH* intermediate for OER and enhances the Na-ion surface adsorption storage process. Owing to the excellent HER and OER performances of the CF/Ni3N/VON electrode, an overall water splitting device denoted as CF/Ni3N/VON//CF/Ni3N/VON was not only assembled showing an operating voltage of 1.63 V at current density of 10 mA cm−2 but was also successfully self-powered by the assembled CF/Ni3N/VON//CF/Na3V2(PO4)3 flexible sodium ion battery. This work will contribute to the development of efficient and cost-effective flexible integrated electrochemical energy devices.