A novel nickel-based honeycomb electrode with microtapered holes and abundant multivacancies for highly efficient overall water splitting

• Published in: Applied catalysis. B, Environmental Environmental, 2020-11, Vol.276, p.119141, Article 119141
• Main Authors: Zhang, Fan, Ji, Renjie, Liu, Yonghong, Pan, Yuan, Cai, Baoping, Li, Zhijian, Liu, Zheng, Lu, Shuaichen, Wang, Yating, Jin, Hui, Ma, Chi, Wu, Xinlei
• Format: Article
• Language: English
• Subjects: Electrodes; Honeycomb electrode; Honeycomb structures; Hydrogen production; Hydrogen-based energy; Microtapered holes; Multiple vacancies; Nickel; Phosphorization; Splitting; Water splitting
• ISSN: 0926-3373; 1873-3883
• DOI: 10.1016/j.apcatb.2020.119141

A novel self-supported nickel-based honeycomb electrode with microtapered holes (NHEMH) is firstly synthesized through a fast electrodeposition method with a high current density. P-doped NHEMH with heterogeneous Ni2P/NiO decorated with multiple vacancies exhibits the outstanding overall water splitting performance in alkaline medium as an alkali-electrolyzer. [Display omitted] •We firstly synthesize a novel nickel-based honeycomb electrode with microtapered holes (NHEMH) through fast electrodeposition method.•The 3D network electrode assembly with abundant microtapered holes vastly improves the electrolyte/active material contact areas.•PNHEMH delivers a lower overvoltage of 1.52 V at 10 mA/cm2 with 12 h durability.•PNHEMH with heterostructure decorated with multiple vacancies can optimize the adsorption free energy of intermediate by DFT analysis. Hydrogen production is the key to the development and utilization of hydrogen energy. In this paper, we find a new phenomenon in which abundant and uniform bubbles evolve and quickly release during water splitting on the surface of a nickel-based honeycomb electrode with microtapered holes (NHEMH). Benefiting from the unique microtapered hole honeycomb structure, the solution circulation on the surface of NHEMH is accelerated, thus generating a dynamically stabilized reactive interface and improving the ionic/mass exchange. Meanwhile, the unique honeycomb skeleton has good hydrophilicity and aerophobic properties. Furthermore, NHEMH with a large surface area, rich multi-vacancies, and highly conductive nickel metal exhibits an outstanding electrocatalytic ability. P-doped NHEMH (PNHEMH) with the Ni2P/NiO heterointerface decorated by multivacancies, when used as an electrolyzer for overall water splitting, requires only 1.52 V to produce a current density of 10 mA/cm2, which is much better than the performance of benchmark Pt/C//IrO2 electrodes.