Construction of ZIF-67/MIL-88(Fe, Ni) catalysts as a novel platform for efficient overall water splitting

• Published in: International journal of hydrogen energy Vol. 48; no. 20; pp. 7170 - 7180
• Main Authors: Chen, Pinghua, Duan, Xueqing, Li, Guifang, Qiu, Xianhua, Wang, Shuai, Huang, Yiping, Stavitskaya, Anna, Jiang, Hualin
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 05.03.2023
• Subjects: Composite; Electrocatalysts; MIL-88(Fe, Ni); Overall water splitting; ZIF-67; Overall water splitting; MIL-88(Fe, Ni); Composite; Electrocatalysts; ZIF-67
• ISSN: 0360-3199; 1879-3487
• DOI: 10.1016/j.ijhydene.2022.11.080

Constructing bifunctional non-precious metal electrocatalysts is necessary for effective overall water splitting (OWS), but challenging. Herein, a novel hybrid nanostructure of ZIF-67/MIL-88(Fe, Ni), denoted as Co-M-Fe/Ni(x) (x represents the mass of ZIF-67), was successfully synthesized by hydrothermal and in-situ growth method, and showed a highly efficient and stable bifunctionality of both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in alkaline electrolyte. The Co-M-Fe/Ni(150) exhibited excellent OER performance with a low overpotential of 269 mV and 149 mV @ 10 mA cm−2 for OER and HER in 1 mol L−1 KOH, respectively. With Co-M-Fe/Ni(150) as cathode and anode, the integrated OWS device had achieved low potential of 1.52 V @ 10 mA cm−2, exhibiting its excellent performance of OWS. Based on the results of experiments, ZIF-67 and MIL-88(Fe, Ni), as metal-organic frameworks (MOFs), which have a large specific surface area, uniform distribution of porous structures facilitates charge transmission, promoting the penetration of electrolytes, and improves electron transfer rate. The mechanism of the superior electrocatalytic performance of Co-M-Fe/Ni(150) may be attributed to the synergy of ZIF-67 and MIL-88(Fe, Ni). This work provides guidance for the rational design or optimization of non-noble composites for energy conversion. [Display omitted] •A hybrid nanostructure of Co-M-Fe/Ni(150) was synthesized by a simple method.•The unique construction facilitates the contact of the electrodes and electrolyte.•The catalyst exhibits high HER and OER activity in alkline with low overpotential.•Co-M-Fe/Ni(150) exhibits excellent performance in OWS with a low total potentials.