Highly active Ni/Co-metal organic framework bifunctional electrocatalyst for water splitting reaction

• Published in: International journal of hydrogen energy Vol. 47; no. 54; pp. 22787 - 22795
• Main Authors: Van Phuc, Tran, Jana, Jayasmita, Ravi, Nivetha, Kang, Sung Gu, Chung, Jin Suk, Choi, Won Mook, Hur, Seung Hyun
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 29-06-2022
• Subjects: Electrocatalyst; HER; Metal-organic framework (MOF); OER; Water splitting; Electrocatalyst; Water splitting; HER; Metal-organic framework (MOF); OER
• ISSN: 0360-3199; 1879-3487
• DOI: 10.1016/j.ijhydene.2022.05.097

Rational design of electrocatalycally active materials with excellent performance for renewable energy conversion is of great interest. We have developed a nanosheet array of Ni/Co metal-organic framework (MOF) grown on CoO modified Ni foam (CoO/NF) substrate via the solvothermal process. The high surface area and low resistance of Ni/Co-MOF@CoO/NF (NC@CoO/NF) catalyst contribute to efficient water splitting. We have prepared a series of NC-n/CoO/NF (n = 1–4) catalysts to optimize the molar ratio of the Co atom in Ni MOF-74. Among them, NC-2@CoO/NF shows an excellent electrochemical performance in alkaline medium, i.e., low overpotential of 290 and 139 mV for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), respectively. For a two-electrode system with NC-2@CoO/NF, a low cell voltage of 1.54 V at 10 mA cm−2 has been obtained for overall water splitting which is much smaller than that with commercial Ir/C– Pt/C pair. This excellent performance can be attributed to the synergistic effects of Ni/Co-MOF and CoO/NF. In addition, the as-prepared NC-2@CoO/NF exhibits excellent long-term stability. The computational simulation also supports experimental results.
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•Highly porous Ni/Co bimetallic MOF were grown on CoO modified Ni Form.•As-synthesized catalysts showed an excellent HER and OER properties.•Computational simulation reveled the synergetic effects of Co on Ni-MOF.