Nanostructured transition metal compound derived from 2d mof for h2 production by electrolysis of alkaline and urea based water

Abstract

The production of hydrogen through water splitting using renewable and clean energy sources is a promising green alternative that serves as a sustainable and environmentally friendly energy carrier. However, its newlinewidespread adoption is hindered by cost-intensive manufacturing, primarily due to the reliance on platinum-group metal (PGM) electrocatalysts, which are essential for driving inherently sluggish water-splitting reactions. Costeffective Metal-organic frameworks (MOFs) based on transition metals have emerged as better alternatives owing to their improved surface area, porosity, newlineand tunability. This study focuses on the design of economically viable and robust MOF-based electrocatalysts comparable to PGMs for water and urea electrolysis. In the first study, the CoPBO/Co3O4 composite derived from MOF was investigated, demonstrating bifunctionality towards overall water splitting. The synthesis involved a solvothermal method to prepare Co-MOF, followed by pyrolysis in the air to form Co3O4 and subsequent chemical reduction to newlineform a composite. The optimized electrocatalyst showed the formation of an newlineamorphous CoPBO phase and crystalline Co3O4 phase and exhibited low overpotentials of 270 mV for Oxygen evolution reaction (OER) and 67 mV for Hydrogen evolution reaction (HER) at a current density of 10 mA/cm2, in 1 M KOH. Electrochemical and physiochemical characterizations, along with kinetic studies, confirmed that the hydrogen spillover (HS) from CoPBO to Co3O4 contributed to enhanced HER activity, while the oxygen vacancies (Ov) formed in CoPBO/Co3O4 composite played a key role in improving OER performance. In a two-electrode configuration, the same current density was newlineachieved at 1.56 V, which is comparable to the Pt/C||RuO2 system. The electrocatalyst demonstrated high robustness, with 1000 cycles of recyclability and 15 hrs of operational stability. The second research work focused on introducing conducting carbon in the above composite to enhance the efficiency of water splitting.