Unveiling the facet-dependent electrocatalytic activity of a 3D-CoSn(OH)₆ perovskite material for overall water splitting: Interfacial engineering with Mn³⁺ and CH₃COO^- ions

In this study, we report morphologically dependent electrocatalytic oxygen and hydrogen evolution reactions in an alkaline medium. The bifunctional electrocatalyst such as cobalt tin hydroxide (CoSn(OH)₆) was prepared by hydrothermal method. Importantly, tuning the morphological variation of CoSn(OH)₆ into cubes, octa- and dodecahedra and their corresponding growth mechanisms are analyzed and explored the electrochemical studies. Among the different morphologies, the CoSn(OH)₆ dodecahedron (CTH-DH) displays a substantially enhanced overall electrocatalytic water splitting reaction. It is firmly due to the [Mn³⁺] and [CH₃COO^-] ions do enable the morphological progression of the CTH cubic crystals with more facets. The highly active catalytic sites on the facets of CTH-DH permit the adsorption of abundant OH groups during the hydrogen and oxygen evolution reactions. Moreover, in a two-electrode system, the CTH-DH ǁ CTH-DH electrolyzer exhibits a cell potential of 1.60 V at 10 mA cm^–2 with a remarkable reliable long-term stability. In addition, the structural transformations of the as-prepared CoSn(OH)₆ crystals are monitored before and after electrocatalysis using TEM study. As a result, the study highlights the potential of Mn-containing CTH-DH facets as viable electrocatalysts in efficient H₂ production.