(150c) Sustainable Electrocatalytic Water Splitting with Earth-Abundant Materials

Water splitting has potential for sustainable solar energy storage in the form of fuels and organic materials. Its practical use requires highly effective electrocatalysts synthesized from earth-abundant materials such as manganese and nickel. We have developed a synthesis method for manganese-based (MnO_x) catalytic films in situ, with steady and excellent water oxidation performance¹. The method involves two series of cyclic voltammetry (CV) over different potential ranges, followed by calcination to increase crystallinity. We have incorporated the catalysts into TiO₂ to build a composite photoanode with excellent activity under ultraviolet (UV) illumination, with current work focused on improving performance by enabling solar energy collection over a wider range of wavelengths. We have also developed an electrodeposition method to synthesize Ni/Ni(OH)₂ electrocatalysts in situ on conductive surfaces for the hydrogen evolution reaction². The new method uses two cycles of CV over a single potential range, producing a film with a large number of Ni(OH)₂/Ni interfaces that significantly shifts performance towards that of platinum.

1. H Yuan, RR Lunt, GJ. Blanchard, and RY Ofoli. Synthesis of MnO_x water oxidation catalyst on fluorine-doped tin oxide with a dual-series cyclic voltammetry method, ChemElectroChem, 3(5): 709-712 (2016).
2. H Yuan, R.R Lunt, JI Thompson, and RY Ofoli Electrodeposition of Ni/Ni(OH)₂ Catalytic films for the hydrogen evolution reaction produced by using cyclic voltammetry. ChemElectroChem, DOI: 10.1002/celc.201600572 (2016)