Molecular hybrid photocatalysts for selective solar H2 and material generation from real life wastes

Solar waste photoreforming is a process that generates valuable H2 fuel and chemicals from discarded waste and water using abundant sunlight, providing solutions to many global challenges including waste management, clean fuel generation, and material production. Despite the potential, current state-of-the-art photoreforming processes suffer from major deficiencies including the use of highly basic medium and nonselective product generation that preclude their large-scale implementation. The "Waste2Fuel" proposal seeks to address these deficiencies by employing hybrid photocatalysts, with molecular oxidation catalysts anchored onto photocatalyst surfaces, to carry out selective waste photoreforming under benign conditions. Inspiration to such an approach comes from the recent success in selective CO2 photoreduction with similar hybrid strategy. Among different objectives, molecular catalysts will be first immobilized onto anodes by covalent bond, and conditions will be optimized to obtain selective electrochemical waste oxidation under aqueous conditions by surface-bound catalysts. The molecular catalysts will then be grafted onto photocatalysts to get hybrid photoanodes, which will be subsequently employed for selective solar waste photoreforming. We surmise that during photoreforming, initial hole transfer from photocatalyst to the anchored molecular catalyst will take place, with the latter oxidizing waste substrates in turn, giving high efficiency and product selectivity as is generally observed with molecular complexes. Our final objective is to develop a scalable 10.10 cm2 panel with surface deposited hybrid catalyst for large-scale solar photoreforming, demonstrating its applicability. Successful completion of the research would enable commercialization of the waste photoreforming process, contributing towards the sustainable production of fuel and materials, while at the same time, recycling the generating wastes of our society.