(286b) A Coating Strategy for Stable H2 Production from Semiconductor Particles

Efficient semiconductors have been updating the records of photoelectrochemical (PEC) solar-to-hydrogen (STH) conversion efficiencies, owing to the recent breakthrough in protective coatings. The solar energy can be directly stored in hydrogen. I will introduce photocatalytic particles suspended in water or sprayed onto a panel: those particles coevolving two chemicals at their surfaces—the fabrication for these coevolution photocatalysts promising solar conversion at scale. However, the design principles for reaching 25% STH efficiency limit have been elusive. Based on our holistic understanding of the photophysical, electrocatalytic, and transport processes coupled at the nanoscale, we employ a stabilization coating to coevolve H₂ at a record rate of 48.5 mmol∙h^-1∙g^-1 or 2.5 mL H₂∙h^-1∙cm^-2 under 1-sun solar illumination. We also discuss strategies to (1) produce electrochemically pressurized H₂, (2) to design two types of coated particles for z-scheme water splitting, and (3) to achieve H₂/O₂ separation without the generation of explosive mixtures. The PEC hydrogen as an energy carrier can produce electricity or heat, desirable for the urgently needed long-duration renewable energy storage.