UC Irvine

Solar-driven photocatalytic conversion of CO₂ into fuels has attracted a lot of interest; however, developing active catalysts that can selectively convert CO₂ to fuels with desirable reaction products remains a grand challenge. For instance, complete suppression of the competing H₂ evolution during photocatalytic CO₂-to-CO conversion has not been achieved before. We design and synthesize a spongy nickel-organic heterogeneous photocatalyst via a photochemical route. The catalyst has a crystalline network architecture with a high concentration of defects. It is highly active in converting CO₂ to CO, with a production rate of ~1.6 × 10⁴ μmol hour^-1 g^-1. No measurable H₂ is generated during the reaction, leading to nearly 100% selective CO production over H₂ evolution. When the spongy Ni-organic catalyst is enriched with Rh or Ag nanocrystals, the controlled photocatalytic CO₂ reduction reactions generate formic acid and acetic acid. Achieving such a spongy nickel-organic photocatalyst is a critical step toward practical production of high-value multicarbon fuels using solar energy.