Solar-powered catalyst converts CO₂ and biowaste into valuable chemicals in tandem

Scientists at the University of Nottingham have developed a solar-powered catalytic system capable of converting carbon dioxide (CO₂) and biowaste into valuable chemicals simultaneously using the energy from a single photon of light. The technology, described in the journal Communications Materials, could help address two major environmental challenges simultaneously: greenhouse gas emissions and the utilization of biomass waste.

The system uses a bias-free photoelectrochemical (PEC) reactor comprising two interconnected chambers equipped with newly designed catalysts. When sunlight strikes one compartment, a biomass-derived molecule undergoes oxidation, releasing an electron that travels to the second chamber, where it reduces CO₂ into formate—a chemical used in textiles, paints, and pharmaceuticals. At the same time, the biomass reaction produces compounds that can serve as precursors for sustainable plastics. Researchers reported conversion efficiencies of approximately 93% for CO₂-to-formate production and about 95% for biomass oxidation, with the process requiring no external electricity or heat.

The catalysts are composed of earth-abundant materials, including carbon nitride, tungsten oxide, and cobalt oxide, avoiding the use of costly precious metals commonly employed in catalytic systems. According to the research team, life cycle analysis confirmed the technology’s environmental benefits, while the modular reactor design could eventually be integrated with industrial CO₂ sources and agricultural biorefineries to enable decentralized chemical manufacturing. The researchers said the approach builds on earlier work on atomically engineered catalysts for hydrogen production and CO₂ conversion and could help advance net-zero emissions targets.

Source: Communications Materials