A nonmetallic plasmonic catalyst for photothermal CO2 flow conversion with high activity, selectivity and durability

The meticulous design of active sites and light absorbers holds the key to the development of high-performance photothermal catalysts for CO₂ hydrogenation. Here, we report a nonmetallic plasmonic catalyst of Mo₂N/MoO₂-x nanosheets by integrating a localized surface plasmon resonance effect with two distinct types of active sites for CO₂ hydrogenation. Leveraging the synergism of dual active sites, H₂ and CO₂ molecules can be simultaneously adsorbed and activated on N atom and O vacancy, respectively. Meanwhile, the plasmonic effect of this noble-metal-free catalyst signifies its promising ability to convert photon energy into localized heat. Consequently, Mo₂N/MoO₂-x nanosheets exhibit remarkable photothermal catalytic performance in reverse water-gas shift reaction. Under continuous full-spectrum light irradiation (3 W·cm^-2) for a duration of 168 h, the nanosheets achieve a CO yield rate of 355 mmol·gcat^-1·h^-1 in a flow reactor with a selectivity exceeding 99%. This work offers valuable insights into the precise design of noble-metal-free active sites and the development of plasmonic catalysts for reducing carbon footprints.