CO₂ Adsorption-Mediated Oxygen Defects for Photothermal Catalysis Self-Decomposition over Low-Crystalline Nb₂O₅ Nanoribbons

Abstract

The direct decomposition of CO 2 to produce CO and O 2 requires extremely high temperatures in catalysis. Here, we proposed the photoassisted oxygen vacancy active sites for CO 2 dissociation to lower the reaction temperature. The designed low-crystalline Nb 2 O 5 nanoribbons (LC-Nb 2 O 5 NRs) showed a good CO production rate under mild conditions (≤250 °C) with Xe lamp irradiation. Under light irradiation, the rate of CO yields of LC-Nb 2 O 5 NRs increased to 68 μmol g –1 h –1 at 250 °C, with no activity at all under light conditions. The high activity arose from unsaturated coordination with low crystallinity and CO 2 reactants as an electron donor for forming an electron cycle with the Nb 2 O 5 NRs, which played a key role in the generation of oxygen vacancies for the subsequent photoexcited electron transfer process at mild temperatures. The feasibility of this approach is further verified over Nb 2 O 5 /C nanofibers that make full use of photothermal and photoelectric effects to achieve long-term stable CO 2 decomposition.