Highly Efficient and Selective Photothermal Catalytic CO2 Reduction to CH4 Using the CoNi Bimetallic-Modified Gd2O3&Co3O4 Nanocomposite

With the increase of CO₂ in the atmosphere, how to convert CO₂ into fuel has become a research hotspot. Photothermal catalysis is a quite promising method to obtain CH₄ via the Sabatier reaction. In this context, it is urgent to design efficient catalysts to improve the conversion and selectivity of aqueous CO₂ to CH₄. In this work, the CoNi/(Gd₂O₃&Co₃O₄) nanocomposite was fabricated via calcination and chemical deposition methods. Compared with Gd₂O₃ and Co₃O₄, 80%-CoNi/(Gd₂O₃&Co₃O₄) shows an enhancement of photothermal catalytic CH₄ evolution rate (4.19 mmol g^–1 h^–1) and high selectivity for CH₄ (98.6%). In addition, this sample also possesses outstanding durable and cyclic catalytic stability. Combined with systematic analysis, it was found that the excellent catalytic performance of 80%-CoNi/(Gd₂O₃&Co₃O₄) can be attributed to two main reasons: (i) the dual-heterostructure formation of the P–N and Schottky junction endows the catalyst with high charge separation efficiency and (ii) the catalyst presents preeminent CO₂ adsorption and redox capacities, which greatly improves its catalytic activity. This study has significant advantages for the resource utilization of CO₂ and the sustainable utilization of catalysts.