Boosting Photocatalytic CO₂ Methanation through Interface Fusion over CdS Quantum Dot Aerogels

In the field of photocatalytic CO₂ reduction, quantum dot (QD) assemblies have emerged as promising candidate photocatalysts due to their superior light absorption and better substrate adsorption. However, the poor contacts within QD assemblies lead to low interfacial charge transfer efficiency, making QD assemblies suffer from unsatisfactory photocatalytic performance. Herein, a novel approach is presented involving the construction of strongly interfacial fused CdS QD assemblies (CdS QD gel) for CO₂ reduction. The novel CdS QD gel demonstrates outstanding photocatalytic performance for CO₂ methanation, achieving a CH₄ generation rate of ≈296 µmol g^-1 h^-1, with a selectivity surpassing 76% and an apparent quantum yield (AQY) of 1.4%. Further investigations reveal that the robust interfacial fusion in these CdS QDs not only boosts their ability to absorb visible light but also significantly promotes charge separation. The present work paves the way for utilizing QD gel photocatalysts in realizing efficient CO₂ reduction and highlights the critical role of interfacial engineering in photocatalysts.