Plasmonic Ag-decorated GaN for efficient photothermal CO2 conversion

The development of photocatalysts for efficient CO 2 conversion to chemicals especially C 2+ products remains a challenge. In this work, Ag nanoparticles (NPs) decorated GaN photocatalysts were synthesized by in-situ nitridation of Ga 2 O 3 combined with chemical deposition of Ag. The photocatalytic performance of Ag/GaN photocatalysts was optimized by tuning the loading amount and ripening time of Ag NPs, among which 0.3Ag/GaN exhibited best photocatalytic CO 2 reduction performance. The production rates of CO and CH 4 reached 421 and 80 μmol g −1 h −1 , respectively, and especially, it also produced C 2 H 6 with a production rate of 79 μmol g −1 h −1 . The introduction of Ag NPs not only significantly promotes visible light absorption as well as charge generation and separation, but also elevates surface temperature of the photocatalyst due to photothermal effect, resulting from localized surface plasmon resonance (LSPR) effect of Ag NPs. Moreover, the addition of Ag NPs enhances the adsorption of both CO 2 and the *CO intermediate, facilitating the CO 2 activation and subsequent C−C coupling process. This study provides new ideas for the design and preparation of photocatalysts capable of converting CO 2 into value-added chemicals.