Synthesis of Ag/Carbon quantum Dots/TiO2 nanotubes for efficient photocatalytic degradation and CO2 reduction

Photocatalytic reduction of CO 2 into chemical fuels under visible light has garnered increasing attention. Herein, we designed silver nanoparticle (Ag NPs)/carbon quantum dot (CQDs)/TiO 2 nanotubes (TNTs) nanocomposites via a hydrothermal process combined with an in-situ photod-eposition method. Results of methylene blue photodegradation tests under visible light demonstrated that Ag/CQDs/TNTs exhibited higher photocatalytic efficiency than pristine TNTs. In addition, in the carbon dioxide photoreduction experiment, the optimized Ag/CQDs/TNTs has a photocatalytic yield of 38.33 µmol g -1 h -1 when carbon dioxide is converted into carbon monoxide, which is 5.3 times that of pure TNTs. Detailed experimental characterizations revealed that the enhanced photocatalytic performance of Ag/CQDs/TNTs stemmed from the surface plasmon resonance effect of Ag NPs and the excellent optoelectronic properties of CQDs. This work offers insights for fabricating ternary catalysts for photocatalytic CO 2 reduction.