Entrapping Ru nanoparticles into TiO2 nanotube: Insight into the confinement synergy on boosting pho-thermal CO2 methanation activity

CO2 methanation is a significant route to decrease carbon emission as well as realize carbon neutrality and has gained considerable concerns from experts in the environment and energy field currently. Herein, highly dispersed ruthenium nanoparticles entrapped in TiO2 nanotubes, labeled as Ru-in/TNT, were constructed and adopted for photo-thermal driven CO2 methanation. The Ru nanoparticles confined in the nanotube exhibited an enhanced CO2 methanation activity, especially under light irradiation. Multiple characterization techniques (XRD, XPS, UV-vis DRS, HRTEM, Raman, etc.) were conducted to reveal the effect of confinement synergy on photo-thermal catalytic performance. A boosted photo-generated electron-hole separation efficiency is achieved as a result of the confinement effect, yielding more hot electrons to accelerate methanation activity. This photo-assisted confinement synergy can be expected for constructing an efficient photo-thermal catalytic system.