Hot Electrons Induced by Localized Surface Plasmon Resonance in Ag/g-CN Schottky Junction for Photothermal Catalytic CO Reduction.

Converting carbon dioxide (CO) into high-value-added chemicals using solar energy is a promising approach to reducing carbon dioxide emissions; however, single photocatalysts suffer from quick the recombination of photogenerated electron-hole pairs and poor photoredox ability. Herein, silver (Ag) nanoparticles featuring with localized surface plasmon resonance (LSPR) are combined with g-CN to form a Schottky junction for photothermal catalytic CO reduction. The Ag/g-CN exhibits higher photocatalytic CO reduction activity under UV-vis light; the CH and CO evolution rates are 10.44 and 88.79 µmol·h·g, respectively. Enhanced photocatalytic CO reduction performances are attributed to efficient hot electron transfer in the Ag/g-CN Schottky junction. LSPR-induced hot electrons from Ag nanoparticles improve the local reaction temperature and promote the separation and transfer of photogenerated electron-hole pairs. The charge carrier transfer route was investigated by in situ irradiated X-ray photoelectron spectroscopy (XPS). The three-dimensional finite-difference time-domain (3D-FDTD) method verified the strong electromagnetic field at the interface between Ag and g-CN. The photothermal catalytic CO reduction pathway of Ag/g-CN was investigated using in situ diffuse reflectance infrared Fourier transform spectra (DRIFTS). This study examines hot electron transfer in the Ag/g-CN Schottky junction and provides a feasible way to design a plasmonic metal/polymer semiconductor Schottky junction for photothermal catalytic CO reduction.