Plasmon-Enhanced Self-Powered UV Photodetectors Assembled by Incorporating Ag@SiO2 Core–Shell Nanoparticles into TiO2 Nanocube Photoanodes

A novel photoelectrochemical self-powered ultraviolet photodetector (UVPD) has been assembled employing Ag@SiO2 core–shell nanoparticles (NPs) incorporated TiO2 nanocubes (NCs) as the photoanode. The incorporation of the plasmonic core–shell NPs can boost the photocurrent of the self-powered UVPD. Finite difference time domain (FDTD) and transient absorption spectroscopy (TAS) were employed to understand plasmonic enhancement processes. By optimizing the incorporated ratio of Ag@SiO2 NPs, the photocurrent of UVPD with 2 wt % Ag@SiO2 NPs reaches the maximum value in view of the enhanced light harvesting and effective inhibition of charge recombination. More importantly, the UVPD with 2 wt % Ag@SiO2 NPs achieves a high on/off ratio of 8212 and a remarkable responsivity of 0.151 A W–1, combined with a rapid response time, prominent spectral selectivity, and photosensitivity linearity response.