SnO2 tetragonal nanonails with enhanced optical and photoelectric performances via localized surface plasmon resonance effect of Au nanoparticles

Abstract

Enhanced optical and photoelectric characteristics of semiconductors via Localized Surface Plasma Resonance (LSPR) effect strategy has drawn extensive attentions and researches in the fields of semiconductor industry. Specially, Au/SnO2 tetragonal nanonails (TNs) Schottky heterojunctions have been innovatively synthesized by modified CVD and hydrothermal methods. Au/SnO2 TNs Schottky heterojunction fabricated at the volume ratio of 0.5/45 HAuCl4/Water (0.5 Au/SO) exhibits the remarkable photocurrent density about of 52.8 μA cm−2 at 0.5 V vs. Ag/AgCl, which is about of 1.5 and 1.2 times than that of SO-550 (36.4 μA cm−2) and 0.7 Au/SO (44.8 μA cm−2) photoelectrodes, respectively. Optical absorption properties of all Au/SnO2 TNs Schottky heterojunctions have obviously improved in ultraviolet–visible regions due to the strong LSPR effect of Au nanoparticles (NPs). Au NPs also act as photosensitizers, which can generate more high-energy active electrons by LSPR excitation and then inject into CB of SnO2 TNs photoelectrode. This process can effectively enhance separation and transportation efficiencies of photogenerated charge carriers, further improving photoelectric performances of Au/SnO2 TNs Schottky heterojunctions. This work can provide novel strategies to synthesize one-dimensional metallic oxide photoelectrodes and Schottky heterojunctions, and further laying the foundation for exploring the interface/surface novel effects of heterojunctions at the applications of catalysis, sensors or detection fields.