Confinement effect of carbon fibres@TiO2 Schottky heterojunctions for Ag-plasmonic photocatalysis with switchable hot/photo electrons

Here, a novel dimension for exploitation of hot electron transport model was presented, which with respect to the formation of Schottky heterojunctions by bridging anatase-TiO2 (anatase) through Ag-carbonized cellulose nanofibers (Ag-C-CNFs) with a diameter of sub-5 nm. The plasmonic metal Ag nanoparticles with a specific structure rapidly transfer one hot electron generated by surface plasmon to anatase by means of 1D pathways to realize carrier separation. The confinement effect of Schottky heterojunctions on hot electron transport is served as a decisive strategy to achieve efficient photocatalytic oxidation and reduction, which is confirmed by modern instrument characterization and theoretical calculations. The product anatase-loaded Ag-C-CNFs (ACCA) can perform autonomous switching of one/two electron migration mechanism under photovoltaic irradiation with different wavelengths, which will undoubtedly broaden the development prospect of ACCA. The reduction efficiency of Cr(VI) by ACCA under the photovoltaic irradiation whose wavelength is 400 nm is 4.7 times higher than that under the UV irradiation. Simultaneously, the high-value utilization of lignin can be promoted by ACCA through breaking the β-O-4 linkages in the lignin model, and the yield of the product can reach more than 90%. Simultaneously, ACCA has a significant mineralizing effect on the residual antimicrobial agents in the water. This work provides a new paradigm for green energy conversion, proposes a new approach to forge Schottky barriers between plasma metals and semiconductors and prepares novel switchable wavelength-selective photocatalysts, through a comprehensive analysis and understanding of the generation and transport of hot electrons, the mechanism of electron migration, and the separation efficiency of carriers.