Controlled synthesis of Au@TiO2 mesoporous hollow nanofibers by one-step polyethylenimine-regulated electrospinning method for efficiently photocatalytic oxidation of CO

Abstract

TiO2 mesoporous hollow nanofibers with excellent mass diffusion is an attractive photocatalytic material to remove toxic gaseous pollutants like CO, while it is highly desired to improve the photogenerated charge separation and O2 activation. Herein, the Au nanoparticles inner-loaded TiO2 mesoporous hollow nanofibers (Au@TO MPHNFs) have been controllably fabricated by one-step coaxial electrospinning, in which it is crucial to use polyethyleneimine as porogen and stabilizer for mesoporous and TiO2 in nanofibers shell. Concurrently, a stepwise phase transfer technique is employed to realize the uniform and stable dispersion of the Au in the paraffin oil as core precursor. The Au@TO MPHNFs exhibits 2.7 and 7.4-fold CO photooxidation enhancement compared with commercial P25 and TO MPHNFs, respectively. The enhanced photoactivity can be attributed to the creation of the mesoporous hollow structure for facilitating better mass transportation, and the incorporation of Au nanoparticles for efficient charge separation and O2 activation. Meanwhile, the photothermal effect of Au expedites intermediaries transformation and product desorption.