Growth mechanism of immobilized WO3 nanostructures in different solvents and their visible-light photocatalytic performance

Controllable growth of nanostructured tungsten trioxide (WO3) films grown on substrates with good adhesion in a single-step process is still challenging. In this paper, immobilized WO3 nanostructures with different microstructure and morphology were prepared by solvothermal methods in various solvents. X-ray diffraction (XRD), scanning electron microscope (SEM), Transmission Electron Microscopy (TEM), Energy Dispersive Spectroscopy (EDS) and Raman spectra results showed that the type of solvents has a great influence on the microstructure, morphology and elemental component of as-prepared WO3 nanostructures, and their growth process had been analyzed with the vapor pressure and viscosity. The electrochromic studies for the WO3 nanostructures (nano-wire arrays) synthesized in ethanol exhibited low electrochemical impedance spectroscopy (EIS), high peak current density, and efficient electron hole separation efficiency with respect to other products. The nanowire arrays showed the highest photocatalytic performance, and the degradation rate can reach 93.3% in 1 h. It is deduced that the excellent photocatalytic performance was mainly attribute to the efficient charge transfer capability.