Photocatalytic NO removal by WO3 samples prepared via a ball milling treatment under different parameters

In this investigation, a series of WO3 samples were achieved by a ball milling treatment under variable synthetic parameters (milling time from 0.5 to 8 h, grinding speed from 100 to 500 rpm, and several solvents as dispersants). These samples were characterized by X-ray diffraction patterns, ultraviolet-visible diffuse reflection spectra, scanning electron microscope, and photoluminescence spectra. It was found that the extension of milling time, increase in grinding speed, and suitable dispersant favored the reduced particles size and crystallinity, and enlarged band gap energies, thus benefiting the separation of charge carriers and photocatalytic removal of NO under visible light. Under the suitable condition, the best prepared candidate could removal NO molecules about 45% upon visible light irradiation. Eventually, the good conservation of photocatalytic performance and structural stability identified the robust nature of prepared samples, and a possible photocatalysis mechanism was proposed.