Synthesis of nanometer-sized WO 3 particles by facile wet process and their photocatalytic properties

Abstract

Nanometer-sized WO 3 particles were prepared from alkaline alcohol-water mixture with WCI 6 and NH 3 under reflux. The resultant particles at various NH 3 /W mole ratios were well crystallized ranging 5-20nm in diameter and the surface area was in the range of 13.70-32.50 m 2 g -1. Samples synthesized at NH 3 /W = 3.2 and 12.9 ratio (mol/mol) had an absorption edge in the visible light range and showed the photocatalytic activity under the irradiation of visible light, and the surface area and the crystallinity of those powders had a strong effect on the photocatalytic degradation. When ln(C 0 /C)(C 0: initial concentration of acetaldehyde, C: final concentration of acetaldehyde after irradiation) was plotted against photoirradiation time, the degradation velocity constant (k) against acetaldehyde estimated from the slope of lines was 12.4 h -1 g -1 at NH 3 /W = 3.2 and 13.9 h -1 g -1 at NH 3 /W = 12.9 ratio (mol/mol), respectively.