Synthesis of hollow carbon-W18O49 composite and its photocatalytic properties

Abstract

Composites of carbon and W18O49 were successfully synthesized by heating the mixtures of WO3 and urea at a temperature between 600 and 800 degrees C in inert atmosphere. The obtained materials were characterized by XRD, SEM, TEM, Raman, XPS, TG-DTA and N-2 adsorption/desorption at 77 K. The results showed that the composites consisted of W18O49 as a main phase which was coated by a thin carbon layer and exhibited a change in shape with heating temperature. The hollow form appeared from the treatment temperature of 700 degrees C and remained till 900 degrees C. However, at treatment 900 degrees C, the W18O49 disappeared and WO2 formed instead. The adsorption and visible-light photocatalytic degradation of methylene blue on the composites were evaluated.