Enhanced dye adsorption and rapid photo catalysis in candle soot coated Bi2WO6 ceramics

Candle soot coated visible light active photocatalyst Bi2WO6 (BW) was studied for the synergistic effect of adsorption and photocatalysis. The candle soot coatings of two different thicknesses (single and multilayer) were applied as an adsorbent on the surface of BW. The maximum removal of methylene blue (MB) was recorded 42, 95, 96 percent in the only adsorption, only photocatalysis and combined adsorption and photocatalysis, respectively with a single layer of candle soot. The time required for removal of MB was reduced by 50% in combined adsorption and photocatalysis than that of only adsorption and only photocatalysis. In the case of multilayer coatings, the maximum removal of MB was recorded 53, 95 and 71% in the only adsorption, only photocatalysis and combined adsorption and photocatalysis respectively. Similar experiments were performed with pharmaceutical drug diclofenac (DF) and trends alike removal of MB were obtained for both single and multilayer of candle soot. The maximum removal of DF was recorded in only photocatalysis, combined photocatalysis with single and multilayer of candle soot was found to be 83, 90 and 75%, respectively.