Photocatalytic degradation of organophosphorus pesticide using semiconductor-sensitized composite in natural water: effect of oxidants

In this work, dichlorvos was degraded with photocatalytically active n-type semiconductors and p-n junction-type semiconductors. The p-n junction-type semiconductors such as GO-TiO2 (GO = graphene oxide) and GO-WO3 were synthesized by photodeposition method using commercial TiO2 and WO3. GO-doped nano-TiO2 was synthesized through sol-gel technique from titanium(IV) isopropoxide by hydrothermal treatment. The synthesized materials were characterized by different techniques such as XRD, UV, FTIR, SEM and TEM. In order to find out the photocatalytic ability towards degradation of dichlorvos, the experiment was carried out in an aqueous suspension under UV light in the presence of oxygen and oxidants such as H2O2 and K2S2O8. From the evaluation, GO-nano-TiO2 with H2O2 was found to be highly active that showed complete degradation of dichlorvos within 15 min under UV light.