Synthesis of silica-functionalized graphene oxide/ZnO coated on fiberglass and its application in photocatalytic removal of gaseous benzene

Volatile organic compounds (VOCs) are a serious threat to public health, causing many serious diseases including cancer. Benzene is a VOC, causing different problems including aplastic anemia, acute leukemia, bone marrow abnormalities, and cardiovascular diseases in human who are exposed to it. Therefore, methods for degradation of benzene are required. In this study, for the first time silicafunctionalized graphene oxide/ZnO (Silica-GO/ZnO) nano composite was synthesized and coated on fiberglass. It was then used for photocatalytic removal of benzene from the polluted air stream in a continuous reactor. The properties of the synthesized catalyst were examined by FTIR, XPS, XRD, SEM-EDX, N-2 adsorption-desorption isotherms, and photoluminescence (PL) analyses, all of which confirming presence of silica and zinc oxide nanoparticles on graphene oxide, suggesting that GO-SiO2-ZnO photocatalyst was synthesized successfully. We investigated the effects of initial benzene concentration, flow rate, and humidity in degradation of benzene. The findings of this study indicated that the maximum removal efficiency of benzene was 87%. The range of optimal humidity for benzene removal was obtained as 35-45%. The results of this study showed that stabilization of ZnO on graphene oxide functionalized with silica has a significant effect in degradation of benzene from polluted air flow. The justification can be related to the fact that strong adsorption of benzene on GO results in further emission of pollutant to the ZnO catalyzer, thereby yielding a greater removal efficiency. With these results we can say the Silica-GO/ZnO is an efficient option for the elimination of benzene and biohazards emitted from industrial chimney streams. (C) 2018 Published by Elsevier B.V. on behalf of Institution of Chemical Engineers.