Photocatalytic degradation of orange G dye using ZnO/biomass activated carbon nanocomposite

Abstract In the present study zinc oxide/waste biomass activated carbon nano composite (ZnO/WBAC) materials were prepared by hydrothermal methods to obtain controlled particle size with uniform distribution zinc oxide onto activated carbon matrix with different loadings of carbon. Activated carbon used in this study was prepared from waste biomass using physical activation method. The prepared ZnO/WBAC nanocomposite was characterized using FT-IR, XRD, UV-DRS, HRSEM and EDAX. From the UV–vis-DRS data, band gap energies of the synthesized materials were found to be 3.17 eV, 3.04 eV and 2.84 eV for the 3:1, 2:2 and 1:3 ZnO/WBAC nanocomposites respectively. HRSEM analysis showed the spherical ZnO particles formed on the activated carbon material. The particle size was ranged from 25 to 30 nm. The photocatalytic activities of the prepared composite material were evaluated for the degradation of orange G dye under UV and Visible light irradiations. Preliminary studies showed that the catalyst exhibited good activities under neutral pH conditions with an optimum dosage of 1 g/L. The kinetics of photodegradation were carried out at different initial dye concentrations and reactions followed pseudo-first order kinetics. The presence of commonly occurring electrolytes marginally decreased the photoactivity of the catalyst. Reusability studies showed the catalyst to retain its original efficiency even after the third cycle of its reuse.