Photocatalytic efficiency of brilliant green dye on ZnO loaded on cotton stalk activated carbon

Abstract

In this study, ZnO loaded on cotton stalk activated carbon (ZnO/CSAC) has been successfully synthesized by the chemical precipitation method. XRD patterns showed that ZnO/CSAC have two phases are hexagonal wurtizite and amorphous structures. The average particle size is reduced (12.4 nm) upon loading CSAC than the ZnO NPs. The band gap value is decreased (2.50 eV) upon loading on CSAC compared to ZnO NPs. The functional groups identify using by FT-IR spectrum. FE-SEM images a pure ZnO revealed a 15–40 nm spherical structure and 10–35 nm large agglomerations spherical structure for ZnO/CSAC and then, EDAX spectrum affirmed the formation of ZnO/CSAC. BET surface area and pore volume of the 22.18 m ^2 g ^−1 and 0.210 cm ^3 g ^−1 for the ZnO NPs and make it increased surface area and pore volume due to the adding CSAC to 263.18 m ^2 g ^−1 and 0.306 cm ^3 g ^−1 . The photocatalytic degradation efficiency of brilliant green (BG) dye and results shows that ZnO/CSAC sample improves photocatalytic activity than the ZnO NPs. Amidst all; ZnO/CSAC showed the maximum degradation the efficiency (90.26%) than the ZnO. These results show that the ZnO/CSAC sample is due to the synergistic effect between ZnO (photocatalysts) and CSAC (adsorption), its also possible mechanism and pseudo-first-order model are used to analysis the kinetics.

Keywords

• zinc oxide
• activated carbon
• sunlight
• photocatalytic activity