Photo-assisted mineralisation of titan yellow dye using ZnO nanorods synthesised via environmental benign route

Abstract

Green synthesis of metal oxide nanoparticles using plant extract is a most promising substitute for regular methods that involve chemical synthesis approach. The present study reports the synthesis of ZnO nano rods (ZNRs) using Calotropis gigantea, a plant rich in flavonoids and alkaloids and their application as a photocatalyst in the degradation of titan yellow dye. The synthesized ZNRs were characterized using XRD, FESEM-EDS and HRTEM-SAED. The XRD results confirm the formation of wurtzite ZnO. The FESEM images confirmed that ZNRs have length ranging from 20 to 200 nm, diameter ranging between 20 and 80 nm and width between 20 and 50 nm. The bio-synthesized ZNRs were used for photo-degradation of titan yellow dye, one of the main effluents from textile industries, discharged directly into water bodies. The ZNRs exhibited 95% dye degradation for 10 ppm TY dye concentration in the presence of 60 mg of the ZNRs catalyst at pH 8 for 60 min UV irradiation. The present study reports eco-friendly method for the synthesis of ZNRs and its efficiency as a photo catalyst in the advanced photo assisted oxidation process for degradation of titan yellow dye.

Sustainable Green Nanotechnologies for Innovative Purifications of Water: Synthesis of the Nanoparticles from Renewable Sources

“…ZnO nanorods synthesized using sustainable pathways were also investigated for photocatalytic activity by Vidya et al [66]. For the green synthesis, Calotropis gigantea leaf extract was used, which was prepared as follows: Firstly, the collected leaves were washed and dried in sun; after that 50 g of them was cut into small pieces and mixed with 500 mL of distilled water.…”

“…For the synthesis of ZnO nanorods, 100 mL of the leaf extract was firstly boiled and stirred at 60-80 • C, and when the extract reached 80 • C, 5 g of zinc nitrate hexahydrate (Zn(NO) 3 •6(H 2 O)) was added and boiled until a deep yellow paste appeared. Finally, this paste was then calcined at 400 • C for 1 h. For the characterization, various techniques were used, such as XRD, SEM, TEM, EDS, FTIR and UV-Vis spectrometry [66]. XRD results proved the wurtzite structure of ZnO as well as the presence of some impurities.…”

UV Photochromism in Transition Metal Oxides and Hybrid Materials

“…Environment friendly approaches for synthesis of ZnO and TiO 2 nanostructures have been one of the focus areas of the research. For example, green synthesis methods such as hydrothermal route utilizing Prunus cerasifera leaf, [ 239 ] calcination of broccoli extract, [ 240 ] using water extract of Calotropis gigantea leaves, [ 241 ] application of Carissa edulis as the capping agent for the preparation of ZnO nanostructures [ 242 ] have been reported recently. Immobilization of such nanostructures is necessary for environment friendly applications of ZnO and TiO 2.…”

Visible Light Induced Photocatalytic Dye Degradation by Cobalt Oxide Nanoparticles

“…The present CoONPs shows 92.20% DE of MX at neutral pH with visible light irradiation indicates faster degradation rate. On the flipside, most of the reported conventional catalysts for the degradation of TY are TiO 2 or ZnO based nanoparticles induced by UV light [46][47][48] . Recently, Pal et al [45] have reported an efficient photocatalyst, ZnO nano particles synthesized by using Moringa Oleifera leaf extract which degrades TY about 96.0% under 60 min visible light irradiation in the pH range 2.0-12.0.…”