Annamalai University

About: Annamalai University is a education organization based out in Chidambaram, Tamil Nadu, India. It is known for research contribution in the topics: Lipid peroxidation & Antioxidant. The organization has 8098 authors who have published 10758 publications receiving 203872 citations.

Direct solvothermal synthesis of zinc oxide nanoparticle decorated graphene oxide nanocomposite for efficient photodegradation of azo-dyes

Abstract: Zinc oxide nanoparticles decorated graphene oxide (ZnO@GO) nanocomposite was successfully prepared using graphene oxide (GO) and zinc oxide nanoparticles (ZnO NPs) as raw materials by simple solvothermal method. The X-ray diffraction pattern, X-ray photoelectron spectroscopic, Fourier transform infrared spectroscopic, and Raman spectroscopic techniques revealed the formation, elemental composition and the purity of ZnO NPs and ZnO@GO nanocomposite. The ZnO NPs were synthesized via simple thermal oxidation, the synthesized ZnO NPs exhibits an excellent near spherical shape with narrow size distribution and mean size of around 20 ± 5 nm which is vividly observed from field emission scanning electron microscopic images. The elemental compositions of ZnO@GO nanocomposite which carbon, oxygen and zinc were revealed by XPS and EDX elemental mapping. The ZnO NPs decorated on GO layers were clearly seen in the high resolution transmission electron microscopic images. The photocatalytic activities of the synthesized pure ZnO NPs and ZnO@GO nanocomposite were investigated by photodegradation of azo-dyes includes neutral red (NR), crystal violet (CV), congo red (CR) and methyl orange (MO) under UV-light irradiation. The results revealed that the ZnO@GO nanocomposite exhibited a remarkably higher photocatalytic efficiency compared to pure ZnO NPs. The enhancement of photocatalytic performance was ascribed to the synergistic effect between ZnO NPs and GO layers. Hence, the synthesized ZnO@GO nanocomposite crucial for efficient degradation of dyes such as NR, CV, CR and MO. The synthesized ZnO@GO nanocomposite exhibits a good photocatalytic activity along with good reproducibility of photodegradation, which is applicable for practical applications.

Larvicidal, ovicidal and repellent activities of the leaf extract of two cucurbitacious plants against filarial vector Culex quinquefasciatus (Say) (Diptera: Culicidae).

Abstract: The leaf extract of two cucurbitacious plants Citrullus colocynthis and Cucurbita maxima with different solvents viz., benzene, ethylacetate, petroleum ether and methanol were tested for larvicidal, ovicidal and repellent activities against the mosquito Culex quinquefasciatus. Larval mortality was observed and recorded after 24 h exposure period. The LC50 values of C. colocynthis were 61.72, 47.58, 66.92 and 118.74 ppm respectively. C. maxima shows the LC50 values of 123.02, 75.91, 117.73 and 171.64 ppm respectively. The mean percent hatchability of the egg rafts were observed after 48 h treatment. 100% mortality was observed at 450 ppm for C. colocynthis and 600 ppm for C. maxima. Skin repellent test at 1.0, 2.5 and 5.0 mg/cm2 concentration of C. colocynthis gives the complete protection time ranges from 107 to 271 minutes. C. maxima exerted the complete protection time of 78 to 215 minutes. The leaf extract of these two plants shows the larvicidal and ovicidal properties and they can also be applied as an effective personal protection measure against mosquito bites.