Low-temperature synthesis of cadmium-doped zinc oxide nanosheets for enhanced sensing and environmental remediation applications

Abstract

In the present study, we report the effect of Cd doping on the photocatalytic and photoluminescence properties of ZnO nanoparticles. Large scale synthesis of pure and Cd-doped zinc oxide (ZnO) nanoparticles was carried out by using the facile solution route at low temperature (60 °C). The synthesized products were characterized by X-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM) attached with energy dispersive spectroscopy (EDS), UV–visible and photoluminescence spectroscopy. The detailed analysis revealed that the synthesized nanostructures were pure and well crystalline in nature and possessed wurtzite hexagonal crystal phase. Further photocatalytic results revealed that almost complete degradation of Rhodamine B (RhB) dye (10 ppm) occurred by 0.05 g of the 10% Cd-doped ZnO nanostructure within 110 min of UV exposure. In contrast, for pure ZnO, only 50% degradation of dye occured under the same set of conditions. Moreover, the photocatalytic degradation efficiency was increased with increase in the concentration of Cd2+ ions as a dopant. The better photodegradation efficiency of samples with an increase in dopant concentration was attributed to increase in the defects and reduction in bandgap width of ZnO nanoparticles. As-synthesized material was also explored as an efficient chemical sensor for the detection of hydrazine. A comparative study revealed a sharp decrease in the limit of detection for hydrazine sensing with the increased concentration of Cd2+ ions as a dopant. The Cd-doped ZnO nanomaterial also showed enhanced magnetism as compared to pure ZnO nanoparticles.