Synthesis, Characterization, and Use of Novel Bimetal Oxide Catalyst for Photoassisted Degradation of Malachite Green Dye

This work reports a simple, novel, and cost effective synthesis of nanobimetal oxide catalyst using cerium and cadmium nitrates as metal precursors. The cerium-cadmium oxide nanophotocatalyst was synthesized by coprecipitation method and characterized by X-ray powder diffraction method to analyze the particle size. XRD study reveals a high degree of crystallinity and 28.43？nm particle size. The photocatalytic efficiency of the synthesized nanobimetal catalyst was examined by using it for the photocatalytic degradation of malachite green dye. Experiments were conducted to study the effect of various parameters, such as the pH of the dye solution, concentration of dye, amount of catalyst, and light intensity on the rate of dye degradation. The progress of the dye degradation was monitored spectrophotometrically by taking the optical density of the dye solution at regular intervals. Experimental results indicate that the dye degrades best at pH 8.0 with light intensity 600？Wm？2 and catalyst loading 0.03？g/50？mL of dye solution. The rate constant for the reaction was 7.67 × 10？4？s？1. 1. Introduction Clean water is a vital commodity, as it is a prerequisite for life. An adequate water supply in both quantity and quality is essential to human existence [1]. But one of the most serious threats related to water is the accumulation of nonbiodegradable and toxic compounds in the ecosystem leading to the degradation of the quality of water [2, 3]. Due to the nature of various chemical processing of textiles, large volume of wastewater with numerous pollutants is discharged [4, 5]. Photocatalysis has been considered and proved as a cost effective alternate for the purification of dye-containing wastewater [6–10]. Studies have demonstrated that photocatalysis can be used to destroy dye compounds using semiconductor photocatalysts under light irradiation. The photocatalysts are able to photosensitize the complete mineralization of a wide range of compounds, like dyes, phenols, and pharmaceutical drugs, without producing harmful by-products at near room temperature and pressure [11–13]. Lately, there have been extensive studies done by researchers around the globe on many photocatalytic systems (UV/semiconductors) since they have been found to be very effective in degrading various organic dyes. Many catalysts like TiO2, ZnO, ZrO2, WO3, Fe2O3, CeO2, CdS, and ZnS have been attempted for the photocatalytic degradation of a wide variety of environmental contaminants [14–21]. Studies have also demonstrated that bimetal catalyst has advantage of low metal leaching during