Photocatalytic degradation of methyl orange using Cerium doped zinc oxide nanoparticles supported bentonite clay

Methyl orange (MO) is a common anionic azo dye that is a serious harmful pollutant to the environmental aquatic systems, so it must be treated before it can be discharged. Photocatalysts are usually semiconducting solid oxides that create an electron-hole pair by absorbing photons. These electron holes can react with molecules on the surface of the particles. Photocatalysts are used in water purification, self-cleaning glasses, the decomposition of organic molecules, etc. Photocatalysts are environmental cleaning materials that remove pollution from surfaces and can destroy organic compounds when exposed to sunlight or fluorescence. The photocatalytic process follows the following principles. Bentonite mineral is a natural adsorbent material that has good adsorption capacity. In this work, zinc oxide nanoparticles doped with cerium were prepared by the sol-gel method (SGM) and deposited on bentonite clay to degrade methyl orange (MO) dye. Important parameters that affected degradation efficiency such as contact time, amount of nanocatalyst, and initial dye concentration were investigated and optimized. Results showed that 100% degradation efficiency was obtained at 60 mg of nanocatalyst and 50 mg L-1 of methyl orange in 120 minutes. The Kinetics of the degradation process was consistent with pseudo-second-order and the adsorption isotherm of MO dye on nanocatalyst was fitted with the Langmuir isotherm model. The reusability of the synthesized nanocatalyst showed that the nanocatalyst was applied successfully seven times without a significant change in degradation efficiency.