The Effects of Hydrothermal Temperatures on ZnO-Bentonite Composite Synthesis on Adsorption and Photodegradation of Methylene Blue Dye

Abstract

This study explores the influence of hydrothermal temperatures on the synthesis of ZnO-Bentonite composites and their efficiency in the adsorption and photodegradation of Methylene Blue dye. ZnO nanoparticles were integrated into Na-Bentonite, with composites synthesized at hydrothermal temperatures of 100°C and 200°C. Various characterization techniques such as XRD, FTIR, UV-Vis DRS, TG-DTA and BET were utilized to analyze the structural and thermal properties. The results show that the composite synthesized at 200°C exhibits superior performance, with a maximum adsorption capacity of 120.48 mg/g at 50°C, significantly higher than the 49.26 mg/g achieved by the composite synthesized at 100°C. Moreover, the enhanced crystallinity and increased surface area, as evidenced by a 16 nm crystallite size at 100°C and 22 nm at 200°C, led to improved photocatalytic activity. The research concludes that higher hydrothermal temperatures improve both adsorption and photodegradation efficiency, making the composite synthesized at 200°C more effective for environmental applications.

Keywords

• zno-bentonite
• hydrothermal synthesis
• adsorption
• photodegradation
• methylene blue