Synthesis of TiO2 nanoparticles by the solvothermal method and application in the catalysis of esterification reactions

Abstract

Abstract TiO2 nanoparticles have numerous applications, prompting extensive efforts to optimize their synthesis for various technologies. This study synthesized TiO2 nanoparticles via the solvothermal method, using a chemometric approach to vary time, temperature, and concentrations of both the precursor and crystallization agent, aiming to understand these variables’ effects on crystallite size. Post-synthesis, a sample underwent treatment for sulfate adsorption to alter surface properties from hydrophobic to hydrophilic. Characterization techniques included X-ray diffraction (XRD), infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). The results indicated the formation of crystalline anatase phase nanoparticles, with particle sizes ranging from 25 to 38 nm and crystallite sizes from 8 to 10 nm. Sulfation was confirmed via FTIR, and SEM revealed particle agglomeration. Catalytic performance was assessed through esterification reactions, with two analyses: one comparing nanoparticles with and without surface modification, and the other examining the effects of variables like time, catalyst amount, and temperature on product formation. Sulfated samples exhibited excellent catalytic performance, achieving 60% conversion after 2 hours at 50 °C. Pure TiO2 samples also showed good conversion rates when synthesized at higher temperatures and Ti4+ concentrations.

Keywords

• catalysis
• esterification
• nanoparticles
• TiO2
• titanium(IV) oxide