Optimizing the photocatalytic performance of SnO₂ nanoparticles for methylene blue removal with variation in calcination temperatures

¹ Universitas Indonesia, Department of Metallurgical and Materials Engineering, 16424 Depok, Indonesia
² Universitas Indonesia, Advanced Materials Research Center, 16424 Depok, Indonesia
³ Nanotech Indonesia Global, Nano Center Indonesia, 15314 South Tangerang, Indonesia
⁴ Universitas Mercu Buana, Department of Mechanical Engineering, 11610 Jakarta, Indonesia

^* Corresponding author: ahyuwono@eng.ui.ac.id

Abstract

In recent years, numerous studies have been conducted to combine tin oxide (SnO₂) with various semiconductor materials to boost its photocatalytic efficiency for water waste treatment, with minimal emphasis placed on intensifying the intrinsic capabilities of pure SnO₂. The primary objective of this study is to enhance the photocatalytic efficiency of pure SnO₂ nanoparticles (NPs) by modifying their morphology, structural, and optical properties. The SnO₂ NPs were synthesized using precipitation method, followed by a calcination process at varying temperatures (non-calcined, 300 °C, and 500 °C). The changes in properties of SnO2 NPs were investigated utilizing X-ray diffraction (XRD), scanning electron microscopy (SEM), particle size analysis (PSA), Brunauer-Emmett-Teller (BET), and ultraviolet-visible (UV-Vis) spectroscopy. The results indicated that elevating the calcination temperature up to 500 °C resulted in an increase in both the average crystallite size (up to 10.50 nm) and crystallinity (up to 85.28 %). However, the highest photocatalytic efficiency for methylene blue degradation of 84.78 % was obtained from the SnO₂ NPs calcined at 300 °C sample exhibiting the largest surface area of 83.97 m²g^-1. This study affirms that the specific surface area of SnO₂ NPs is a critical factor in their efficacy for degrading dye-contaminated water waste.