Exploring pH-Controlled Hydrothermal SnO2 Nanomaterials from Local Indonesian Precursor for Methylene Blue Dye Degradation

Tin oxide (SnO2) as a wide bandgap semiconductor shows promising photocatalytic properties; however, commercially available precursors, which are costly, are often used to develop its nanomaterial. With its abundant natural resources, Indonesia has the potential to replace these commercial precursors with locally sourced alternatives. This study explores the synthesis of SnO2 using a local tin chloride (SnCl4) and investigates its photocatalytic performance through methylene blue degradation. The SnO2 samples were synthesized using the hydrothermal process at 180 ?C for 24 h. Furthermore, to optimize the process, the pH of the solution was also tuned at 1, 7, and 11 to analyze its effect on material properties. Characterization techniques, including X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, UV-Vis spectroscopy, particle size analyzer, zeta potential, and N2 adsorption-desorption analysis, were used to evaluate the structural, morphological, and optical properties of the synthesized materials. The samples synthesized in all pH conditions after the hydrothermal process were confirmed to be tetragonal rutile SnO2. Additionally, the crystallite size, optical properties, and morphology of the samples are affected by different pH conditions. SnO2 synthesized at pH 11 has a high BET surface area of 132.12 m2/g and mesoporous properties. The photocatalytic performance of the synthesized SnO2 achieved a degradation of methylene blue over 95% using UV irradiation for 120 min. The high degradation of dye can be attributed to the adsorption capability exhibited by the high surface area of the synthesized sample. This study proves that SnO2 synthesized using locally sourced SnCl4 shows comparable photocatalytic performance to commercial materials.

Adsorption; Hydrothermal; pH control; Photocatalyst; SnO2

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