Ti\(O_2\) Nanoparticles Acid-assisted Synthesis and the Enhanced Visible-light Photocatalytic Activity

Abstract

The simple synthesis of TiO₂ and improved visible-light photocatalytic performance of TiO₂ have been the goal of researchers. When compared to pure phase TiO2, mixed-phase TiO2 nanoparticles with oxygen vacancies can aid in lowering the band gap and carrier recombination rate, which improves the performance of visible light photocatalysis. In this study, three different acids were separately applied in the hydrothermal synthesis of TiO₂ nanoparticles without any post-heat treatment. The reaction was carried out at a relatively low temperature not exceeding \(140^{\circ}\)C. Under the visible light illumination-assisted photocatalytic degradation of methyl orange in water, the TiO₂ nanoparticles obtained from HCl (H-TiO₂) and CH₃COOH (A-TiO₂) showed stable photocatalysis performance for increasing the cycles up to ten times while only five cycles for TiO₂ nanoparticles obtained by HNO₃-assisted (N-TiO₂). Compared with efficiencies of N-TiO₂ nanoparticles, H-TiO₂ and A-TiO₂ showed superior efficiencies and have excellent photocatalytic performances when assisting in the degradation of methyl orange in water under visible light illumination. The high visible-light photocatalytic performance and the simple acid-assisted synthesis of the H-TiO₂ and A-TiO₂ nanoparticles will promote the industrial application.