Synthesis of barium titanate nanocrystals decorated with PtO for enhanced photooxidative desulfurization of thiophene

Abstract

Perovskite titanates have emerged as promising photocatalysts for environmental remediation. One particular challenge is the removing of sulfur-containing compounds like thiophene (TPH) from fuels. Herein, we synthesized mesoporous BaTiO₃ (BTO) nanostructures using a surfactant-assisted hydrothermal method and subsequently modified with varying amounts (0.5–2.0 wt%) of PtO nanoparticles (NPs) to form PtO-BTO composites. The characterization of the composite materials reveals a mesoporous structure that enhances their optical properties after adding PtO NPs. Specifically, incorporating 1.5 wt% PtO significantly reduced the bandgap energy (Eg) from 2.68 to 1.93 eV, leading to improved visible light absorption. This composite demonstrated superior photocatalytic performance, achieving complete photooxidative desulfurization of TPH during 90 min under visible light irradiation, with a remarkable oxidation rate constant of 0.035 min⁻¹. Moreover, the photocatalyst exhibited excellent recyclability. Photoluminescence and photocurrent measurements confirmed that the introduction of PtO effectively suppressed charge carrier recombination. The proposed photoconversion mechanism involves a step-scheme charge transfer process facilitated by the heterojunction between PtO and BTO. This mechanism enables effective charge isolation and transfer, resulting in increased photocatalytic activity. This research accentuates the potential of BaTiO₃-based photocatalysts for use in fuel processing and corresponding industries.