The enhanced visible-light-driven photocatalytic performance of nanocrystalline TiO2 decorated by quinazolinone-photosensitizer toward photocatalytic treatment of simulated wastewater

Abstract

Semiconductor-assisted photocatalysis is an efficient, green, low-cost technology employed for wastewater treatment. TiO2-based photocatalysts are the common photocatalysts; however, their large bandgap energy excludes their photocatalytic activities under UV irradiation. Hence, this work investigates the synthesis of quinazolinone photosensitizer to improve the photocatalytic activity of TiO2 in the visible region and efficiently maximize the utilization of solar irradiation. Quinazolinone photosensitizer is a heterocyclic compound exhibits a wide spectrum in the visible region. The prepared samples are characterized by XRD, FE-SEM, FTIR, DRS, and PL. The photocatalytic activity of the Quinazolinone photosensitized-TiO2 catalyst is evaluated toward the degradation of rhodamine B (RB) as a model of organic pollutants in wastewater under UV-A and visible light irradiations. Quinazolinone photosensitized-TiO2 catalyst exhibited a wider absorption spectrum range and lower bandgap of 2.65 eV extending its activity to the visible region compared to bare TiO2 (3.00 eV). Control tests and factors affecting the photocatalytic degradation rate of RB dye such as pH of the medium, dye concentration and catalyst dose are investigated. Degradation of RB follows 1st-order kinetics. The mechanism of degradation is described based on trapping experiments.