Enhanced photocatalytic decomposition of phenol in wastewater by using La-TiO2 nanocomposite

Abstract

In this work, La-TiO₂ nanocomposite was synthesized by loading lanthanum onto TiO₂ and used for improving photodegradation of phenol in wastewater. The characterizations of La-TiO₂ demonstrated that the loading of La onto TiO₂ not only increased its adsorption light zone up to 470 nm but also decreased the band gap energy from 3.1 to 2.64 eV. Photoluminescence spectra of La-TiO₂ confirmed the enhancing separation rate between electron and hole, leading to improve photodegradation efficiency of phenol. The removal rate of phenol was influenced by solution pH and alkaline conditions could bring better removal efficiency. In presence of light, the photodegradation efficiency of phenol by TiO₂ was 64.1%, while it increased up to 93.4% by La-TiO₂ photocatalyst. La-TiO₂ nanocomposite was tested for five cycles and it showed only 13.8% dropping in the photodegradation efficiency of phenol. Besides, over 82% of phenol was removed from the wastewater sample by modified TiO₂, demonstrating the potential of La-TiO₂ photocatalyst for water pollution control.

Keywords: La doping; Nanocomposite; Phenol removal; Photodegradation; TiO(2); Wastewater.