Exploring the Photocatalytic Efficiency of Heterostructured TiO2 Nanobelts for Emerging Liquid Contaminants in Different Water Matrices

This study reports the development of shape-controlled TiO2 (B)/anatase heterostructures for the degradation of emerging environmental pollutants, including phenol, methomyl (insecticides), and diclofenac sodium (drug), under UV-visible-light irradiation in ultrapure water and alkaline stormwater. TiO2 nanobelts were synthesized via a surfactant-free hydrothermal method, yielding structures with widths ranging from 40 to 80 nm and lengths extending up to several micrometers. The synthesized nanobelts were calcined at 400 °C, 600 °C, and 800 °C to form a TiO2 (B)/anatase heterostructure. For comparison, calcination at 900 °C was also performed, resulting in the formation of pure anatase. The samples calcined at 800 °C (~92% anatase, ~8% nanobelts) exhibited enhanced photocatalytic efficiency, achieving significant total organic carbon (TOC) removal and complete mineralization in both water matrices. These findings contribute to a cost-effective method for developing efficient TiO2 (B)/anatase heterostructures to avoid rapid charge carrier recombination, with strong potential for advanced wastewater treatment.