Efficacy and mechanism of nano-biochar supported TiO2 in removing dichloroacetic acid from swimming pools

Abstract

This study synthesized novel nano-biochar supported TiO₂ composites using various methods and biochar/TiO₂ ratios to effectively remove dichloroacetic acid (DCA) from swimming pool water. The hydrothermally prepared HBT-5 composite with 5 wt% biochar exhibited the highest photocatalytic activity, degrading 92.5% of DCA within 180 min under UV-vis light irradiation, outperforming pure TiO₂ and HBT-1. Comprehensive characterization confirmed the strong interaction and synergistic effects between biochar and TiO₂, attributing the enhanced performance to high surface area, pore volume, interfacial Ti-O-C bonding, visible light absorption, efficient charge separation, and N and O heteroatoms in biochar. The photocatalyst showed excellent reusability, maintaining 87.3% of its initial activity after three cycles. This work provides insights into designing biochar-based photocatalysts for water purification, benefiting public health and environmental protection.

Keywords:
Photocatalytic degradation; Haloacetic acid; Water treatment; Hydrothermal synthesis; Synergistic effect