Construction of Magnetically Retrievable g-C3N4/TiO2-MnFe2O4 Halloysite Composites with Enhanced Visible-Light Photocatalytic Activity and Antibacterial Properties

Constructing heterojunction photocatalyst is an effective method to enhance the separation of photogenerated electron and hole, which significantly improves ability of visible light response. In this study, calcination methods have been proposed to prepare highly efficient magnetic ternary photocatalyst g-C 3 N 4 /TiO 2 -MnFe 2 O 4 halloysite. It showed an enhanced photocatalytic degradation for dyes (crystal violet) and nonsteroidal anti-inflammatory drugs (acetaminophen) under vision light irradiation. Compared to pure g-C 3 N 4 , TiO 2 , MnFe 2 O 4 halloysite and binary g-C 3 N 4 -MnFe 2 O 4 halloysite, the optimized ternary g-C 3 N 4 /TiO 2 -MnFe 2 O 4 halloysite displayed enhanced photodegradation efficiency with 91.1% removal of crystal violet (10 ppm) in 90 min under visible light irradiation, the optimized ternary g-C 3 N 4 /TiO 2 -MnFe 2 O 4 halloysite composite showed significantly enhanced photocatalytic activity with more than 79.1% removal of acetaminophen (10 ppm) within 90 min under visible light. The photocatalytic mechanism was identified through the free radical quenching experiment. The heterojunction photocatalyst could be easily recovered by an extra magnetic field and reused several times without any obvious deterioration in catalytic activity. Besides, the ternary heterojunction also exhibited antibacterial ability against Escherichia coli . The superior photocatalytic performance of composite should be mainly attributed to both the improvement of light harvesting as well as the enhanced separation and transfer efficiency. It is expected that this novel ternary visible-light responding composite would be a promising candidate material for organic pollutants degradation and bacteria inactivation.