Fabrication of Ag3PO4/polyaniline-activated biochar photocatalyst for efficient triclosan degradation process and toxicity assessment

Triclosan (TCS) isa typical environmental pollutant, which seriously threatens the health of humans and organisms. A novel strategy of biochar/Ag3PO4/polyaniline (PANI) composite photocatalyst was synthesized by a facile chemical precipitation method to efficiently degrade TCS. XRD, Raman, ESR, etc. were used to reveal the effective associations among physiochemistry, photochemistry and photocatalytic properties of the composite. It was proved the synergistic effects of biochar (T-Bio) and PANI resulted in the decrease of Ag3PO4 particle size, the enhancement of adsorption, the improvement of light utilization, the increase of photogenerated carrier separation and the promotion of reactive spe-cies. The photocatalytic mechanism showed h(+) was the main active species, center dot O-2(-) and center dot OH played minor roles. Under the irradiation of visible light, the optimal photocatalyst (1.0% T-Bio/AP/1.0% PANI) displayed excellent photocata-lytic activity with the removal rate of 85.21% for TCS within 10 min, and the apparent rate constant K' was 2.38 times of Ag3PO4. 11 main intermediates for TCS degradation were identified, and their toxicity was significantly reduced. The possible degradation pathways were proposed. This work is the first systematic study on the degradation behavior of TCS by Ag3PO4-based photocatalyst, and it provides a new approach to fabricate photocatalysts with synergistic effects and amazing photocatalytic activity by biochar.

Automated summary

The novel biochar/Ag3PO4/polyaniline composite photocatalyst showed excellent photocatalytic activity in efficiently degrading TCS, with synergistic effects of biochar and PANI enhancing the catalytic properties. The study provides a new approach for fabricating photocatalysts with amazing photocatalytic activity using biochar.