Construction of biochar modified multi-morphologies Fe2O3 for efficient boosting photo-Fenton organic antibiotic pollutants degradation: Mechanism and toxicity evaluation in degradation pathways

Constructing advanced photo-Fenton catalyst provides an effective strategy to improve photogenerated charge separation for catalytic removal of organic contaminants, however it faces challenges in efficient morphology control and recovery methods. Biochar has become a promising material on account of its high efficiency and adjustable physicochemical properties. For the purpose of enhancing the economic applicability of biochar catalysts, a series of the biochar modified multi-morphologies Fe 2 O 3 photo-Fenton catalysts (Fe 2 O 3 /BC) were prepared for efficient removal tetracycline (TC) in this work. The obtained characterization results revealed that the adoption of biochar can avoid the agglomeration of Fe 2 O 3 nanoparticles and obtained the Nanosheet-, Cube- and Ring-like photo-Fenton catalysts, respectively. The Nanosheet-like Fe 2 O 3 /BC displayed the highest TC removal of 97.0 % within 80 min, which the degradation rate constant was approximately 3 and 18 times those of Cube-like Fe 2 O 3 /BC and Ring-like Fe 2 O 3 /BC photo-Fenton catalysts. The photocurrent signal density was in the order of Nanosheet-like Fe 2 O 3 /BC>Cube-like Fe 2 O 3 /BC>Ring-like Fe 2 O 3 /BC, while the semicircle radius of electrochemical impedance spectroscopy (EIS) results in the order of Nanosheet-like Fe 2 O 3 /BC