Precise fabrication of biochar nanosheets through CoAl-layered double hydroxide template-oriented effect for water...

Fabrication of high catalytic activity, cost-efficient and eco-friendly carbon-based materials for water decontamination still possessed huge challenges. From this, in this research, the unique biochar nanosheets (FABN) were prepared from Fructus Aurantii residues by using CoAl-layered double hydroxide as template-oriented materials. Subsequently, the as-prepared FABN were employed as the peroxymonosulfate (PMS) activator to degrade tetracycline, a probe antibiotic contaminant in wastewater, achieving excellent catalytic degradation rate (0.67195 min^-1) in optimal FABN/PMS system through the synergistic effect of radical and non-radical pathways. Characterization results and mechanism analysis demonstrated that high sp²/sp³ carbon ratio, abundant graphitic N, oxidized N, oxygen-containing functional groups (C=O and O-C=O) as well as large specific surface area were significant factors for PMS trigger. Moreover, the FABN/PMS system exhibited good catalytic activity towards various antibiotic contaminants (such as, oxytetracycline, chlortetracycline hydrochloride, ciprofloxacin and minocycline hydrochloride) and possessed beneficial adaptability to interference, including humic acid, ubiquitous inorganic anions, pH and various actual natural water samples. Finally, the possible catalytic degradation mechanism and catalytic degradation pathways were proposed and the related biological toxicological experiments were performed through the cultivation of wheat seeds and ECOSAR predictive model, respectively. Overall, this work not only provided novel insights into the fabrication of biochar nanosheets green catalysts, but also offered technical support for the decontamination of the wastewater containing various antibiotic contaminants.