Preparation of Biochar-Loaded Er3+-Doped BiOCl Ultrathin Nanosheets Composite Photocatalysts and Their Photodegradation Performance of TC-HCl

In this study, biochar-loaded E3+:BiOCl (C/3E3+:BiOCl) was synthesized with varying levels of E3+ doping using a one-step solvothermal method and used for tetracycline hydrochloride (TC-HCl) degradation. Their structure, shape and morphology were not only characterized by power X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscopy (TEM) but also by UV-vis diffuse reflectance spectra and upconversion (UC). The results indicated a significant enhancement in the photocatalytic activity of the catalyst following the introduction of Er3+. The composite material C/3E3+:BiOCl, with a doping concentration of 3 mol%, demonstrated the highest photocatalytic activity, achieving an impressive visible light degradation efficiency of 89.2% for TC HCl within 90 min. This marks an increase of 33.5% compared to the BiOCl monomer and 17.4% compared to C/BiOCl. Additionally, when exposed to light with wavelengths exceeding 600 nm, C/3E3+:BiOCl maintained a photodegradation efficiency of 44.3%, while BiOCl and C/BiOCl showed no photocatalytic activity under the same conditions. This finding highlights the effectiveness of BiOCl as a doping matrix, which enhances the photocatalytic performance of BiOCl through the upconversion effect of E3+ and the electron transfer mechanisms associated with biochar.