Synthesis of Unique Flowerlike Bi₂O₂(OH)(NO₃) Hierarchical Microstructures with High Surface Area and Superior Photocatalytic Performance

Abstract

Unique flowerlike Bi₂ O₂ (OH)(NO₃ ) (denoted as BION) hierarchical microstructures assembled by ultrathin nanosheets were hydrothermally synthesized from incomplete hydrolysis of anhydrous bismuth nitrate (Bi(NO₃ )₃ ) after adsorption of glacial acetic acid (HAc). The structure, composition, and optical properties of the products were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), UV/Vis spectroscopy, etc. The as-prepared flowerlike BION possessed an ultra-high surface area and thus exhibited exceptional photocatalytic activity for rhodamine B (RhB) degradation under UV light irradiation with an efficiency of about 17; 6 and 2.5 times higher than spherical, aggregated sheet-like BION and P25 TiO₂ , respectively, and also superior to the reported sheet-like BION. It also showed good photocatalytic activity for crystal violet (CV) degradation. This work opens new routes for the rational design and synthesis of nontoxic basic bismuth nitrates with a facile synthetic approach, controllable morphology, and excellent photoreactivity.