Fabrication of 3D porous peony flower-like β-Bi2O3/BiOCl heterostructure for synergistically boosting the visible-light-driven degradation of organic pollutants

Abstract

Photocatalytic degradation seems an efficient way for the purification of polluted water bodies which demand an appropriate environment-friendly photocatalyst with high efficiency. Presently, a flower-like β -Bi 2 O 3 /BiOCl binary composite has been fabricated via the in-situ precipitation method. Different characterizations such as XRD, XPS, HRTEM-EDX, elemental mapping, FESEM with EDS, UV-DRS, PL were conducted, indicating a crystalline flower-like nanostructure with a narrow bandgap (2.25 eV) energy, and low recombination tendency. The BET N 2 adsorption–desorption analysis showed a large surface area (78 m 2 /g) along with a mesoporous structure (42.98 nm). The photocatalyst degraded a model dye, methylene blue (MB), and a model insecticide, fipronil (FIP) having ∼ 93% and ∼ 79% degradation efficiency at lofty rate constants (0.05883 and 0.01481min −1 , respectively). The enhanced photodegradation was attributed to the β -Bi 2 O 3 /BiOCl heterojunction promoting the charge carrier segregation. The variation in pH and catalyst concentrations showed degradation efficiency of 93.27% for MB and 79.96% for FIP at pH 8 and 4 respectively with 0.13 g/L catalyst concentration. The scavenging experiments disclosed the prominent role enacted by O 2 • − (superoxide radical) and h + (holes) in toxin degradation. The stoutness of the binary composite was affirmed by a reusability experiment executed for 4 sequential cycles (79.95% degradation efficiency for MB and 69.82% efficiency for FIP). XRD scrutiny proved its solidity/intact structure after degradation reaction. The as-synthesized catalyst offers a propitious binary photocatalyst with a viable design and elevated visible light efficiency for noxious waste removal. • Composites of β -Bi 2 O 3 /BiOCl nanoflowers fabricated via the in-situ method. • Surface active sites unhindered owing to the position of β -Bi 2 O 3 nanorods. • A heterojunction electric field generated via β -Bi 2 O 3 enhanced charge separation. • ∼ 93% and ∼ 79% efficiency in visible light for MB and FIP respectively.