Biosynthesized δ-Bi 2 O 3 Nanoparticles from Crinum viviparum Flower Extract for Photocatalytic Dye Degradation and Molecular Docking.

Bioinspired delta-bismuth oxide nanoparticles (δ-Bi 2 O 3 NPs) have been synthesized using a greener reducing agent and surfactant via co-precipitation method. The originality of this work is the use of Crinum viviparum flower extract for the first time for the fabrication of NPs, which were further calcined at 800 °C to obtain δ-Bi 2 O 3 NPs. Physicochemical studies such as FTIR spectroscopy and XPS confirmed the formation of Bi 2 O 3 NPs, whereas XRD and Raman verified the formation of the cubic delta (δ) phase of Bi 2 O 3 NPs. However, HRTEM revealed the spherical shape with diameter 10-20 nm, while BET studies expose mesoporous nature with a surface area of 71 m 2 /gm. The band gap for δ-Bi 2 O 3 NPs was estimated to be 3.45 eV, which ensured δ-Bi 2 O 3 to be a promising photocatalyst under visible-light irradiation. Therefore, based on the results of physicochemical studies, the bioinspired δ-Bi 2 O 3 NPs were explored as active photocatalysts for the degradation of toxic dyes, viz ., Thymol blue (TB) and Congo red (CR) under visible-light irradiation. The study showed 98.26% degradation of TB in 40 min and 69.67% degradation of CR in 80 min by δ-Bi 2 O 3 NPs. The photogenerated holes and electrons were found responsible for this enhancement. Furthermore, molecular docking investigations were also performed for δ-Bi 2 O 3 NPs to understand its biological function as New Delhi metallo-β-lactamase 1 (NDM-1) [PDB ID 5XP9] enzyme inhibitor, and studies revealed good interaction with various amino acid residues and found good hydrogen bonding with a fine pose energy of -3.851 kcal/mole.