Biosynthesis and photocatalytic evaluation of ZnO nanoparticles using banana flower perianth

Owing to the recalcitrant and toxic nature of textile effluents, the development of environmentally sustainable technology for dye degradation is in high demand. Another area that requires attention is the treatment and reuse of alternate waters wherein a high load of microbial pollution is an impeding factor. In this regard, the present study reports the one-pot green synthesis of ZnO nanoparticles (ZnONPs) using non-edible banana flower perianth as the template with water, ethanol, and methanol as green solvents. The study involves using ZnONPs for the photocatalytic degradation of industrial model dye, methylene blue, and microbial load reduction (MLR) in Air conditioner Condensate water (ACW), an example of potential alternate water that is garnering more attention among the scientific community. Systematic characterization of ZnONPs with Electron Microscopy and Spectroscopic techniques substantiated the material properties. The synthesized ZnONPs were spherical with a crystallite size of 14 nm possessing wurtzite crystal structure and a band gap of 3.52 eV. Optimization experi-ments validated that the maximum photocatalytic efficiency of 97% does not decrease even for 100 ppm dye concentration and 800 ppm catalyst at pH-7 under sunlight and visible light irradiation. Enhanced photocatalytic efficiency is due to the defect bands of K. The highest MLR efficacy in ACW within 30 min was 82% for Aquincola tertiaricarbonis (Gram-negative) and 50% for Bacillus sp. (Gram-positive), the predominant species in ACW. No colonies grew after 60 min of light irradiation in the plating assay. Thus, the template-synthesized ZnONPs could be employed for textile wastewater treatment and water purification applications, owing to their superior photocatalytic proficiency.

Automated summary

Due to the recalcitrant and toxic nature of textile effluents, there is a high demand for environmentally sustainable technology for dye degradation. This study successfully synthesized zinc oxide nanoparticles using non-edible banana flower perianth as the template and green solvents. The synthesized nanoparticles exhibited excellent photocatalytic efficiency, making them suitable for textile wastewater treatment and water purification applications.