Biosynthesized Metallic Nanoarchitecture for Photocatalytic Degradation of Emerging Organochlorine and Organophosphate Pollutants: A Review

The use of efficacious and cost-effective pesticides (OP and OC) has undoubtedly proven to be a blessing and a baron because these pesticides are safeguarding the world from food insecurity. Unfortunately, their presence in aquatic bodies brings about an upsurge in water pollution. Amazingly, the photocatalytic degradation approach utilizing biogenic nanoparticles (BNPs) is a trendy state-of-the-art approach and has been established to be a sustainable methodology for the complete mineralization of contaminants into harmless molecules. Thus, this work holistically explores the use of BNPs for photocatalytic degradation of OP and OC. Based on the review, it was found that the least amount of time needed for degradation was less than 5 minutes, while the maximum degradation efficiency was >80 %. The dominant radicals participating in the degradation are ⋅OH and O₂⋅ and this radical dominance was enhanced by the oxygenated functional groups present in the biogenic entities employed for the biosynthesis of BNPs. The photocatalytic degradation data fits the pseudo-first-order and Langmuir isotherm models (R² > 0.9), which indicates that the main adsorption mechanisms involved during electron-hole pair formation and photocatalytic degradation are physisorption and monolayer at the surface of the BNPs. BNPs can sustain a >80 % degradation efficiency for approximately 5 cycles and are reusable for up to 8 cycles. It was also revealed that plants constitute 80 % of the engaged biogenic entities for BNP synthesis. Ultimately, this work offers novel avenues and future research hotspots that might accelerate the use of BNPs for sustainable agricultural and wastewater management practices.