Advances in biogenic nanoparticles: synthesis pathways and emerging applications

This review highlights the chemical and biogenic synthesis methods of nanoparticles, their characterisation, and comparative analysis in detail. The chemical methods used for the synthesis of NPs uses hazardous chemicals, involves high energy consumption and produces toxic byproducts thereby could affect the natural resources and organisms negatively. The alternative biogenic method used for the synthesis of NPs relies on a broad range of microorganisms and plants, is cost-effective and has emerged as an eco-friendly and non-toxic alternative to that of physical and chemical methods. Although biogenically synthesised NPs lack crystallinity, scalability, size, shape, and purity compared to chemically synthesised NPs, environmental impact is a major concern in today’s world, and biogenic synthesis is the best alternative method to address this. The review further highlighted the importance of reaction kinetics, process optimisation, and multiphase systems in controlling NPs growth, their morphology, functionality and stability. These biogenic NPs have various applications in industrial wastewater treatment, environmental remediation, bioactivity, drug delivery and agriculture. Furthermore, we have discussed the applications of both chemically synthesised and biogenically synthesised NPs. The study concludes the toxicity assessment, mechanistic understanding, process scalability and commercialisation barriers associated with the biogenic NPs. Overall, this review emphasises the pivotal role of biogenic NPs in advancing sustainable chemical engineering and next-generation multifunctional nanotechnology thereby emphasising on integrating chemical engineering, nanotechnology and a sustainable design framework to accelerate the transition of biogenic NPs from laboratory to industrial applications.