Microwave-assisted synthesis of nanomaterials: a green chemistry perspective and sustainability assessment

Abstract

This review critically evaluates microwave-assisted synthesis (MAS) as a sustainable approach for nanomaterial fabrication, addressing environmental concerns associated with conventional methods. MAS offers significant advantages through rapid, uniform heating that reduces energy consumption, reaction times, and hazardous waste generation. By systematically comparing energy, reaction efficiency, waste reduction, selectivity, product uniformity and scalability of MAS with conventional techniques, this review provides a comprehensive framework for sustainable nanomaterial production. The review applies green chemistry metrics and sustainability assessment tools to evaluate the environmental performance and industrial viability of various MAS protocols. Moreover, the integration of MAS with eco-friendly precursors, including plant extracts, biomolecules, and ionic liquids, for synthesising three key nanomaterial classes, such as metal nanoparticles, carbon quantum dots (CQDs), and hybrid nanocomposites was discussed in detail. The discussion further extends to practical applications in catalysis, environmental remediation, energy storage, and biomedical technologies, highlighting how MAS-derived nanomaterials address contemporary sustainability challenges. The review concludes by identifying current challenges and future directions for advancing MAS toward industrial-scale implementation, emphasizing its potential to transform nanomaterial manufacturing into a more environmentally responsible process aligned with circular economy principles.