Case Studies on Multifunctional Green Quantum Dots – From Lab Bench to Commercialization

Abstract

Green quantum dots (GQDs) are an emerging group of nanomaterials exhibiting remarkable optical, biological, and electrical properties modulated by their unique size-dependent surface chemistry. Since the 21st century, the demand for GQDs has taken a quantum leap, causing a paradigm shift to use novel protocols for large-scale continuous flow synthesis (CFS). The design and fabrication of high-quality GQDs require superior process intensification to ensure that the rationally developed continuous flow chemistry routes, driven by the nucleation-growth mechanisms, are sustainable, cost-effective, eco-friendly, and aligned toward the principles of “green chemistry”. These critical attributes of pilot-scale CFS assembly make this an excellent state-of-the-art process in contrast to the conventional batch synthesis, paving the way for novel material discovery in an efficient manner. The versatile GQDs fabricated via CFS have opened up many opportunities in energy storage appliances, catalysis, biomedicine, environmental remediation, agriculture, and optoelectronics. For instance, the defect engineered zinc oxide (ZnO) and cerium oxide (CeO2) GQDs have manifested their tremendous potential as antioxidants, anti-cancer, and antibacterial agents, making them desirable in pharmaceutics and biomedicine. In the agricultural sector, they have been explored for crop health improvement and enhancing crop yield. Additionally, CeO2 GQDs play a vital role in mitigating the environmental hazards caused due to harmful exhaust emissions from diesel engines. In this chapter, the novelty of ZnO and CeO2 GQDs synthesized by pilot-scale continuous flow approaches is discussed and an insight into the case studies which are primarily related to the work done in our laboratory for evaluating the fascinating properties tailored to cater to the need of these GQDs in leading-edge technological innovations is provided.