Introducing “Green” and “Nongreen” Aspects of Noble Metal Nanoparticle Synthesis: An Inquiry-Based Laboratory Experiment for Chemistry and Engineering Students

In recent years, nanoscience and nanotechnology have been drawing enormous attention due to the numerous applications of nanomaterials. In an attempt to nurture interest towards these areas in young minds and to develop the next generation of environmentally conscious scientists and engineers, this new laboratory module focuses on the green and nongreen aspects of noble metal nanoparticles (NPs) synthesis. The element of novelty is represented by the guided, inquiry-based exploration of alternative, green fabrication methods using environmentally friendly reducing agents (e.g., tea extracts, coffee, honey, coconut oil, and banana peel). The inquiry-based learning was developed according to the five essential features laid by the National Research Council (NRC), and was successfully implemented after science and engineering students gained theoretical knowledge and hands-on experience with conventional, nongreen fabrication methods of colloidal silver and gold NPs (i.e., the Lee-Meisel and Turkevich methods). The student assignments and evaluations demonstrated that this inquiry-based laboratory increased students’ interest in green nanochemistry, provided them with new laboratory skills, and stimulated their critical thinking.