Synthesis and Characterization of Copper-Based Dilute Alloy Nanorods: An Undergraduate Laboratory

In recent decades, rapid advancements in nanoscience and nanotechnology have transformed both academic research and industrial innovation. To prepare the next generation of scientists and engineers, it is critical to incorporate cutting-edge developments into upper-level undergraduate curricula through immersive, hands-on laboratory experiences. Here, we present an advanced undergraduate laboratory experiment focused on the solution-phase synthesis and characterization of copper-based dilute alloy nanocrystals. By systematically varying the concentration of Au nanocrystal seeds, students synthesized copper nanorods covering a wide range of aspect ratios, allowing them to correlate the nanorod dimensions with localized surface plasmon resonance properties. Observing vivid color transitions during synthesis and distinct colors of nanocrystal colloids reinforced key nanochemistry concepts, such as bottom-up synthesis, redox chemistry, nucleation and growth, and size- and shape-dependent optical properties. Students also gained hands-on experience in crystal structure modeling and microscopy image analysis. Furthermore, they employed a suite of structural and spectroscopic characterization techniques, including electron microscopy, powder X-ray diffraction, X-ray photoelectron spectroscopy, and UV–vis-NIR extinction spectroscopy, to thoroughly analyze the synthesized nanocrystals and elucidate their structure–property relationships. Implemented successfully over four consecutive years at Indiana University, this modular, five-session laboratory demonstrated reproducibility and adaptability in classroom settings. Assessment through in-class quizzes and laboratory reports revealed marked enhancements in students’ understanding of metal alloy nanomaterials and scientific writing skills. Overall, this laboratory experiment equips undergraduate students with essential knowledge and practical skills in materials and inorganic chemistry, preparing them for advanced studies and professional careers in nanotechnology, materials science, and advanced manufacturing.