The Huge Role of Tiny Impurities in Nanoscale Synthesis.

Nanotechnology is vital to many current industries, including electronics, energy, textiles, agriculture, and theranostics. Understanding the chemical mechanisms of nanomaterial synthesis has contributed to the tunability of their unique properties, although studies frequently overlook the potential impact of impurities. Impurities can show adverse effects, clouding the interpretation of results or limiting the practical utility of the nanomaterial. On the other hand, as successful doping has demonstrated, the intentional introduction of impurities can be a powerful tool for enhancing the properties of a nanomaterial. This Review examines the complex role of impurities, unintentionally or intentionally added, during nanoscale synthesis and their effects on the performance and usefulness of the most common classes of nanomaterials: nanocarbons, noble metal and metal oxide nanoparticles, semiconductor quantum dots, thermoelectrics, and perovskites.