Lead Halide Perovskites Nanocrystals Synthesized in a Green, Reusable Solvent

The widespread development of nanomaterials calls for searching for alternative processes that can reduce the impact, both from an environmental and economic point of view, of the syntheses employed to prepare such materials. Here, we report the synthesis of CsPbX₃ (X = Cl, Br, I) nanocrystals using (R)- and (S)-limonene, two molecules extracted from natural sources, as possible solvents. The nanocrystals prepared in this solvent have structural, optical, and morphological properties that are comparable to those of their homologs synthesized using more traditional solvents, i.e., 1-octadecene. The relatively high volatility of limonene is then exploited for its recovery from the waste of the reactions and its reuse for subsequent syntheses. The replacement of 1-octadecene with limonene as the reaction solvent is carefully evaluated by examining the consequences of the environmental impact of the entire synthesis process through a life cycle assessment procedure (CO₂ footprint analysis), aiming at verifying any gain in Global Warming Potential reduction and identifying the most environmentally impactful steps of the process.