Simultaneously with the continuous stirring of the reaction mixture with a magnetic stirrer , vortex , or bath sonication , the organic solvent is evaporated by gentle heating, which triggers the solidification of the oily materials in the solution. Finally, the CSHNs are collected and purified by dialysis , ultrafiltration , or ultracentrifugation . Regarding the experimental details, it should be noted that some key parameters (e.g., the optimal reaction time and temperature) are largely case-dependent and therefore cannot be generalized according to the relevant literature. However, these and other parameters could be quickly optimized by monitoring the entire process using analytical methods such as gas chromatography.