Facile Synthesis of a Broad Range of Colloidal Nanocrystals by Membrane-Mediated pH Gradient under Ambient Conditions

• Published in: Crystals (Basel) Vol. 14; no. 3; p. 240
• Main Authors: Ranjbar Bahadori, Shahab, Hart, Ryan, Mulgaonkar, Aditi, Wang, Yunfeng, Fuentes, Samuel, Hong, Yi, Cao, Ye, Jiang, Jiechao, Sun, Xiankai, Hao, Yaowu
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.03.2024
• Subjects: Acids; Analysis; Aqueous solutions; Cellulose; Cerium oxides; Chemical synthesis; Chloride; Citric acid; Copper; Dialysis; Gold; Hemodialysis; Hydrogen-ion concentration; Identification and classification; Ligands; liquid diffusion; Membranes; Metal oxides; Metallic elements; Methods; Nanocrystals; nanoparticle synthesis; Nanoparticles; Palladium; Synthesis; Transition metals; United States; United States > US
• ISSN: 2073-4352; 2073-4352
• DOI: 10.3390/cryst14030240

We report a simple synthesis process for a wide variety of ultrasmall nanocrystals. Simply immersing a dialysis bag containing an aqueous solution of a metal salt mixed with citric acid in a NaOH solution reservoir for 10 min, nanocrystals measuring only a few nanometers in size are formed inside the dialysis bag. We demonstrated the synthesis of ultrasmall nanocrystals of Co, Ni, Cu, Ag, Au, Pd, Cu2O, FeO, and CeO2, and found that the gradual change in pH caused by the diffusion of OH− ions through the dialysis membrane played an essential role in the formation of these nanocrystals. This method can be readily adapted for almost all transition metal elements, providing researchers in the fields of catalysis and nanomedicine an easy access to a wide range of ultrasmall metal and oxide nanocrystals.