Premium
Oleylamine‐Assisted Phase‐Selective Synthesis of Cu 2− x S Nanocrystals and the Mechanism of Phase Control
Author(s) -
Fu Wenping,
Liu Lige,
Yang Gaoling,
Deng Luogen,
Zou Bingsuo,
Ruan Weidong,
Zhong Haizheng
Publication year - 2015
Publication title -
particle and particle systems characterization
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.877
H-Index - 56
eISSN - 1521-4117
pISSN - 0934-0866
DOI - 10.1002/ppsc.201500083
Subject(s) - oleylamine , nanocrystal , nanorod , phase (matter) , monoclinic crystal system , materials science , crystal (programming language) , copper , chemical engineering , tetragonal crystal system , nanotechnology , crystal structure , crystallography , chemistry , organic chemistry , metallurgy , engineering , computer science , programming language
Environmentally friendly Cu 2− x S compounds exist in many different mixed phases in nature, while their nanoscale counterparts can be pure phase with interesting localized surface plasmon resonance properties. Because of the complexity of composition and phase, controllable synthesis of Cu 2− x S nanocrystals becomes an important scientific issue in colloidal chemistry. In this work, a hot‐injection method is developed to synthesize Cu 2− x S nanocrystals by injecting a sulfur precursor into a copper precursor using oleylamine and octadecene as solvents. By varying the reaction parameters (temperature, volume ratio of oleylamine/octadecene, molar ratio of Cu/S in the precursors), hexagonal CuS, monoclinic Cu 1.75 S, and rhombohedral Cu 1.8 S, nanocrystals can be selectively synthesized, providing a platform to illustrate the mechanism of crystal phase control. The crystal phase control of Cu 2− x S nanocrystals is oleylamine‐determined by controlling the molar ratio of Cu/S in the reaction precursors as well as the ratio of Cu 2− x S clusters/Cu + in the subsequent reaction. More importantly, temperature plays an important role in varying the molar ratio of Cu/S and Cu 2− x S clusters/Cu + in the reaction system, which significantly influences the crystal phase of the resulting Cu 2− x S nanocrystals. The understanding into crystal control provides a guideline to realize reproducible phase‐selective synthesis and obtain well‐defined high‐quality materials with precise control.