Single-phase and well-dispersed Cu1.75S nanocrystals by ambient pressure diethylene glycol solution synthesis

Abstract Single-phase, well-dispersed Cu 1.75 S nanocrystals were synthesized by an ambient pressure, hydrazine hydrate and ethylenediamine co-assisted diethylene glycol based solution chemical process using copper chloride and thioacetamide as precursors at the temperature range from 180 to 210 °C. Influence of hydrazine hydrate and ethylenediamine adding amounts, synthetic temperature on crystal growth, size distribution and optical properties of the synthesized Cu 1.75 S nanocrystals were investigated by XRD, TEM, HRTEM, EDX and UV–vis measurements. The synthetic reaction at above 200 °C grew flaky-shaped nanocrystals with relatively narrow size distribution. The formation of single-phase Cu 1.75 S nanocrystals in the diethylene glycol based solution process might be involved in the presence of intermediate [Cu(en) n ] 1+ and [Cu(NH 3 ) 4 ] 2+ complexes in reaction solution, providing a stable Cu(I) and Cu(II) valent-mixed precursor.