Synthesis and Phase Analysis of CuFeS2 Powders Prepared by Hydrothermal Method

In recent years, CuFeS2 optoelectronic materials are widely concerned by scientists because of their advantages of safety, non-toxicity and low price. In this work, the CuFeS2 powders were synthesized by simple hydrothermal co-reduction method, the effects of different heat treatment conditions and different sulfur sources on preparation of CuFeS2 phase were systematically studied with CuCl2·2H2O and FeCl3·6H2O as raw materials. The phase structure and surface morphology of the samples were analyzed by X-ray Powder diffractometer (XRD) and scanning electron microscope (SEM). It was found that when the sulfur source was sulfur powder, the sample crystallized well and has no impurity formation. With the reaction temperature extending to 220 °C, the diffraction peak intensity is obviously improved while the grain size decreases slightly with the increase of temperature. The extension of heat treatment temperature and holding time is favorable for preparation of CuFeS2 power and the impurity Fe3O4 crystal can be effectively eliminated by prolonging the time and increasing temperature. With the reaction temperature extending to 220 °C, the shorter the time required for Fe3O4 crystal to disappear. Therefore, the optimum heat treatment temperature for preparing CuFeS2 powder is 220 °C and the time is 20 h.