Phase purification of Cu–S system towards Cu1.8S and its catalytic properties for a clock reaction

Abstract

Controlling the composition and crystal phase is an important issue to tune material physical/chemical properties. Herein, it was found that triphenyl phosphine (TPP) can be used as a phase transfer agent to transform CuS, Cu₃₉S₂₈ phases into pure low-sulfur Cu_1.8S phase. When mixed phase copper sulfides were reacted with triphenyl phosphine under suitable temperature, sulfur was extracted to produce the low-sulfur Cu_1.8S phase. It was also demonstrated that the Cu–S product can effectively catalyze a clock reaction between methylene blue and hydrazine in aqueous medium. In addition, the photothermal conversion properties of the Cu–S based products were studied. The results show that the purified Cu_1.8S materials show enhanced or similar properties than the original mixed-phase Cu–S products.