Synthesis and characterization of layered FePS3 for hydrogen uptake

Iron phosphorus trisulfide FePS₃ is related to the chalcogenides. It is characterized by layered structure. FePS₃ powder was prepared by solid state reaction and heated up to 650 °C using two different heating rates 1 °C/min and 40 °C/min. The results showed that the FePS₃ produced with slow heating rate was highly ordered single crystalline phase while the powder produced with the fast heating rate was poly crystalline phase. The surface morphology and the grain size were influenced by the heating rate used for preparation. The thermal resistance of the highly ordered crystalline phase extended till 680 °C while the less ordered one extended to 660 °C. The products at 900 °C revealed partial decomposition of FePS₃ with subsequent formation of iron sulfide phases poorer with sulfur element. The FePS₃ of single crystalline phase exhibited higher hydrogen sorption capacity at different temperatures than the less ordered crystalline phase. Hydrogen capacity was reduced by cycling as the interlayer gap shrinks.