Simple synthesis, kinetics and thermodynamics of rod-like Cu2(OH)PO4 microparticles and rod-like Cu4O(PO4)2 nanoparticles

Abstract

Rod-like Cu2(OH)PO4 microparticles were synthesized via a simple wet chemical reaction by mixing the solutions of CuSO4·5H2O and Na3PO4·12H2O at 90 °C for 24 h. Thermal transformation of the prepared Cu2(OH)PO4 microparticles were related to endothermic dehydroxylation and its final decomposed product rod-like Cu4O(PO4)2 nanoparticles were obtained. The XRD results indicated that Cu2(OH)PO4 and Cu4O(PO4)2 crystallize orthorhombic (space group Pnnm, D2h 12) and triclinic (space group P1‾, Ci 1) phases, respectively. The thermal transformation mechanisms from Cu2(OH)PO4 to Cu4O(PO4)2 were expressed thought the relation of the graphical shape of isothermal combined with the non-isothermal multi-heating rate equation and kinetic models (P3/2 and R2) to discuss the change of morphologies from microparticles to nanoparticles. Kinetic parameters and triplet thermodynamic functions of activated compound were determined and fully discussed. The obtained data will be useful for academic scientists and industrial researchers to apply these copper phosphates for special applications.