Microwave-Assisted Synthesis of (C12H25NH3)2MCl4 Hybrid Perovskites (M: Zn, Cu, and Mn): Metal-Ion Effects on Structural and Thermal Properties.

Hybrid perovskites are emerging as promising candidates for thermal management and thermal energy storage (TES). Compared to traditional solid-liquid phase change materials, these hybrids offer tunable structures, enhanced thermal conductivity, and comparable latent heats. This study extends a rapid, scalable microwave (MW)-assisted synthesis to a broader suite of organic-inorganic hybrid perovskites with the general formula (C12H25NH3)2MCl4 (where M = Zn, Cu, Mn). Beyond broadening the synthetic scope, we provide a comprehensive comparative analysis of how metal center substitutions influence material properties. The structural integrity, morphology, and phase purity were systematically characterized via XRD, SEM, EDX, and FTIR, while thermal behaviors were evaluated using DSC and TGA. The results demonstrate that the specific metal ion significantly dictates both the crystalline structure and phase transition thermodynamics. Transition enthalpies ranged from 58 to 112 J/g, with peak temperatures between 46 and 74 °C. Thermal stability also varied across the series, with decomposition onset occurring between 270 and 335 °C. By elucidating how metal selection steers performance, this work establishes MW-assisted synthesis as a versatile, energy-efficient platform for the tailored fabrication of advanced solid-solid phase change materials for practical energy storage applications.