In vitro crystallization and comprehensive physicochemical characterization of zinc urate: structural, spectral, morphological, thermal, electrochemical and dielectric insights into a bioinspired coordination crystal
摘要
In the present study, zinc urate (ZNU) crystals are grown by the single diffusion gel method. FT-IR analysis confirmed key functional groups such as N–H, C=O, and C–N bonds, with the Zn–O bond at 618 cm−1 confirming the inclusion of zinc in the urate matrix. An average crystallite size of 20.75 ± 2.12 nm, microstrain of 3.38083 ± 1.086 × 10−3 and a dislocation density of 2.848 ± 1.96 × 10−3 nm−2 consistent with a monoclinic crystal system (space group P21/c), yielded a profile R-factor (Rp) of 2.396%, a weighted profile R-factor (R_wp) of 5.071% and a R-factor (R_exp) of 4.811%, (χ2) value of 1.111 and a Goodness-of-Fit (GoF) factor of 1.054 is confirmed by XRD analysis. FESEM–EDAX analysis confirmed the elemental composition, revealing a weight percentage of carbon (40.59%), nitrogen (32.79%), oxygen (20.38%) and zinc (6.24%), indicating zinc incorporation into the urate matrix. CHNS analyzer confirms the presence of hydrogen and exclusion from impurities. UV–visible spectroscopy indicated a hypochromic shift of the primary absorption maximum from 283 nm, resulting in an optical bandgap of 4.05 eV. A three-phase thermal decomposition process, with ZNU as the thermally stable final product and an approximately 34% residual mass, is revealed by TG–DTA. Cyclic voltammetry demonstrated excellent pseudocapacitive nature with a specific capacitance of 1139 F/g at a scan rate of 5 mV/s. The hopping mediated charge transport has an exceptionally high to low-frequency dielectric constant and a characteristic relaxation peak at 105 Hz. These observed structure–property correlations highlight ZNU as a promising crystalline material for applications in energy storage and functional electronics.