Ammonium zinc phosphate hydrates (NH₄ZnPO₄: NZPO) precursor powder was synthesized by a facile hydrothermal method at 200°C for 8 h. Effect of calcination temperature on structure, morphology and electrochemical properties of zinc pyrophosphate nanostructure (Zn₂P₂O₇: ZPO Nstr) was studied by calcination NZPO precursor powder at 500 (ZPO5), 600 (ZPO6), 700 (ZPO7) and 800 (ZPO8) °C under argon flow for 1 h. Calcination temperature significantly affect structure of samples, since the X-ray diffraction (XRD) analysis confirmed a monoclinic phase with space group P2₁/n (Z = 4) in NZPO precursor powder, an orthorhombic phase of γ-Zn₂P₂O₇ with space group Pbcm in ZPO5 Nstr, and a monoclinic phase of space group I2/c (Z = 12) in ZPO6, ZPO7 and ZPO8 Nstr. Moreover, the crystallite size of calcined ZPO Nstr increased with increasing calcination temperature. The micrographs of all ZPO Nstr revealed by scanning electron microscope (SEM) indicated the dependence of morphology on calcination temperature i.e. a dense agglomeration of perfect rectangular bars of smooth surface with irregular size intercalated by small incomplete grown crystals with small cracked fractures spread on their surfaces was observed in ZPO5 Nstr. For ZPO6 and ZPO7 Nstr, similar morphology was observed with a less dense agglomeration. Selected area electron diffraction (SAED) patterns of all samples obtained by transmission electron microscope (TEM) confirmed their crystal structures. The analyzed data of X-ray absorption near edge spectroscopy (XANES) indicated the presence of Zn²⁺ cations in all ZPO Nstr samples. Electrochemical properties of all active ZPO Nstr working electrodes studied by the cyclic voltammetry (CV), galvanostatic charge-discharge (GCD) and electrochemical impedance spectrum (EIS) using a three–electrode system in a 3 M KOH electrolyte displayed the pseudo-capacitor performance correlated with Faradaic redox reaction. In addition, the specific capacitance (C_s) was found to decrease at higher calcination temperature. The highest C_s of 102.9 F g⁻¹ at 1 A g⁻¹ with 81.58% retention of cycling stability after 1000 cycle test was achieved in ZPO5 Nstr electrode.

磷酸铵水合物（NH ₄ ZnPO ₄：NZPO）前体粉末是通过简便的水热方法在200°C加热8小时合成的。通过在500（ZPO5），600（ZPO6），700（ZPO7）和800下煅烧NZPO前体粉末，研究了煅烧温度对焦磷酸锌纳米结构（Zn ₂ P ₂ O ₇：ZPO Nstr）的结构，形态和电化学性能的影响。（ZPO8）°C在氩气流下保持1小时。煅烧温度显著影响样品的结构中，由于X射线衍射（XRD）分析证实，空间群单斜晶相P2 ₁ / n的（Z = 4）在NZPO前体粉末，γ-Zn的正交相₂ PZPO5 Nstr中空间群为Pbcm的₂ O ₇，空间群I2 / c为单斜相ZPO6，ZPO7和ZPO8 Nstr中的（Z = 12）。而且，煅烧的ZPO Nstr的微晶尺寸随着煅烧温度的升高而增加。扫描电子显微镜（SEM）揭示的所有ZPO Nstr的显微照片均表明形态对煅烧温度的依赖性，即，光滑的，表面尺寸不规则的完美矩形棒的密集团聚，中间夹杂着小的不完整生长的晶体以及散布在其表面的小裂纹在ZPO5 Nstr中观察到。对于ZPO6和ZPO7 Nstr，观察到相似的形态，但团聚程度较小。通过透射电子显微镜（TEM）获得的所有样品的选择区域电子衍射（SAED）图案证实了它们的晶体结构。X射线吸收近边缘光谱法（XANES）的分析数据表明存在锌所有ZPO Nstr样品中的²⁺阳离子。在3 M KOH电解质中使用三电极系统，通过循环伏安法（CV），恒电流充放电（GCD）和电化学阻抗谱（EIS）研究了所有活性ZPO Nstr工作电极的电化学性能。与法拉第氧化还原反应有关。另外，发现在较高的煅烧温度下比电容（C _s）降低。在ZPO5 Nstr电极中，在1000次循环测试后，在1 A g ^-1下的最高C _s为102.9 F g ^-1，具有81.58％的循环稳定性。