Nitrate is extensively accepted as a kind of thermal storage material in solar thermal power generation because of its wide temperature range, high boiling point, low vapor pressure at high temperature, large specific heat and low viscosity. In this paper, the base salt NaNO₃ was modified by solution combustion method by using urea as fuel. The configuration and thermal properties of the as-prepared salt were investigated by using X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FT-IR), Field Emission Scanning Electron Microscope (FE-SEM), X-ray Photoelectron Spectroscopy (XPS) and Differential Scanning Calorimeter (DSC). The outcome showed that the structure and thermal properties of NaNO₃ were improved by solution combustion process. The particle size and shape of as-prepared salt were modified. As the proportion of the fuel increasing, the special morphology like linear, needle and spherule gradually grown at the surface and the interior of the modified salt. The phase of as-prepared salt was remaining NaNO₃. With the change of urea fuel, the specific heat was increased by 53.1% in solid phase, in addition increased by 51.2% in liquid phase in the maximum extent. This work not only studied the specific heat of chemically modified NaNO₃, but also discussed the influence of NaNO₃ microscopic appearance on its properties, which provides a creative idea for molten salt modification and thermal energy storage.

硝酸盐由于其温度范围宽，沸点高，高温下蒸气压低，比热大且粘度低而被广泛用作太阳能热发电中的一种蓄热材料。本文以尿素为燃料，通过固溶燃烧法对碱式NaNO ₃进行了改性。通过使用X射线衍射（XRD），傅里叶变换红外光谱（FT-IR），场发射扫描电子显微镜（FE-SEM），X射线光电子能谱（X射线衍射（XRD））来研究所制盐的构型和热性能。 XPS）和差示扫描量热仪（DSC）。结果表明，NaNO ₃的结构和热性质通过固溶燃烧过程得到改善。修改了制得的盐的粒径和形状。随着燃料比例的增加，改性盐的表面和内部逐渐形成线性，针状和球状等特殊形态。所制备的盐的相保留为NaNO ₃。随着尿素燃料的变化，固相比热最大增加了53.1％，液相比热最大增加了51.2％。这项工作不仅研究了化学改性的NaNO ₃的比热，而且还讨论了NaNO ₃微观外观对其性能的影响，这为熔融盐的改性和热能存储提供了创新的思路。