The invention provides a multi-shell-layer
metal oxide hollow ball and a preparation method thereof. A hydrothermal method is used for preparing a carbon ball template;
metal salts are dissolved in carbon ball suspension liquid, and the gradient distribution, the depth and the number of
metal salts entering carbon balls are controlled through regulating adsorption conditions such as metal salt concentration, solution pH value, soaking temperature and time and the like; and the heat treatment is carried out on the carbon balls adsorbing metal ions, and the multi-shell-layer metal
oxide hollow ball can be obtained. The shell-layer of the hollow ball prepared by the method is formed by accumulating nanometer
crystal particles of metal oxides, the shell layer number can be regulated and changed from two to four, and both the size of the hollow ball and the thickness of the shell
layers are controllable. The method provided by the invention is simple and is easy to implement, the
controllability is high, the
pollution is little, the cost is low, and in addition, the general applicability is realized. The prepared product has a hollow structure and the shell
layers with the thickness inthe nanometer level, simultaneously, the internal space can be effectively utilized through the multilayer structure, and the multi-shell-layer metal
oxide hollow ball is applied to gas sensitivity and
photocatalysis and has the more excellent performance through being compared with the traditional nanometer material and a single-layer hollow ball.