将这些关键点和结论用学术化的语言风格扩写成文字。关键点：1 GaNZnO固溶体可以实现ZnO含量的全范围调控；2 催化活性最好的固溶体ZnO含量在125至25左右；3 采用不同方法制备的固溶体带隙值大小不同；4 固溶体制备过程中存在微观结构问题。结论：固溶体制备过程中需要考虑微观结构问题以实现最佳催化活性。

1. GaN/ZnO solid solution can achieve the full range control of ZnO content;
2. The solid solution with ZnO content ranging from 12.5% to 25% exhibits the best catalytic activity;
3. The bandgap of the solid solution prepared by different methods varies;
4. There are microstructural issues in the preparation process of the solid solution.

Conclusion: Microstructural issues need to be considered in the preparation process of the solid solution to achieve the best catalytic activity.