ZnO has a strong UV absorption capacity, but also has a high photocatalytic performance, which limits its application in the field of UV shielding. In order to explore the possibility of ZnO's application in the field of ultraviolet shielding, this article uses VASP to construct a ZnO/CeO₂ heterojunction and performs electronic and optical simulation calculations on it. Then lignin is used to combine with the synthesized ZnO/CeO₂ heterojunction to prepare lignin-modified nano-ZnO/CeO₂ heterojunction. Through the FT-IR, XRD, SEM, UV-Vis-DRS means the characterization of samples. The UV shielding properties of the synthesized samples were investigated with methylene blue as the protection object. The results show that the light absorption performance of the samples at 280～420 nm is better than that of ZnO/CeO₂ samples. The retention rate of methylene blue for 70 min under UV irradiation was 77.92%, indicating that the synthesized sample was a UV shielding material with high UV shielding properties and low photocatalytic activity.

This paper mainly studies a technical method for detecting the metal content in oil, that is, the combination of microwave digestion and ICP?AES detection technology. Studies have shown that the method has good applicability to the elements measured in the sample, and each element has a good linear correlation with its mass concentration, both greater than 0.999, and the detection limits of iron, manganese, and lead are 0.005 0 mg/L, 0.000 3 mg/L, 0.007 0 mg/L. The reliability of the data obtained by the method was verified by the spiked recovery experiment and the precision of the experimental method. The relative standard deviation of each element was less than 2%, and the recoveries were between 94.1% and 107.6%. Compared with the conventional single detection method, the detection method constructed in this paper has the characteristics of high sensitivity, fastness and high precision.