Study on preparation of core-shell structure VO2(M)@SiO2 by silica sol-gel coating
The core-shell structured VO2(M)@SiO2 materials can be prepared by sol-gel method aiming to significantly en-hance their visible light transmittance(Tium)and effectively slow down the oxidation process of VO2(M).It has significant implications for enhancing the application value of smart windows.While the Stober method was a traditional approach for fabricating VO2(M)@SiO2 core-shell structures,the sol-gel method was used to simplify the preparation process,reduce production cost,and minimize process control factors.Preliminary investigations on the silica sol-gel experiment were con-ducted to explore the process parameters for silica sol gelation and verify the feasibility of silica sol-gel coating on VO2(M).The research results demonstrated that the optimal gelation capacity of the silica sol was achieved with a pH value of 5~6 and a solid content of 15%~20%.Additionally,the gelation time was shortened with the increase of gelation temperature,and the crystallinity and thermal stability of SiO2 powder obtained after roasting were increased.Dense and stable core-shell structured VO2(M)@SiO2 materials were successfully synthesized using the optimized process parameters for silica sol-gel.The coating coverage reached 93.3%,and the transmittance of the thin film was improved to 65%.Furthermore,the phase transition temperature of the material was decreased,and the hysteresis loop width was narrowed.Therefore,the sol-gel method with silica sol provided a simplified and cost-effective approach for preparing highly performance core-shell struc-tured VO2(M)@SiO2 materials,holding significant potential for applications such as smart windows.
sol-gel method using silica solcoatingcore-shell structureVO2(M)@SiO2 materials