Controllable preparation of Ag@Fe3O4 core-shell nanoparticles and evaporation characteristics of nanoparticles-modified carbon membranes

To improve the ability of the medium to capture solar energy, Ag@Fe3O4 core-shell nanoparticles (NPs) were prepared in this paper. The influences of different preparation conditions on the particle structure and photothermal properties were investigated, and the growth and spectral absorption properties of Ag@Fe3O4 NPs were analyzed. At the same time, nanoparticles-modified carbon membranes (NPCMs) were prepared by electrostatic adsorption method. The influences of radiation intensity and preparation concentration on photothermal properties were investigated, and the local evaporation mechanism of NPCMs was deeply explored. Experiments showed that changing the molar ratio of the precursor can effectively regulate the structure and optical properties of the NPs. The increase of the core radius of the NPs will increase the electric field strength (E) of the core surface and promote the absorption of light. Optimizing the temperature and heating time of the preparation process is very important for the successful realization of Fe3O4 coated Ag, while deepening the coupling between plasmons on the surface of adjacent NPs. Compared with the intensity of 5 sun, the evaporation efficiency at 2 sun is increased by 13.37%. The local evaporation effect caused by NPCMs makes the system still have good evaporation efficiency at low radiation intensity.