Synthesis And Properties Of CuS And LaB₆Photothermal Nano Materials

Currently, energy is one of the most prominentproblems in the world. Solar energy is inexhaustible and pollution free.In order to meet the demand of application of solar energy, there has been a significant development in the area of solar energy materials. The ideal solar functional materials could help to solve the problemof the shortage of energy in the world, meanwhile, to avoid environmental pollution. So solar material has a very attractive prospect. Especially, the photothermalmaterials, one of the important solar materials, have been receiving attention.Copper sulfide, and Lanthanum hexaboride, two kinds of near infrared ray（NIR） photothermal materials, were selected as the investigated targets in this work.The Copper sulfidecrystals were synthesized bysolvothermalmethod.The Lanthanum hexaboridenanocrystals wereprepared bymagnesiumhydrolysis assistedroute. The crystal structure and optical properties of the as-synthesized samples were investigated by XRD, FT-IR, and UV-vis. Some results were obtained and listed as follows.Copper sulfide crystals were synthesized by a solvothermal route employing copper chloride and thiourea as raw materials, ethylene glycol- ammonium hydroxide mixing solution as the solvent. The crystal structure and optical properties of the as-synthesized samples were investigated by XRD, FT-IR, UV-vis, and FL. The influence of synthesis conditions on the optical properties of the as-prepared samples were also discussed. The results show that the single-phase hexagonal structure copper sulfide crystals can be obtained in this way. The photoluminescence spectrum shows strong blue and green emission at 470.8nm, 498.4nm, and 577.6nm, respectively. The ultraviolet-visible spectra exhibit that the synthesis conditions have a significant influence on the optical properties of the samples. When the concentration of reactant is 0.3mol/L, the mole ratio of copper chloride to thiourea at start materials is 3:2, the volume ratio of ethylene glycol to ammonium hydroxide is 4:1, the solvothermal temperature is 140 oC, the solvothermal reaction time is 2 h, the as-prepared sample display excellent near-infrared absorption properties. The simulated photothermal results display that the heat conversion efficiency reaches as high as 33.34% for the as-synthesized samples.Copper sulfide crystals were synthesized by a solvothermal route employing copper chloride and thiourea as raw materials, ethanol-water mixing solution as the solvent. The crystal structure and optical properties of the as-synthesized samples were investigated by XRD, UV-vis, SEM, and FT-IR. The influence of synthesis conditions on the optical properties of the as-prepared samples were also studied.The X-ray diffractionspectra exhibit that the single-phase hexagonal structure copper sulfide crystals can be obtained in this way with the p H10 to 12. The Fourier transform infrared spectrumshows thatthe as-synthesized sample was not oxidized. The ultraviolet-visible spectra display that the synthesis conditions have a significant influence on the optical properties of the samples. When the concentration of reactant is 0.2 mol/L, the mole ratio of copper chloride to thiourea at start materials is 1:2, the volume ratio of ethanol to water is 4:1, the solvothermal temperature is 140 oC, the solvothermal reaction time is 10 h, the as-prepared sample display excellent near-infrared absorption properties. The simulated photothermal results display that the heat conversion efficiency reaches as high as 28.65 % for the as-synthesized samples.The Lanthanum hexaboridenanocrystals weresuccessfully prepared bymagnesiumhydrolysis assistedmethod. The crystal structure and optical properties of the as-synthesized samples were investigated by XRD, UV-vis,TEM, and FT-IR.The influence of synthesis conditions were also discussed.The results show that the single-phase cubic structure Lanthanum hexaboride nanocrystals can be obtained in this way. Fourier transform infrared spectroscopy is the further evidence of the as-synthesized samples were Lanthanum hexaboride crystals.TEM image suggests that the size of the samples isabout 30 nm with narrow size distribution. When the temperature of the reaction is 150 oC, the water’s dosage is 3 ml, the magnesium powder’s dosage is 0.15 mol, under those conditions would like to have the maximum yield of LaB₆ nanocrystals. The simulated photothermal results display that the heat conversion efficiency reaches as high as 28.28 % for the as-synthesized samples.