B-Mg共掺杂纳米VO_(2)的制备及其热致变色特性

Preparation and thermochromic properties of B-Mg co-doped nano-VO_(2)

为降低二氧化钒(VO_(2))材料的相变温度并提高VO_(2)材料的光学特性,采用溶胶-凝胶辅助水热法,控制硼(B)的掺杂原子数分数为6.0%,通过后续的高温退火处理制备硼-镁(B-Mg)共掺杂的纳米VO_(2)粉体,然后将粉体制备成薄膜.通过对B-Mg共掺纳米VO_(2)粉体微结构进行表征,探究Mg的原子数分数对复合材料相变温度和光学特性的影响,获得满足应用标准的B-Mg共掺杂纳米VO_(2)材料.结果表明,复合材料中掺杂的B元素和Mg元素分别以B^(3+)和Mg^(2+)形式存在于VO_(2)结构中,当Mg的原子数分数为1.8%时,复合材料表现出相对优秀的热致变色特性,且具有最低的相变温度(tc=30.8℃),其太阳光调制幅度(ΔT_(sol)=11.8%)能维持在10%以上,平均可见光透过率(Tˉ_(lum)=69.7%)比未掺杂的VO_(2)薄膜高12.1%,满足热致变色智能窗户的要求.研究结果为制备适用于热致变色智能窗户领域的VO_(2)材料提供了理论依据.

In order to reduce the phase transition temperature of vanadium dioxide(VO_(2))materials and improve the optical properties of VO_(2) materials,the boron-magnesium(B-Mg)co-doped vanadium dioxide(VO_(2))powders were prepared through a sol-gel-assisted hydrothermal method in combination with the subsequent high-temperature annealing.The obtained powder was further prepared into a thin film.X-ray diffraction(XRD),X-ray electron spectroscopy(XPS),field emission scanning electron microscope(FESEM),differential scanning calorimeter(DSC),ultraviolet-visible-near-infrared spectrophotometer(UV-vis-NIR)were used to explore the microstructure of the material and effects of the doping concentrations of Mg on the phase transition temperature t_(c) and the optical properties of VO_(2) materials.The B-Mg co-doped nano-VO_(2) material that satisfies various application standards was obtained.The results show that the doped elements of B and Mg exist in the VO_(2) structure as the form of B^(3+) and Mg^(2+).When the atomic percentages of B and Mg are 6.0%and 1.8%,the material shows a relatively excellent thermochromic properties,with the lowest phase transition temperature tc=30.8℃.The sunlight modulation amplitudeΔT_(sol) of the material is 11.8%,which is maintained above 10%.The average visible light transmittance T_(lum) of the material is 69.7%,which is 12.1%higher than that of the undoped VO_(2) film.The properties above meet the requirements for the application in thermochromic smart windows.This work provides scientific basis for the preparation of VO_(2) materials suitable for thermochromic smart windows.