钨掺杂二氧化钒/石墨烯复合物的制备及性能

Preparation and properties of tungsten-doped vanadium dioxide / graphene composites

摘要:

以氧化石墨烯粉末(GO)、五氧化二钒(V2O5)、草酸(C2H2O4·2H2O)和钨酸铵〔(NH4)10H2(W2O7)6〕为原料，用水热法制备了一系列钨掺杂二氧化钒/石墨烯复合物，考察了钨掺杂量、氧化石墨烯复合量对复合材料的相变温度及导热率的影响。通过XRD、SEM、DSC、FTIR、激光导热系数测量仪对复合材料的结构形貌、相变性能等进行了表征。结果表明：石墨烯复合后二氧化钒粒子团聚情况得到有效改善，并均匀复合在石墨烯表面。当钨的原子百分比含量为2.5%、氧化石墨烯含量为4%（以五氧化二钒质量为基准）时，形成的钨掺杂二氧化钒/石墨烯复合物与纯二氧化钒相比，相变温度由66 ℃降低到32.2 ℃，导热率由0.700 W/(m·K)提升到16.341 W/(m·K)，该复合材料能同时满足良好的隔热性与高导热等性能要求，取得了隔热性与散热性这一矛盾的对立与统一。

Abstract:

Using graphene oxide powder (GO), vanadium pentoxide(V2O5), oxalic acid(C2H2O4·2H20) and ammonium tungstate((NH4)10H2(W2O7)6)as raw materials, tungsten-doped vanadium dioxide /graphene composite were prepared by hydrothermal method. The effects of W doping and graphene oxide on the phase transition temperature and thermal conductivity of the composites were investigated. XRD, SEM, DSC, FTIR, and laser thermal conductivity measuring instruments were used to characterize the structural morphology and phase transition properties of composites. The results show that the agglomeration of vanadium dioxide particles is effectively improved after graphene compounding, and is uniformly compounded on the surface of graphene. When the atomic percentage of tungsten is 2.5% and the content of graphene oxide composite is 4% (based on the quality of V2O5), compared with the pure vanadium dioxide, the phase transition temperature of the tungsten Doped Vanadium Dioxide / graphene composite decreased from 68 ℃ to 32.2 ℃, and the thermal conductivity was increased from 0.700 W/(m·K) to 16.341 W/(m·K). The composite material can meet the requirements of good thermal insulation and high thermal conductivity at the same time, and overcome the unity of opposites between thermal insulation and heat dissipation.