在还原性气氛中制备V_2O_3纳米粉体  

Preparation V_2O_3 Nanopowder in Reductive Atmosphere

作　　者：何山[1] 郑臣谋[2] 

机构地区：[1]中山大学物理系,99硕广州510275 [2]中山大学化学与化学工程学院,副教授广州510275

出　　处：《中山大学研究生学刊（自然科学与医学版）》2002年第1期21-31,共11页Journal of the Graduates Sun YAT-SEN University(Natural Sciences.Medicine)

摘　　要：在H_2气氛中热解一种前体——(NH_4)_5[(VO)_6(CO_3)_4(OH)_9]·10H_2O,得到了球状的纳米V_2O_3粉体。利用TGA和DTA观察了前体的热解过程,发现纯净的V_2O_3在620℃形成,并且在730℃晶化、本文研究了在多种还原条件下得出的粉体。SEM图片表明在650℃保温30分钟获得的粉体粒径大约为30纳米,并且具有很好的均匀性。热重实验表明纳米粉体比微米粉体对气体有更强的吸附作用,在室温条件下更容易被空气重新氧化。DSC实验表明纳米V_2O_3粉体在降温与升温过程中相变温度分别是-119.5℃和-99.2℃,对应的相变热分别是-12.55J g^(-1)和11.42J g^(-1)。V_2O_3 nanopowder with spherical particles was prepared by reducing pyrolysis of the precursor, (NH_4)_5[(VO)_6(CO_3)_4 (OH)_9]·10H_2O, in H_2 atmosphere. The thermolysis process of the precursor in a H_2 flow was investigated by TGA and DTA. The results indicate that pure V_2O_3 forms at 620℃ and crystallizes at 730℃. The effects of various reductive pyrolysis conditions on compositions of V_2O_3 products were studied. SEM mierograph shows that the particles of the V_2O_3 powder obtained at 650℃ for lh are sphere about 30 nm in size with more homogeneous distribution. Themogravimetrie experiment shows that the nanopowder has larger adsorption capacity to gases and is more easily reoxidized by air in room temperature than the micropowder. DSC indicatesthat the temperature of phase transition of nano V_2O_3 powder is-119.5℃ on cooling or-99.2℃ on heating. The transition heats are-12.55J g^(-1) on coding and 11.42J g^(-1) on heating, repeetively.

关 键 词：还原性气氛 制备 铵氧钒碳酸氢氧化合物 热解 球形V2O3纳米粉体 前体 相变温度 相变热 

分 类 号：TB383[一般工业技术—材料科学与工程]