氧化石墨烯在水热法制备Sc_2W_3O_(12)粉体中的应用

Application of Graphene Oxide in Synthesis of Sc_2W_3O_(12) Powder

以硝酸钪,钨酸铵等为原料,氧化石墨烯为表面活性剂,采用水热法制备了类十字架状Sc2W3O12粉体。利用XRD、TG-DSC、Raman及SEM考察了加入氧化石墨烯对所合成产物结构和形貌的影响,采用TMA测试了所得Sc2W3O12粉体的热膨胀性质。分析表明：在200℃水热条件下,氧化石墨烯包裹在Sc2W3O12晶粒表面并抑制了原有某些晶面的增长,使晶粒逐渐长为棒状,进而纳米棒团聚成类十字架状,产物经620℃热处理10 min后得到纯净的Sc2W3O12粉体,其在室温~800℃均呈现出负热膨胀特性,且平均热膨胀系数为-4.75×10-6/K。

Cross-like Sc2W3O12 powder was synthesized via hydrothermal method by using scandium nitrate, ammonium tungstate hydrate as raw materials and graphene oxide as surfactant. XRD, TG-DSC, Raman and SEM were used to study the influence of graphene oxide on structures and morphologies of the as-prepared product, and the negative thermal expansion properties were detected by TMA. Results show that graphene oxide wraps the grain of Sc2W3O12 and inhibits the growth of some of the original crystal faces, which makes the grain grow to nanorods, then the nanorods assemble into cross-like structure. The pure cross-like Sc2W3O12 powder is obtained by hydrothermal method at 200℃ followed by heat treatment at 620℃ for 10 min. The TMA data indicate that the thermal expansion coefficient of Sc2W3O12 is-4.75×10-6 /K from room temperature to 800℃.