CAJ | 학술논문

锰氧化物是一类重要的且具有广泛应用背景的材料,控制合成不同形貌和组成的锰氧化物纳米结构将有助于拓宽其应用领域.本文报道了以Mn_3O_4为前驱体,通过水热法控制合成MnO_2纳米结构的方法.用X射线衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)等手段对产物进行表征.在硫酸体系中,当反应温度为80和180℃时,所得产物分别为γ-MnO_2海胆结构和β-MnO_2单晶纳米棒.此外,MnOOH纳米线可以在稀酸溶液中合成.考察了反应温度、溶液酸度、反应时间对产物结构的影响,并提出了基于γ-MnO_2为中间产物的反应机理.实验结果表明,水热体系促进了产物的各向异性生长并最终形成不同形貌和结构的锰氧化物.
맹양화물시일류중요적차구유엄범응용배경적재료,공제합성불동형모화조성적맹양화물납미결구장유조우탁관기응용영역.본문보도료이Mn_3O_4위전구체,통과수열법공제합성MnO_2납미결구적방법.용X사선연사(XRD)、소묘전경(SEM)、투사전경(TEM)등수단대산물진행표정.재류산체계중,당반응온도위80화180℃시,소득산물분별위γ-MnO_2해담결구화β-MnO_2단정납미봉.차외,MnOOH납미선가이재희산용액중합성.고찰료반응온도、용액산도、반응시간대산물결구적영향,병제출료기우γ-MnO_2위중간산물적반응궤리.실험결과표명,수열체계촉진료산물적각향이성생장병최종형성불동형모화결구적맹양화물.
Manganese oxides show huge structural flexibility and appear in various crystallographic polymorphs. Hence, morphological and phase control of desired manganese oxide nanostructures could enable their properties to be tuned with a greater versatility, and endow them with potential applications. Herein, we report a simple hydrothermal route for the synthesis of various MnO_2 nanostructures using Mn_3O_4 powder as raw material. The obtained products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Results show that in H_2SO_4 solution, urchin-like γ-MnO_2 nanostructures and single-crystal β-MnO_2 nanorods are obtained at 80 and 180 ℃, respectively. In addition, MnOOH nanowires were obtained in a dilute acid solution. The influence of synthetic parameters including temperature, acidity, and reaction time are discussed. Theγ-MnO_2 intermediate might play an important role in the formation of nanorods. The evolution of phases and morphologies in the reaction process suggested the anisotroplc crystal growth for the formation of nanostructures under acidic conditions.