Nagyné-Kovács Teodóra, Studnicka Levente, Lukács István Endre, László Krisztina, Pasierb Pawel, Szilágyi Imre Miklós, Pokol György
Department of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics, Műegyetem rakpart 3, H-1111 Budapest, Hungary.
Research Institute for Technical Physics and Materials Science, Eötvös Loránd Research Network, Konkoly Thege M. út 29-33, H-1121 Budapest, Hungary.
Nanomaterials (Basel). 2020 May 7;10(5):891. doi: 10.3390/nano10050891.
Effects of different reaction parameters in the hydrothermal synthesis of molybdenum oxides (MoO) were investigated and monoclinic (β-) MoO was prepared hydrothermally for the first time. Various temperatures (90/210 °C, and as a novelty 240 °C) and durations (3/6 h) were used. At 240 °C, cetyltrimethylammonium bromide (CTAB) and CrCl additives were also tested. Both the reaction temperatures and durations played a significant role in the formation of the products. At 90 °C, h-MoO was obtained, while at 240 °C the orthorhombic (α-) MoO formed with hexagonal rod-like and nanofibrous morphology, respectively. The phase transformation between these two phases was observed at 210 °C. At this temperature, the 3 h reaction time resulted in the mixture of h- and α-MoO, but 6 h led to pure α-MoO. With CTAB the product was bare o-MoO, however, when CrCl was applied, pure metastable m-MoO formed with the well-crystallized nanosheet morphology. The gas sensing of the MoO polymorphs was tested to H, which was the first such gas sensing study in the case of m-WO. Monoclinic MoO was found to be more sensitive in H sensing than o-MoO. This initial gas sensing study indicates that m-MoO has promising gas sensing properties and this MoO polymorph is promising to be studied in detail in the future.
研究了水热合成氧化钼（MoO）过程中不同反应参数的影响，并首次通过水热法制备了单斜晶系（β-）MoO。使用了各种温度（90/210 °C，以及新的240 °C）和反应时长（3/6 h）。在240 °C时，还测试了十六烷基三甲基溴化铵（CTAB）和CrCl添加剂。反应温度和反应时长对产物的形成都起着重要作用。在90 °C时，得到了h-MoO，而在240 °C时，分别形成了具有六方棒状和纳米纤维形态的正交晶系（α-）MoO。在210 °C时观察到了这两个相之间的相变。在此温度下，3 h的反应时间导致h-MoO和α-MoO的混合物，但6 h则得到纯α-MoO。使用CTAB时，产物是裸露的o-MoO，然而，当使用CrCl时，形成了具有良好结晶纳米片形态的纯亚稳m-MoO。对MoO多晶型物对H的气敏性能进行了测试，这是m-WO情况下首次进行此类气敏研究。发现单斜晶系MoO在H传感方面比o-MoO更敏感。这项初步的气敏研究表明，m-MoO具有良好的气敏性能，这种MoO多晶型物有望在未来进行详细研究。
