Hanif Muhammad Bilal, Thirunavukkarasu Guru Karthikeyan, Liapun Viktoriia, Makarov Hryhorii, Gregor Maros, Roch Tomas, Plecenik Tomas, Hensel Karol, Sihor Marcel, Monfort Olivier, Motola Martin
Department of Inorganic Chemistry, Faculty of Natural Sciences, Comenius University Bratislava, Ilkovicova 6, 842 15 Bratislava, Slovakia.
Department of Experimental Physics, Faculty of Mathematics, Physics, and Informatics, Comenius University Bratislava, 842 48 Bratislava, Slovakia.
Nanoscale. 2022 Aug 18;14(32):11703-11709. doi: 10.1039/d2nr03379h.
TiO nanotube (TNT) layers are generally prepared in fluoride-based electrolytes electrochemical anodization that relies on the field-assisted dissolution of Ti metal forming nanoporous/nanotubular structures. However, the usage of fluoride ions is considered hazardous to the environment. Therefore, we present an environmentally friendly synthesis and application of TNT layers prepared in fluoride-free nitrate-based electrolytes. A well-defined nanotubular structure with thickness up to 1.5 μm and an inner tube diameter of ∼55 nm was obtained within 5 min using aqueous X(NO) electrolytes (X = Na, K, Sr, Ag). For the first time, we show the photocatalytic performance (using a model organic pollutant), HO˙ radical production, and thorough characterization of TNT layers prepared in such electrolytes. The highest degradation efficiency ( = 0.0113 min) and HO˙ radical production rate were obtained using TNT layers prepared in AgNO (Ag-NT). The intrinsic properties of Ag-NT such as the valence band maximum of ∼2.9 eV, surface roughness of ∼6 nm, and suitable morphological features and crystal structure were obtained. These results have the potential to pave the way for a more environmentally friendly synthesis of anodic TNT layers in the future using the next generation of fluoride-free nitrate-based electrolytes.
二氧化钛纳米管（TNT）层通常是在基于氟化物的电解质中通过电化学阳极氧化制备的，这种方法依赖于钛金属的场辅助溶解以形成纳米多孔/纳米管状结构。然而，氟离子的使用被认为对环境有害。因此，我们展示了一种在无氟的硝酸盐基电解质中制备TNT层的环境友好型合成方法及其应用。使用X(NO₃)₂水溶液电解质（X = Na、K、Sr、Ag），在5分钟内获得了厚度达1.5μm且内管直径约为55nm的结构明确的纳米管状结构。首次展示了在此类电解质中制备的TNT层的光催化性能（使用一种典型有机污染物）、羟基自由基生成情况以及全面表征。使用在硝酸银（Ag - NT）中制备的TNT层获得了最高降解效率（k = 0.0113 min⁻¹）和羟基自由基生成速率。获得了Ag - NT的固有特性，如价带最大值约为2.9eV、表面粗糙度约为6nm以及合适的形态特征和晶体结构。这些结果有可能为未来使用下一代无氟硝酸盐基电解质更环境友好地合成阳极TNT层铺平道路。
