Materials that depend on high temperature, pressure, or long periods of crystallization in the obtention of the pure phase have been the focus of several studies due to the economic and ecological aspects. The high-energy ball milling method (HEBM) has been adopted to synthesize different materials using solid-state reactions. In this study, bare barium niobate was efficiently synthesized at room temperature using the HEBM. The materials synthesized at different synthesis times were characterized by X-ray diffraction (XRD) and Rietveld refinement, which confirms the orthorhombic structure for BaNb₂O₆, with a high crystallinity degree at 3 h (BaNb_3) and 4 h (BaNb_4) of synthesis. The main vibrational modes of the structure were identified by Raman spectroscopy. In contrast, band-gap values between 3.77 and 3.84 eV were obtained by diffuse reflectance spectroscopy for the samples BaNb_3 and BaNb_4, respectively. The electrochemical experiments using the modified glassy carbon electrode (GCE) with BaNb_3 sample as a working electrode show the almost reversible profile for the cyclic voltammetry curves in potassium ferrocyanide in the scanning speed range of 1 to 100 mV s^–1. Moreover, the flat band energy (E_fb) indicates the p-type semiconductor characteristic for BaNb₂O₆, and a specific capacitance of 3375.66 mF cm^–2, suggesting an interesting material for composition n–p heterojunctions.

中文翻译：

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室温下球磨法测定 BaNb2O6：结构、光学、形态和电化学特性


由于经济和生态方面，依赖于高温、高压或在纯相中长时间结晶的材料一直是多项研究的重点。高能球磨法 （HEBM） 已被用于使用固态反应合成不同的材料。在这项研究中，使用 HEBM 在室温下高效合成裸铌铌酸盐。通过X射线衍射（XRD）和Rietveld精修对不同合成时间合成的材料进行表征，证实了BaNb₂O₆的正交结构，在合成3 h（BaNb_3）和4 h（BaNb_4）时具有高结晶度。通过拉曼光谱确定了结构的主要振动模式。相比之下，通过漫反射光谱法分别获得了 BaNb_3 和 BaNb_4 样品的带隙值在 3.77 和 3.84 eV 之间。使用改性玻碳电极 （GCE） BaNb_3样品作为工作电极的电化学实验表明，在 1 至 100 mV s^–1 的扫描速度范围内，亚铁氰化钾的循环伏安曲线几乎是可逆的。此外，平带能量 （E_fb） 表示 BaNb₂O₆ 的 p 型半导体特性，比电容为 3375.66 mF cm^–2，表明是一种有趣的材料组成 n-p 异质结。