Pinatti Ivo M, Trench Aline B, Tello Ana C M, Pereira Paula F S, Souza Josiane C, Teodoro Marcio D, Rosa Ieda L V, Andrés Juan, Longo Elson, Simões Alexandre Z
Faculty of Engineering of Guaratinguetá, São Paulo State University (UNESP), Guaratinguetá 12516-410, SP, Brazil.
CDMF, LIEC, Federal University of São Carlos (UFSCar), P.O. Box 676, São Carlos 13565-905, Brazil.
Inorg Chem. 2021 Apr 19;60(8):5937-5954. doi: 10.1021/acs.inorgchem.1c00368. Epub 2021 Mar 26.
In this paper, we report the synthesis of silver selenite (AgSeO) by different methods [sonochemistry, ultrasonic probe, coprecipitation, and microwave-assisted hydrothermal methods]. These microcrystals presented a structural long-range order as confirmed by X-ray diffraction (XRD) and Rietveld refinements and a structural short-range order as confirmed by Fourier transform infrared (FTIR) and Raman spectroscopies. X-ray photoelectron spectroscopy (XPS) provided information about the surface of the samples indicating that they were pure. The microcrystals presented different morphologies and sizes due to the synthesis method as observed by field emission scanning electron microscopy (FE-SEM). The optical properties of these microcrystals were evaluated by ultraviolet-visible (UV-vis) spectroscopy and photoluminescence (PL) measurements. Thermal analysis confirmed the temperature stability of the as-synthetized samples. Further trapping experiments prove that the holes and hydroxyl radicals, to a minor extent, are responsible for the photocatalytic reactions. The experimental results are sustained by first-principles calculations, at the density functional theory (DFT) level, to decipher the structural parameters, electronic properties of the bulk, and surfaces of AgSeO. By matching the experimental FE-SEM images and theoretical morphologies, we are capable of finding a correlation between the morphology and photocatalytic activity, along with photodegradation of the Rhodamine B dye under UV light, based on the different numbers of unsaturated superficial Ag and Se cations (local coordination, i.e., clusters) of each surface.
在本文中，我们报道了通过不同方法[声化学法、超声探头法、共沉淀法和微波辅助水热法]合成亚硒酸银（Ag₂SeO₃）的过程。这些微晶呈现出长程结构有序，这通过X射线衍射（XRD）和Rietveld精修得以证实，同时也呈现出短程结构有序，这通过傅里叶变换红外（FTIR）光谱和拉曼光谱得以证实。X射线光电子能谱（XPS）提供了有关样品表面的信息，表明它们是纯净的。通过场发射扫描电子显微镜（FE - SEM）观察发现，由于合成方法的不同，这些微晶呈现出不同的形态和尺寸。通过紫外 - 可见（UV - vis）光谱和光致发光（PL）测量对这些微晶的光学性质进行了评估。热分析证实了合成样品的温度稳定性。进一步的俘获实验证明，空穴和羟基自由基在较小程度上是光催化反应的原因。实验结果得到了密度泛函理论（DFT）水平的第一性原理计算的支持，以解释Ag₂SeO₃的结构参数、体相和表面的电子性质。通过匹配实验FE - SEM图像和理论形态，我们能够基于每个表面不饱和表面Ag和Se阳离子（局部配位，即簇）的不同数量，找到形态与光催化活性之间的相关性，以及紫外光下罗丹明B染料的光降解情况。
