Institute of Chemistry, State University of Campinas, Unicamp, 13083-970 Campinas, SP Brazil.
Department of Physical and Analytical Chemistry, Jaume I University, 12071 Castelló de la Plana, Spain.
Inorg Chem. 2021 Jan 18;60(2):1062-1079. doi: 10.1021/acs.inorgchem.0c03186. Epub 2020 Dec 29.
Silver tungstate (AgWO) shows structural polymorphism with different crystalline phases, namely, orthorhombic, hexagonal, and cubic structures that are commonly known as α, β, and γ, respectively. In this work, these AgWO polymorphs were selectively and successfully synthesized through a simple precipitation route at ambient temperature. The polymorph-controlled synthesis was conducted by means of the volumetric ratios of the silver nitrate/tungstate sodium dehydrate precursors in solution. The structural and electronic properties of the as-synthesized AgWO polymorphs were investigated by using a combination of X-ray diffraction and Rietveld refinements, X-ray absorption spectroscopy, X-ray absorption near-edge structure spectroscopy, field-emission scanning electron microscopy images, and photoluminescence. To complement and rationalize the experimental results, first-principles calculations, at the density functional theory level, were carried out, leading to an unprecedented glimpse into the atomic-level properties of the morphology and the exposed surfaces of AgWO polymorphs. Following the analysis of the local coordination of Ag and W cations (clusters) at each exposed surface of the three polymorphs, the structure-property relationship between the morphology and the photocatalytic and antibacterial activities against amiloride degradation under ultraviolet light irradiation and methicillin-resistant , respectively, was investigated. A possible mechanism of the photocatalytic and antibacterial activity as well the formation process and growth of the polymorphs is also explored and proposed.
钨酸银（AgWO）具有多种晶体相的结构多态性，分别为正交、六方和立方结构，通常被称为α、β和γ。在这项工作中，通过在环境温度下的简单沉淀路线成功地选择性合成了这些 AgWO 多晶型物。通过溶液中硝酸银/钨酸钠二水合物前体的体积比来进行多晶型控制合成。通过使用 X 射线衍射和 Rietveld 精修、X 射线吸收光谱、X 射线吸收近边结构光谱、场发射扫描电子显微镜图像和光致发光的组合，研究了合成的 AgWO 多晶型物的结构和电子性质。为了补充和合理化实验结果，在密度泛函理论水平上进行了第一性原理计算，这使得人们对 AgWO 多晶型物的形貌和暴露表面的原子级性质有了前所未有的了解。在分析了三种多晶型物每个暴露表面上的 Ag 和 W 阳离子（簇）的局部配位之后，研究了形貌与光催化和抗菌活性之间的结构-性质关系，分别是在紫外光照射下对阿米洛利降解和耐甲氧西林的降解的活性。还探索并提出了光催化和抗菌活性以及多晶型物的形成过程和生长的可能机制。
