Abstract This article describes the synthesis of α-Ag2W0.75Mo0.25O4 using a coprecipitation method followed by microwave irradiation for different times. The samples were characterized using X-ray and neutron diffractions with Rietveld refinement, Raman spectroscopy, X-ray fluorescence, and ultraviolet-visible diffused reflectance spectroscopy, as well as by photoluminescence emissions. To complement and rationalize the experimental results, first-principles calculations were performed. The formation and growth of metallic Ag nanoparticles on the surfaces of α-Ag2W0.75Mo0.25O4 were studied by transmission electron microscopy and energy dispersive X-ray spectroscopy. Results show that α-Ag2W0.75Mo0.25O4 samples obtained correspond to α-Ag2WO4/β-Ag2MoO4 heterostructure, and the posterior microwave irradiation favors the process of substituting W by Mo, with subsequent formation of a solid solution. Photocatalytic tests were performed to verify the photocatalytic efficiency against the Rhodamine B. Photoluminescence emissions and photocatalytic results showed that the samples obtained at the longest microwave irradiation time promoted the formation of structural defects and enhanced the material properties.

中文翻译：

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α-Ag2W0.75Mo0.25O4的结构、光学性质和光催化活性

摘要 本文描述了使用共沉淀法和不同时间的微波辐射合成 α-Ag2W0.75Mo0.25O4。使用带有 Rietveld 精修的 X 射线和中子衍射、拉曼光谱、X 射线荧光和紫外-可见漫反射光谱以及光致发光发射对样品进行表征。为了补充和合理化实验结果，进行了第一性原理计算。通过透射电子显微镜和能量色散X射线光谱研究了α-Ag2W0.75Mo0.25O4表面金属Ag纳米颗粒的形成和生长。结果表明，获得的α-Ag2W0.75Mo0.25O4样品对应于α-Ag2WO4/β-Ag2MoO4异质结构，后部微波辐射有利于 Mo 取代 W 的过程，随后形成固溶体。进行光催化测试以验证对罗丹明 B 的光催化效率。光致发光发射和光催化结果表明，在最长微波照射时间下获得的样品促进了结构缺陷的形成并增强了材料性能。