The present joint experimental and theoretical work provides in-depth understanding on the morphology and structural, electronic, and optical properties of ZnWO nanocrystals. Monoclinic ZnWO nanocrystals were prepared at three different temperatures (140, 150, and 160 °C) by a microwave hydrothermal method. Then, the samples were investigated by X-ray diffraction with Rietveld refinement analysis, field-emission scanning electron microscopy, transmission electronic microscopy, micro-Raman and Fourier transform infrared spectroscopy, ultraviolet-visible spectroscopy, and photoluminescence measurements. First-principles theoretical calculations within the framework of density functional theory were employed to provide information at the atomic level. The band structure diagram, density of states, Raman and infrared spectra were calculated to understand the effect of structural order-disorder on the properties of ZnWO. The effects of the synthesis temperature on the above properties were rationalized. The band structure revealed direct allowed transitions between the VB and CB and the experimental results in the ultraviolet-visible region were consistent with the theoretical results. Moreover, the surface calculations allowed the association of the surface energy stabilization with the temperature used in the synthesis of the ZnWO nanocrystals. The photoluminescence properties of the ZnWO nanocrystals prepared at 140, 150, and 160 °C were attributed to oxygen vacancies in the [WO] and [ZnO] clusters, causing a red shift of the spectra. The ZnWO nanocrystals obtained at 160 °C exhibited excellent photodegradation of Rhodamine under ultraviolet light irradiation, which was found to be related to the surface energy and the types of clusters formed on the surface of the catalyst.

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CaTiO 3 (CT) and α-Ag 2 WO 4 (AW) semiconductors are widely known for their interesting electrical and photoluminescence (PL) properties. In this study, we decorated CT with AW for obtaining CaTiO 3 :α-Ag 2 WO 4 (CT:AW), and investigated the properties of the produced materials, especially their PL properties. The X-ray diffraction peaks of the synthesized microcrystals were well indexed to the orthorhombic phase for all the samples. Two morphologies: cube-like for CT and rod-like for AW were observed by field-emission scanning electron microscopy (FE-SEM). The FE-SEM and transmission electron microscopy (TEM) studies indicated the presence of rod-shaped AW deposited on the surfaces of cube-shaped CT morphology. PL emission of the decorated samples overlaps all the visible region spectra because of the contribution from both the constituent materials that induce maximum emissions in the blue and red regions. The examination of Commission internationale de ĺéclairage (CIE) coordinates confirmed that the decorated samples exhibit favored emission the red wavelength region.

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