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The present joint experimental and theoretical work provides in-depth understanding on the morphology and structural, electronic, and optical properties of ZnWO4 nanocrystals. Monoclinic ZnWO4 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 ZnWO4. 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 ZnWO4 nanocrystals. The photoluminescence properties of the ZnWO4 nanocrystals prepared at 140, 150, and 160 °C were attributed to oxygen vacancies in the [WO6] and [ZnO6] clusters, causing a red shift of the spectra. The ZnWO4 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. [ABSTRACT FROM AUTHOR]

This work combines experimental and computational techniques to exploit the best of both methodologies and thus provide a tool for understanding the geometry, cluster coordination, electronic structure, and optical properties of Ag4V2O7 crystals. This tool has been developed to create structural models and enable a much more complete and rapid refinement of 3D (three dimensional) structures from limited data, aiding the determination of structure–property relationships and providing critical input for materials simulations. Ag4V2O7 crystals were synthesized by a simple precipitation method from an aqueous solution at 30 °C for 10 min. The obtained crystals were characterized by X-ray diffraction (XRD) and Rietveld refinement, and micro-Raman spectroscopy. The crystal morphology was determined by field emission scanning electron microscopy (FESEM), and the optical properties were investigated by ultraviolet-visible (UV-vis) diffuse reflectance spectroscopy and photoluminescence (PL) measurements. The geometric and electronic structures of Ag4V2O7 crystals were investigated by first-principles quantum-mechanical calculations based on the density functional theory. The theoretical results agree with the experimental data to confirm that Ag4V2O7 crystals have an orthorhombic structure, and that the building blocks of the lattice comprise two types of V clusters, [VO4] and [VO5], and two types of Ag clusters, [AgO5] and [AgO6]. This type of fundamental studies, which combine multiple experimental methods and first-principles calculations, have been proved valuable in obtaining a basic understanding of the local structure, bonding, band gap, and electronic and optical properties of Ag4V2O7 crystals. [ABSTRACT FROM AUTHOR]

Multivariate metal-organic frameworks (MTV MOFs) have emerged as promising materials due to their ability to combine properties that enhance features beyond those of their pristine counterparts. Despite the potential for tailoring electronic properties through structural distortions and defects introduced by linkers of variable lengths, examples remain scarce, and information on the electronic structure is limited. Here, we present the multivariate mismatching linker approach to generate photoswitching nanoparticulated MOFs with variable lattice parameters and porosity features controlled by mixed-linker composition. Structural defects, such as dangling linkers, are generated due to mismatching crystal lattices, tuning the electronic structure. Combining biphenyl and azobenzene ditopic linkers promotes cis - trans photoswitching of dangling azobenzene linkers, which is constrained in Zr 6 -azobenzene MOFs. Moreover, introducing low quantities of azobenzene drastically reduces the bandgap of the materials due to the contribution of the azo group, which is supported by first-principles calculations. This paves the way for new photo-responsive materials for photo-switching applications., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

The multivariate modulation of Metal-Organic Frameworks is presented as a valuable tool to introduce multiple functional units into UiO-66 while increasing its porosity. This manuscript encloses a comprehensive study using p -functionalised benzoate -NO 2 , -SO 3 and -SH modulators, rationalizing the defects introduced and their impact on properties.

In this study, several methods were employed to investigate the electrical characteristics of β-Ag 2 MoO 4 systems, both Eu-doped and undoped, synthesized using the microwave-assisted hydrothermal method. The focus extended to understanding how synthesis time influences material defects, with doping fixed at 1%. A systematic shift in the silver vacancy (V Ag ) concentration was observed within the doped β-Ag 2 MoO 4 system. Specifically, this study demonstrated that the incorporation of Eu 3+ into polycrystalline β-Ag 2 MoO 4 initially increases the V Ag concentration. However, as the synthesis time progresses, the V Ag concentration decreases, resulting in alterations in the resulting electrical properties, arising from the intricate interplay between the number of grain boundaries and carrier density. By combining information obtained from photoluminescence, positron annihilation lifetime spectroscopy, and impedance spectroscopy, a comprehensive conduction mechanism was formulated, shedding light on both doped and undoped β-Ag 2 MoO 4 systems.

Here, we present the synthesis of a highly efficient V-doped α-Ag 2 WO 4 catalyst for the oxidation of sulfides to sulfones, exhibiting a high degree of tolerance towards various sensitive functional groups. Remarkably, the catalysts with 0.01% V-doping content exhibited outstanding selectivity towards the oxidation process. Scavenger experiments indicated the direct involvement of electron-hole (e - /h + ) pairs, hydroxyl radical (˙OH), and singlet oxygen ( 1 O 2 ) in the catalytic mechanism. Based on the experimental and theoretical results, the higher activity of the V-doped α-Ag 2 WO 4 samples was associated with the preferential formation of the (100) surface in the catalyst morphology.

This study demonstrates that the electron beam irradiation of materials, typically used in characterization measurements, could be employed for advanced fabrication, modification, and functionalization of composites. We developed irradiation equipment using an electron beam irradiation source to be applied in materials modification. Using this equipment, the formation of a thick Ag film on the Ag 3 PO 4 semiconductor is carried out by electron beam irradiation for the first time. This is confirmed by various experimental techniques (X-ray diffraction, field-emission scanning electron microscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy) and ab initio molecular dynamics simulations. Our calculations demonstrate that, at the earlier stages, metallic Ag growth is initiated preferentially at the (110) surface, with the reduction of surface Ag cations forming metallic Ag clusters. As the (100) and (111) surfaces have smaller numbers of exposed Ag cations, the reductions on these surfaces are slower and are accompanied by the formation of O 2 molecules., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

In the current communication, the synthesis of metallic Bi nanoparticles with coexisting crystallographic structures (rhombohedral, monoclinic, and cubic) obtained via direct femtosecond laser irradiation of NaBiO3 is demonstrated for the first time. By exploring the use of high laser power values, it is revealed that the promoted laser-mediated reactions lead to the synthesis of coexisting phases in metal nanoparticles, which may be a widely occurring phenomenon in other materials under femtosecond laser irradiation, and a fundamental concern for laser-based nanofabrication.

The present joint experimental and theoretical work provides in-depth understanding on the morphology and structural, electronic, and optical properties of ZnWO 4 nanocrystals. Monoclinic ZnWO 4 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 4 . 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 4 nanocrystals. The photoluminescence properties of the ZnWO 4 nanocrystals prepared at 140, 150, and 160 °C were attributed to oxygen vacancies in the [WO 6 ] and [ZnO 6 ] clusters, causing a red shift of the spectra. The ZnWO 4 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.