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In this work, we present the potassium niobate (KNbO 3 ) nanoparticles as a suitable mesoporous photoelectrode for dye-sensitized solar cells (DSSCs). The KNbO 3 particles were synthesized by the microwave-assisted hydrothermal method using mild conditions and characterized by SEM, XRD, Raman, and UV-Vis diffuse reflectance. The particles presented a pyramidal tower-like shape with an orthorhombic structure and an indirect bandgap of (3.0 ± 0.1) eV. Dye-sensitized solar cells were assembled using the synthesized KNbO 3 nanoparticles, which were deposited as a photoelectrode on a TiO 2 recombination charge blocking layer. It is noticeable that the synergistic operation of the TiO 2 blocking layer and KNbO 3 photoelectrode is essential to achieve photovoltaic behaviour in our solar cells. The short-circuit current density of J sc = 2.82 mA, open-circuit voltage V oc = 669 mV, fill factor FF = 0.62, and a power conversion efficiency PCE = 1.17%, reports elevated parameters if compared to other DSSCs alternative materials, becoming potassium niobate suitable as photoelectrode.

In this work, we investigated the effects of chemical substitution on the structural, electronic, and optical properties of α-Ag2-2xNixWO4 (0 ≤ x ≤ 0.08) solid solutions prepared by a facile microwave-assisted hydrothermal method. The results showed that the increase of Ni concentration in α-Ag2WO4 microcrystals as a host matrix caused a morphological transformation and a shift of the electronic and optical properties. Based on first principles calculations and using Wulff's construction, particle shapes and their transformations in α-Ag2WO4 and α-Ag2-2xNixWO4 can be affected by controlling the ratios of surface energy values between the different facets. In addition, theoretical calculations revealed that Ni substitution in α-Ag2WO4 is more favorable in the Ag2 and Ag4 positions, in which the local coordination of Ag atoms corresponds to clusters with coordination numbers of seven and four, respectively. This behavior could be related to the degree of medium-range structural disorder in α-Ag2-2xNixWO4 crystals. The experimental results were correlated with theoretical simulations to achieve a deeper understanding of the relationship between morphology and properties. These results provide the basis for a rational design for the compositional modulation of structural and optical properties.

This paper reports a theoretical and experimental study of the heterostructure photocatalytic activity in a CdS or ZnS and CdS@ZnS decorated system prepared by a microwave assisted solvothermal (MAS) method. A theoretical model of the decorated system was created in order to analyze the electronic transition mainly in their interface. The results show that CdS and ZnS interfaces produce an electron charge transfer from the CdS electron-populated clusters to the ZnS hole-populated clusters which helps to enhance the photocatalytic activity of the CdS@ZnS decorated system.