Improving the power conversation efficiency of dyesensitized solar cells (DSSCs) has become a challenge and a matter of interest for researchers. Designing a simple device structure with better performance by a cost-effective fabrication technique is essential for photovoltaic technology. This study emphasizes an alternative hybrid composite photoanode material for the DSSC devices. Pristine Zn 2 SnO 4 and Zn 2 SnO 4 -SnO 2 and Zn 2 SnO 4 -ZnO composites were synthesized by facile solid-state calcination to prepare the photoanode for DSSCs. The structural, surface morphological, optical, and band structural properties of the synthesized samples were studied. An attempt has been made to correlate the power conversion efficiency of the fabricated devices with the investigated properties. The X-ray diffraction analysis confirms the presence of multiphases that depend on the stoichiometric ratio of precursor materials. The surface morphology analysis reveals that the Zn 2 SnO 4 -SnO 2 and Zn 2 SnO 4 -ZnO composites exhibit microsheet and microrod structures, respectively. The composite materials show a higher amount of dye loading, leading to better performance than the pristine Zn 2 SnO 4 sample. A better band matching of the synthesized composite materials with other layers provides a higher carrier density. The composite photoanodes exhibit higher efficiency (6.26% for Zn 2 SnO 4 -SnO 2 and 4.48% for Zn 2 SnO 4 -ZnO) than the pristine Zn 2 SnO 4 photoanode (3.76%). The results indicate that the Zn 2 SnO 4 -based composites can be potential materials for photoanode applications.

Metal oxide and metal dichalcogenide heterostructure composites are promising candidates for electrochemical use. In this study, a hybrid heterostructure composite electrode material was made using a straightforward hydrothermal process using transition metal oxide (NiO) and metal dichalcogenide (MoS2). The surface of the flower-like structured MoS2 was grown with granular structured NiO, and this heterostructure composite exhibited considerably improved specific capacitance when compared to the pure NiO and MoS2 materials. The pseudocapacitive performance was effectively supported by the heterostructure combination of transition metal oxide (TMOs) and metal dichalcogenide (MDC), which greatly improved ion transport within the material and storage. At a current density of 1 A/g, the prepared heterostructure composite electrode material exhibited a specific capacitance of 289 F/g, and, after 2000 cycles, the capacitance retained 101% of its initial value. The symmetric device was constructed and put through tests using LED light. This finding opens up a new avenue for the quickly increasing the field of heterostructure materials.

Photodegradation of methylene blue dye was studied with pure and graphene oxide incorporated zinc oxide thin films as catalysts. Graphene oxide content in the precursor solution was varied from 0.0005 to 0.005 g/L. Thin films were prepared by automated spray pyrolysis technique at a substrate temperature of 425 °C. Structural studies revealed the formation of hexagonal wurtzite structure of zinc oxide. Carbon presence in the films was confirmed with energy‐dispersive spectroscopy. Optical band gap of the samples was determined using Tauc method. Intensity of the near band emission of photoluminescence spectrum was found to decrease upon increasing graphene oxide concentration. Photocatalytic activity of all the films has been studied against methylene blue dye under solar irradiation for 180 minutes and it is found that the highest graphene oxide content attributes to better degradation efficiency of 91.2 %.

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