Zinc molybdate (ZnMoO₄) was prepared by thermal decomposition of an oxalate complex under a controlled temperature of 500 °C. Analyses of the oxalate complex were carried out using Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). On the other hand, analyses of the synthesized zinc molybdate were carried out by X-ray diffraction (XRD), transmission electron microscopy (TEM), and Brunauer-Emmett-Teller technique (BET). The efficiency of the synthesized catalyst was tested with the reduction reaction of 3-nitrophenol (3-NP), and was also applied as a sorbent for methylene blue dye (MB) in aqueous solutions. The catalytic test of zinc molybdate shows a very high activity. The concentration reduction progress and adsorption of the dye were followed by an ultraviolet-visible (UV-vis) spectrophotometer.

Nano Molybdenum trioxide (α-MoO₃) was synthesized in an easy and efficient approach. The removal of methylene blue (MB) in aqueous solutions was studied using this material. The effects of various experimental parameters, for example contact time, pH, temperature and initial MB concentration on removal capacity were explored. The removal of MB was significantly affected by pH and temperature and higher values resulted in increase of removal capacity of MB. The removal efficiency of Methylene blue was 100% at pH = 11 for initial dye concentrations lower than 150 ppm, with a maximum removal capacity of 152 mg/g of MB as gathered from Langmuir model. By comparing the kinetic models (pseudo first-order, pseudo second-order and intraparticle diffusion model) at various conditions, it has been found that the pseudo second-order kinetic model correlates with the experimental data well. The thermodynamic study indicated that the removal was endothermic, spontaneous and favorable. The thermal regeneration studies indicated that the removal efficiency (99%) was maintained after four cycles of use. Fourier Transform Infrared (FTIR) and Scanning Electron Microscopy (SEM) confirmed the presence of the MB dye on the α-MoO₃ nanoparticles after adsorption and regeneration. The α-MoO₃ nanosorbent showed excellent removal efficiency before and after regeneration, suggesting that it can be used as a promising adsorbent for removing Methylene blue dye from wastewater.

Removing methylene blue (MB) dye from aqueous solutions was examined by the use of nickel molybdate (α-NiMoO₄) as an adsorbent produced by an uncomplicated, rapid, and cost-effective method. Different results were produced by varying different parameters such as the pH, the adsorbent dose, the temperature, the contact time, and the initial dye concentration. Adsorbent dose and pH had a major removal effect on MB. Interestingly, a lower amount of adsorbent dose caused greater MB removal. The amount of removal gained was efficient and reached a 99% level with an initial methylene blue solution concentration of ≤160 ppm at pH 11. The kinetic studies indicated that the pseudo-second-order kinetic model relates very well with that of the obtained experimental results. The thermodynamic studies showed that removing the MB dye was favorable, spontaneous, and endothermic. Impressively, the highest quantity of removal amount of MB dye was 16,863 mg/g, as shown by the Langmuir model. The thermal regeneration tests revealed that the efficiency of removing MB (11,608 mg/g) was retained following three continuous rounds of recycled adsorbents. Adsorption of MB onto α-NiMoO₄ nanoparticles and its regeneration were confirmed by Fourier transform infrared spectroscopy (FTIR) analysis and scanning electron microscopy (SEM) analysis. The results indicated that α-NiMoO₄ nanosorbent is an outstanding and strong candidate that can be used for removing the maximum capacity of MB dye in wastewater.

Perovskite solar cells (PSCs) have emerged as potential substitutes to conventional photovoltaic devices due to their outstanding performance, affordability, and simplicity of construction. This study focuses on optimizing rubidium-based halide perovskite solar cells using numerical simulation tools, specifically SCAPS-1D (Solar Cell Capacitance Simulator), with rubidium germanium bromide (RbGeBr3) as the absorber material. The aim is to improve both efficiency and durability, addressing challenges in creating sustainable and cost-effective photovoltaic technologies. The performance of the proposed solar cell configuration was evaluated by examining various parameters such as the thickness of the absorber, the thickness of the electron transport layer and hole transport layer (HTL), defect densities, temperature, etc. Various hole transport layer materials, including Copper Barium Tin Sulfide (CBTS), Copper Iodide (CuI), PEDOT: PSS, and Spiro-MeOTAD, were analyzed to evaluate their impact on open-circuit voltage, short-circuit current, fill factor, and power conversion efficiency. The findings indicate significant potential for RbGeBr3-based solar cells, with the CBTS HTL yielding the highest efficiency. Among the structures, the ITO/WS2/RbGeBr3/CBTS/Au structure was found to be optimal, achieving a power conversion efficiency of 31.48%, a current density of 26.27 mA/cm2, a voltage of 1.39 V, and a fill factor of 85.76%. This research provides valuable insights for designing and optimizing future perovskite solar cells, contributing to the advancement of renewable and sustainable energy technologies.

Solid-state dye-sensitized solar cells (SSDSC) have been fabricated using two different metal oxide materials, graphene oxide and titanium oxide, are used as hole and electron transport materials, respectively. The N719 dye ruthenium between the hole and electron transport materials to act as an absorber layer in your Go/N719dye/TiO2 solar cells. Through the SCAPS-1D simulation, it was found that the Go/N719dye/TiO2 solar cells have significantly improved the performance of the solar cells compared to the Go/TiO2 solar cells. Specifically, the short circuit current (Jsc) has increased from 0.17 mA/cm2 to 1 mA/cm2, the open circuit voltage (Voc) has increased from 0.2 V to 1 V, and the power conversion efficiency (η) has increased from 0.02% to 2.5%. Additionally, Various factors that can affect the performance of Go/N719 dye/TiO2 solar cells. It was found that the optimal dye thickness for achieving high short circuit current density, high power conversion efficiency, and high open circuit voltage is between 200nm and 300nm. Furthermore, the operating temperature of the solar cells also affects their performance. Increasing the operating temperature negatively affects the open circuit voltage and power conversion efficiency of the cells, while the short circuit current density is slightly enhanced. Finally, the efficiency of a solar cell can be affected by the type of metal used for the electrode and the type of semiconductor material used in the cell. In Ni and Cu electrodes solar cells ohmic contacts allow for efficient transfer of electrons, whereas Schottky barriers can impede electron flow and reduce efficiency in Mo and Ag electrodes solar cells .