Bi2MoO6 hierarchical microflowers for electrochemical oxygen evolution reaction

Solvothermal Bi₂MoO₆ hierarchical microflowers synthesis has been successfully attempted. Methanol, ethanol and isopropanol have been mediated to synthesize three kinds of Bi₂MoO₆ hierarchical microflowers. Highly oriented (311) plane growth of orthorhombic Bi₂MoO₆ hierarchical microflowers have been confirmed. Interstitial vacancies and its role on electrochemical activity have been extensively discussed. Electrode fabrication was constructively done by using Ni foam substrate. Half cell arrangement of each electrode in alkaline medium has been designed to measure the electrochemical activity towards water oxidation. High current density of 356 mA/cm² was afforded by Bi₂MoO₆ hierarchical microflowers mediated by ethanol solvent during synthesis. Low Tafel slope value of 43 mV/dec has been reported to obtain 10 mA/cm² current density. Higher conductivity long with very good electron transportation has been achieved and is also adapted for 12 h long time stability test and achieved 86% of retention in its performance. Hence, optimally prepared Bi₂MoO₆ hierarchical microflowers could be an efficient electrode for clean energy fabrication.     

An approach to enhance the photocatalytic activity of ZnTiO3

ZnTiO₃ nanoparticles and Ag-Fe co-doped ZnTiO₃ nanoparticles were prepared using sol–gel method. The prepared samples were annealed at 700 °C and showed pure hexagonal ZnTiO₃. All the samples were characterized by using X-ray diffraction (XRD), field-emission scanning electron microscope, energy-dispersive X-ray analysis, and UV analyses. The result showed that the hexagonal structure of Ag-Fe ZnTiO₃ is affected with the increase in Ag-Fe concentrations. The zinc titanate nanoparticles were used for determining the degradation of cationic dye. Photocatalytic activity of ZnTiO₃ nanoparticles was studied and compared with that of bare control. The results showed enhanced photocatalytic activity of the Ag-Fe co-doped ZnTiO₃ compared to pure ZnTiO₃, showing that the Ag-Fe co-doping deposition has a major function in enhancing the degradation capability of cationic dye.     

Preparation of NiCo2O4 microspheres employing hydrothermal approach

In this study, nickel cobalt oxide (NiCo₂O₄) microspheres were prepared by using facile hydrothermal route. The structural confirmation of bimetal oxide formation was acquired by X-ray powder diffraction and Raman studies. The formation of microspheres combined via irregular nanosheets was confirmed by scanning electron microscopy. Highly oriented NiCo₂O₄ microspheres yielded a high current density (258 mA/g) at 10 mV/s and low overpotential (224 V). The highly active electrode showed efficient electron transportation towards oxygen evolution reaction. Long-term stability over 16 h was achieved by the fabricated high-performance NiCo₂O₄ electrode. It is recommended that NiCo₂O₄ microspheres obtained from 3:1 stoichiometry ratio of Ni and Co would lead to new electrocatalysts that give best performance than expensive catalysts used currently in the water oxidation process.