Morphology-Dependent Photoelectrochemical and Photocatalytic Performance of γ-Bi2O3 Nanostructures.

Simple one-step solvothermal route was used to synthesize γ-Bi2O3 nanostructures. Well-defined nanoflowers and finite nanorods surface morphology of the samples were revealed. The physical characterization and material confirmation was explored by employing X-ray diffraction (XRD), Raman, photoluminescence (PL), and Fourier transform infrared (FTIR) studies. The optical bandgap of about 2.71 and 2.72 eV was observed for nanoflower and nanorods, respectively. The highest specific surface area of 0.877 m²/g with mesoporous feature was reported for nanoflower sample. The improved photocurrent of 12.47 µA/cm² was observed for the nanoflower photoanode with lowest internal resistance and the highest stability over 3600 s, with 87% retention in photocurrent was estimated from chronoamperometry (CA) study. The effective methyl orange degradation of MO as 94% was investigated by nanoflower photocatalyst. The synthesis of metastable γ-Bi2O3 nanostructures with hierarchical morphology to adapt as an efficient photoanode for solar water splitting and pollutant degradation applications was reported.

Hydrothermal synthesis of ZnO nanorods in the presence of a surfactant.

Controlling the dimensions, positioning, and shapes of semiconductor nanowires, nanorods, and nanobelts lies in the synthesis and understanding of their growth mechanism. Controlled growth and synthesis is required in the fabrication of nanodevices and nanosensors. Among methods utilized for one-dimensional nanostructure synthesis, the hydrothermal process--a simple and cost-effective technique involving a low process temperature--has emerged as a powerful tool for the fabrication of anisotropic nanomaterials. Under hydrothermal conditions, many starting materials can undergo quite unexpected reactions, which are often accompanied by the formation of nanoscopic morphologies that are not accessible by classical routes. Synthesized ZnO nanostructures from aqueous solutions are usually poor in terms of morphology and size control. To improve the growth conditions and the controllability of the process, the use of surfactants or organic solvents has been attempted. In the present work, ZnO nanorods were grown on templates with a pre-sputtered ZnO seed layer over oxidized Si (100) substrates, and polyvinyl pyrrolidone (PVP) was used as a surfactant. By varying the PVP concentration in the growth solution, we can control the diameter and density of ZnO nanorods. The optical property of ZnO nanorods is highly improved by PVP addition.