Fabrication of TiO2 nanorods/nanosheets photoelectrode on Ti mesh by hydrothermal method for degradation of methylene blue:influence of calcination temperature

Abstract

In the study, Using the strategy of hydrothermal reaction followed by annealing at different temperatures, TiO2 nanorods/nanosheets (NRs/NSs) photoelectrodes with diverse microcosmic morphologies and crystal structures were successfully fabricated. Moreover, all samples were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM) and Ultraviolet-visible diffuse reflectance spectroscopy (UV-vis DRS). Meanwhile the photoelectrochemical (PECH) properties were recorded through open circuit potential (OCP) and electrochemical impedance spectroscopy (EIS) curves. The photocatalytic (PC) activity of TiO2 NRs/NSs photoelectrodes were further measured by methylene blue (MB) degradation. Results suggest that the nanosheets possessed the width and thickness in the range of 100–400 and 10–20nm, and the nanorods possessed the diameter in the range of around 10–20nm, respectively. Also, the TiO2 NRs/NSs photoelectrode calcined at 500°C exhibited the best proportion of both nanosheets and nanorods and higher photocatalytic activity (73.56%) than those of other TiO2 NRs/NSs photoelectrodes within 150min under visible light illumination, which was ascribed to higher photoproduction electrons-holes (e/h+) pairs separation and visible light absorption. Therefore, the calcination temperature plays a significant role in altering the morphology and crystal structure of TiO2 NRs/NSs photoelectrode, and then enhanced PC performance.