Preparation and photoelectrochemical performance of nano Bi2S3–TiO2 composites

Abstract

TiO2 nanorod (NR) arrays were prepared on FTO by the simple hydrothermal synthesizing method. On this basis, a layer of Bi2S3 quantum dots (QDs) was covered on the surface of TiO2 NRs array by solvothermal method, by which the Nano Bi2S3/TiO2 NRs composites films were obtained. The phase structure, morphologies, optical absorptions and photoelectrochemical (PEC) properties of the as-prepared materials were characterized by X-ray diffraction (XRD), Scanning Electron Microscope (SEM), High Resolution Transmission Electron Microscopy (HRTEM), Ultraviolet–visible spectroscopy (UV-Vis), Photoluminescence (PL) and electrochemical workstation. The results indicate that the concentration of tetrabutyl titanate (TBT) has a great influence on the morphology of the film, with the increase of TBT content, the array of TiO2 NRs changed from loose to tight, and the thin films were cracked when the TBT volume is up to 0.7[Formula: see text]mL; The absorption of the TiO2 NRs array film to the visible light is enhanced significantly when sensitized with Bi2S3 and the absorption wavelength is increased from 400[Formula: see text]nm to 800[Formula: see text]nm. Compared with the pure TiO2, the fluorescence intensity of the TiO2/Bi2S3 NRs is weakened, and there is no obvious fluorescence diffraction peak. Under the irradiation of standard (AM1.5[Formula: see text]G 100[Formula: see text]mW/cm[Formula: see text], the photocurrent density of the composite film increased significantly. When the external bias voltage is 1.2[Formula: see text]V, the current density of the composite films is five times of that of the pure TiO2.