Effect of carbon nanotubes loading on the photocatalytic activity of BiSI/BiOI as a novel photocatalyst

In this paper, a simple hydrothermal method is employed to synthesize BiSI/BiOI/CNT nanocomposite with enhanced photocatalytic activity. The properties of the prepared samples were studied using nitrogen adsorption-desorption isotherm, photoluminescence, X-ray diffraction analysis (XRD), field-emission scanning electron microscopy (FE-SEM), energy dispersive spectrometry (EDS), UV–vis diffuse reflectance spectroscopy (DRS), and electrochemical impedance spectroscopy (EIS). The loading amount of CNT had a significant influence on the photoactivity of the BiSI/BiOI/CNT composite. In this study, several BiSI/BiOI/CNT nanocomposite samples with various mass ratios of CNT were made-up for further investigation to scrutinize the influence of CNT content on the photocatalytic activity of the nanocomposite. Photocatalysis measurements revealed that 2% Wt of CNT possesses the highest photocatalytic activity in the visible light irradiation with 93.1% photodegradation of malachite green (MG) as a test dye. The enhanced photocatalytic performance can be due to the large surface area, excellent conductivity performance, and high absorption ability in the visible light region. The synergistic effect of the factors mentioned above makes BiSI/BiOI/CNT nanocomposite a high-performance photocatalyst under visible light irradiation. An appropriate reaction mechanism of dye photodegradation has suggested according to the result of active species trapping experiments.