Photocatalytic property of MWCNTs/BiOI with rich oxygen vacancies

In this paper, BiOI was surface decorated by multiwall carbon nanotubes (MWCNTs) via a hydrothermal method. The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), high resolution transmission electron microscope (HRTEM), UV-Vis diffusion reflectance spectrometry (DRS), X-ray photoelectron spectroscopy (XPS), surface photovoltage spectroscopy (SPS), and electron spin-resonance (ESR). Rich oxygen vacancies (OVs) were generated on the surface of BiOI, confirmed by ESR and XPS characterization. Trapping tests prove that superoxide (center dot O-2(-)) is the key active species. When the mass ratio of MWCNTs/BiOI is 1.0%, the photocatalytic activity of MWCNTs/BiOI is 5.6 times of that of the bare BiOI. Finally, photocatalytic enhancement mechanism was proposed based on the experimental consequences. After surface modification by MWCNTs, electrons will transfer to MWCNTs due to the strong interaction between MWCNTs and BiOI, and the excellent conductivity of MWCNTs, significantly boosting the separation of e(-)/h(+) pairs.

Automated summary

In this study, BiOI was surface decorated with multiwall carbon nanotubes (MWCNTs) using a hydrothermal method. The samples were characterized using various techniques, and the results showed that the surface modification with MWCNTs significantly enhanced the photocatalytic activity of BiOI. This enhancement can be attributed to the strong interaction between MWCNTs and BiOI, as well as the excellent conductivity of MWCNTs, which promoted the separation of electron-hole pairs.