Graphene composite nanofibers as a high-performance photocatalyst for environmental remediation

摘要

It is imperative to design and develop a technology which would completely remove pollutants from contaminated waters due to agricultural, industrial, and domestic uses. For the first time, we discovered that graphene incorporated composite nanofibers (TZB-Gr) (Titanium dioxide-Zinc Oxide-Bismuth Oxide-Graphene) with a band gap of (2.5 eV) can effectively activate organic dyes under visible-light and UV-light irradiation to produce active center dot O2(-) and center dot OH radicals. The produced radicals are powerful oxidizing species to degrade most of the organic pollutant to become CO2 and H2O. TZB-Gr demonstrated a higher activity than TZB (Titanium dioxide-Zinc Oxide-Bismuth Oxide) and P25 (Commercial TiO2 nanoparticles). Kinetic study of composite nanofibers (NFs) was carried out. Furthermore, a reasonable catalytic mechanism of the TZB-Gr (NFs) was proposed, based on electron-hole pairs and recombination of photogenerated charges. It was shown that graphene-based nanofiber photocatalysis is superior to that on transition metal oxide (TZB) and P25 in degradation of a dye (methylene blue, MB) and (rhodamine B, RhB) in water, therefore providing a novel strategy for environmental remediation.