The Loading of Fe Ions on N-Doped Carbon Nanosheets to Boost Photocatalytic Cascade for Water Disinfection

Abstract

The widespread presence of pathogenic bacteria in the water environment poses a serious threat to public health. Here, a photocatalytic cascade was developed to reveal great water disinfection. Firstly, N-doped carbon nanosheets (N-CNSs) about 30-50 nm in size were synthesized by a hydrothermal strategy. It revealed wide-spectrum photocatalysis for H2O2 generation via a typical two-step single electron process. A Fenton agent, Fe ion, was loaded to obtain N-CNSs-Fe, which realized photocatalytic H2O2 formation and conversion in-situ to produce ·OH with high oxidation potential. Moreover, the Fenton active is 3 times more than pure Fe2+ owing to the electron enrichment from N-CNSs to Fe. Therefore, the nanocomposite can effectively inactivate E. coli with a lethality rate of 99.7 % under stimulated sun irradiation. The further investigation reveals that Fe loading still can decrease bad gap and promote charge separation to boost photocatalysis. In addition, N-CNSs-Fe possesses positive surface potential to exhibit strong interaction with negative bacteria, facilitating the capture. In addition, the nanocomposite also was employed to treat complex lake water sample, revealing great antibacterial (95.1 %) and dye-decolored (92.8 %) efficiency at the same time. With the novel biocompability and antibacterial ability, N-CNSs-Fe possesses great potential for water disinfection.

Keywords: photocatalysis, Nanozyme, antibacteria, wide-spectrum, Fe loaded carbon nanosheets