The loading of Fe ions on N-doped carbon nanosheets to boost photocatalytic cascade for water disinfection

The pervasive presence of pathogenic bacteria in 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 H 2 O 2 generation via a typical two-step single-electron process. A Fenton agent (Fe ion) was loaded, N -CNSs-Fe can in-situ convert photocatalytic H 2 O 2 into ·OH with high oxidation potential. Moreover, its Fenton active is three times greater than pure Fe 2+ owing to electron enrichment from N -CNSs to Fe for Fe 3+ /Fe 2+ cycle. Further investigation displayed that Fe loading also could 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. Therefore, the nanocomposite can effectively inactivate E. coli with a lethality rate of 99.7 % under stimulated sunlight irradiation. In addition, it also was employed to treat a complex lake water sample, revealing great antibacterial (95.1 %) and dye-decolored (92.3 %) efficiency at the same time. With novel biocompatibility and antibacterial ability, N -CNSs-Fe possessed great potential for water disinfection.