Novel visible-light-induced P-doped g-C3N4/α-Bi2O3 nanocomposite photocatalysts for enhanced degradation of refractory endocrine disruptors-benzophenones

The Z-scheme heterojunction design can not only minimize photogenerated electron-hole pair recombination but also ensure strong redox abilities for driving photocatalytic reactions. Hence, novel P-g-C3N4/alpha-Bi2O3 binary nanocomposites were successfully fabricated by a combined hydrothermal-calcination method. The as -synthesized samples were systematically characterized by X-ray diffraction, Fourier transform infrared spec-troscopy, X-ray photoelectron spectroscopy, scanning electron microscopy/energy-dispersive X-ray spectroscopy, transmission electron microscopy, ultraviolet-visible spectroscopy, photoluminescence (PL) spectroscopy, N2 isotherm measurement, electrochemical impedance spectroscopy (EIS), thermogravimetric analysis, and electron paramagnetic resonance. The photocatalytic efficiency of the as-prepared samples was assessed via decontami-nation of refractory and endocrine-disrupting benzophenones (BPs) under visible light irradiation. The 25 wt% P-g-C3N4/alpha-Bi2O3 nanocomposite exhibited higher photocatalytic activity for 4-hydroxybenzophenone (4H-BP) and benzophenone-1 degradation than P-g-C3N4 and alpha-Bi2O3. The apparent enhancement of the photocatalytic activity might be mainly attributed to the enhanced light-harvesting ability and the heterojunction formation, which significantly facilitates photogenerated charge carrier separation and transfer, as confirmed by the PL and EIS findings. Notably, 25 wt% P-g-C3N4/alpha-Bi2O3 exhibited robust reusability and stability with high efficiency in 4H-BP removal after four repeated photocatalytic cycles.

Automated summary

Novel P-g-C3N4/alpha-Bi2O3 binary nanocomposites were successfully fabricated using the Z-scheme heterojunction design, which exhibited higher photocatalytic activity for 4H-BP and benzophenone-1 degradation under visible light irradiation. The enhanced photocatalytic activity was attributed to improved light harvesting ability and heterojunction formation, facilitating charge separation and transfer.