Synthesis of mediator free hollow BiFeO3 spheres/porous g-C3N4 Z-scheme photocatalysts for CO2 conversion and Alizarin Red S degradation

In this current research work, we fruitfully prepared a mediator-free BiFeO3 hollow spheres/porous g-C3N4 Zscheme based photocatalysts and utilized it for CO2 conversion and Alizarin Red S degradation. Remarkably, the porous g-C3N4 are prepared by acidic treatment and double calcination method, while BiFeO3 hollow spheres are prepared by employing carbon nanospheres as hard templates. Our results demonstrated that porosity and hollow spheres efficiently upgraded the surface area, light absorption capacity, and photocatalytic activities of gC3N4 and BiFeO3. Based on electrochemical impedance spectroscopy (EIS), SPS, TEM, FS spectrum associated with the formed center dot OH amount, and UV-absorbance spectra, it is confirmed that coupling of BiFeO3 hollow spheres with porous g-C3N4 not only thermodynamically provide a suitable platform for receiving the high energy level electrons but also enhanced charge separation. Compared to pristine P-CN, the most optimal sample, 6HBFO/ P-CN, showed a 3.5-times enhancement in activities for Alizarin Red S decontamination and CO2 conversion under visible light irradiation. Finally, our present work will open a new gateway to synthesize BiFeO3 hollow spheres/porous g-C3N4 Z-scheme materials as effective photocatalysts for organic contaminants decontamination and CO2 conversion.

Automated summary

In this study, mediator-free BiFeO3 hollow spheres/porous g-C3N4 Z-scheme photocatalysts were successfully prepared and used for CO2 conversion and Alizarin Red S degradation. The porous g-C3N4 and hollow spheres greatly enhanced the surface area, light absorption capacity, and photocatalytic activities of g-C3N4 and BiFeO3. The coupling of BiFeO3 hollow spheres with porous g-C3N4 improved charge separation and electron transfer, leading to a 3.5-fold enhancement in the activities for Alizarin Red S degradation and CO2 conversion under visible light irradiation. This work provides a new approach to synthesize BiFeO3 hollow spheres/porous g-C3N4 Z-scheme materials as efficient photocatalysts for organic contaminant decontamination and CO2 conversion.