One step grinding method to prepare BiFeO3/α-Fe2O3 type-II heterojunction for enhancing phenolic wastewater degradation

A serious of novel and stable BiFeO3/alpha-Fe2O3 type-II heterojunction photocatalysts with different weight contents of alpha-Fe2O3 were prepared just by a facile one step grinding method. XRD, TEM, SEM, XPS, UV-vis, and photoluminescence spectra, etc. were used to analyze the structure, surface state, optical properties, and interfacial interactions of the as-prepared catalysts. The results showed that type-II heterojunction were successfully formed by this one step grinding method at the interface between BiFeO3 and alpha-Fe2O3, and thus the transformation of the photogenerated electrons, separation of the photogenerated electron-hole pairs and visible-light absorption were enhanced. Among them, BiFeO3/alpha-Fe2O3-30% composite exhibits the optimal activity, there is 85.87% of phenol degraded under simulated solar irradiation after 2 h, which is 1.97 times of single alpha-Fe2O3 and 4.23 times of single BiFeO3, respectively. Besides, the BiFeO3/alpha-Fe2O3-30% heterojunction composite also keeps an excellent catalytic performance after 3 cycles.

Automated summary

A series of novel and stable BiFeO3/alpha-Fe2O3 type-II heterojunction photocatalysts with different weight contents of alpha-Fe2O3 were prepared using a one-step grinding method. Various analytical techniques were used to study the structure, surface state, optical properties, and interfacial interactions of the catalysts. The results showed that the one-step grinding method successfully formed type-II heterojunction between BiFeO3 and alpha-Fe2O3, leading to enhanced electron transformation, separation of electron-hole pairs, and visible-light absorption. The BiFeO3/alpha-Fe2O3-30% composite exhibited the highest activity, with 85.87% phenol degradation under simulated solar irradiation after 2 hours, significantly outperforming single alpha-Fe2O3 and single BiFeO3. Additionally, the BiFeO3/alpha-Fe2O3-30% heterojunction composite maintained excellent catalytic performance after 3 cycles.