Graphitic carbon nitride grown in situ on aldehyde-functionalized α-Fe2O3: All-solid-state Z-scheme heterojunction for remarkable improvement of photo-oxidation activity.

Aldehyde-functionalized α-Fe2O3/graphitic carbon nitride (α-Fe2O3-DBD/g-C3N4) was successfully synthesized through Schiff-based reaction between aromatic aldehydes in 3,4-dihydroxybenzaldehyde and NH2 groups in urea. The 3,4-dihydroxybenzaldehyde around α-Fe2O3 were advantageous to in situ growth of graphitic carbon nitride on α-Fe2O3 to form the contact interface by chemical bonds and beneficial to the electron transfer, leading to the formation of Z-scheme photocatalytic system. The α-Fe2O3-DBD/g-C3N4 photocatalysts exhibited a remarkable improvement in the degradation of bisphenol A (BPA) compared with bulk g-C3N4. The enhanced photocatalytic activity was attributed to the enhanced charge separation efficiency and higher redox potential. This study presents a simple and efficient method to construct all-solid-state Z-scheme photocatalytic system with the formation of tight contact interface and nonmetal materials (aromatic rings) as electron mediators for the removal of complex pollutants.