“…Thus, constructing a composite with a suitable band energy gap is a mainstream approach to widen the light absorption region and reduce the charge recombination. [16][17][18][19][20] Graphitic carbon nitride (g-C 3 N 4 ), as a two-dimensional layered semiconductor, has drawn particular attention in photocatalysis due to its element abundance, facile preparation, great visible light activity, high thermal and outstanding chemical stabilities, and excellent electronic structure. 21 Recently, the composite photocatalysts combining a-Fe 2 O 3 and g-C 3 N 4 have been successfully fabricated and showed great performance in water splitting, 22 carbon dioxide reduction, 23 photochemical reaction, 24 and heavy metal ion reduction.…”