Low temperature fabrication of Fe(2)O(3) nanorod film coated with ultra-thin g-C(3)N(4) for a direct z-scheme exerting photocatalytic activities

We engineered high aspect ratio Fe(2)O(3) nanorods (with an aspect ratio of 17 : 1) coated with g-C(3)N(4) using a sequential solvothermal method at very low temperature followed by a thermal evaporation method. Here, the high aspect ratio Fe(2)O(3) nanorods were directly grown onto the FTO substrate under relatively low pressure conditions. The g-C(3)N(4) was coated onto a uniform Fe(2)O(3) nanorod film as the heterostructure, exhibiting rational band conduction and a valence band that engaged in surface photoredox reactions by a direct z-scheme mechanism. The heterostructures, particularly 0.75g-C(3)N(4)@Fe(2)O(3) nanorods, exhibited outstanding photocatalytic activities compared to those of bare Fe(2)O(3) nanorods. In terms of 4-nitrophenol degradation, 0.75g-C(3)N(4)@Fe(2)O(3) nanorods degraded all of the organic pollutant within 6 h under visible irradiation at a kinetic constant of 12.71 × 10(−3) min(−1), about 15-fold more rapidly than bare Fe(2)O(3). Further, the hydrogen evolution rate was 37.06 μmol h(−1) g(−1), 39-fold higher than that of bare Fe(2)O(3). We suggest that electron and hole pairs are efficiently separated in g-C(3)N(4)@Fe(2)O(3) nanorods, thus accelerating surface photoreaction via a direct z-scheme under visible illumination.