Fe-Doped g-C 3 N 4 /Bi 2 MoO 6 Heterostructured Composition with Improved Visible Photocatalytic Activity for Rhodamine B Degradation.

The binary heterostructured semiconducting visible light photocatalyst of the iron-doped graphitic carbon nitride/bismuth molybdate (Fe-g-C 3 N 4 /Bi 2 MoO 6 ) composite was prepared by coupling with Fe-doped g-C 3 N 4 and Bi 2 MoO 6 particles. In the present study, a comparison of structural characteristics, optical properties, and photocatalytic degradation efficiency and activity between Fe-doped g-C 3 N 4 particles, Bi 2 MoO 6 particles, and Fe-g-C 3 N 4 /Bi 2 MoO 6 composite was investigated. The results of X-ray diffraction (XRD) examination indicate that the hydrothermal Bi 2 MoO 6 particles have a single orthorhombic phase and Fourier transform infrared (FTIR) spectroscopy analysis confirms the formation of Fe-doped g-C 3 N 4 . The optical bandgaps of the Fe-doped g-C 3 N 4 and Bi 2 MoO 6 particles are 2.74 and 2.73 eV, respectively, as estimated from the Taut plots obtained from UV-Vis diffuse reflectance spectroscopy (DRS) spectra. This characteristic indicates that the two semiconductor materials are suitable for absorbing visible light. The transmission electron microscopy (TEM) micrograph reveals the formation of the heterojunction Fe-g-C 3 N 4 /Bi 2 MoO 6 composite. The results of photocatalytic degradation revealed that the developed Fe-g-C 3 N 4 /Bi 2 MoO 6 composite photocatalyst exhibited significantly better photodegradation performance than the other two single semiconductor photocatalysts. This property can be attributed to the heterostructured nanostructure, which could effectively prevent the recombination of photogenerated carriers (electron-hole pairs) and enhance photocatalytic activity. Furthermore, cycling test showed that the Fe-g-C 3 N 4 /Bi 2 MoO 6 heterostructured photocatalyst exhibited good reproducibility and stability for organic dye photodegradation.