Carbon Nanofiber-Bridged Carbon Nitride-Fe2O3 Photocatalyst: Hydrogen Generation and Degradation of Aqueous Organics

Graphitic carbon nitride (g-C3N4)-supported ferric oxide (Fe2O3) nanocomposite modified with carbon nanofibers (CNFs) has been synthesized for the first time for photocatalytic H-2-generation and the degradation of aqueous organics. In its first dual role, Fe2O3 served as the photocatalyst and the chemical vapor deposition (CVD) catalyst to grow CNFs over the g-C3N4 substrate. Time of CVD was found to be critical for synthesizing Fe2O3-CNF/g-C3N4 with a good photocatalytic efficiency. The synthesized materials were characterized for various physicochemical and photocatalytic properties. The creation of a Z-scheme heterostructure between g-C3N4 and Fe2O3 resulted in the greater H-2-generation rate (2095 mu mol/g h) than that (1119 mu mol/g h) over the substrate. The photocatalytic degradation data showed similar to 95 and 91% removal of methylene blue and 4-nitrophenol in 180 and 300 min, respectively at 22 degrees C using the Fe2O3 -CNF/g-C3N4 dose of 0.5 mg/mL. The photocatalytic reactions followed the indirect Z-scheme charge transfer path, with the graphitic CNFs acting as the electron-transfer medium between Fe2O3 and g-C3N4. The simple fabrication route and high photocatalytic efficiency of the ternary CNF-bridged Fe2O3-g-C3N4 composite system indicate the utility of the material in integrated environmental and energy applications including microbial fuel cells and microelectrolysis cells. [GRAPHICS] .