Preparation And Photocatalytic Properties Of Iron Doped Semiconductor Composites

Graphitic carbon nitride?g-C₃N₄?is a novel 2D layered semiconductor material which has great application foreground in photocatalysis because of its appropriate band gap?2.7 eV?,high thermal and chemical stability.However,tthe low utilization of visible light due to the small specific surface area and easy recombination of photogenerated hole-electron pairs limit the application of g-C₃N₄.Thus,Fe doping was used in this paper to improve the specific surface area,photo-absorption efficiency and the photoelectric conversion properties of g-C₃N₄.The researches are as follow:?1?A one-step method was used to synthesis iron doped g-C₃N₄ by using Fe?NO?₃ and melamine.The results reflected that iron has been doped into the lattice of g-C₃N₄ in the form of Fe³⁺based on characterization of the composition and crystal structure.Fe³⁺doping decreased the interlayer space,changed pore structure and raised specific surface area to 14.7 m²/g which is 121%higher than that of pure g-C₃N₄.Besides,the thermal stability of g-C₃N₄was reduced with the decomposition temperature of 510.6°C??2?Based on the systemically research of the electron structure and electrochemical performances of Fe³⁺doped g-C₃N₄,a red shift was observed in light absorbance curve and the absorption edge is around 470 nm.The band gap and conduction band potential were 2.35 eV and-1.1 eV respectively,which demonstrated Fe³⁺doping change the electron structure of g-C₃N₄ and promoted the generation and transfer of photogenerated electrons.The weaker fluorescence intensity of Fe³⁺doped g-C₃N₄ showed that Fe³⁺doping can suppress the recombination process of carriers.?3?Fe/g-C₃N₄ was utilized as pholocatalyst to photocatalytic degradation of Rhodamine B in visible light with the results shown that Rhodamine B was run out within 150 min,which exhibit more than 46%improvement to that of pure g-C₃N₄.The degradation test indicated that Fe³⁺doping can provide more active sites by improved specific surface area and reduced band gap to promote transport of carriers,thus boosting the photochemical catalysis peroformance.