Preparation,Characterization And Application Of G-C₃N₄-based Visible-light Photocatalyst

Fe₂O₃/g-C₃N₄ composite photocatalysts were prepared via an in-situ synthesis method with melamine and ferric chloride as the main raw materials.The prepared materials were characterized by X-ray diffraction?XRD?,Fourier transform infrared spectroscopy?FTIR?,UV-vis diffuse reflection spectroscopy?DRS?,photoluminescence spectroscopy?PL?,Electrochemical impedance spectra?EIS?,X-ray photoelectron spectroscopy?XPS?,transmission electron microscopy?TEM?,and scanning electron microscopy?SEM?.The results reveals that a small amount of Fe₂O₃ nanoparticles do not change the chemical composition and crystalline of g-C₃N₄ significantantly,while obviously improve the visible-light absorption and electron-hole separation efficiency of Fe₂O₃/g-C₃N₄ nanocomposites.With Rhodamine B?RhB?as a model pollutant,the visible-light photocatalytic activity and stability of Fe₂O₃/C₃N₄ nanocomposites were investigated by evaluating the decomposition of RhB under visible-light irradiation.The effects of the Fe₂O₃ content in the nanocomposites,calcination temperature and time of the investigated materials on their visible-light photocatalytic activity were systematically investigated.The results reveal that g-C₃N₄ modified by a small amount of Fe₂O₃ nanoparticles exhibits excellent visible-light photocatalytic activity and stability.The visible-light photocatalytic activity of the Fe₂O₃/C₃N₄ composite photocatalysts increases at first and then decreases with the increment in Fe₂O₃ content in the nanocomposites,calcination temperature or time.The capture agent experiments indicate that the photogenerated holes in the Fe₂O₃/C₃N₄composite photocatalysts might be the main active species for RhB photodegradation.The Cu₂O/g-C₃N₄ composite materials were prepared via in-situ ion charge method and reduction reaction using g-C₃N₄,copper nitrate,sodium hydroxide and glucose as main precursors.The heterojunction structure has formed between Cu₂O and g-C₃N₄,which greatly enhances the visible light photocatalytic activity of g-C₃N₄.The Fe₂O₃/g-C₃N₄-loaded photocatalyst was prepared using absorbent cotton as a carrier.The visible-light photocatalytic activity of the Fe₂O₃/g-C₃N₄-loaded absorbent cotton was investigated by evaluating the decomposition of RhB under visible-light irradiation.The experimental results show that the Fe₂O₃/g-C₃N₄-loaded absorbent cotton exhibits well visible light catalytic activity,meaning that the as-prepare material can become an efficient visible light photocatalyst in the practical applications.