The Controllable Preparation And Photocatalytic Performance Of G-C₃N₄/CNFs Composite Photocatalytic Materials

Environmental pollution and energy shortage are two major problems faced by mankind.In recent decades,how to effectively use solar energy to purify the environment or transform it into hydrogen energy has become the focus of researchers.Graphite carbon nitride?g-C₃N₄?as a non-metal semiconductor material with non-toxicity,good chemical stability and thermal stability,is applied in the field of photocatalysis.However,the photocatalytic efficiency of g-C₃N₄ powder is low and it is difficult to recover in application.To fully realize its advantages,it needs to be modified to explore its application potential.In this study,electrospinning-based fibers were used as carriers to obtain photocatalysts by combining them with g-C₃N₄,and on this basis,further removal of the fibrous supports we can get the graphite phase carbonitride tubes?GCNTs?.The photocatalytic degradation of organic contaminants such as methyl orange and the cycling stability of the catalyst were investigated under illumination of light.Firstly,the g-C₃N₄ obtained by thermal polycondensation using melamine as a raw material was ultrasonically exfoliated,and then the g-C₃N₄ nanosheet was composited with the carbon fibers by a hydrothermal reaction.The composite was characterized by SEM,FT-IR,XRD and XPS to analyze the appearance,structure,chemical composition and valence state.The results showed that the composite photocatalyst has broad applicability to the degradation of various organic dyes under UV light irradiation and has a certain cycle performance.Secondly,the carbon fibers obtained by carbonization of the electrospun fibers were used as a carrier,and the carbon fibers loaded g-C₃N₄ composite material is obtained by vapor-deposition reaction with melamine in a self-made reactor.This method is used to increase the effectiveness load of g-C₃N₄ on carbon fibers and to further improve the photocatalytic performance of catalyst.The results of the characterization of its morphology proved that g-C₃N₄ was evenly coated on the carbon fibers.The photocatalytic activity of the photocatalyst was tested in the system of catalytic degradation of organic dyes under UV light and visible light irradiation.The results showed that the composite catalyst includes the adsorption of carbon fibers and the photocatalytic activity of g-C₃N₄,in which carbon fibers play dual role of carrying g-C₃N₄ and transmitting electrons.Thirdly,change the composition of the spinning precursor solution and add aluminum nitrate to form a new precursor solution,and then the polymer film was obtained by electrospinning technique,furthermore,the alumina fibers were obtained by high temperature calcination.Then,the alumina fibers loaded g-C₃N₄ composite material was prepared by vapor deposition reaction.The acid removal method was used to remove the alumina fibers and get the GCNTs having a hollow structure.By testing its morphology and structure,it was proved that the composition of GCNTs was consistent with that of g-C₃N₄,and the diameter of the tube was about 270 nm,the thickness of the tube wall was about 30nm.The photocatalyst has better photocatalytic degradation performance and cycle stability performance for the degradation of different organic dyes under visible light.In summary,g-C₃N₄ can be supported on carbon fibers to obtain composite catalysts by different methods,and then tubular g-C₃N₄ can be obtained by further improving the preparation method.These prepared photocatalysts have good photocatalytic performance and good stability,and the modification will effectively improve the shortcomings of easy loss of powder materials and have potential application prospects in improving the environment.