Study On Visible-light Photocatalytic Ability Of G-C₃N₄ Modified By Derivatives Of PVC

A facile method has been developed to prepare an efficient visible-light photocatalyst using g-C₃N₄ and ordinary polyvinyl chloride（PVC）as main precursors.Firstly,g-C₃N₄ was dispersed into PVC solution with tetrahydrofuran as solvent.Secondly,the above suspension containing g-C₃N₄ was heated at 50 ℃ to obtain PVC/g-C₃N₄ composite via solvent volatilization.Finally,the product was heated at 150 ℃ for 2 h,which made the surface of PVC take off HCl to be conjugated polymer/g-C₃N₄（DPVC/g-C₃N₄）.The as-prepared photocatalyst was characterized by Scanning electron microscopy（SEM）,UV-visible diffuse reflectance spectroscopy（UV-Vis DRS）,X-ray diffraction（XRD）,X-ray photoelectron spectroscopy（XPS）,Raman Spectroscopy,photoluminescence spectroscopy（PL）,Electrochemical Impedance Spectroscopy（EIS）,et al.The results showed the crystallization of g-C₃N₄ modified by DPVC didn’t change obviously,The absorption DPVC/g-C₃N₄ composites increased in the visible region,the surface of g-C₃N₄ exist conjugated polymer.The photocatalytic activity of the as-prepared photocatalyst was evaluated by photodegradation of Rhodamine B（RhB）solution under visible-light irradiation.Discussing some Preparation conditions such as mass ratio.of PVC and g-C₃N₄、the temperature of thermal-treatment、the time of thermal-treatment and so on,had an influence on the photocatalytic ability of DPVC/g-C₃N₄ composites under visible light.The results showed when mass ratio of PVC and g-C₃N₄ was 1:300,the temperature of thermal-treatment was 150℃ and the time of thermal-treatment was 2h,the photocatalytic ability of DP VC/g-C₃N₄ composites was the best.By the experiment of adding capture agent,analyzing the active centre of photocatalytic degradation of DPVC/g-C₃N₄ composites for Rhodamine B,and discussing the visible-light photocatalytic mechanism.Results show that the in the process of photocatalytic degradation of DPVC/g-C₃N₄ composites for Rhodamine B,photoproduction electron and hole work at the same time,and photoproduction hole is the main role.