Preparation And Property Study Of WO₃/Ag₃PO₄-based Photocatalysts

With the rapid development of the industrial economy,the discharge of a large amount of dye wastewater brings enormous pollution and damage to the environment and human.Photocatalysis has great research prospects and application value in degrading dye wastewater.WO3 has excellent physicochemical properties,which makes it a very promising photocatalyst.Ag3PO4 has also attracted much attention due to its wide range of visible light absorption.However,due to the recombination of photogenerated electrons and holes,it is necessary to further increase the photocatalytic activity.In this paper,WO3/Ag3PO4,WO3/Ag/Ag3PO4 and WO3-Fe/Ag3PO4 composite photocatalysts were prepared by using WO3 and Ag3PO4 as the core photocatalysts,and Rhodamine B was used to evaluate the photocatalytic performance of the composite photocatalyst.At the same time,the crystal structure,micromorphology and photocatalytic properties of the photocatalyst were analyzed by a series of characterization methods and tests.Mainly carried out the following three aspects of work:(1)Different weight ratios of WO3/Ag3PO4 composite photocatalysts were prepared by ultrasonic assisted two-step deposition method,and RhB was degraded under visible light,The experimental results show that the photocatalyst with the weight of 60%Ag3PO4 has the highest photocatalytic activity;the negative charge on the surface of WO3 plays a key role in the strong selective adsorption of cationic dye molecules;A joint discussion of adsorption and photocatalysis of WO3 and AW-60 indicates that electrons flow from WO3 to Ag3PO4 in the composite catalyst and confirm the Z-type photocatalytic mechanism and supported by the zeta potential test results.(2)WO3/Ag3PO4 and WO3/Ag/Ag3PO4 composite photocatalysts with different weight ratios and different time of light were prepared.WO3 was monoclinic and had no adsorption and catalytic activity,which is benefit for the discussion of catalytic activity of composite photocatalysis.The experimental results show that WA-60(the weight of 60%Ag3PO4 composite photocatalyst)has the strongest photocatalytic activity for RhB;compared with WA-60,the photocatalytic activity of WAA-60 for RhB photodegradation is improved by nearly 2 times,indicating that the introduction of Ag at the interface can enhance the catalytic activity;h+ is the active substance in the photodegradation process of RhB on WO3,WA-60 and WAA-60.(3)The WO3-Fe/Ag3PO4 composite photocatalyst was prepared by grinding ultrasonic method.WO3-Fe/Ag3PO4 has the strongest photocatalytic activity for RhB,indicating that WO3 is more suitable for loading Fe as an electron-rich side;WO3-Fe/Ag3PO4 has the highest catalytic activity,and the degradation efficiency of rhodamine B after 60 min of visible light irradiation was 96%,and the photocatalytic activity of WO3-Fe/Ag3PO4 for rhodamine B was 83%in the same light irradiation time,indicating that doping Fe is beneficial for the catalytic performance improvement of binary composite photocatalyst,d-electron injection may be the main reason for the improvement in performance;h+is the active substance in the photodegradation process of RhB on WO3-Fe/Ag3PO4.