g-C_(3) N_(4)/MXene/Ag_(3)PO_(4)异质结催化剂构建及催化性能

Preparation of g-C_(3)N_(4)/MXene/Ag_(3)PO_(4) Heterostructure and Catalytic Property

为了改善g-C_(3)N_(4)的光催化性能,利用静电组装的方法制备g-C_(3)N_(4)/MXene/Ag_(3)PO_(4)异质结光催化剂,采用TEM、FTIR、XRD、XPS和DRS等方法对其进行了表征。随后将g-C_(3)N_(4)/MXene/Ag_(3)PO_(4)催化剂应用于活性红195的氧化降解反应中,考察了催化剂用量、pH值以及初始染料浓度等因素对催化性能的影响,并对催化机理进行了研究。结果表明,通过静电组装的方法能够成功制备具有片状结构的g-C_(3)N_(4)/MXene/Ag_(3)PO_(4)催化剂;异质结的构建能够显著提高g-C_(3)N_(4)的催化活性,60 min时,活性红195的降解率由74.92%提高到93.64%;降低初始染料浓度、增加催化剂用量均能加快染料氧化降解反应的进行;酸性和碱性条件下,催化剂对染料的催化氧化性能均高于中性条件;五次重复实验后催化剂对活性红195依然具有较高的降解率(80.11%),且反应前后催化剂的结构没有发生改变;反应过程中染料的偶氮键共轭体系和芳香环结构均遭到破坏,而且·O_(2)-是染料降解反应中的主要活性物质。

In order to improve the photocatalytic performance of g-C_(3)N_(4),g-C_(3)N_(4)/MXene/Ag_(3)PO_(4) heterojunction photocatalyst were prepared via a self-assembly procedure with the help of TEM,FTIR,XRD,XPS,and DRS.And then the effects of catalyst dosage,pH value and initial dye concentration on the catalytic performance,and catalytic mechanism were investigated by the experiment of photocatalytic oxidative degradation of Reactive Red 195 being carried out with g-C_(3)N_(4)/MXene/Ag_(3)PO_(4) under visible light illumination.The results showed that the g-C_(3)N_(4)/MXene/Ag_(3)PO_(4) catalyst with sheet structure could be successfully prepared.The catalytic activity of g-C_(3)N_(4) significantly was improved due to heterojunction.The degradation rate of Reactive Red 195 increased from 74.92%to 93.64%in the treatment of 60 min reaction time.Reduced the initial dye concentration and increased the amount of catalyst could accelerate the oxidative degradation of Reactive Red 195.Additionally,under acidic and alkaline conditions,the catalytic oxidation performance of the catalyst was higher than that under neutral conditions.After 5 cycles of g-C_(3)N_(4)/MXene/Ag_(3)PO_(4),the degradation rate of Reactive Red 195 remained high(80.11%),and the structure of the catalyst did not change before and after usage.This probably due to the azo bond and aromatic ring structure of Reactive Red 195 were destroyed,and·O_(2)-participated in the reaction as the main active substance,during the reaction.