聚吡咯负载氮化碳光催化剂的制备及其光降解性能研究

Preparation of polypyrrole-supported carbon nitride photocatalyst and study on its photodegradation properties

通过原位聚合法,成功制备了聚吡咯改性石墨氮化碳(PPy/g-C_(3)N_(4))复合材料,旨在探究其在可见光下降解染料亚甲基蓝(MB)的性能。实验结果表明,当聚吡咯的摩尔分数为0.6%时,该PPy/g-C_(3)N_(4)光催化剂在60 min内对MB的降解率可达90%,相较于纯g-C_(3)N_(4)材料,光催化性能显著提升。此外,该复合材料还表现出优异的循环稳定性。通过自由基捕获实验,确认超氧自由基(·O_(2)^(-))和空穴(h^(+))是该复合材料降解污染物的主要活性物种。这是由于g-C_(3)N_(4)与PPy两者形成的p-n异质结有效减少了电子-空穴对的复合,从而增强了光催化降解活性。这将有助于深入了解反应机理,为制备具有能源和环境应用价值的g-C_(3)N_(4)基高效光催化剂提供可行的途径。

Through the in-situ polymerization method,this study successfully prepared polypyrrole-modified graphite carbon nitride(PPy/g-C_(3)N_(4))composite materials,aiming to explore its performance in degrading the dye methylene blue(MB)under visible light.Experimental results show that when the molar fraction of polypyrrole is 0.6%,the PPy/g-C_(3)N_(4)photocatalyst can degrade MB up to 90%within 60 min,indicating that compared with pure g-C_(3)N_(4)material.The catalytic performance was significantly improved.In addition,the composite exhibits excellent cycling stability.Through free radical capture experiments,it was confirmed that superoxide radicals(•O_(2)^(-))and holes(h^(+))are the main active species for the degradation of pollutants by this composite material.This is because the p-n heterojunction formed by g-C_(3)N_(4)and PPy effectively reduces the recombination of electron-hole pairs,thereby enhancing its photocatalytic degradation activity.This work will help us deeply understand the reaction mechanism and provide a feasible way to prepare g-C_(3)N_(4)-based high-efficiency photocatalysts with energy and environmental application value.