Type II heterojunction in hierarchically porous zinc oxide/graphitic carbon nitride microspheres promoting photocatalytic activity
Type II heterojunction in hierarchically porous zinc oxide/graphitic carbon nitride microspheres promoting photocatalytic activity
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分级多孔氧化锌/石墨氮化碳微球中的 II 型异质结促进光催化活性
DOI：
10.1016/j.jcis.2018.11.076
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发表时间：
2019
影响因子：
9.9
通讯作者：
Su Bao-Lian
中科院分区：
文献类型：
--
作者：
Wu Sijia;Zhao Hong-Juan;Li Chao-Fan;Liu Jing;Dong Wenda;Zhao Heng;Wang Chao;Liu Yang;Hu Zhi-Yi;Chen Lihua;Li Yu;Su Bao-Lian
石墨化碳氮化物(g-C3N4)是一种可见光活性半导体。然而，其电导率低，光生电子和空穴的复合速率高，限制了其在光催化中的应用。在这项工作中，我们设计并合成了具有第二类异质结的分级多孔氧化锌/石墨化碳氮化物(ZnO/g-C3N4)微球，通过提高电荷分离效率来有效地降解罗丹明B(RhB)。紫外-可见(UV-Vis)吸收光谱、Mott-Schottky图和价带X射线光电子能谱证实了氧化锌纳米晶与g-C3N4纳米片之间形成了II型异质结。结果表明，与纯g-C3N4和g-C3N4相比，1.5-ZnO/g-C3N4复合材料(醋酸锌与g-C3N4的质量比为1.5)具有最高的光催化活性和良好的稳定性和较高的光催化降解率。此外，我们的结果也证实了−/g-C3N4是氧化锌/g-C3N4降解罗丹明B的主要活性物种。
Graphitic carbon nitride (g-C3N4) is a visible light active semiconductor. However, low conductivity and high recombination rate of photogenerated electrons and holes limit its application in photocatalysis. In this work, we design and synthesize hierarchically porous zinc oxide/graphitic carbon nitride (ZnO/g-C3N4) microspheres with type-II heterojunction to effectively degrade rhodamine B (RhB) via increasing the charge-separation efficiency. The ultraviolet-visible (UV–Vis) absorption spectra, Mott-Schottky plots and valence band X-ray photoelectron spectroscope confirm the formation of type-II heterojunction between ZnO nanocrystals and g-C3N4nanosheets. As a result, the 1.5-ZnO/g-C3N4composite (the mass ratio of zinc acetate dihydrate to g-C3N4is 1.5) exhibits the highest photocatalytic activity with good stability and higher photocatalytic degradation rate comparing to pure g-C3N4and pure ZnO. In addition, our results confirm thatradical dotO2−and h+are the main active species for ZnO/g-C3N4in degradation of RhB.