Construction of reduced graphene oxide-supported Ag–Cu2O composites with hierarchical structures for enhanced photocatalytic activities and recyclability
Construction of reduced graphene oxide-supported Ag–Cu2O composites with hierarchical structures for enhanced photocatalytic activities and recyclability
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DOI：
10.1039/c4ta06772j
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发表时间：
2015-03
影响因子：
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通讯作者：
Li Xu;Fengying Zhang;Xinyu Song;Zhilei Yin;Yuxiang Bu
中科院分区：
文献类型：
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作者：
Li Xu;Fengying Zhang;Xinyu Song;Zhilei Yin;Yuxiang Bu
通过简单的室温下一锅两阶段还原合成路线，无需任何表面活性剂，开发出具有优异分级结构的三元球形Ag-Cu2O/还原氧化石墨烯（rGO）纳米杂化物。在所得的复杂异质结构中，Ag和rGO都与Cu2O直接接触，Ag纳米晶体主要沉积在Cu2O球的表面。所得三元球形Ag-Cu2O/rGO复合材料在可见光照射下对甲基橙（MO）的光催化降解表现出优异的光催化活性，远高于单组分（Cu2O）或双组分体系（球形Cu2O/rGO和Ag-Cu2O）。特别是，所得三元复合材料具有优异的稳定性并扩大了光吸收范围。 PL光谱结果表明，不仅Ag，rGO也可以捕获Cu2O的光生电子，从而实现电子和空穴的有效分离。特别是，我们发现三元复合材料中Ag和Cu2O之间的直接连接和相互作用比Ag和rGO（标记为样品Ag-rGO-Cu2O）之间的直接接触更有利于电荷传输，因此具有这种复杂异质结构的Ag-Cu2O/rGO复合材料表现出比样品Ag-rGO-Cu2O更好的光活性。这项工作为设计和合成新型 Cu2O 基杂化材料以有效提高光催化性能提供了见解。
Ternary spherical Ag–Cu2O/reduced graphene oxide (rGO) nanohybrids with excellent hierarchical structures are developed through a simple one-pot, two-stage reduction synthetic route at room temperature without any surfactant. In the resultant complex heterostructures, both Ag and rGO are in direct contact with Cu2O, and Ag nanocrystals are mainly deposited on the surface of Cu2O spheres. The resultant ternary spherical Ag–Cu2O/rGO composite exhibits excellent photocatalytic activity in photocatalytic degradation of methyl orange (MO) under visible light irradiation, which is much higher than that of either the single component (Cu2O) or two component systems (spherical Cu2O/rGO and Ag–Cu2O). In particular, the resultant ternary composites possess excellent stability and extend the light absorption range. The PL spectrum results have demonstrated that not only Ag but also rGO could capture the photogenerated electrons from Cu2O, thus leading to effective separation of electrons and holes. In particular, it is found that the direct junction and interaction between Ag and Cu2O in the ternary composites are more beneficial for charge transportation than the direct contact between Ag and rGO (labeled as sample Ag-rGO-Cu2O), and thereby the resultant Ag–Cu2O/rGO composites with such complex heterostructures exhibit a better photoactivity than the sample Ag-rGO-Cu2O. This work provides an insight into designing and synthesizing new Cu2O-based hybrid materials for effectively improving the photocatalytic performance.