Novel C3N4-CdS composite photocatalysts with organic-inorganic heterojunctions: in situ synthesis, exceptional activity, high stability and photocatalytic mechanism
Novel C3N4-CdS composite photocatalysts with organic-inorganic heterojunctions: in situ synthesis, exceptional activity, high stability and photocatalytic mechanism
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新型有机-无机异质结C3N4-CdS复合光催化剂：原位合成、优异的活性、高稳定性和光催化机理
DOI：
10.1039/c2ta00672c
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发表时间：
2013-01-01
影响因子：
11.9
通讯作者：
Dong, Xiaoping
中科院分区：
文献类型：
--
作者：
Fu, Jie;Chang, Binbin;Dong, Xiaoping
采用“原位”沉淀法成功地合成了由两种可见光响应型半导体材料C3N4和CdS组成的新型有机-无机复合材料。通过在C3N4表面沉积CdS纳米颗粒，制备了C3N4-CDS异质结构。通过调节C3N4-CDS的质量比，可以调节复合材料的形貌和光学性质，从而决定了光催化活性的提高程度。0.7C(3)N(4)-0.3CdS光催化剂对甲基橙的最佳降解活性分别是C3N4和CDS的20.5倍和3.1倍，对4-氨基苯甲酸的最佳降解活性分别是C3N4和CDS的41.6倍和2.7倍。此外，其活性也远高于C3N4-TiO2光催化剂、CdS-TiO2光催化剂以及氮改性的TiO2光催化剂。具有特殊意义的是，与CDS相比，目前的C3N4-CDS复合材料在光照下表现出高的稳定性。性能和稳定性的提高应归功于有效分离和转移来自匹配良好的重叠带结构和紧密接触界面的光生电荷。我们的工作突出表明，具有良好匹配能带的耦合半导体为提高光催化剂的活性和稳定性提供了一条灵活的途径，并为设计和合成其他高活性和稳定的材料提供了思路。
Novel organic-inorganic composites composed of two visible light responsive semiconductors of graphitic carbon nitride (C3N4) and CdS were successfully synthesized via an "in situ" precipitation-deposition method. The C3N4-CdS heterostructures were fabricated by depositing CdS nanoparticles onto the surface of C3N4. The morphology and optical property of compsoites can be tuned by adjusting the mass ratio of C3N4-CdS, which determines the enhanced level of photocatalytic activity. The optimum activity of 0.7C(3)N(4)-0.3CdS photocatalyst is almost 20.5 and 3.1 times higher than those of individual C3N4 and CdS for the degradation of methyl orange, and 41.6 and 2.7 fold higher for the degradation of 4-aminobenzoic acid, respectively. Moreover, its activity is also much higher than those of C3N4-TiO2 and CdS-TiO2 composites, as well as N-modified TiO2. Of special significance is that the present C3N4-CdS composites exhibit high stabilities under illumination, in contrast with CdS. The enhancement in both performance and stability should be assigned to the effective separation and transfer of photogenerated charges originating from the well-matched overlapping band-structures and closely contacted interfaces. Our work highlights that coupling semiconductors with well-matched band energies provides a flexible route to improve the activity and stability of photocatalysts, and gives ideas for the design and synthesis of other highly active and stable materials.