Research progress on the improved performance of cuprous oxide photocatalyst and its enhancement mechanism

doi:10.16085/j.issn.1000-6613.2018-1645

Abstract

Abstract:

As one of the most promising visible light photocatalysts, Cu₂O has potential applications in many multidisciplinary fields such as solar cells, carbon monoxide oxidation, photocatalysts, sensors, chemical templates. However, due to the easy recombination of its photo-generated electron-hole, quick photocorrosion and poor stability, Cu₂O still faces great challenges in its practical application. Therefore, the studies in the improvement of the photocatalytic performance of Cu₂O has gained extensive attentions. Firstly, three improvement methods of morphology control, heteroatom doping, and semiconductor heterojunction are introduced. It is concluded that the construction of semiconductor heterojunction is the most effective method to improve the photocatalytic performance of Cu₂O and the heterostructures with noble metal, metal oxides, and carbon material are preferred. Secondly, the photocatalytic enhancement mechanism of Cu₂O was discussed with respect to the composited semiconductor heterojunction, Schottky junction and Z-scheme mechanism. Finally, the research directions of Cu₂O-based nanocomposites, which contains electronic structure, interface properties, and composition and thickness of surface loads are given.

Key words: cuprous oxide, photochemistry, catalysis, morphology control, heteroatom doping, semiconductor heterojunction, optimization

摘要：

Cu₂O是目前最有潜力的可见光光催化剂之一，在太阳能电池、一氧化碳氧化、光催化剂、传感器、化学模板等方面有着广泛的应用。然而，Cu₂O光生电子-空穴对具有容易复合、易发生光腐蚀、稳定性不好等特性，使其在实际应用上面临很大的挑战，因此如何有效地提高Cu₂O的光催化性能成为国内外研究者关注的焦点。首先，本文围绕Cu₂O半导体的形貌控制、杂原子掺杂以及构建半导体异质结这三方面对Cu₂O光催化性能的提升进行系统阐述，其中构建半导体异质结是提升Cu₂O光催化性能最有效的方法，Cu₂O与贵金属、金属氧化物以及碳材料构成的复合半导体异质结均有效地提高了Cu₂O的光催化活性；其次，从复合半导体异质结、肖特基结以及Z-scheme机制三方面分析并讨论了Cu₂O光催化增强机制；最后对Cu₂O基纳米复合材料在电子结构、界面性质以及表面负载的成分和厚度等方面的研究进行了展望。

关键词: 氧化亚铜, 光化学, 催化, 形貌控制, 杂原子掺杂, 半导体异质结, 优化

CLC Number:

TB332

Dan LONG, Junling ZHOU, Hongmin SHI, Guanran WANG, Hongshuang LI, Biyi ZHAO, Zhenyu LI. Research progress on the improved performance of cuprous oxide photocatalyst and its enhancement mechanism[J]. Chemical Industry and Engineering Progress, 2019, 38(06): 2756-2767.

龙丹, 周俊伶, 时洪民, 王冠然, 李红双, 赵苾艺, 李贞玉. 氧化亚铜光催化剂性能提升及增强机制的研究进展[J]. 化工进展, 2019, 38(06): 2756-2767.

Figures/Tables 11

References 68

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光催化剂	添加量/mg	MO/mg·L^-1	降解率/%		光源	参考文献
Ni-Cu₂O纳米线	20	20	94	80	300W 氙灯 (λ > 420nm)	[22]
Cu@Cu₂O核壳	4	20	90	100	太阳光（300~2500nm）	[24]
中空Cu@Cu₂O	10	100	92	30	500W 氙灯 (λ > 400nm)	[25]
Cu-Cu₂O多面体	150	10	约为80	90	500W 氙灯(λ≥400nm)	[26]
Au@Cu₂O八面体	10.6	13	91	40	500W 氙灯(λ > 400nm)	[27]
Ag/Cu₂O类花状	40	30	81.2	40	500W 氙灯(λ > 400nm)	[23]

光催化剂	添加量/mg	MO/mg·L^-1	降解率/%		光源	参考文献
Ni-Cu₂O纳米线	20	20	94	80	300W 氙灯 (λ > 420nm)	[22]
Cu@Cu₂O核壳	4	20	90	100	太阳光（300~2500nm）	[24]
中空Cu@Cu₂O	10	100	92	30	500W 氙灯 (λ > 400nm)	[25]
Cu-Cu₂O多面体	150	10	约为80	90	500W 氙灯(λ≥400nm)	[26]
Au@Cu₂O八面体	10.6	13	91	40	500W 氙灯(λ > 400nm)	[27]
Ag/Cu₂O类花状	40	30	81.2	40	500W 氙灯(λ > 400nm)	[23]

光催化剂	E _VB /eV	E _CB/eV	E _g/eV	参考文献	光催化剂	E _VB /eV	E _CB/eV	E _g/eV	参考文献
Ti₂O	2.91	-0.29	3.2	[50]	Ag₃PO₄	2.67	+0.25	2.42	[54]
ZnO	3.0	-0.2	3.2	[51]	Bi₂O₃	3.13	+0.33	2.8	[55]
CdS	1.88	-0.52	2.4	[52]	C₃N₄	1.57	-1.13	2.7	[54]
Ce₂O	2.56	-0.44	3.0	[53]	Cu₂O	0.9	-1.3	2.2	[53]

光催化剂	E _VB /eV	E _CB/eV	E _g/eV	参考文献	光催化剂	E _VB /eV	E _CB/eV	E _g/eV	参考文献
Ti₂O	2.91	-0.29	3.2	[50]	Ag₃PO₄	2.67	+0.25	2.42	[54]
ZnO	3.0	-0.2	3.2	[51]	Bi₂O₃	3.13	+0.33	2.8	[55]
CdS	1.88	-0.52	2.4	[52]	C₃N₄	1.57	-1.13	2.7	[54]
Ce₂O	2.56	-0.44	3.0	[53]	Cu₂O	0.9	-1.3	2.2	[53]

光催化剂	制备	形貌	性能提升	增强机制	参考文献
Cu₂O/ZnO	简单水热法和电沉积法	纳米棒	在可见光照射下5h后，Cu₂O/ZnO对MO 的降解率是纯Cu₂O纳米棒的20倍	增大了表面积；增强了光吸收范围；p-n异质结有效地分离了光生电子空穴对	[56]
Cu₂O/SrTiO₃	溶胶-凝胶法和溶液还原法	纳米颗粒	在可见光下照射80min后，对MB 光降解率是Cu₂O的3倍，是SrTiO₃的1.5倍	形成p-n异质结加速光生电荷载体的分离和迁移	[20]
Cu₂O/SnO₂	简单的水热浸渍法	纳米球	在可见光下照射90min后，对RhB 的降解速率比单个SnO₂和混合相Cu₂O高近2倍	p-n结的形成增强了光响应；促进了光生电子空穴的分离；比表面积和孔隙率增大	[57]
Cu₂O/Bi₂WO₆	界面自组装法	类花状	在可见光下照射120min后，Cu₂O/Bi₂WO₆对MB 的降解率是纯Bi₂WO₆和Cu₂O的2.14倍和12.25倍	可见光吸收效率的提高；紧密接触界面中的强相互作用有效地提高光生电荷分离	[58]
Cu₂O/TiO₂/ g-C₃N₄	简单的化学法	纳米颗粒（NPs）	在可见光照射下，在3 ~ 15min可使 RhB、MB和MO变色	匹配能带以及p-n结的形成	[59]
CQDs/Cu₂O	一步超声处理法	纳米球	在近红外光照下(λ> 700nm、240min)，对MB 的降解率可达90%，而纯CQDs和Cu₂O均不足3%	形成肖特基能垒，阻止了光生电子- 空穴对的重组	[47]
Au/Cu₂O	低温化学法；简单的化学法	Au NPs沉积在Cu₂O微晶表面	在可见光下照射90min，对MO 的光降解率以及光解水是纯Cu₂O微球的1.2倍	Au和Cu₂O界面形成肖特基能垒，在内电场的作用下，有效地促进了光生电子和空穴的分离	[63]
Cu₂O/Ag₃PO₄	简单的化学法	八面体	在可见光照射下（8min）对MB 的光降解速率分别为Cu₂O和Ag₃PO₄的7倍和2.1倍	Z-scheme机理；光生载流子的有效分离	[64]
Cu₂O/Cu/g-C₃N₄	一步还原法	Cu₂O/Cu NPs沉积在g-C₃N₄表面	在可见光照射下（60min），对MO的光催化降解率分别是P25 TiO₂、g-C₃N₄和Cu₂O/Cu的9倍、3.3倍和2倍	Z-scheme电荷转移机理；Cu 为电荷分离中心	[65]