Xiaoyou Yuan,Hai Yuan,Lina Ye,Junjie Hu,Ying Xu,Peng Li
In this work, we have successfully synthesized ultrasmall Cu2O nanocrystals with uniform sizes through a solution-based method. By virtue of the ideal Cu2O building blocks, 2D or 3D Cu2O superstructures can be easily achieved by tailoring the assembly process. The results indicate that diethyl carbonate (DEC) plays a crucial role for controlled self-assembly of Cu2O nanoparticles into a range of superstructures. Interestingly, the aggregative growths of Cu2O nanocrystals in the self-assembly process are accompanied by oriented attachment and Ostwald ripening. Furthermore, Cu2O and Cu2O–Au 3D colloidal spheres can be also obtained by an emulsion-based bottom-up self-assembly strategy. The results show that, compared with pure Cu2O nanospheres, the as-obtained Cu2O–Au nanospheres exhibit remarkable photocatalytic activities in the photodegradation of methyl orange (MO).
In this study, Cu 2 O crystals with different morphologies were synthesized to investigate the effect of exposed crystalline facets on photocatalytic degradation efficiency. By adjusting the addition amount of PVP, different morphologies of Cu 2 O crystals were obtained, such as cubic, decahedral, octahedral, etc. XRD , SEM, and TEM characterizations were used to observe the properties of the synthesized Cu 2 O in terms of morphology, size, and lattice structure. The results showed that the octahedral cuprous oxide had the strongest photocatalytic degradation effect (78.3%). The study also explored the connection between different crystalline facets and MO microstructure, and the effect of crystalline facet selectivity on the pre-absorption and photocatalytic degradation of MO. Density Functional Theory (DFT) calculations were used to investigate the connection between the energy level structure of different crystalline facets of Cu 2 O and its photocatalytic activity . Finally, based on the experimental analysis and theoretical calculation, a new charge separation model on crystalline surface was proposed.
Graphical Shape-dependent nanocatalysis : Monodisperse cubic, rhombic dodecahedral, and octadecahedral Cu 2 O nanocrystals (NCs) were selectively synthesized. Cu 2 O octadecahedra exhibited the best activity upon recycling, though etched on nanoframes, in the ligand-free oxidative arylation of phenylacetylene. Rhombic dodecahedra had moderate activity and optimal stability, whereas cubes suffered significant loss of activity during recycling.
Xiaofeng Wei,Jiaqi Pan,Jie Mei,Yingying Zheng,Can Cui,Chaorong Li
The orderly nano array is able to improve the light utilization efficiency and has been thought to be a promising way for advancing photocatalysis. The orderly nano array of truncated octahedra Cu 2 O nanocrystals have been successfully fabricated by the facile solution-based one-step reduction and self-assembly method. The results of XRD, SEM and TEM indicate that the Cu 2 O nano array is successfully assembled on the Si substrate. The photocatalytic activity of the Cu 2 O orderly nano array is investigated under visible light irradiation, and it is demonstrated to be significantly enhanced after the Cu 2 O is self-assembled orderly. Furthermore, the surface orderly structure of the nano array is considered as the main reason for the enhancement.
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