title: Colloidal synthesis of Cu-ZnO and Cu@CuNi-ZnO hybrid nanocrystals with controlled morphologies and multifunctional properties.
abstract: Metal-semiconductor hybrid nanocrystals have received extensive attention owing to their multiple functionalities which can find wide technological applications. The utilization of low-cost non-noble metals to construct novel metal-semiconductor hybrid nanocrystals is important and meaningful for their large-scale applications. In this study, a facile solution approach is developed for the synthesis of Cu-ZnO hybrid nanocrystals with well-controlled morphologies, including nanomultipods, core-shell nanoparticles, nanopyramids and core-shell nanowires. In the synthetic strategy, Cu nanocrystals formed in situ serve as seeds for the heterogeneous nucleation and growth of ZnO, and it eventually forms various Cu-ZnO hetero-nanostructures under different reaction conditions. These hybrid nanocrystals possess well-defined and stable heterostructure junctions. The ultraviolet-visible-near infrared spectra reveal morphology-dependent surface plasmon resonance absorption of Cu and the band gap absorption of ZnO. Furthermore, we construct a novel Cu@CuNi-ZnO ternary hetero-nanostructure by incorporating the magnetic metal Ni into the pre-synthesized colloidal Cu nanocrystals. Such hybrid nanocrystals possess a magnetic Cu-Ni intermediate layer between the ZnO shell and the Cu core, and exhibit ferromagnetic/superparamagnetic properties which expand their functionalities. Finally, enhanced photocatalytic activities are observed in the as-prepared non-noble metal-ZnO hybrid nanocrystals. This study not only provides an economical way to prepare high-quality morphology-controlled Cu-ZnO hybrid nanocrystals for potential applications in the fields of photocatalysis and photovoltaic devices, but also opens up new opportunities in designing ternary non-noble metal-semiconductor hybrid nanocrystals with multifunctionalities.
authors.affiliation: Department of Materials Science and Engineering, Collaborative Innovation Center of Chemistry for Energy Materials, College of Materials, Xiamen University, Xiamen, 361005, P.R. China. yuanzhi@xmu.edu.cn dlpeng@xmu.edu.cn.
authors.forename: Deqian
authors.initials: D
authors.lastname: Zeng
authors.affiliation: Department of Materials Science and Engineering, Collaborative Innovation Center of Chemistry for Energy Materials, College of Materials, Xiamen University, Xiamen, 361005, P.R. China. yuanzhi@xmu.edu.cn dlpeng@xmu.edu.cn.
authors.forename: Pingyun
authors.initials: P
authors.lastname: Gong
authors.affiliation: Department of Materials Science and Engineering, Collaborative Innovation Center of Chemistry for Energy Materials, College of Materials, Xiamen University, Xiamen, 361005, P.R. China. yuanzhi@xmu.edu.cn dlpeng@xmu.edu.cn.
authors.forename: Yuanzhi
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Department of Materials Science and Engineering, Collaborative Innovation Center of Chemistry for Energy Materials, College of Materials, Xiamen University, Xiamen, 361005, P.R. China. yuanzhi@xmu.edu.cn dlpeng@xmu.edu.cn.
authors.forename: Qinfu
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Department of Materials Science and Engineering, Collaborative Innovation Center of Chemistry for Energy Materials, College of Materials, Xiamen University, Xiamen, 361005, P.R. China. yuanzhi@xmu.edu.cn dlpeng@xmu.edu.cn.
authors.forename: Qingshui
authors.initials: Q
authors.lastname: Xie
authors.affiliation: Department of Materials Science and Engineering, Collaborative Innovation Center of Chemistry for Energy Materials, College of Materials, Xiamen University, Xiamen, 361005, P.R. China. yuanzhi@xmu.edu.cn dlpeng@xmu.edu.cn.
authors.forename: Dong-Liang
authors.initials: DL
authors.lastname: Peng