Novel Heterostructure of CdSe Nanobridge on ZnO Nanorods: Cd‐Carboxyl‐RGO‐Assisted Synthesis and Enhanced Photoelectrochemical Efficiency
Novel Heterostructure of CdSe Nanobridge on ZnO Nanorods: Cd‐Carboxyl‐RGO‐Assisted Synthesis and Enhanced Photoelectrochemical Efficiency
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DOI：
10.1002/admi.201500737
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发表时间：
2016-06
影响因子：
5.4
通讯作者：
Zhuo Zhang;Mingi Choi;Minki Baek;K. Yong
中科院分区：
文献类型：
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作者：
Zhuo Zhang;Mingi Choi;Minki Baek;K. Yong
光电化学（PEC）制氢是解决能源危机的绿色有效策略。在这项研究中，通过水热法制造了 CdSe 异质纳米桥 (HNB) 结构作为 PEC 光阳极。 “桥墩”是使用装饰有 CdSe 纳米颗粒 (NP) 的 ZnO 纳米棒 (NR) 构建的，而“桥梁”是使用覆盖有还原氧化石墨烯 (RGO) 层并与 ZnO NR 交联的 CdSe 纳米线构建的。 CdSe NBs 的形成归因于在碱性溶液中形成 Cd-羧基-RGO 键，用 RGO 层钝化 CdSe 非极性表面，从而引导 CdSe 沿 c 轴优先生长。此外，尽管用HAuCl4溶液蚀刻功能化的RGO，也合成了用Au NP装饰的CdSe NB作为另一种异质纳米结构。这项研究表明，CdSe 异质纳米带的光转换可以通过 CdSe 和 ZnO 的 II 型级联能带排列以及通过网状桥结构的有效电荷转移来增强。此外，Cd-羧基-RGO层和Au NPs可以通过抑制电子空穴复合来提高CdSe NBs的电子寿命。总体而言，具有更高 PEC 效率的 CdSe 异质纳米结构代表了一种有前途的光阳极材料，并且该合成路线可用于构建其他材料的高度网络化的异质纳米结构。
Photoelectrochemical (PEC) hydrogen generation is a green and effective strategy for addressing energy crises. In this study, a CdSe heteronanobridge (HNB) structure is fabricated as PEC photoanode via a hydrothermal method. The “pier” is built using ZnO nanorods (NRs) decorated with CdSe nanoparticles (NPs), and the “bridge” is constructed using CdSe nanowire covered by an reduced graphene oxide (RGO) layer and cross‐linked with ZnO NRs. The formation of the CdSe NBs is ascribed to the passivation of the CdSe nonpolar surface with an RGO layer by the formation of Cd‐carboxyl‐RGO bond in alkaline solution, which directs the preferential growth of CdSe along c‐axis. Additionally, despite etching the functionalized RGO with HAuCl4 solution, CdSe NBs decorated with Au NPs are also synthesized as another heteronanostructure. This study demonstrates that the photoconversion of the CdSe hetero‐NBs can be enhanced via the type II cascade band alignment of CdSe and ZnO and efficient charge transfer through net‐like bridge structures. Moreover, the Cd‐carboxyl‐RGO layer and Au NPs can improve the electron lifetime of the CdSe NBs by suppressing electron–hole recombination. Overall, CdSe hetero‐NBs with increased PEC efficiency represent a promising photoanode material, and the synthesis route can be used to build highly networked heteronanostructures of other materials.