In-situ photo-reducing graphene oxide to create Zn0.5Cd0.5S porous nanosheets/RGO composites as highly stable and efficient photoelectrocatalysts for visible-light-driven water splitting
In-situ photo-reducing graphene oxide to create Zn0.5Cd0.5S porous nanosheets/RGO composites as highly stable and efficient photoelectrocatalysts for visible-light-driven water splitting
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DOI：
10.1016/j.ijhydene.2013.10.118
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发表时间：
2014-01
影响因子：
7.2
通讯作者：
Jin Zhang;Weiwei Zhao;You Xu;Haolan Xu;Bin Zhang
中科院分区：
文献类型：
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作者：
Jin Zhang;Weiwei Zhao;You Xu;Haolan Xu;Bin Zhang
在纳米多孔Zn0.5Cd0.5S单晶纳米片存在的情况下，在可见光照射下，采用原位光还原氧化石墨烯（GO）的方法制备了纳米多孔Zn0.5Cd0.5S纳米片/还原氧化石墨烯（Zn0.5Cd0.5S/RGO）复合材料。采用TEM、IR和拉曼光谱对Zn0.5Cd0.5S/RGO光电极进行了表征。电化学测量表明，在相同条件下，与纯Zn0.5Cd0.5S光电极相比，Zn0.5Cd0.5S/RGO光电极具有更高的阳极光电流密度，更低的零电流电位，在可见光照射下具有更高的光电响应。这种高光化学活性主要归因于RGO的存在，RGO作为电子收集器有效地延长了激发Zn0.5Cd0.5S纳米片的光诱导电子的寿命。此外，复合材料中RGO的含量对光电极的光电化学行为有显著影响，最佳RGO含量为5 wt%。当RGO含量为5wt %时，Zn0.5Cd0.5S/RGO复合材料的产氢速率稳定在12.05 μmol h−1cm−2，外加偏压为0.6 V。此外，发现Zn0.5Cd0.5S/RGO复合材料作为光电极具有高度稳定的析氢反应。存储在RGO中的电子很容易被施加到对电极的正偏压放电或清除，从而纠正电子的流动。重要的是，这项工作可能为使用还原氧化石墨烯支架创建具有增强光电化学活性的稳定光电极开辟了一种简单的原位方法。
Nanoporous Zn0.5Cd0.5S nanosheets/reduced graphene oxide (Zn0.5Cd0.5S/RGO) composites were prepared by a facile in-situ photoreduction method of graphene oxide (GO) in the presence of nanoporous Zn0.5Cd0.5S single-crystal-like nanosheets under visible light irradiation. The Zn0.5Cd0.5S/RGO photoelectrodes was characterized by TEM, IR and Raman spectra. Electrochemical measurements demonstrated that Zn0.5Cd0.5S/RGO photoelectrodes own a higher anodic photocurrent density, a lower zero current potential, and a higher photoelectrochemical response than that of pure Zn0.5Cd0.5S photoelectrodes under visible light irradiation under the same conditions. This high photochemical activity is predominately ascribed to the presence of RGO, which serves as the electron collector to efficiently prolong the lifetime of photoinduced electrons from the excited Zn0.5Cd0.5S nanosheets. In addition, the content of RGO in the composites had a remarkable influence on the photoelectrochemical behaviors of the photoelectrodes and the optimal RGO content was found to be 5 wt%. Zn0.5Cd0.5S/RGO composites at RGO content of 5 wt% reached a stable hydrogen production rate of 12.05 μmol h−1cm−2at an externally applied bias of 0.6 V. Furthermore, the Zn0.5Cd0.5S/RGO composites as photoelectrodes were found to be highly stable for hydrogen evolution reaction. The electrons stored in RGO are readily discharged or scavenged on demand by the applied positive bias to the counter electrode, and thus rectify the flow of electrons. Importantly, this work may open up a facile in-situ method for using RGO scaffold to create a stable photoelectrode with enhanced photoelectrochemical activities.