Li Haolong, Gupta Jyotsana, Wang Shan, Zhang Na, Bubeck Christoph
Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany; State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun 130012, China.
Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany; Department of Physics, Indian Institute of Technology Madras, Chennai 600036, India.
J Colloid Interface Sci. 2014 Aug 1;427:25-8. doi: 10.1016/j.jcis.2013.11.030. Epub 2013 Nov 19.
We investigated the photocatalytic abilities of three Keggin-type polyoxometalate (POM) clusters, H3PW12O40 (PW), H4SiW12O40 (SiW), and H3PMo12O40 (PMo) to reduce graphene oxide (GO) under UV-irradiation in water. UV-vis absorption and X-ray photoelectron spectroscopy were performed and show that PW and SiW can photoreduce GO effectively, in contrast to PMo. We conclude that the LUMO levels of POMs should be located energetically above the work function of GO to enable electron transfer from POM to GO. We also investigated the saturable absorption of GO and reduced GO by means of z-scan experiments at 532 nm. The POM-assisted photoreduction of GO can greatly enhance the saturable absorber properties of GO, which appears useful for modelocking in ultrafast laser systems.
我们研究了三种Keggin型多金属氧酸盐（POM）簇合物，即H3PW12O40（PW）、H4SiW12O40（SiW）和H3PMo12O40（PMo）在水中紫外线照射下还原氧化石墨烯（GO）的光催化能力。进行了紫外可见吸收和X射线光电子能谱分析，结果表明，与PMo不同，PW和SiW能够有效地光还原GO。我们得出结论，POM的最低未占分子轨道（LUMO）能级在能量上应高于GO的功函数，以便使电子从POM转移到GO。我们还通过532nm的z扫描实验研究了GO和还原态GO的饱和吸收。POM辅助的GO光还原可以大大增强GO的饱和吸收特性，这对于超快激光系统中的锁模似乎是有用的。
