Charge Doping of Large-Area Graphene by Gold-Alloy Nanoparticles
Charge Doping of Large-Area Graphene by Gold-Alloy Nanoparticles
复制标题
DOI：
10.1021/jp409368c
复制
发表时间：
2013-12-19
影响因子：
3.7
通讯作者：
Saito, Nagahiro
中科院分区：
文献类型：
--
作者：
Bratescu, Maria Antoaneta;Saito, Nagahiro
我们提出了一种简便，一步，和无表面活性剂的方法，用于直接合成和负载的稳定的金和金合金纳米粒子（NP）在大面积石墨烯上使用放电在液体环境中，称为溶液等离子体。我们观察到金纳米颗粒对石墨烯的电荷掺杂，这取决于颗粒的化学组成，即使纳米颗粒含有几个百分比的三价sp金属，如铟（In）或镓（Ga）。拉曼和电子能量损失光谱（EELS）方法表明，在金纳米颗粒的情况下，石墨烯掺杂有电子（n型），而在金合金纳米颗粒的情况下，石墨烯掺杂有空穴（p型）。拉曼带位移表明从金NP转移到石墨烯的电子的量为每个晶胞约2 × 10（-4）个电子。如果金NP分别包含In和Ga，则金合金NP每单位晶胞从石墨烯接收（2和4）X 10（-5）个电子。在EELS光谱中，1 s-pi * 跃迁强度的降低和pi* 峰向更高能量的移动证实了由从石墨烯到金合金NP的电子转移引起的反键态的减少，
We present a facile, one-step, and surfactant-free method for direct synthesis and loading of stable gold and gold-alloy nanoparticles (NPs) on large-area graphene using an electrical discharge in a liquid environment, termed solution plasma. We observed a charge doping of graphene by the gold NPs, which depends on the particles' chemical composition, even if the NPs contain a few percent of trivalent sp metals, such as indium (In) or gallium (Ga). Raman and electron energy loss spectroscopy (EELS) methods show that graphene is doped with electrons (n-type) in the case of gold NPs and with holes (p-type) in the case of gold-alloy NPs. The Raman band shift indicates that the amount of the transferred electrons from the gold NPs to graphene is -2 x 10(-4) electrons per unit cell. The gold-alloy NPs receive from graphene (2 and 4) x 10(-5) electrons per unit cell if the gold NPs contain In and Ga, respectively. In the EELS spectra, the decrease in the intensity of the 1s-pi* transition and the shift of the pi* peak to higher energy confirm the depopulation of the antibonding states caused by the electron transfer from graphene to the gold-alloy NPs,