石墨烯/钴掺杂氧化锌准壳核纳米材料的制备

Synthesis of Quasi-core-shell Co-doped ZnO/graphene Nanoparticles

通过简单的化学方法合成了ZnCoO/石墨烯准壳核结构复合纳米材料.高分辨透射电子显微镜谱(HRTEM)检测结果显示ZnCoO完全被石墨烯壳包裹;从ZnCoO/石墨烯的光电子能谱(XPS)可以证实钴离子成功的掺杂到ZnO中;这些结果证明ZnCoO/石墨烯纳米颗粒已被成功合成.变温拉曼中I_D/I_G的峰位强度随着温度的增加而变强,说明样品中缺陷的密度增加,导致缺陷载流子增多;G峰的半高宽随着温度的增加而增大,说明碳原子的sp2轨道耦合相互作用减弱,从而导致自旋作用减弱,与I_D/I_G结果吻合;计算得出G峰的温度系数χ_G为-0.089cm^(-1)/K,说明ZnCoO/石墨烯的载流子浓度随温度升高而增加.实验结果说明,ZnCoO纳米颗粒在包裹石墨烯后,复合结构的电学性能发生较大改变.

Co-doped ZnO/graphene quasi-core-shell hybrid nanoparticles with a graphene shell around the ZnCoO core are successfully synthesized through a simple chemical approach. HRTEM measurements reveal that the ZnCoO is fully covered with the graphene shell.The successful doping of Co ions into the ZnO host is illustrated by the XPS spectra of Co ions.The outcomes confirm that ZnCoO/graphene nanoparticles are successfully synthesized.The peak intensity of I_D/I_G enhances with increasing temperature,which indicates that the density of defects becomes higher,then the density of defect carriers becomes higher.The increasing FWHM of the G band with rising of temperature shows that interaction of carbon sp2 orbitals becomes weaker,resulting in the weaker of spin interaction,which is consistent with I_D/I_G.The extracted value of the temperature coefficient of G mode of ZnCoO/graphene isχ_G=-0.089 cm^(-1)/K,which displays the carrier concentration enhance with increasing temperature.Therefore,ZnCoO/graphene nanoparticles have a promising application in semiconductor electronic devices.