Dipartimento di Fisica, Università di Roma Tor Vergata, Roma, Italy.
Nanotechnology. 2011 Jan 21;22(3):035701. doi: 10.1088/0957-4484/22/3/035701. Epub 2010 Dec 9.
We show that Cu metal nanoparticle-multiwall carbon nanotube (MWCNT) assemblies can act as a new hybrid photoactive layer in photo-electrochemical devices. The carbon nanotube (CNT) composites were formed by a controlled thermal deposition of copper which produced crystalline metal nanoparticles localized on the carbon tube outer walls. The photoresponse evaluated in terms of IPCE (incident photon-to-charge carrier generation efficiency) varied for different sized-Cu-MWCNT samples across all the visible and near ultraviolet photon energy range with respect to the response of bare MWCNTs. In the case of 0.2 nm Cu nominal thickness, the IPCE increased, reaching 15%, a value 2.5 times higher than that measured for bare MWCNTs. As the Cu nominal coverage thickened, the IPCE started to decrease and become totally ineffective after 1 nm deposited Cu. The IPCE increase found was interpreted as being the result of a remarkable charge transfer between the Cu metal nanoparticles and the CNTs due to the formation of a strong ionic bond at their interface. The results obtained prove that the metal nanoparticle-CNT composites have optical, electrical and structural properties that can be applied in a variety of nanoscale architectures for novel photo-electrochemical devices.
我们展示了铜金属纳米粒子-多壁碳纳米管（MWCNT）组件可以作为光电化学器件中的新型混合光活性层。通过受控的热沉积铜形成碳纳米管（CNT）复合材料，在碳管外壁上产生结晶金属纳米粒子。根据 IPCE（入射光子到电荷载流子产生效率）评估的光响应在整个可见光和近紫外光子能量范围内因不同尺寸的 Cu-MWCNT 样品而异，相对于裸 MWCNTs 的响应。在 0.2nm 铜名义厚度的情况下，IPCE 增加，达到 15%，比裸 MWCNTs 测量的值高 2.5 倍。随着 Cu 名义覆盖率的增加，IPCE 开始下降，在沉积 1nmCu 后完全失效。发现的 IPCE 增加被解释为由于在它们的界面处形成强离子键，Cu 金属纳米粒子和 CNT 之间的电荷转移显著增加的结果。所获得的结果证明了金属纳米粒子-CNT 复合材料具有光学、电学和结构性能，可应用于各种新型光电化学器件的纳米级架构中。
