Tunneling Interlayer for Efficient Transport of Charges in Metal Oxide Electrodes

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• 作者：Jiazang Chen ; Liping Zhang ; Zhenhui Lam ; Hua Bing Tao ; Zhiping Zeng ; Hong Bin Yang ; Jianqiang Luo ; Lin Ma ; Bo Li ; Jianfeng Zheng ; Suping Jia ; Zhijian Wang ; Zhenping Zhu ; Bin Liu
• 刊名：Journal of the American Chemical Society
• 出版年：2016
• 出版时间：March 9, 2016
• 年：2016
• 卷：138
• 期：9
• 页码：3183-3189
• 全文大小：477K
• ISSN：1520-5126

文摘

Due to the limited electronic conductivity, the application of many metal oxides that may have attractive (photo)-electrochemical properties has been limited. Regarding these issues, incorporating low-dimensional conducting scaffolds into the electrodes or supporting the metal oxides onto the conducting networks are common approaches. However, some key electronic processes like interfacial charge transfer are far from being consciously concerned. Here we use a carbon-TiO₂ contact as a model system to demonstrate the electronic processes occurring at the metal–semiconductor interface. To minimize the energy dissipation for fast transfer of electrons from semiconductor to carbon scaffolds, facilitating electron tunneling while avoiding high energy-consuming thermionic emission is desired, according to our theoretical simulation of the voltammetric behaviors. To validate this, we manage to sandwich ultrathin TiO₂ interlayers with heavy electronic doping between the carbon conductors and dopant-free TiO₂. The radially graded distribution of the electronic doping along the cross-sectional direction of carbon conductor realized by immobilizing the dopant species on the carbon surface can minimize the energy consumption for contacts to both the carbon and the dopant-free TiO₂. Our strategy provides an important requirement for metal oxide electrode design.