In-situ Electrical Conductivity of LixMnO2 Nanowires as a Function of "x" and Size.

Mya Le, Yu Liu, Hui Wang, Rajen Dutta, Wenbo Yan, Xiaowei Li, Yu Liu, John C. Hemminger, Ruqian Wu, and Reginald M. Penner*
Chemistry of Materials 27 (2015) 3494.

Mya addresses two questions that strongly influence the efficiency with which a LixMnO2 nanowire is able to function as an energy storage element: First, what is the dc electrical conductance of a LixMnO2 nanowire and the dc conductivity of the LixMnO2 within it as a function of x? Second, what influence, if any, do the lateral dimensions of a nanowire have on these parameters? To answer these two questions, Mya used the LPNE method to prepare arrays of 200 MnO2 nanowires where each nanowire is 40 - 60 nm in height, 275 - 870 nm in width, and 10 microns in length, spanning two gold electrical contacts. The answers are interesting...

Catalytically Activated Palladium@Platinum Nanowires for Accelerated Hydrogen Gas Detection

Xiaowei Li, Yu Liu, John C. Hemminger, and Reginald M. Penner*
ACS Nano, 9 (2015) 3215.

The response/recovery speed of nanoscale chemical sensors is prone to retardation by rate-limiting surfacechemical kinetics because as the critical dimension of the sensor is reduced, the diffusional flux of molecules to sensor surfaces is increased. The performance of nanoscale sensors should therefore be hypersensitive to catalysts. Here Xiaowei has demonstrated that H2 response and recovery kinetics for a highly optimized H2 sensor consisting of a Joule-heated Pd nanowire can be significantly accelerated by the addition of minute quantities (e.g., 1 ML) of a Pt metal catalyst to the nanowire surface..

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