Woo-Young Lee

Palladium (Pd) has received attention as an ideal hydrogen sensor material due to its properties such as high sensitivity and selectivity to hydrogen gas, fast response, and operability at room temperature. Interestingly, various Pd nanostructures that have been realized by recent developments in nanotechnologies are known to show better performance than bulk Pd. This review highlights the characteristic properties, issues, and their possible solutions of hydrogen sensors based on the low-dimens

A novel stress-induced method to grow semimetallic Bi nanowires along with an analysis of their transport properties is presented. Single crystalline Bi nanowires were found to grow on as-sputtered films after thermal annealing at 260-270 degrees C. This was facilitated by relaxation of stress between the film and the thermally oxidized Si substrate that originated from a mismatch of the thermal expansion. The diameter-tunable Bi nanowires can be produced by controlling the mean grain size of th

MOTIFE chemical sensors: A novel, low-cost, scalable, and lithography-free but nanogap-based chemical sensing method is presented. This method, termed highly-mobile thin film on elastomer (MOTIFE), utilizes crack formation in a Pd and PdNi thin film generated by stretching the film on an elastomeric substrate to reliably and reproducibly provide highly sensitive H2 sensors.

Abstract With the recent reillumination of the hydrogen economy around the world, the demand for H 2 sensors is expected to increase rapidly. Due to safety issues caused by the highly flammable and explosive character of hydrogen gas (H 2 ), it is imperative to develop the sensors that can quickly and sensitively detect H 2 leaks. For the development of H 2 sensors, Pd‐based materials have been extensively used due to the high affinity of Pd metal for H 2 . Among Pd‐based H 2 sensors, Pd nanogap

Herein, we describe a microwave-assisted hydrothermal process to synthesize α-Fe2O3 nanotubes/SnO2 nanorods/reduced graphene oxide (FNT/S/RGO) for application as a high-performance anode in lithium-ion batteries (LIBs). The composite products exhibit anisotropic growth because of heteronucleation and the preferred orientation of SnO2. SnO2 nanorods on the FNT surfaces are converted into Sn metal during the alloying/dealloying reaction, which offers improved electrical conductivity. The FNT/S/RGO

Alpha-phase iron oxide nanoparticles (α-NPs), α-iron oxide hollow nanobarrels (α-HNBs), and α-HNBs on reduced graphene oxide (α-HNBs/RGO) for Li-ion batteries (LIBs) were synthesized by a time-efficient microwave method to improve the low electrical conductivity of iron oxide and exploit the porous structure of RGO, which prevents the volume expansion of α-Fe2O3 during the insertion/extraction. On the other hand, α-HNBs (∼200 nm in diameter, ∼360 nm in length) provide a short diffusion path for