Publications

We report an approach to fabricating patterned horizontal ZnO nanowire arrays with a high degree of control over their dimensionality, orientation, and uniformity. Our method combines electron beam lithography and a low temperature hydrothermal decomposition. This approach opens up possibilities to fabricate ZnO NW array based strain and force sensors, two-dimensional photonic crystals, integrated circuit interconnects, and alternative current nanogenerators.

Rectifying diodes of single nanobelt/nanowire-based devices have been fabricated by aligning single ZnO nanobelts/nanowires across paired Au electrodes using dielectrophoresis. A current of 0.5 μA at 1.5 V forward bias has been received, and the diode can bear an applied voltage of up to 10 V. The ideality factor of the diode is ∼3, and the on-to-off current ratio is as high as 2000. The detailed IV characteristics of the Schottky diodes have been investigated at low temperatures. The formation of the Schottky diodes is suggested due to the asymmetric contacts formed in the dielectrophoresis aligning process.

We have rationally synthesized and optimized catalytic nanoparticles consisting of a gold core, covered by a palladium shell, onto which platinum clusters are deposited (Au@Pd@Pt NPs). The amount of Pt and Pd used is extremely small, yet they show unusually high activity for electrooxidation of formic acid. The optimized structure has only 2 atomic layers of Pd and a half-monolayer equivalent of Pt (θPt ≈ 0.5) but a further increase in the loading of Pd or Pt will actually reduce catalytic activity, inferring that a synergistic effect exists between the three different nanostructure components (sphere, shell and islands). A combined electrochemical, surface-enhanced Raman scattering (SERS) and density functional theory (DFT) study of formic acid and CO oxidation reveals that our core–shell–cluster trimetallic nanostructure has some unique electronic and morphological properties, and that it could be the first in a new family of nanocatalysts possessing unusually high chemical reactivity. Our results are immediately applicable to the design of catalysts for direct formic acid fuel cells (DFAFCs).

Abstract For existing triboelectric nanogenerators (TENGs), it is important to explore unique methods to further enhance the output power under realistic environments to speed up their commercialization. We report here a practical TENG composed of three layers, in which the key layer, an electric double layer, is inserted between a top layer, made of Al/polydimethylsiloxane, and a bottom layer, made of Al. The efficient charge separation in the middle layer, based on Volta’s electrophorus, results from sequential contact configuration of the TENG and direct electrical connection of the middle layer to the earth. A sustainable and enhanced output performance of 1.22 mA and 46.8 mW cm −2 under low frequency of 3 Hz is produced, giving over 16-fold enhancement in output power and corresponding to energy conversion efficiency of 22.4%. Finally, a portable power-supplying system, which provides enough d.c. power for charging a smart watch or phone battery, is also successfully developed.

Abstract Triboelectric nanogenerators (TENGs) and electromagnetic generators (EMGs) are hybridized together to harvest ambient mechanical energy. The TENGs employ a circle‐in‐circle structure and therefore act as a support for the EMG's magnet. The EMG possesses a double‐coil construction and works under external motions or vibrations. The outputs of the hybrid generators are systematically investigated. It is found that, a 1000 µF capacitor can be charged to 1.69 V after five cycles of vibrations. Therefore, the hybrid device can be applied as a self‐powered portable power bank to charge lithium batteries, cell phones, and to directly drive electronics.

'Precritical Clusters' published in 'Encyclopedia of Nanotechnology'

Transient electronics provide an effective technology to develop bioabsorbable implantable medical devices (IMDs). In article number 1801625, Yubo Fan, Zhong Lin Wang, Zhou Li, and co-workers design a new fully bioabsorbable capacitor as an energy storage unit for IMDs. This capacitor achieves good working performance and full biodegradability in animals.

RuO2 nanowires and RuO2/TiO2 core/shell nanowires are synthesized by reactive sputtering. The core/shell nanowires are obtained by coating RuO2 nanowires with TiO2. The mechanical, optical, electrical and optoelectronic properties of the nanowires are characterized, and indicate several potential applications of the nanowires.