Publications by authors named "Kejun Tu"

3 Publications

  • Page 1 of 1

Self-adaptive cardiac optogenetics device based on negative stretching-resistive strain sensor.

Sci Adv 2021 Nov 24;7(48):eabj4273. Epub 2021 Nov 24.

National Key Laboratory of Science and Technology on Micro/Nano Fabrication, Shanghai Jiao Tong University, Shanghai 200240, China.

[Figure: see text].
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http://dx.doi.org/10.1126/sciadv.abj4273DOI Listing
November 2021

A Novel Heterostructure Based on RuMo Nanoalloys and N-doped Carbon as an Efficient Electrocatalyst for the Hydrogen Evolution Reaction.

Adv Mater 2020 Nov 15;32(46):e2005433. Epub 2020 Oct 15.

The Meso-Entropy Matter Lab, State Key Laboratory of Metal Matrix Composites, Shanghai Key Laboratory of Electrical Insulation and Thermal Aging, School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, Shanghai Jiao Tong University, 800 Dongchuan RD., Shanghai, 200240, China.

Heterostructures exhibit considerable potential in the field of energy conversion due to their excellent interfacial charge states in tuning the electronic properties of different components to promote catalytic activity. However, the rational preparation of heterostructures with highly active heterosurfaces remains a challenge because of the difficulty in component tuning, morphology control, and active site determination. Herein, a novel heterostructure based on a combination of RuMo nanoalloys and hexagonal N-doped carbon nanosheets is designed and synthesized. In this protocol, metal-containing anions and layered double hydroxides are employed to control the components and morphology of heterostructures, respectively. Accordingly, the as-made RuMo-nanoalloys-embedded hexagonal porous carbon nanosheets are promising for the hydrogen evolution reaction (HER), resulting in an extremely small overpotential (18 mV), an ultralow Tafel slope (25 mV dec ), and a high turnover frequency (3.57 H s ) in alkaline media, outperforming current Ru-based electrocatalysts. First-principle calculations based on typical 2D N-doped carbon/RuMo nanoalloys heterostructures demonstrate that introducing N and Mo atoms into C and Ru lattices, respectively, triggers electron accumulation/depletion regions at the heterosurface and consequently reduces the energy barrier for the HER. This work presents a convenient method for rational fabrication of carbon-metal heterostructures for highly efficient electrocatalysis.
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http://dx.doi.org/10.1002/adma.202005433DOI Listing
November 2020

Ionic Polyimide Derived Porous Carbon Nanosheets as High-Efficiency Oxygen Reduction Catalysts for Zn-Air Batteries.

Chemistry 2020 May 28;26(29):6525-6534. Epub 2020 Jan 28.

The Meso-Entropy Matter Lab, School of Chemistry and Chemical Engineering, State Key Laboratory of Metal Matrix Composites, Shanghai Key Laboratory of Electrical Insulation and Thermal Aging, Shanghai Jiao Tong University, Shanghai, 200240, P. R. China.

Two-dimensional (2D) porous carbon nanosheets (2DPCs) have attracted great attention for their good porosity and long-distance conductivity. Factors such as templates, precursors, and carbonization-activation methods, directly determine their performance. However, rational design and preparation of porous carbon materials with controlled 2D morphology and heteroatom dopants remains a challenge. Therefore, an ionic polyimide with both sp - and sp -hybridized nitrogen atoms was prepared as a precursor for fabricating N-doped hexagonal porous carbon nanosheets through a hard-template approach. Because of the large surface area and efficient charge-mass transport, the resulting activated 2D porous carbon nanosheets (2DPCs-a) displayed promising electrocatalytic properties for oxygen reduction reaction (ORR) in alkaline and acidic media, such as ultralow half-wave potential (0.83 vs. 0.84 V of Pt/C) and superior limiting current density (5.42 vs. 5.14 mA cm of Pt/C). As air cathodes in Zn-air batteries, the as-developed 2DPCs-a exhibited long stability and high capacity (up to 614 mA h g ), which are both higher than those of commercial Pt/C. This work provides a convenient method for controllable and scalable 2DPCs fabrication as well as new opportunities to develop high-efficiency electrocatalysts for ORR and Zn-air batteries.
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http://dx.doi.org/10.1002/chem.201904769DOI Listing
May 2020
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