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Your search keyword '"Wu, Yuzhe"' showing total 76 results
Start Over Author "Wu, Yuzhe" Publisher elsevier bv
76 results on '"Wu, Yuzhe"'

19. Carbon particles co-doped with N, B and Fe from metal-organic supramolecular polymers for boosted oxygen reduction performance

Author

Wu Yuzhe, Li Yuntong, Li Zhongyu, Haiyang Wu, Zhang Hong, Lizong Dai, Tong Wu, Conghui Yuan, Birong Zeng, and Yiting Xu

Subjects
chemistry.chemical_classification, Materials science, Renewable Energy, Sustainability and the Environment, Coordination polymer, Energy Engineering and Power Technology, chemistry.chemical_element, 02 engineering and technology, 010402 general chemistry, 021001 nanoscience & nanotechnology, Electrocatalyst, 01 natural sciences, 0104 chemical sciences, Catalysis, Supramolecular polymers, chemistry.chemical_compound, chemistry, Chemical engineering, Methanol, Electrical and Electronic Engineering, Physical and Theoretical Chemistry, 0210 nano-technology, Platinum, Carbon, Pyrolysis
Abstract

Rational design of high-efficiency and cost-effective nonprecious metal-based catalysts with outstanding oxygen reduction reaction (ORR) performance, is of great importance to replace platinum-based electrocatalysts in fuel cell. Herein, a novel N, B and Fe co-doped carbon materials (Fe-NBC) electrocatalyst is designed through the pyrolysis of a metal-organic coordination polymer precursor, which is formed from the coordination between dendrimer-like terpyridinic monomer and Fe3+. The as-prepared Fe-NBC catalyst exhibits superior ORR activity with an onset potential of 0.98 V and a half-wave potential of 0.86 V, which are comparable to that of the Pt/C catalyst. The formation of Fe-Nx moieties is considered to be the most important factor for the improved ORR activity of Fe-NBC. Besides, Fe-NBC catalyst displays a better methanol tolerance as well as durability (5 mV negative shift of E1/2, after 1000 cycles) in comparison with Pt/C (12 mV negative shift of E1/2, after 1000 cycles). This work provides a facile protocol for the design and fabrication of multi-element co-doped carbon materials. Moreover, the excellent ORR performance of these N, B and Fe co-doped carbon materials may be a potential candidate to replace Pt-based catalyst in fuel cells.

Published
2019

21. A high synergistic P/N/Si-containing additive with dandelion-shaped structure deriving from self-assembly for enhancing thermal and flame retardant property of epoxy resins

Author

Birong Zeng, Chen Ting, Li Yuntong, Lizong Dai, Wu Yuzhe, Haiyang Wu, and Guorong Chen

Subjects
Materials science, Polymers and Plastics, General Chemical Engineering, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, Biochemistry, chemistry.chemical_compound, symbols.namesake, X-ray photoelectron spectroscopy, Materials Chemistry, Environmental Chemistry, Thermal stability, Char, Triazine, Quenching, General Chemistry, Epoxy, 021001 nanoscience & nanotechnology, 0104 chemical sciences, chemistry, Chemical engineering, visual_art, visual_art.visual_art_medium, symbols, 0210 nano-technology, Raman spectroscopy, Fire retardant
Abstract

In order to improve thermal and flame-retardant as well as mechanical properties of epoxy resins efficiently, a new P/N/Si-containing nano-filler called 2,4-(bis-polyhedral-oligomeric-silsesquioxane)-6-[(bis-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-yl)amine]-(p-4-hydroxyphenyl)-1,3,5-triazine (abbrev. PDT) was synthesized by nucleophilic aromatic substitution reaction and was combined with curing-agent to prepare epoxy resin composites, incorporating both nanocaged framework of Si O and rigid phenyl-rings from triazine and DOPO into the epoxy matrix at molecular level. The prepared EP-PDT composites were characterized by means of techniques such as TGA-IR, Raman, SEM, EDX analysis, Py-GC/MS and XPS etc. It showed that all samples had a single Tg, indicating that these epoxy composites were homogeneous phase for long-term use. Both the LOI value and char yield increased with the increasing of PDT content, while the corresponding PHRR and THR data of EP composites dropped. SEM revealed that PDT in EP composites self-assembled into nano-sized particles, resulting in an enhanced mechanical property. Py-GC/MS and XPS characterizations showed that PDT could release free radicals and promote the char formation deriving from the synergic effect of phosphorus, nitrogen and silicon during combustion, which resulted in the formation of quenching and barrier effects to endow the EP composites with excellent thermal stability and flame retardancy for potential applications in many fields.

Published
2018

29. B, N co-doped carbon from cross-linking induced self-organization of boronate polymer for supercapacitor and oxygen reduction reaction

Author

Liu Cheng, Haiyang Wu, Lizong Dai, Conghui Yuan, Birong Zeng, Wu Yuzhe, Yiting Xu, Li Yuntong, Chang Ying, and Mao Jie

Subjects
Supercapacitor, chemistry.chemical_classification, Catechol, Renewable Energy, Sustainability and the Environment, Inorganic chemistry, Heteroatom, Energy Engineering and Power Technology, 02 engineering and technology, Polymer, 010402 general chemistry, 021001 nanoscience & nanotechnology, Electrochemistry, Condensation reaction, 01 natural sciences, 0104 chemical sciences, chemistry.chemical_compound, Monomer, chemistry, Chemical engineering, Methanol, Electrical and Electronic Engineering, Physical and Theoretical Chemistry, 0210 nano-technology
Abstract

A novel strategy has been developed to generate B, N co-doped carbon materials (CNBs) through the pyrolysis of boronate polymer nanoparticles (BPNs) derived from the condensation reaction between catechol and boronic monomers. The morphology, surface area and heteroatom ( viz . B and N) content of the CNBs can be easily adjusted by altering the molar ratio between catechol and boronic monomers. The supercapacitor and oxygen reduction reaction (ORR) performance of the CNBs are optimized. CNBs derived from equal molar ratio of catechol and boronic monomers exhibit favorable performance for supercapacitor, featuring a specific capacitance of up to 299.4 F/g at 0.2 A/g, an improved rate capability and excellent cycle stability. Notably, CNBs prepared using 1/2 molar ratio of catechol to boronic monomers show excellent ORR performance, as they demonstrate good electrocatalytic activity, high tolerance for methanol and long durability. Our findings may be of interest in the design of carbon materials with optimized electrochemical properties through the control over surface area and the content of heteroatom.

Published
2017

30. An etching approach to bimetal-doped hollow carbon nanospheres with boosted oxygen reduction reaction

Author

Cai Qipeng, Li Yuntong, Liu Huixiang, Mao Jie, Lizong Dai, Birong Zeng, Yiting Xu, Conghui Yuan, Wu Yuzhe, and Lu Zhenwu

Subjects
Materials science, Kirkendall effect, Carbonization, Mechanical Engineering, Alloy, Metals and Alloys, chemistry.chemical_element, 02 engineering and technology, engineering.material, 010402 general chemistry, 021001 nanoscience & nanotechnology, Electrochemistry, 01 natural sciences, 0104 chemical sciences, Bimetal, Catalysis, Chemical engineering, chemistry, Mechanics of Materials, Etching (microfabrication), Materials Chemistry, engineering, 0210 nano-technology, Carbon
Abstract

Incorporation of two or more types of metallic atoms into carbon matrix is of particular interest in the fabrication of high performance electrode materials. This normally requires complex synthetic routes or intricate post-processing process. Moreover, the composition and morphology of the resultant carbon materials are uncontrollable. Herein, we show the first time that a bimetal ions (Sn4+ and Fe3+) etching method based on Kirkendall effect can transform boronate polymer assemblies into metallosupramolecular polymer hollow spheres, which can be carbonized into carbon shells comprising FeSn2 alloy. The carbon shells display evidently improved activity towards oxygen reduction reaction with onset potential 0.94 V and half-wave potential 0.84 V vs. RHE, which are comparable to that of Pt/C. The as formed FeSn2 alloy in the carbon matrix possesses characteristics of rich in electrons, excellent conductivity and high chemical activity. Our supramolecular approach is simple, and able to control both the composition and morphology of the carbon materials, which may afford a new strategy for the design of higher performance electrochemical catalysts.

Published
2020

31. A high performance flexible recyclable supercapacitor with polyaniline by casting in unconventional proportion

Author

Lizong Dai, Wu Zhangfeng, Birong Zeng, He Kaiwei, Mao Jie, Conghui Yuan, Yiting Xu, Wu Yuzhe, and Zhengchun Yang

Subjects
Supercapacitor, Materials science, Renewable Energy, Sustainability and the Environment, Energy Engineering and Power Technology, 02 engineering and technology, Carbon black, Polyethylene glycol, 010402 general chemistry, 021001 nanoscience & nanotechnology, Electrochemistry, 01 natural sciences, Polyvinylidene fluoride, Casting, 0104 chemical sciences, chemistry.chemical_compound, chemistry, Chemical engineering, Polyaniline, Electrode, Electrical and Electronic Engineering, Physical and Theoretical Chemistry, 0210 nano-technology
Abstract

A new type of recyclable flexible solid-state supercapacitor with good electrochemical performance and folder ability is produced through a facile method. Polyvinylidene fluoride - acetylene black - polyethylene glycol - polyaniline (PVDF-AB-PEG-PANI) film electrode with excellent processability and tailorability is prepared by casting strategy, which uses large amount of PVDF as film former. The new electrode has good performance with excellent flexibility (dr

Published
2019

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