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Energy & Environmental Materials 2022年第1期5卷 313-320页

作者： Hanqing Zhao Dan Zhao Jianqi Ye Pengfei Wang Maosheng Chai Zhong Li Key Laboratory of Coal Science and Technology of Ministry of Education and Shanxi Province Taiyuan University of TechnologyTaiyuan Shanxi 030024China State Key Laboratory of Coal Conversion Institute of Coal ChemistryChinese Academy of SciencesTaiyuan Shanxi 030001China Center for Nano and Micro Mechanics Tsinghua UniversityBeijing 100084China

As the limiting factor for an energy storage technique from lab-scale to industrial-scale,cost means not only the price of raw materials but also the simplicity of processing technics.In this work,the oxygen functionalized carbon materials were obtained from three representative different metamorphic-grade coals,that is,lignite,bitumite,anthracite.oxygen functional groups like quinones,carboxylic anhydrides,and lactones are easier to form near defects according to the thermogravimetric-mass spectrometry measurements and density functional theory calculation.Considering the highest amount of defects and C=O contained functional groups,the low metamorphic-grade lignite derived carbon exhibits a reversible capacity of 259.7 mA h g^(-1)after 50 cycles at 0.03 A g^(-1),best among these micron sized coal-based carbons.The surface active sites contribute highly stable and majority of sodium storage capacity evidenced by in situ Raman spectra and cyclic voltammetry curves at different scan rates.The coal-based carbon materials in this work offer options for industrial applications of sodium-ion battery anode materials.

关键词： anode coal-based carbon oxygen functional groups sodium-ion battery

Structure evolution of oxygen removal from porous carbon for optimizing supercapacitor performance

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Journal of Energy Chemistry 2020年第12期29卷 396-404页

作者： Siting Yuan Xianhong Huang Hao Wang Lijing Xie Jiayao Cheng Qingqiang Kong Guohua Sun Cheng-Meng Chen CAS Key Laboratory of Carbon Materials Institute of Coal ChemistryChinese Academy of SciencesTaiyuan 030001ShanxiChina Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China University of Chinese Academy of Sciences Beijing 100049China

The presence of oxygen functional groups is detrimental to the capacitive performance of porous carbon electrode in organic electrolyte. In this regards, hydrogen thermal reduction has been demonstrated effective approach in removing the unstable surface oxygen while maintaining the high porosity of carbon matrix. However, the exact evolution mechanism of various oxygen species during this process, as well as the correlation with electrochemical properties, is still under development. Herein, biomass-based porous carbon is adopted as the model material to trace its structure evolution of oxygen removal under hydrogen thermal reduction process with the temperature range of 400–800 °C. The optimum microstructure with low oxygen content of 0.90% and proper pore size distribution was achieved at 700°C. XPS, TPRMS and Boehm titration results indicate that the oxygen elimination undergoes three distinctive stages(intermolecular dehydration, hydrogenation and decomposition reactions). The optimum microstructure with low oxygen content of 0.90% and proper pore size distribution was achieved at 700 °C. Benefiting from the stable electrochemical interface and the optimized porous structure, the as-obtained HAC-700 exhibit significantly suppressed self-discharge and leak current, with improved cycling stability, which is attributable to the stabilization of electrochemical interface between carbon surface and electrolyte. The result provides insights for rational design of surface chemistry for high-performance carbon electrode towards advanced energy storage.

关键词： Starch-based activated carbon oxygen functional groups Hydrogen thermal reduction Structural evolution Organic electrolytes Electrochemistry

Plasma activation towards oxidized nanocarbons for efficient electrochemical synthesis of hydrogen peroxide

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Plasma Science and Technology 2021年第2期23卷 38-46页

作者：蔡伟王燕肖长山吴浩斌遇鑫遥 School of Materials Science&Engineering Zhejiang UniversityHangzhou 310027People's Republic of China Institutes of Physical Science and Information Technology Anhui UniversityHefei 230601People's Republic of China Wendian College Anhui UniversityHefei 230601People's Republic of China 不详

Oxidized nanocarbons(ONCs)have been regarded as efficient electrocatalysts for H2O2 production.However,wet chemical procedures involving large volumes of strong acid and long synthetic time are usually needed to obtain these ONCs.Herein,a plasma activation strategy is developed as a rapid and environmentally benign approach to obtain various ONCs,including oxidized multiwalled carbon nanotubes,single-walled carbon nanotube,graphene,and super P carbon black.After a few minutes of plasma activation,oxygen-containing functional groups and defects can be effectively introduced onto the surface of nanocarbons.Enhanced electrocatalytic activity and selectivity are demonstrated by the plasma-ONCs for H2O2 production.Taking oxidized multiwalled carbon nanotubes as an example,high selectivity(up to 95%)and activity(0.75 V at 1 mA cm^(−2))can be achieved in alkaline solution.Moreover,ex situ x-ray photoelectron spectroscopy and in situ Raman measurements reveal that C–O,C=O,edge defect,and sp2 basal planar defect are probably the active sites.

关键词： plasma activation hydrogen peroxide nanocarbon defect oxygen functional groups

High-performance Li-ion batteries based on graphene quantum dot wrapped carbon nanotube hybrid anodes

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Nano Research 2020年第4期13卷 1044-1052页

作者： Xuewei Zhao Yizeng Wu Yunsong Wang Huaisheng Wu Yawei Yang Zhipeng Wang Linxiu Dai Yuanyuan Shang Anyuan Cao Department of Materials Science and Engineering College of EngineeringPeking UniversityBeijing 100871China School of Physics and Microelectronics Zhengzhou UniversityZhengzhou 450001China

Since Akira Yoshino first proposed the usage of the carbonaceous materials as an anode of lithium ion batteries(LIBs)in 1985,carbonaceous materials such as graphite and graphene have been widely considered as LIB anodes.Here,we explored the application of novel carbonaceous UB anodes incorporating graphene quantum dots(GQDs).We fabricated a freestanding all-carbon electrode based on a porous carbon nanotube(CNT)sponge via a facile in-situ hydrothermal deposition technique,creating coaxial structure of GQD-coated CNTs(GQD@CNTs)through electrostatic interaction and n-n stacking with tunable loading and functionalization.This hybrid structure combined conductive CNTs with highly active GQDs,in which GQDs with predesigned functional groups provided massive storage sites for Li ions and the 3D CNT frameworks avoided the agglomeration of GQDs,together contributing to a high specific capacity(700 mAh·g^-1 at 100 mA·g^-1 after 100 cycles)and rate performance.Even at a high current density of 1,000 mA·g^-1,the reversible specific capacity remained at 483 mAh g-1 after 350 cycles.In particular,the mechanism study demonstrated the important role of oxygen functional groups of GQDs in promoting the performance of the LIB anodes by controlled grafting of GQDs onto various porous-carbon and metal-foam based structures.

关键词： graphene quantum dots carbon nanotubes lithium ion batteries anodes oxygen functional groups

Study on the action and mechanism of humic acids in Kaschin-Beck disease

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Journal of Environmental Sciences 1991年第4期3卷 87-94页

作者： Wang Weizhe, Yang Zhiwei and You Shengzhidepartment of Pathophysiology.Liaoning Institute of Basic Medicine.Shenyang.China

Humic acids, especially FA in fractions, contain more oxygen functional groups. In this experiment, on the basis of confirming the action of humic acids on KBD, what was studied is the biological effects of one of main oxygen functional groups, hydroxy group (-OH). The results indicate that inducing pathologic process of KBD, obviously decrease the GSH-Px activity and induce peroxidation membrane injury of tissue. The SOD activity increase in the tissues caused by oxygen functional groups showed that enhancing of free radical reaction should not be neglected.

关键词： Kaschin-Beck disease humic acids oxygen functional groups free radical antioxidase.

Tuning Optical Properties of Graphene Oxide under Compressive Strain Using Wet Ball Milling Method

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Graphene 2016年第2期5卷 73-80页

作者： M. Venkat Narayana S. Narayana Jammalamadaka Magnetic Materials and Device Physics Laboratory Department of Physics Indian Institute of Technology Hyderabad Hyderabad-502285 India

We report on the effect of compressive stress on the optical properties of graphene oxide using a wet ball milling technique. For this purpose, graphene oxide was prepared using the modified Hummer’s method and subsequently processed with wet ball milling. X-ray diffraction infers a peak at 9.655° which is the allowed reflection for the graphene oxide. The Williamson-Hall method is used to quantify the strain on the 10 hrs and 20 hrs ball milled graphene oxide samples and is found to be 4.2% and 4.8% respectively. Although we applied strain on the graphene oxide, it actually helped to reduce the defects which are confirmed by the intensity drop-off of D-peak in Raman spectroscopy. Indeed there exists a band gap alteration of 0.14 eV for an applied compressive strain of ~4.8%, hinting that the reduction in oxygen functional groups and the same is confirmed with the Fourier Transform Infrared Spectroscopy (FTIR). The present results would be helpful in developing graphene oxide based flexible memories and optoelectronic devices.

关键词： Graphene Oxide Band Gap oxygen functional groups Optical Properties

Adsorption of NH3 onto activated carbon prepared from palm shell impregnated with H2SO4

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Adsorption of NH3 onto activated carbon prepared from palm s...