共查询到20条相似文献,搜索用时 15 毫秒
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Dr. Xunyu Lu Tze Hao Tan Dr. Yun Hau Ng Prof. Rose Amal 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(34):11991-11996
A stable and selective electrocatalyst for CO2 reduction was fabricated by covalently attaching graphitic carbon nitride onto multiwall carbon nanotubes (g‐C3N4/MWCNTs). The as‐prepared composite is able to reduce CO2 exclusively to CO with a maximum Faraday efficiency of 60 %, and no decay in the catalytic activity was observed even after 50 h of reaction. The enhanced catalytic activity towards CO2 reduction is attributed to the formation of active carbon–nitrogen bonds, high specific surface area, and improved material conductivity of the g‐C3N4/MWCNT composite. 相似文献
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Hainan Shi Dr. Saran Long Dr. Jungang Hou Dr. Lu Ye Yanwei Sun Wenjun Ni Dr. Chunshan Song Dr. Keyan Li Dr. Gagik G. Gurzadyan Dr. Xinwen Guo 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(19):5028-5035
Fundamental photocatalytic limitations of solar CO2 reduction remain due to low efficiency, serious charge recombination, and short lifetime of catalysts. Herein, two-dimensional graphitic carbon nitride nanosheets with nitrogen vacancies (g-C3Nx) located at both three-coordinate N atoms and uncondensed terminal NHx species were prepared by one-step tartaric acid-assistant thermal polymerization of dicyandiamide. Transient absorption spectra revealed that the defects in g-C3N4 act as trapped states of charges to result in prolonged lifetimes of photoexcited charge carriers. Time-resolved photoluminescence spectroscopy revealed that the faster decay of charges is due to the decreased interlayer stacking distance in g-C3Nx in favor of hopping transition and mobility of charge carriers to the surface of the material. Owing to the synergic virtues of strong visible-light absorption, large surface area, and efficient charge separation, the g-C3Nx nanosheets with negligible loss after 15 h of photocatalysis exhibited a CO evolution rate of 56.9 μmol g−1 h−1 under visible-light irradiation, which is roughly eight times higher than that of pristine g-C3N4. This work presents the role of defects in modulating light absorption and charge separation, which opens an avenue to robust solar-energy conversion performance. 相似文献
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Dr. Jie Yin Dr. Lei Wang Dr. Chungui Tian Dr. Taixing Tan Dr. Guang Mu Dr. Lu Zhao Prof. Honggang Fu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(41):13979-13986
The high cost of platinum electrocatalysts for the oxygen reduction reaction (ORR) has hindered the commercialization of fuel cells. An effective support can reduce the usage of Pt and improve the reactivity of Pt through synergistic effects. Herein, the vanadium nitride/graphitic carbon (VN/GC) nanocomposites, which act as an enhanced carrier of Pt nanoparticles (NPs) towards ORR, have been synthesized for the first time. In the synthesis, the VN/GC composite could be obtained by introducing VO3? and [Fe(CN)6]4? ions into the polyacrylic weak‐acid anion‐exchanged resin (PWAR) through an in‐situ anion‐exchanged route, followed by carbonization and a subsequent nitridation process. After loading only 10 % Pt NPs, the resulting Pt‐VN/GC catalyst demonstrates a more positive onset potential (1.01 V), higher mass activity (137.2 mA mg?1), and better cyclic stability (99 % electrochemical active surface area (ECSA) retention after 2000 cycles) towards ORR than the commercial 20 % Pt/C. Importantly, the Pt‐VN/GC catalyst mainly exhibits a 4 e?‐transfer mechanism and a low yield of peroxide species, suggesting its potential application as a low‐cost and highly efficient ORR catalyst in fuel cells. 相似文献
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Zhong‐Guo Liu Jia‐Yun Wan Ze Yang Prof. Shi‐Quan Wang Dr. Hang‐Xing Wang 《化学:亚洲杂志》2016,11(13):1864-1864
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Lin Ye Yiran Ying Dengrong Sun Zhouyang Zhang Linfeng Fei Zhenhai Wen Jinli Qiao Haitao Huang 《Angewandte Chemie (International ed. in English)》2020,59(8):3244-3251
We report a straightforward strategy to design efficient N doped porous carbon (NPC) electrocatalyst that has a high concentration of easily accessible active sites for the CO2 reduction reaction (CO2RR). The NPC with large amounts of active N (pyridinic and graphitic N) and highly porous structure is prepared by using an oxygen‐rich metal–organic framework (Zn‐MOF‐74) precursor. The amount of active N species can be tuned by optimizing the calcination temperature and time. Owing to the large pore sizes, the active sites are well exposed to electrolyte for CO2RR. The NPC exhibits superior CO2RR activity with a small onset potential of ?0.35 V and a high faradaic efficiency (FE) of 98.4 % towards CO at ?0.55 V vs. RHE, one of the highest values among NPC‐based CO2RR electrocatalysts. This work advances an effective and facile way towards highly active and cost‐effective alternatives to noble‐metal CO2RR electrocatalysts for practical applications. 相似文献
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Dr. Hong Wang Jia Jia Prof. Pengfei Song Dr. Qiang Wang Dr. Debao Li Prof. Shixiong Min Dr. Chenxi Qian Dr. Lu Wang Young Feng Li Chun Ma Prof. Tom Wu Prof. Jiayin Yuan Prof. Markus Antonietti Prof. Geoffrey A. Ozin 《Angewandte Chemie (International ed. in English)》2017,56(27):7847-7852
Herein we introduce a straightforward, low cost, scalable, and technologically relevant method to manufacture an all-carbon, electroactive, nitrogen-doped nanoporous-carbon/carbon-nanotube composite membrane, dubbed “HNCM/CNT”. The membrane is demonstrated to function as a binder-free, high-performance gas diffusion electrode for the electrocatalytic reduction of CO2 to formate. The Faradaic efficiency (FE) for the production of formate is 81 %. Furthermore, the robust structural and electrochemical properties of the membrane endow it with excellent long-term stability. 相似文献
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Yuanyuan Zhang Prof. Jian Liu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(55):e202201430
Natural photosynthesis is a highly unified biocatalytic system, which coupled cofactor (NAD(P)H) regeneration and enzymatic CO2 reduction efficiently for solar energy conversion. Mimicking nature, a novel system with Rh complex covalently grafted onto NH2-functionalized polymeric carbon nitride (NH2-PCN) was constructed. The integrated connection of the light-harvesting and electron mediation modules as Rhm3-N-PCN could promote the efficient NAD+ reduction to NADH. As a result, the integrated system exhibited a conversion of ∼66 % within 20 minutes. By further coupling in situ generated NADH with formate dehydrogenase (FDH), a photoenzymatic production of formic acid (HCOOH) from CO2 was accomplished. Moreover, by immobilizing FDH onto a hydrophobic membrane, an enhanced HCOOH production of ∼5.0 mM can be obtained due to the concentrated CO2 on the gas-liquid-solid three-phase interface. Our work herein provides an integrated strategy for coupling the anchored electron mediator with immobilized enzyme for enhanced artificial photosynthesis. 相似文献
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Inside Back Cover: Metal‐Free Fluorine‐Doped Carbon Electrocatalyst for CO2 Reduction Outcompeting Hydrogen Evolution (Angew. Chem. Int. Ed. 31/2018) 下载免费PDF全文
Dr. Jiafang Xie Xiaotao Zhao Prof. Maoxiang Wu Prof. Qiaohong Li Prof. Yaobing Wang Prof. Jiannian Yao 《Angewandte Chemie (International ed. in English)》2018,57(31):9981-9981
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David M. Koshy Shucheng Chen Dong Un Lee Michaela Burke Stevens Ahmed M. Abdellah Samuel M. Dull Gan Chen Dennis Nordlund Alessandro Gallo Christopher Hahn Drew C. Higgins Zhenan Bao Thomas F. Jaramillo 《Angewandte Chemie (International ed. in English)》2020,59(10):4043-4050
Ni,N‐doped carbon catalysts have shown promising catalytic performance for CO2 electroreduction (CO2R) to CO; this activity has often been attributed to the presence of nitrogen‐coordinated, single Ni atom active sites. However, experimentally confirming Ni?N bonding and correlating CO2 reduction (CO2R) activity to these species has remained a fundamental challenge. We synthesized polyacrylonitrile‐derived Ni,N‐doped carbon electrocatalysts (Ni‐PACN) with a range of pyrolysis temperatures and Ni loadings and correlated their electrochemical activity with extensive physiochemical characterization to rigorously address the origin of activity in these materials. We found that the CO2R to CO partial current density increased with increased Ni content before plateauing at 2 wt % which suggests a dispersed Ni active site. These dispersed active sites were investigated by hard and soft X‐ray spectroscopy, which revealed that pyrrolic nitrogen ligands selectively bind Ni atoms in a distorted square‐planar geometry that strongly resembles the active sites of molecular metal–porphyrin catalysts. 相似文献
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Back Cover: Multipurpose Nature of Rapid Covalent Functionalization on Carbon Nanotubes (Chem. Eur. J. 51/2015) 下载免费PDF全文
Dr. Jose M. González‐Domínguez Ana Santidrián Dr. Alejandro Criado Dr. Caroline Hadad Dr. Martin Kalbáč Prof. Tatiana Da Ros 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(51):18864-18864
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Inside Cover: Electrocatalytic and Solar‐Driven CO2 Reduction to CO with a Molecular Manganese Catalyst Immobilized on Mesoporous TiO2 (Angew. Chem. Int. Ed. 26/2016) 下载免费PDF全文
Timothy E. Rosser Dr. Christopher D. Windle Dr. Erwin Reisner 《Angewandte Chemie (International ed. in English)》2016,55(26):7268-7268
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