JOURNAL OF ORGANIC CHEMISTRY
·
2024
·
IF 3.3
Jin Yan,Suijie Zhong,Xu Chen,Yihuan Luo,Hua Cao,Xiang Liu,Limin Zhao
Here, we report controlled and site-selective C–H alkenylation and dialkenylation of indolizines and pyrrolo[1,2-a]quinolines with β-alkoxyvinyl trifluoromethylketones under simple and practical conditions. Moreover, this direct C–H alkenylation strategy can also be extended to imidazo[1,2-a]pyridines. Notably, without a transition metal and external oxidant, efficient dehydrogenative β-alkenylation of tertiary amines with β-alkoxyvinyl trifluoromethylketones is presented.
研究领域:
有机化学
·
合成化学
✓ 已验证
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2017
·Vol. 41
·期 19
·10613-10618
·
IF 3.269
Zheng Gong,Yu Lei,Peng Zhou,Zehui Zhang
In this study, the one-pot heterocyclization of nitro compounds with 2,5-hexadione was studied for the synthesis of N-substituted pyrroles via a Paal–Knorr condensation process. The heterogeneous cobalt–nitrogen catalyst (Co–Nx/C-800-AT) was found to be active for this reaction with formic acid. Formic acid served as a hydrogen donor for the transfer hydrogenation, and also acted as an acid catalyst. More importantly, this method was tolerant of other functional groups, and hence various N-substituted pyrroles were produced with good to excellent yields. The Co–Nx/C-800-AT catalyst was highly stable, and could be reused several times without loss of its catalytic activity.
研究领域:
有机化学
·
催化化学
✓ 已验证
DOI
高影响因子
ACS Applied Energy Materials
·
2021
·
IF 6.024
Zheng Jiang,Jun Wang,Enyi Hu,Jingjing Liu,Lei Yu,Faze Wang
The p-i-n junction structure has garnered great interest from researchers due to its increased photoactive area and wider space charger region compared with that of the p-n junction. Herein the ultrawide bandgap (∼6.7 eV) semiconductor alumina (Al2O3) has been introduced to construct a p-i-n junction with ZnO and NiO. ZnO–Al2O3–NiO powders are suitable for electrolyte membrane material of low-temperature solid oxide fuel cells (LT-SOFCs). The insulating Al2O3 brings a doubled depletion region and more effective charge separation compared with the p-n junction consisting of ZnO and NiO. The fuel cell based on the p-i-n junction membrane material delivers an enhanced maximum power density (MPD) of 917 mW cm–2 along with a high open-circuit voltage (OCV) of 1.013 V at 550 °C. An analysis based on the space charge region and energy band alignment in the p-i-n junction is proposed to account for the appreciable cell performance and ionic conductivity, as well as the electron blocking and charge separation ability. This study presents a practical p-i-n junction design based on ZnO–Al2O3–NiO via a solution process for LT-SOFC electrolyte material and sheds light on the extensive exploration of p-i-n junctions applied in LT-SOFCs.
研究领域:
材料科学
·
能源工程
✓ 已验证
DOI
高影响因子
Carbon Letters
·
2025
·
IF 5.8
Du Xue,Han Tong,Jin Biao,Meng Long-Yue,Han Lian-Hua
Contamination of food with heavy metal ions and nitrites poses a serious threat to human health. Consequently, the development of fast and sensitive platforms for detecting these contaminants is urgently required. In this paper, a novel MnMgFe-LDHs/DC sensor is constructed based on a simple strategy, in which MnMgFe layered double hydroxide (LDHs) is used as a metal precursor, and a unique "island bridge" carbon network structure is generated by its pyrolysis with ZIF-8@B, N-WMCNTs. The electrical conductivity was enhanced, and a large electroactive surface area was provided for the MnMgFe-LDHs/DC. The electrochemical properties of Pb 2+ , Cd 2+ and nitrite were investigated using this electrode as a working electrode. Under optimized conditions, the sensing platform exhibited a wide linear range with the Pb 2+ , Cd 2+ , and NO 2 − limits of detection of 46.16 nM, 59.25 nM, and 0.083 μM, respectively. Of particular note is that this sensing platform exhibits outstanding anti-interference capabilities. It can precisely and efficiently conduct the detection of nitrite and heavy metal ions in pickled foods.
研究领域:
食品科学
·
环境科学
·
分析化学
✓ 已验证
DOI
高影响因子
APPLIED ORGANOMETALLIC CHEMISTRY
·
2020
·Vol. 34
·期 10
·e5814
·
IF 3.14
Yongcen Lin,Xue Dong,Lang Zhao
N-ZIF-(1:0)@NiCo-LDH, N-ZIF-(1:3.5)@NiCo-LDH and N-ZIF-(0:1)@NiCo-LDH were prepared by mixing solvents in various volume ratios ( V methanol : V water = 1:0, 1:3.5 and 0:1) when synthesizing precursors. These composite materials were characterized using scanning and transmission electron microscopies, X-ray diffraction, X-ray photoelectron spectroscopy and nitrogen adsorption–desorption measurements, and investigated as catalysts for reduction of 4-nitrophenol, methyl orange and methylene blue. The NaBH 4 concentration as an important factor that may affect catalytic activity for reduction of 4-nitrophenol was examined. Under optimal experimental conditions, the excellent catalytic activity of the N-ZIF-(0:1)@NiCo-LDH composite, compared to that of N-ZIF-(1:0)@NiCo-LDH and N-ZIF-(1:3.5)@NiCo-LDH composites, could be attributed to the presence of graphitic nitrogen. In addition, compared with previously reported catalysts, all catalysts prepared show excellent catalytic activity owing to the unique structure exposing more active sites.
研究领域:
材料科学
·
环境化学
·
催化化学
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2017
·Vol. 28
·期 16
·11563-11568
·
IF 2.019
Sun Xinjie,Tong Hua,Yuan Xiao,Liu Cui,Yuan Shuanglong,Chen Guorong,Yang Yunxia
Thermal boron diffusion, which forms highly doped and shallow p-emitters on phosphor-doped silicon wafers, is one of the primary processes in commercial-scale production of n-type cells. Here, we report on the use of nontoxic and nonvolatile borosiloxane sols as the spin-on boron source. In comparison to the tribromide (BBr 3 ) boron diffusion that is applied in the production of most commercial n-type cells, borosiloxane boron diffusion may have potential advantages in terms of cost, safety, operability, etc. The borosiloxane sols studied here were formed from a cross-linking reaction between boron acid and a mixture of two types of silicon alkoxides, methyltriethoxysilane (MTEOS) and dimethyldiethoxysilane (DMDEOS). The MTEOS/DMDEOS ratio was found to be the key factor determining the synthetic period, net structure, thermal transformation property, and coating behavior of the borosiloxane sols. In combination with the spin-coating method, the performance of borosiloxane boron diffusion into phosphor-doped silicon wafers (1–3 Ω·cm) was systematically investigated by varying the borosiloxane composition (boron/silicon or MTEOS/DMDEOS ratio) and the diffusion process parameters (temperature, ambience, and period of individual sub-steps), and by relating them to the resulting sheet resistance and boron doping profile. The results show that under the diffusion conditions in conventional cell production lines, the formed p-emitters can have variable sheet resistance in the range of 35–582 Ω/□ and boron doping depth of 100–300 nm.
研究领域:
材料科学
·
半导体物理
·
光伏技术
·
表面工程
·
纳米材料
·
化学气相沉积
·
微电子学
✓ 已验证
DOI
高影响因子
Frontiers of Chemical Science and Engineering
·
2023
·Vol. 17
·期 12
·1986-2000
·
IF 4.5
Xue Yi-Fan,Feng Jie,Song Yun-Cai,Li Wen-Ying
Breakage of the C–N bond is a structure sensitive process, and the catalyst size significantly affects its activity. On the active metal nanoparticle scale, the role of catalyst size in C–N bond cleavage has not been clearly elucidated. So, Ru catalysts with variable nanoparticle sizes were obtained by modulating the reduction temperature, and the catalytic activity was evaluated using 1,2,3,4-tetrahydroquinoline and o -propylaniline with different C–N bond hybridization patterns as reactants. Results showed a 13 times higher reaction rate for sp 3 -hybridized C–N bond cleavage than sp 2 -hybridized C–N bond cleavage, while the reaction rate tended to increase first and then decrease as the catalyst nanoparticle size increased. Different concentrations of terrace, step, and corner sites were found in different sizes of Ru nanoparticles. The relationship between catalytic site variation and C–N bond cleavage activity was further investigated by calculating the turnover frequency values for each site. This analysis indicates that the variation of different sites on the catalyst is the intrinsic factor of the size dependence of C–N bond cleavage activity, and the step atoms are the active sites for the C–N bond cleavage. When Ru nanoparticles are smaller than 1.9 nm, they have a strong adsorption effect on the reactants, which will affect the catalytic performance of the Ru catalyst. Furthermore, these findings were also confirmed on other metallic Pd/Pt catalysts. The role of step sites in C–N bond cleavage was proposed using the density function theory calculations. The reactants have stronger adsorption energies on the step atoms, and step atoms have d-band center nearer to the Fermi level. In this case, the interaction with the reactant is stronger, which is beneficial for activating the C–N bond of the reactant.
研究领域:
催化化学
·
材料科学
·
理论化学
✓ 已验证
DOI
高影响因子
Journal of Nanoelectronics and Optoelectronics
·
2021
·Vol. 16
·期 11
·1834-1843
·
IF 0.961
Yuan Wenfeng,Yang Jia,Yuan Mengmeng,Fan Jiacheng,Li Ke,Wang Libo,Zhou Aiguo
In this paper, a novel conductive hydrogel was made by a one-pot method at 60 °C for 12 hours in one step without any cross-linking agent. The hydrogel was composited of Ti3C2 MXene nano slices, poly(vinyl alcohol) (PVA) and poly-N-(2-hydroxyethyl acrylamide)
(PHEAA), named as MXene/PVA/PHEAA hydrogel. Compared with previous methods to make MXene hydrogel, this one-pot method was facile and fast. The as-prepared hydrogel was highly stretchable with the breaking elongation of 1300% and tensile strength of 1.1 MPa. MXene nano sheets dispersed in
the hydrogel formed a three-dimensional conductive network, which increased the strength and conductivity of the gels. The conductivity changed with the gel’s deformation and could be applied as strain sensors. The strain sensors made of the hydrogels were highly stretchable, bendable
and flexible with the response range of 1%–300% and a large gauge factor of 4.23. The sensors can be applied to detect human movements such as finger bending, leg bending, water drinking. The MXene/PVA/PHEAA hydrogel made by this facile one-pot method is promising to make strain sensors
for health detection.
研究领域:
材料科学
·
生物医学工程
✓ 已验证
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2022
·Vol. 46
·期 27
·13010-13020
·
IF 3.925
Jianke Tang,Yanfeng Xue,Chunlei Ma,Shengjian Zhang,Qiaoling Li
The construction of p–n heterojunctions instead of p-type or n-type semiconductors can improve the separation efficiency of photoinduced electrons and holes. In this work, BiOI/tetrapod-like ZnO whisker (T-ZnOw) p–n heterojunction photocatalysts with different Bi/Zn molar ratios were prepared by the in situ precipitation of BiOI on a T-ZnOw substrate. The BiOI/T-ZnOw photocatalysts efficiently degraded rhodamine B (RhB) and oxytetracycline (OTC) under visible light irradiation. The photocatalyst with a Bi/Zn molar ratio of 1 : 10 (BZ-10) exhibited the highest photocatalytic activity, with 97.1% and 88.0% removal of RhB and OTC, respectively. After degradation cycling experiments, the OTC removal efficiency was still 80.7%. The photocatalytic activity of the BZ-10 composite was improved compared to those of pure T-ZnOw and BiOI. This was attributed to the large specific surface area and the efficient separation of charge carriers caused by the formation of p–n heterojunctions between BiOI and T-ZnOw. The photodegradation mechanism was put forward based on radical trapping experiments and electron spin resonance (ESR) results. The synthesized BiOI/T-ZnOw heterojunction composite could be a promising photocatalyst in environmental photocatalysis.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2022
·
IF 9.136
Zhimin Lv,Shuya Liu,Yuxin Liu,Peisheng Liu,Ming Fang,Xiaoli Tan,Wei Xu,Mingguang Kong,Xiangke Wang
The pollution of poisonous Cr(VI) poses a severe threat to our health, and the reduction of Cr(VI) to Cr(III) has become a high-efficiency way for wastewater remediation. Herein, the catalyst with metallic Ni confined in an N-doped mesoporous carbon sphere was prepared by the easy pyrolysis method of carbon sphere with Ni salts and showed remarkable activity, selectivity, and stability for reducing Cr(VI) with HCOOH. Notably, the Ni-N-C600 can rapid and 100 % reduction of the high concentrations of Cr(VI) (100 mg/L, 100 ml) using HCOOH within 7 min at room temperature over the reported Ni-based catalysts. Even in the presence of coexisting ions (0.1 M of Na + , K + , Ca 2+ , Zn 2+ , NO 3 − , Cl − , CO 3 2− , and SO 4 2− ), its catalytic efficiency is not affected at all. The catalytic activity of the Ni-N-C600 declined little even after five cycles because the confinement effect of the mesoporous carbon sphere physical barrier prevented the leaching and aggregation of Ni NPs. The magnetism of metallic Ni greatly facilitates the separation of the catalyst. The reduction mechanism is mainly achieved by active hydrogen produced through the dehydrogenation of HCOOH. In addition, the electronic donation of C-containing functional groups also caused a partial reduction of Cr(VI). This work provides a rational design and development of high-efficiency non-noble metal catalysts to reduce Cr(VI).
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
Frontiers in Energy
·
2025
·
IF 6.2
Tang Wenbin,Xia Shuyue,Chou Haiwen,Zhao Jianan,Zhou Yi,Huang Qinghong,Yu Nengfei,Wu Yuping
The oxygen reduction reaction (ORR) plays a crucial role in key processes of fuel cells and zinc-air batteries. To enable commercialization, reducing the platinum (Pt) content and increasing the specific activity per unit mass is essential. A promising approach involves synthesizing of Fe-N-C precursors via the polyaniline (PANI) pathway, which ensures a uniform distribution of Fe-N-C species and facilitates the subsequent adsorption of platinum ions. This leads to the formation of Pt-Fe bimetallic alloys. The synergistic interaction between Pt and Fe-N-C sites promotes the homogeneous dispersion of Pt and the formation of smaller particle sizes, which in turn enhances intrinsic activity and stability of the catalyst. Notably, the Pt/Fe-N-C catalyst, featuring an ultra-low Pt loading of just 1.79 wt%, exhibits a remarkable doubling of mass activity compared to conventional catalysts. Moreover, zinc-air batteries using this catalyst achieve an impressive peak power density of 200 mW/cm 2 .
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
STAR Protocols
·
2022
·
IF 0
Cong Niu,Jianjing Yang,Kelu Yan,Jiafang Xie,Wei Jiang,Bingwen Li,Jiangwei Wen
Here, we present a protocol to decyanopyridate inert N-heterocycles access to N-fused heterocycles via the mechanism of dual proton-coupled electron transfer (PCET). We describe a detailed guide to performing an electrochemical gram-scale protocol for decyanopyridation of inert N-heterocycles. The desired pyridylated quinolone is synthesized in a 5.0 mmol scale with a yield of 76%. The protocol is limited to cyanopyridines. For complete details on the use and execution of this protocol, please refer to Niu et al. (2022) .
研究领域:
有机化学
·
电化学
·
合成化学
✓ 已验证
DOI
PubMed
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