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
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
APPLIED ORGANOMETALLIC CHEMISTRY
·
2013
·Vol. 27
·期 6
·337-340
·
IF 2.011
Junyu Dong,Tianbin Li,Chuan Dai,Wen Weng,Xinghua Xue,Yuyu Zhang,Qingle Zeng
A straightforward, protecting-group-free protocol for the synthesis of chiral 6-substituted and 6,6’-disubstituted binols (binol = 1,1’-bi-2-naphthol) by palladium-catalyzed hydroxylation, C–N and C–O coupling of chiral 6-bromo- and 6,6’ -dibromo-1,1’-binaphthols is developed. The protecting group free palladium-catalyzed hydroxylation, C–O and C–N cross-coupling protocol affords a straightforward and general method for the synthesis of chiral 6-substituted and 6,6’-disubstituted binols with good yields, avoiding the tedious procedures of introduction and removal of protecting groups. Copyright © 2013 John Wiley & Sons, Ltd.
研究领域:
有机化学
·
合成化学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2024
·
IF 4.1
Yibo Qin,Longfei Chen,Lixia Ge,Yanfeng Zhu,Wanting Li,Xinxin Cao,Tianchang Wang,Jiong Li,Wei Han,Xinqing Chen
Hydrogen spillover plays a crucial role in heterogeneous catalysis, significantly enhancing the activity of catalysts. However, the promotion mechanism of hydrogen spillover on non-reducible oxide supports (such as zeolite) is rarely reported. Herein, we prepared Ru@Beta sample by in-situ approach, effectively encapsulating Ru species into Beta zeolite. Additionally, three samples (Ru/SiO 2 , Ru@Naβ, and Ru@Hβ) with different hydrogen spillover effect were prepared. The optimal concentration of Ru was 0.5 wt%, and the Ru@Hβ sample with the strongest hydrogen spillover has 100 % conversion rate of N-ethylcarbazole (NEC) and 98 % selectivity towards to 12H-NEC. In contrast, the Ru/SiO 2 with weak hydrogen spillover has only 89.5 % conversion rate and 28.9 % selectivity of 12H-NEC. Notably, the Ru@Hβ can still completely convert NEC even after 7 cycles, thereby exhibiting its remarkable activity and stability. Various characterizations (HAADF-STEM, XPS, EXAFS, in-situ DRIFT, and H 2 -TPD) indicate the superior catalytic performance of Ru@Hβ with strong hydrogen spillover effect, originating from the presence of more hydroxyl (–OH) and Brønsted acid on the surface, while Lewis acid act as hydrogen acceptors and NEC hydrogenation sites. This work not only expands our understanding of the hydrogen spillover, but also paves the way onto the potential applications in heterogeneous catalysis for efficient hydrogenation.
研究领域:
催化化学
·
材料科学
·
能源存储
✓ 已验证
DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2015
·Vol. 23
·期 4
·3399-3405
·
IF 2.828
Yang Bin,Li Zhongjian,Lei Lecheng,Sun Feifei,Zhu Jingke
The solubilities of 19 different kinds of N-heteroaromatic compounds in aqueous solutions with different concentrations of NaCl were determined at 298.15 K with a UV-vis spectrophotometry and titration method, respectively. Setschenow constants, K
s , were employed to describe the solubility behavior, and it is found that the higher ring numbers of N-heteroaromatics gave rise to the lower values of K
s . Moreover, K
s showed a good linear relationship with the partial charge on the nitrogen atom ( Q
N ) for either Q
N > 0 or Q
N < 0 N-heteroaromatics. It further revealed that Q
N was well-matched in the prediction of salting-out effect for N-heteroaromatics compared to the conventional descriptors such as molar volume ( V
H ) and the octanol-water partition coefficient ( K
ow ). The heterocyclic N in N-heteroaromatics may interact with Na + ions in NaCl solution for Q
N < 0 and with Cl − for Q
N > 0.
研究领域:
物理化学
·
药物化学
✓ 已验证
DOI
PubMed
高影响因子
CHINESE JOURNAL OF POLYMER SCIENCE
·
2020
·Vol. 38
·期 7
·685-695
·
IF 3.154
Wang Sheng,Cai Si-Liang,Zhang Jie,Wan Xin-Hua
A series of novel cis poly(phenylacetylene)s (PPAs) substituted at meta -position(s) by two alkoxycarbonyl pendants, i.e. , sP-Me-C8/rP-Me-C8 , P-Me-C12 , sP-Et-C4 , sP-2C4 and sP-Oct-C4 , were synthesized under the catalysis of [Rh(nbd)Cl] 2 (nbd = norbornadiene). The dependence of elongation, screw sense, and stimuli response of helical polyene backbone on the structure of pendant, solvent, and temperature was systematically investigated in both solution and solid states. Because of n → π * interaction between vicinal carbonyl groups, sP-Me-C8/rP-Me-C8 could adopt contracted cis-cisoid helix in THF, toluene, CH 2 Cl 2 , and CHCl 3 . Such an intramolecular interaction was sensitive to the hydrogen bond donating ability of solvent and temperature, but insensitive to the dielectric constant and polarity of solvent. In poly(3-methoxycarbonyl-5-alkoxycarbonylphenylacetylene), the longer the chiral alkyl chain was, the easier the stable cis-cisoid helix could be achieved. However, when the methoxycarbonyl was changed to ethoxycarbonyl, sec -butyloxycarbonyl, and octyloxycarbonyl pendant groups, only cis-transoid helix was obtained at room temperature due to the increased steric hindrance. Moreover, lowering temperature was found to facilitate the stabilization of n → π * interactions, and reversible temperature-dependent stereomutations were achieved in sP-Me-C8 and sP-Et-C4 depending on the solvent where they were dissolved. These results suggested that the long alkyl chain, small pendant size, and lower temperature favored the stabilization of intramolecular n → π * interactions and the formation of contracted, cis-cisoid helices for poly(3,5-diester substituted phenylacetylene)s.
研究领域:
高分子化学
·
物理有机化学
✓ 已验证
DOI
高影响因子
MICROCHEMICAL JOURNAL
·
2020
·
IF 3.594
Jiujun Wang,Ya Wu,Qinghua Wu,Li Li,Yun Wang,Hualin Yang
Melamine has a high nitrogen content thus is often illegally added to milk powder to phonily boost the protein percentage composition. Milk products containing melamine are harmful to babies and children. In the present work, a simple, label-free and turn-on fluorescence method to detect melamine with a high sensitivity and selectivity has been developed. The N -methylmesoporphyrin IX (NMM)/G-quadruplex structure is used as a signal reporter in this method to realize label-free detection of melamine. The detection limit of this method is 12.5 nM, which is much less than the maximum level permitted for infant formulas. The linear range is 0.05–1 μM ( R 2 = 0.98). The selectivity of this method is also very satisfactory. Furthermore, this method can be successfully applied for detection melamine in raw milk and milk powder.
研究领域:
食品安全
·
分析化学
·
生物传感
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）