Cell Reports Physical Science
·
2021
·
IF 0
Ming Shi,Hongpeng Zhou,Wenming Tian,Bin Yang,Songqiu Yang,Keli Han,Rengui Li,Can Li
Although bismuth (Bi)-based halide perovskites have attracted profound attention in photocatalysis, the undesirable photophysical properties are not well modulated, and the effect of surface structure on adsorption and activation of reactant molecules is still unclear. Here, we report the structural design, via precise incorporation of antimony (Sb) atoms into the host lattice of Cs 3 Bi 2 Br 9 , of a series of B-site bimetallic perovskites (Cs 3 Sb x Bi 2-x Br 9 , 0 ≤ x ≤ 2) with tunable band structures. The incorporation of Sb dramatically enhances the separation and transfer of photogenerated charges and prolongs their lifetimes. Considering these advantages, Cs 3 SbBiBr 9 exhibits significantly enhanced photocatalytic activities in challenging benzylic C–H activation while maintaining a high selectivity of 96%. Theoretical calculations reveal that the introduction of Sb breaks the symmetry of the local structure and leads to asymmetric charge distribution that not only increases the adsorption capacity for methylbenzene but also reduces the energy barriers for C–H bond activation.
研究领域:
材料科学
·
光化学
✓ 已验证
DOI
JOURNAL OF ORGANIC CHEMISTRY
·
2023
·
IF 3.6
Jianyu Dong,Shaofeng Wu,Furong Geng,Yani Yan,Long Liu,Yongbo Zhou
A metal-free and selective oxidative methyl C–H functionalization of BHT with aniline compounds has been developed. This innovative method enables the facile and efficient synthesis of a diverse array of BHT-functionalized N-containing skeletons, including arylamines, benzoxazoles, benzothiazoles, benzimidazoles, quinazolines, and quinazolinones, all of which are challenging to access. The control experiment involving TEMP18O suggests that the radical adduct of TEMPO with the benzyl radical of BHT may serve as an intermediate.
研究领域:
有机化学
·
合成化学
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF ORGANOMETALLIC CHEMISTRY
·
2023
·
IF 2.3
Run-Ze Yuan,Peng-Fei Cui,Guo-Xin Jin
Herein, we describe the synthesis of a series pincer-type half-sandwich complexes containing selective B(3)-H activation of m -carborane. Four pincer-type complexes containing Cp*M (M = Ir/Rh) and (η 6 -pcym)Ru metal-corner, ionic Cp*M[ m -C 2 B 10 H 9 (CS 2 CH 3 ) 2 ](CF 3 SO 3 ) (M = Ir ( 2 ), Rh ( 3 )), (η 6 -pcym)Ru[ m -C 2 B 10 H 9 (CS 2 CH 3 ) 2 ](CF 3 SO 3 ) ( 4 ) and neutral solvolysis product Cp*Ir[ m -C 2 B 10 H 9 (CS 2 CH 3 )(COS)] (Complex 5 ), have been prepared. The addition reaction of MeO − toward 2 3 and 4 causes the formation of moderately stable neutral unsymmetrical pincer-type complexes Cp*M{ m -C 2 B 10 H 9 (CS 2 CH 3 )[CS(SCH 3 )(OCH 3 )]} (M = Ir ( 6 ), Rh ( 7 )) and (η 6 -pcym)Ru{ m -C 2 B 10 H 9 (CS 2 CH 3 )[CS(SCH 3 )(OCH 3 )]} ( 8 ). The substitution reaction of 2 3 and 4 have also been also explored, unsymmetrical chelate complexes Cp*M( t BuNC)[ m -C 2 B 10 H 9 (CS 2 CH 3 ) 2 ](BPh 4 ) (M = Ir ( 9 ), Rh ( 10 )) can be obtained by using t BuNC and NaBPh 4 . All of these complexes have been characterized, including X-Ray single crystal diffraction, NMR spectroscopy, IR spectroscopy and elemental analysis methods.
研究领域:
无机化学
·
配位化学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2020
·
IF 3.83
Yunzi Li,Fei Chen,Xiaoyu Li,Qiang Shen,Lianmeng Zhang
Ceramic/metal composites, as high-temperature structural materials, have limited applications because of their poor machinability . AlN/Mo/Mo 2 B machinable composites were fabricated by adding h-BN to AlN/Mo composites by plasma-activated sintering at various temperatures and at an axial pressure of 30 MPa under argon atmosphere. The sample sintered at 1500 °C exhibited excellent machinability for cemented carbide tools, with a bending strength of approximately 500 MPa and a Vickers hardness value of 9.34 GPa. The effects of sintering temperature on the microstructure, mechanical properties, and machinability were investigated, and the reactions introduced by adding h-BN were studied. These reactions reinforced the composite and newly introduced a Mo 2 B phase, which showed better ability to deflect cracks and prevent them from moving deep inside the composite, thus improving its machinability. This research provides a possible solution for improving the machinability of ceramic/metal composites without sacrificing the strength .
研究领域:
材料科学
·
机械工程
✓ 已验证
DOI
高影响因子
Frontiers of Chemical Science and Engineering
·
2024
·Vol. 18
·期 11
·1-11
·
IF 4.3
Gao Huimin,Zhang Jinpeng,Zhang Fangyuan,Jing Jieying,Li Wen-Ying
The photocatalytic reduction of CO 2 into formic acid is a feasible approach to alleviate the effects of global climate change and achieve chemical energy storage. It is important to design highly active photocatalysts to improve the selectivity and yield of formic acid. In this study, TiO 2 -based catalysts were prepared and loaded with Pd nanoparticles via an impregnation process. The Pd/H-TiO 2 catalyst demonstrated superior CO 2 reduction activity and a high formic acid production rate of 14.14 mmol cat ·g −1 ·h −1 . The excellent catalytic performance observed in the presence of a Pd/H-TiO 2 catalyst is ascribed to the synergy between O v and Pd. The presence of O v led to increase in CO 2 adsorption while Pd loading enhanced the photogenerated electron-hole pair separation. Electron transfer from H-TiO 2 to Pd also contributed to CO 2 activation.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
INORGANIC CHEMISTRY
·
2020
·
IF 4.825
Ji Wu,Ke Cao,Cai-Yan Zhang,Tao-Tao Xu,Xin-Yu Wen,Bo Li,Junxiao Yang
A palladium catalyzed selective B(3)–H activation/oxidative dehydrogenative coupling for the synthesis of bis(o-carborane)s connected with B(3)–B(3′) and B(3)–B(6′) bonds has been developed for the first time. A plausible mechanism involving stepwise activation of B(3)–H and B(3′/6′)–H bonds by PdII and PdIV was proposed. This work is the first example and the most efficient protocol for synthesis of bis(o-carborane)s connected with B(3)–B(3′) and B(3)–B(6′) bonds, which has important reference for design, synthesis, and application of bis(o-carborane)s in related fields.
研究领域:
有机化学
·
材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2022
·Vol. 33
·期 22
·17587-17598
·
IF 2.779
Yu Bo,Miao Chun,Wang Dandan,Li Hongji,Sun Dongshu,Jiang Wei,Liu Chunbo,Che Guangbo
The development of high-efficiency heterojunction with improved photocatalytic property is regarded as a promising way to decontaminate wastewater. In this study, Z-Scheme g-C 3 N 4 /H-TiO 2 heterojunctions with different proportions were synthesized. The photocatalytic degradation of rhodamine B (RhB) was studied under visible light irradiation. Among them, 10% g-C 3 N 4 /H-TiO 2 photocatalyst had the best performance, and the degradation rate of RhB was 65% within 120 min. In addition, 10% g-C 3 N 4 /H-TiO 2 photocatalyst had high stability, and its photocatalytic activity did not decrease significantly after four cycles. Through photocurrent analysis, it is found that the photogenerated carriers have obviously excellent separation and transfer characteristics, which makes the 10% g-C 3 N 4 /H-TiO 2 photocatalyst have good degradation performance. Electron paramagnetic resonance (ESR) experiments showed that ·OH and ·O 2 − were active radicals during degradation.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2020
·
IF 16.683
Wei Li,Xiao Wang,Qiong Ma,Fei Wang,Xiao-shan Chu,Xue-chuan Wang,Chuan-yi Wang
Solar light driven hydrogen evolution is a prospective strategy to solve the energy problem. However, the poor photoresponse, low photocurrent density and easy electron-hole recombination remarkably restrict the HER activity of the conventional photocatalyst. Herein, we constructed a CdS@hexagonal boron nitride (h-BN) heterostructure on reduced graphene oxide (rGO) to synthesize a ternary CdS@h-BN/rGO catalyst via a structural reconstruction strategy. The CdS@h-BN heterointerface promoted the electrons transferring to the CdS active centers from the valence band of h-BN under photoinduction, overcoming the wide bandgap defect of pristine h-BN. The easily photoexcited property of CdS cocatalyst resulted in superhigh photocurrent density (2.7·μA cm −2 ) under simulated solar light, which was 3.3-fold greater of pristine CdS NPs. Meanwhile, the interfacial interactions of three components remarkably restrained the carriers recombination. Hence, the resultant ternary hybrid catalyst presented remarkably improved photoresponse and interfacial conductivity, thereby the optimal catalyst represented remarkably enhanced HER activity (6465.33 μmol h −1 g −1 ) under simulated solar light, which was about 10.9-fold greater of the pristine CdS NPs and 218.3-fold greater of the optimal h-BN/rGO hybrid. About 19.8 % of apparent quantum yield was achieved under illumination of λ =420 nm, and the excellent regenerability and durability were represented during six cycles and 20 h of continued illumination. Thereby, this study provides a prospective idea for constructing low-cost nonprecious metal based photocatalyst with highly efficient HER performance.
研究领域:
材料科学
·
能源科学
·
光催化技术
✓ 已验证
DOI
高影响因子
CRYSTENGCOMM
·
2022
·Vol. 24
·期 46
·8060-8069
·
IF 3.756
Shu-Qin Qin,Wei Xu,Wen-Cai Ye,Ren-Wang Jiang
Guanidinium–naphthalenedisulfonic acid (GNPS) was used as a molecular catcher because (i) it contains a cavity and channel in the network; (ii) NH2+ can be used as a hydrogen bond donor, and SO3− can be used as a hydrogen bond acceptor; (iii) the co-planar naphthalene rings can form aromatic interactions with guest molecules. The liquid guests 1–8 [(−)-isopulegol (1), (−)-menthyl acetate (2), isoeugenol (3), 2,6-dimethylaniline (4), methyleugenol (5), 2,6-diisopropylaniline (6), methyl salicylate (7) and L(−)-carvone (8)] are successfully encapsulated in the cavity of GNPS and eight new crystals were obtained. Both aromatic and non-aromatic molecules form hydrogen bonds and C–H⋯π interactions with GNPS. Co-crystallization of 1–4 with GNPS led to stronger C–H⋯π interactions as compared to the previously reported GBPS. Furthermore, compounds 5–8 which were not co-crystallized with GBPS were found to be encapsulated in the cavity of GNPS. We found that the aromatic cavity of GNPS with hydrogen bonding and enhanced C–H⋯π interactions can be regarded as a useful tool for the structural determination of liquid molecules. Furthermore, the correct absolute configurations of 1, 2 and 8 can be assigned based on the small Flack parameters because of the presence of sulfur atoms in the host molecule GNPS.
研究领域:
化学晶体学
·
分子结构分析
·
材料科学
✓ 已验证
DOI
高影响因子
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
JOURNAL OF ORGANIC CHEMISTRY
·
2019
·
IF 4.745
Na Li,Jinku Bai,Xiaolin Zheng,Honghua Rao
An iron-catalyzed methylene forming strategy is disclosed through sequential C–H and C–O bond functionalization of methanol with cosolvent water. This protocol provides an easy and novel access to methylene-tethered imidazo[1,2-a]pyridine and 2-aminopyridine analogues in a sustainable manner and represents a complementary approach to traditional methylene forming strategies.
研究领域:
有机化学
·
催化化学
✓ 已验证
DOI
PubMed
高影响因子
ChemistrySelect
·
2024
·Vol. 9
·期 28
·e202402061
·
IF 1.9
Jiankang Ou,Haoyu Liu,Zeguo Fang,Qian Zhang,Dong Li
Graphical Construction of C−C bonds of alkyl-substituted naphthoquinones through C−H/C−H cross dehydrogenation coupling of naphthoquinones with acetone and 1,3-dicarbonyl compounds was developed. A direct C−H alkylation of naphthoquinones with acetone and 1,3-dicarbonyl compounds was developed to construct C−C bonds of alkyl-substituted naphthoquinone derivatives. It proceeded through an oxidative radical cross dehydrogenation coupling process under simple and mild conditions. This method provides a facile and efficient route for synthesis of functionalized naphthoquinones from readily available feedstocks.
研究领域:
有机化学
·
合成化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）