TRANSACTIONS OF TIANJIN UNIVERSITY
·
2020
·Vol. 27
·期 6
·460-472
·
IF 0
Wei Hongyuan,Gao Ningcan,Dang Leping
In this work, a new crystallization method was used to prepare two polymorphs of sulfamethazine–saccharin (SMT–SAC) cocrystal in bulk. The purity and crystal form of both polymorphs were confirmed by optical microscopy, scanning electron microscopy, powder X-ray diffraction, differential scanning calorimetry, and thermogravimetric analysis. Moreover, the solubility of the stable form (form II) was determined by gravimetric analysis in nine pure solvents and one binary (acetonitrile + 2-propanol) solvent at temperatures ranging from 278.15 to 348.15 K at atmospheric pressure. Experimental data were correlated using the modified Apelblat model, the λh equation, the nonrandom two-liquid (NRTL) model, the Jouyban–Acree model, and the CNIBS/Redlich–Kister model. Finally, the apparent thermodynamic properties, such as \(\Delta_{\text{dis}} G\) , Δ dis H , and Δ dis S , were calculated on the basis of the activity coefficient obtained by the NRTL model. All the models correlate well, and all the experimental and calculated results indicate that the dissolution behavior of SMT–SAC cocrystal form II is a spontaneous, endothermic, and entropy-driven process.
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MOLECULES
·
2024
·Vol. 29
·期 14
·3396
·
IF 4.2
Zhengyang Wang,Shuting Wang,Yuexing Zhang,Mingliang Ma
A series of fluorescent molecules with 1,1-dimethylnaphthalene-2(1H)-one as the core were synthesized to overcome aggregation quenching and emit bright green fluorescence. The low molecular weight of these molecules led to them to smoothly pass through the cell membrane and penetrate deep into the nucleus to emit the corresponding fluorescence. Among them, NC-4-Br and NC-5-3O have good optical and in vitro properties and showed potential for use as fluorescent probes.
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PubMed
高影响因子
Catalysis Science & Technology
·
2020
·Vol. 10
·期 13
·4412-4423
·
IF 5.721
Qiang Liu,Zhenbo Zhao,Masahiko Arai,Chao Zhang,Ke Liu,Ruhui Shi,Peixuan Wu,Zhuangqing Wang,Weiwei Lin,Haiyang Cheng,Fengyu Zhao
The transformation of γ-valerolactone (GVL) into 1,4-pentanediol (1,4-PDO) and 2-methyltetra-hydrofuran (2-MTHF) in the presence of H2, one of the useful biomass conversion and utilization processes, was investigated with monometallic Cu/Al2O3 and bimetallic ZnCu/Al2O3 catalysts. A 10 wt% Cu-loaded monometallic catalyst produced 1,4-PDO and 2-MTHF in comparable quantities at a medium conversion (∼50%). When Zn was added in a range of Zn/Cu molar ratios of up to 2, in contrast, the catalysts yielded 1,4-PDO in a high selectivity of about 97% at low and high conversion levels. In addition, the 1,4-PDO selectivity over the ZnCu/Al2O3 catalysts remained almost unchanged during recycled runs. That is, the addition of Zn to Cu/Al2O3 switched the product selectivity and improved the catalyst stability and reusability. Furthermore, the physicochemical properties of the catalysts were characterized by several methods including XRD, TEM, TPR, XPS, FTIR of adsorbed pyridine, and so on. On the basis of those results, the relationships between the catalytic performance (activity, selectivity, and reusability) and the catalyst structural features were discussed.
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高影响因子
International Journal of Electrochemical Science
·
2023
·
IF 1.5
Jiao Chen,Hongye Qin,Yaping Pan,Jinli Wu,Jianan Liu,Wanying Lin,Jun Jiang,Enzuo Liu,Junwei Sha,Fang He,Liying Ma,Naiqin Zhao
It is necessary and challenging to develop platinum-based electrocatalysts with low Pt content and high performance for industrial development in a suitable strategy. Herein, ultralow Pt (0.35 wt%) loading Ni(OH) 2 nanosheets (named as 2-Pt/Ni(OH) 2 ) with cataphracted structure is synthesized on nickel foam by one-step hydrothermal process. It only needs an overpotential of 34 mV to achieve a current density of 10 mA cm -2 without any significant decrease for 40 hours. This excellent performance of hydrogen evolution reaction (HER) is attributed to the fact that the cataphracted structure not only has a larger active area and more active sites, but also effectively limits the size of Pt nanoparticles to 2~3 nm, which results in a higher active quality. In addition, the relatively simple and easily operational one-step method can reduce the Pt content to 0.35 wt% significantly. This facile strategy opens up new approaches in the rational design and synthesis of low loading Pt electrocatalysts with eminent electrocatalytic activity for industrial production.
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高影响因子
ELECTROCHIMICA ACTA
·
2022
·
IF 7.336
Junru Liu,Qiushi Wang,Liang Chen,Jun Zhang,Jiemiao Pan,Xiaomin Wang,Zhaoping Liu
The choice of anode materials for high-voltage aqueous batteries beyond 1.5 V is still far from satisfactory, due to the narrow electrochemical stability window of aqueous electrolytes . With the inherent advantages of low working voltage and fast ionic diffusion, niobium phosphates with polyanionic framework groups built of NbO 6 octahedra and PO 4 tetrahedra are very promising anode materials for high-voltage aqueous batteries. Herein, carbon-coated NbOPO 4 (NPO/C) materials with monoclinic structure has been prepared by the solid-state reaction & chemical vapor deposition method. Between -1.34 V and 0.6 V vs. standard hydrogen electrode, it could deliver a specific capacity of 116 mAh/g with a high coulombic efficiency of 92.0% at a low current rate of 0.33C in aqueous electrolytes based on methylsulfonylmethane, LiClO 4 and H 2 O (DES). The diffusion-controlled process dominates the electrochemical reaction of NPO/C. Upon the reversible insertion/extraction of lithium ion into/from NPO/C, it maintains the monoclinic structure with a small lattice expansion, which is a characteristic of zero-strain effect. Finally, the full cell based on NPO/C anode, LiMn 2 O 4 cathode and DES electrolytes with a high specific energy 101.6 Wh/kg and a high voltage output beyond 2 V has been validated. It also shows excellent cycling performance with the capacity retention of 94.3% after 1000 times at 2C rate, which suggests that monoclinic β-NbOPO 4 can be used as a promising electrode material for aqueous lithium-ion batteries with high voltage output for energy storage in the future.
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高影响因子
INORGANIC CHEMISTRY
·
2024
·
IF 4.3
Dan Wang,Han Luo,Tingyu Wang,Xuehua Dong,Liling Cao,Ling Huang,Guohong Zou
Birefringent crystals play a crucial role in modulating and controlling the polarization of light in the optical communication and laser industries. Recently, adopting appropriate strategies to enhance the birefringence of crystals has become a prominent area of research focus. Herein, four UV antimony oxalate birefringent crystals, namely, K5Sb2(C2O4)5.5·3H2O, BaSb(C2O4)2.5·3H2O, Na4Sb2O(C2O4)4·6H2O, and Na3Sb(C2O4)2F2·2H2O, have been successfully synthesized. These compounds feature a similar zero-dimensional (0D) cluster structure and share the same functional groups, including π-conjugated [C2O4]2– groups and Sb3+-based distorted polyhedra with stereochemically active lone pairs (SCALPs). Interestingly, we achieved a stepwise increase in birefringence by precisely controlling the Sb3+/[C2O4]2– ratio, ultimately resulting in the compound Na3Sb(C2O4)2F2·2H2O exhibiting a large birefringence (0.21@546 nm). Additionally, we confirmed that the synergistic effects between the π-conjugated [C2O4]2– groups and the distorted polyhedra based on Sb3+ are responsible for the excellent optical properties observed in the reported compounds.
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高影响因子
CARBON
·
2021
·
IF 9.594
Qi Huang,Yuwei Xu,Yuanyuan Guo,Linjie Zhang,Yue Hu,Jinjie Qian,Shaoming Huang
To meet the increasing energy demand, the research and development of efficient and clean fuel cells and metal-air batteries are of great significance. Under these circumstances, these hierarchically porous carbon nanomaterials obtained by pyrolysis of coordination polymers are regarded as excellent oxygen reduction catalysts and are expected to be used as air cathode materials . Herein, a type of 2-dimensional structure of InOF-26 has been thermally converted into ultrathin graphitized nitrogen-doped carbon nanosheets , denoted as NG-CNS. During the carbonization , the addition of ferric chloride assists in breaking the intermolecular forces between crystal structures, which is further conducive to the formation of carbon nanosheets with an improved graphitization degree. Meanwhile, the subsequent ammonia impregnation together with secondary calcination can readjust the coordination environment of nitrogen species in the carbonaceous matrix. The obtained product of NG-CNS exhibits excellent ORR performance with a high half-wave potential of 0.80 V, a large diffusion-limited current density of 6.00 mA cm −2 , a small Tafel slope of 57.3 mV dec −1 , to show unexpected practicability in Zn-air battery and Al-air battery. The relatively simple synthetic procedure, low cost, high repeatability, and satisfactory electrochemical performance of NG-CNS will provide a direction for the facile preparation of coordination polymer-derived carbon nanomaterials in energy storage and conversion applications.
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高影响因子
APPLIED SURFACE SCIENCE
·
2022
·
IF 7.392
Yu-Xuan Dai,Wen-Li Xin,Lian-Hua Xu,Ji Li,Yi-Xuan Li,Junji Li,Serge Cosnier,Xue-Ji Zhang,Robert S. Marks,Dan Shan
Rational design highly active transition metal or transition metal oxides/nanocarbon hybrids is one of the feasible way to deliver a cooperative oxygen reduction (ORR) with a synergistic effect of the hybrid interface. Herein, based on benzimidazole-5-carboxylate (BIMC), CoO/Co-N-C nanocomposites are fabricated via 2-methylimidazole (2-MeIm)-tuned “4-Self” strategy, namely, self-templating, self-adapting, self-assembly and self-catalysis. As a base competitive ligand with N and C sources, 2-MeIm modulates the dispersion of BIMC in methanol to generate collodial-like BIMC tiny particles, the coordination ability of BIMC to Co(II), the composition and morphology of the self-assembled precursor (Co-BM), and as well as the conductivity of the resultant electrocatalyst. Impressing, carbonization of Co-BM at 800 °C under N 2 atmosphere endows the pyrolysis product (Co-BM-800) with the well-dispersed Co/CoO riveted on nitrogen-doped carbon, as well as the enhanced ORR performance in terms of positive onset-potential (0.890 V vs. RHE), large diffusion limiting current density (5.21 mA cm −2 ), and high stability.
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高影响因子
Journal of Materials Chemistry C
·
2024
·
IF 5.7
Yixin Sun,Yining Wang,Minliang Deng,Xiaole Xing,Yiying Zhu,Mengmeng Shang
Near-infrared-II (NIR-II) luminescence, which serves as a promising spectral window for biomedical applications and spectral analysis, has numerous potential applications. In this work, the NIR-II luminescence is realized in Li4SrCa(SiO4)2:Cr4+ phosphors. Under 465 nm excitation, the emission peak of Li4SrCa(SiO4)2:3%Cr4+ is located at 1215 nm and the full width at half maximum (FWHM) is more than 230 nm, covering the ultra-long range of 950–1600 nm. The photoluminescence spectra, diffuse reflectance spectra, Raman spectra and time-resolved emission spectra confirm the NIR-II luminescence mechanism. Furthermore, a novel post-reduction strategy is proposed to realize the leap-forward enhancement of NIR-II luminescence from Cr4+. By mutually substituting Sr2+ and Ca2+, a series of Li4Sr1+zCa1−z(SiO4)2:3%Cr4+ (z = −1 to 1) samples are prepared to investigate the universality and applicable conditions of the post-reduction strategy. Benefitting from the NIR-II emission of Cr4+, it has great application potential in optical temperature measurement and spectral analysis.
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高影响因子
Current Protocols
·
2024
·Vol. 4
·期 1
·e956
·
IF 0
Xuan Chen,Long Xie,Chenglong Zhang,Shen Tian,Zeyu Tang,Ming Xiang,Weiwei Tian,Patrick Lu,Xianbin Yang
The integration of fluorine atoms into biologically active organic compounds has proved to be a vital technique in small molecule drugs. This technique can substantially enhance crucial properties, including metabolic stability, lipophilicity, and bioavailability, often with a mere addition of a single fluorine atom or a trifluoromethyl group. Over the past few decades, this concept has also been applied in nucleic acid chemistry. A commonly employed 2′-OH substitution is the introduction of a 2′-deoxy-2′-fluoro (2′-F) group. The strong electronegativity of fluorine prompts the modified siRNA to readily adopt a C3′- endo conformation, resulting in significant advantages in terms of binding affinity. To enrich the toolbox of chemical modification of oligonucleotides, the replacement of the 2′-OH with the 2′- O -trifluoromethyl group has been developed in RNA analog synthesis. Oligodeoxynucleotides containing the 2′- O -trifluoromethyl group can greatly increase the thermal stability of DNA/RNA duplexes depending on the position and amount of the modification. Moreover, 2′- O -trifluoromethylated oligodeoxynucleotide also exhibited a slightly higher resistance to snake venom phosphodiesterase than the unmodified oligodeoxynucleotide. The 2′- O -trifluoromethylated oligonucleotides can emerge as a label to study RNA structure and function as well, or to develop DNA/RNA-based diagnostics. Hence, it is necessary to report an effective method for the synthesis, deprotection, purification, and characterization of oligonucleotides bearing a 2′ -O -trifluoromethyl group. © 2024 Wiley Periodicals LLC. Basic Protocol 1 : Preparation of 6- N -benzoyl-5′- O -dimethoxytrityl-2′- O -trifluoromethyl adenosine 3′-(2-cyanoethyl N,N -diisopropyl)phosphoramidite Basic Protocol 2 : Preparation of 4- N -acetyl-5′- O -dimethoxytrityl-2′- O -trifluoromethyl cytidine 3′-(2-cyanoethyl N,N -diisopropyl)phosphoramidite Basic Protocol 3 : Preparation of 2- N -isobutyryl-5′- O -dimethoxytrityl-2′- O -trifluoromethyl guanine 3′-(2-cyanoethyl N,N -diisopropyl)phosphoramidite Basic Protocol 4 : Preparation of 5′- O -dimethoxytrityl-2′- O -2-trifluoromethyl uridine 3′-(2-cyanoethyl N,N -diisopropyl) phosphoramidite Basic Protocol 5 : Solid-phase synthesis of 2′- O -trifluoromethylated RNA analogs Basic Protocol 6 : Deprotection and purification of 2′- O -trifluoromethyl-RNAs
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Carbon Letters
·
2023
·Vol. 33
·期 5
·1395-1406
·
IF 4.5
Chen Zhangjing,Li Liangliang,Cheng Gang
Photocatalytic CO 2 reduction is a promising approach for reducing CO 2 emissions and achieving the goal of carbon neutrality. In this work, selectively coupling Cu(OH) 2 and CuO with amine-modified brookite TiO 2 (NH 2 –B–TiO 2 ) has been achieved by a simple precipitation method. The results show that CuO is better than Cu(OH) 2 as a co-catalyst to enhance the CO 2 photoreduction capability of NH 2 –B–TiO 2 . The highest rates of CO 2 conversion to CH 4 and CO of NH 2 –B–TiO 2 –CuO composite reach 6.05 and 3.25 μmol h −1 g −1 , respectively, which is higher than 8 times the yield of CH 4 of NH 2 –B–TiO 2 . It is proposed that the NH 2 –B–TiO 2 –CuO composite offers an effective charge transfer through the formation of a p–n junction between NH 2 –B–TiO 2 and CuO interfaces, while in the NH 2 –B–TiO 2 –Cu(OH) 2 composite, the Cu(OH) 2 dominantly serves as an electron sink to capture photo-induced electrons, promoting photo-induced carrier separation. This work provides an ingenious synthetic method for selectively anchoring Cu(OH) 2 and CuO on semiconductors with different charge transfer routes for an efficient CO 2 photoreduction. Graphical abstract
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高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2022
·
IF 5.518
Yeyin Tao,Xingyun Chen,Shusen Peng,Yongcun Ma
Self-assembled organothiol is a well-known process to endow specific protective properties and usually involves passive incubation. Researchers have recently confirmed that the potential-assisted method is more selective and faster than the passive method. This paper provides an original and promising approach for Cu protection by 2-mercaptobenzobthiazole (MBT) assembled film prepared from an aqueous solution within minutes under potential control. Electrochemical studies, salt spray tests, and XPS highlight and confirm the benefits of this method to result in film features, organic solvent-free, and considerable savings of preparation time. Experimental results also demonstrate that the substrate potential exerts a significant effect on the quality of MBT film. The effectiveness of negative potential in MBT film formation can be attributed to two aspects: first, it can inhibit the oxidation of Cu metal to Cu(II) in the aqueous solution, and second, it can make MBT molecule bond to Cu mainly through forming thiolate Cu-S bond with its exocyclic S atom.
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高影响因子
危险品化学品经营许可证（带存储）