Catalysts
·
2022
·Vol. 12
·期 3
·304
·
IF 4.501
Xinxing Gao,Qianqian Pei,Nianqing Zhu,Yi Mou,Jilei Liang,Xin Zhang,Shoushuai Feng
(S)-N-Boc-3-hydroxypiperidine is an important intermediate of the anticancer drug ibrutinib and is mainly synthesized by the asymmetric reduction catalyzed by ketoreductase coupled with glucose dehydrogenase at present. In this study, the coexpression recombinant strainsE. coli/pET28-K-rbs-G with single promoter andE. coli/pETDuet-K-G with double promoters were first constructed for the coexpression of ketoreductase and glucose dehydrogenase in the same cell. Then, the catalytic efficiency ofE. coli/pET28-K-rbs-G for synthesizing (S)-N-Boc-3-hydroxypiperidine was found to be higher than that ofE. coli/pETDuet-K-G due to the more balanced activity ratio and higher catalytic activity. On this basis, the catalytic conditions ofE. coli/pET28-K-rbs-G were further optimized, and finally both the conversion of the reaction and the optical purity of the product were higher than 99%. In the end, the cell-free extract was proved to be a better catalyst than the whole cell with the improved catalytic efficiency of different recombinant strains. This study developed a better coexpression strategy for ketoreductase and glucose dehydrogenase by investigating the effect of activity ratios and forms of the biocatalysts on the catalytic efficiency deeply, which provided a research basis for the efficient synthesis of chiral compounds.Keywords:(S)-N-Boc-3-hydroxypiperidine;coexpression strategy;activity ratio;ketoreductase;glucose dehydrogenase
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ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2022
·Vol. 30
·期 6
·16156-16165
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IF 5.19
Hou Guangying,Huang Zaihui,Ding Xiaohu,Liu Chunguang
4,4′-Sulfonyl-diphenol (BPS), as a widespread environmental hormone-like micropollutant, is difficult to be degraded in the environment. In this study, the removal of BPS with multi-enzymes extracted from waste sludge and reed sediment was studied at 298 K, 310 K, and 328 K. Results show that BPS could be removed efficiently and was time–temperature dependent, which could involve enzymolysis and bio-flocculation. The mechanism and pathways of the enzymolysis were identified with ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Polymerization of BPS with enzymolysis further improved the removal by bio-flocculation due to the production of BPS oligomers. Furthermore, the interaction mechanism between BPS and multi-enzyme was explored through a series of spectroscopic experiments. Results show that more loose skeletal structure of the multi-enzymes and more hydrophobic microenvironment of the amino acid residues are responsible for the removal of BPS. This research not only provided a method for refractory micropollutants removal but also a way for the utilization of waste sludge and reed sediment.
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JOURNAL OF CATALYSIS
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2022
·
IF 8.047
Feiying Tang,Guangji Zhang,Liqiang Wang,Jianhan Huang,You-Nian Liu
Engineering unsymmetrical coordination is an efficient strategy for improving the performance of carbon supported single-atom catalysts for diverse applications. However, the exploration of this strategy to prepare carbon supported single-atom catalysts for hydrogenation reaction is still in infancy, especially for hydrogenation of quinolines. Herein, we report a protein-metal-ion-network strategy for preparation of single-atom cobalt supported on hierarchically porous carbon (SA-Co/NSPC). SA-Co/NSPC features unsymmetrically N/S-coordinated metal center, i.e., Co 1 –N 3 S 1 . Moreover, the carbon matrices possess an ultra-thin two-dimensional morphology and hierarchically porous structures. SA-Co/NSPC catalyst with Co 1 –N 3 S 1 active site exhibits excellent catalytic performance for hydrogenation of N-heterocycles. The DFT calculation results show that the site of Co 1 –N 3 S 1 reveals a significant electron redistribution in comparison to the Co 1 –N 4 , leading to a lower H* diffusion barrier and quinoline hydrogenation reaction barrier. SA-Co/NSPC catalyst combined with the unique hierarchically porous structure and high active Co 1 –N 3 S 1 owns extraordinary catalytic performance for hydrogenation of quinolines.
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Solar RRL
·
2022
·Vol. 6
·期 8
·2200279
·
IF 9.173
Jie Deng,Wanying Lei,Junwei Fu,Huile Jin,Quanlong Xu,Shun Wang
Herein, photocatalytic selective oxidation of hydrocarbons through O 2 represents a promising way for fine chemical industry on account of its mild reaction condition. In this work, Co 3 O 4 -modified BiOBr/AgBr S-scheme heterojunction can effectively oxidize sp 3 C H bonds at benzylic position to its corresponding aldehydes, with a toluene to benzaldehyde selectivity of 94%, which is much higher than that of pure BiOBr (21.7%) and AgBr (58.9%). A unique S-scheme charge-transfer mode is confirmed for the ternary composites by the X-ray photoelectron spectroscopy and reactive species quenching measurement. The remaining photogenerated electrons in AgBr with powerful reduction ability can react with O 2 to generate •O 2 − species, which can further oxidize the benzyl radical formed on the Co 3 O 4 surface to peroxyl radicals and then thermodynamically decompose to benzaldehyde. Herein, this work has important guiding significance for the structure regulation of photocatalysts and application in selective oxidation of sp 3 C H bond of hydrocarbons.
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CHEMOSPHERE
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2022
·
IF 8.943
Yanzhuo Zhang,Jing Zhao
The goal of this work was to elucidate the ability of biochar materials prepared by different methods to degrade antibiotics by activating peroxymonosulfate (PMS). S atom was doped into biochar using diphenyl disulfide (DD), sodium thiosulfate (ST), and thiourea (TU) as S precursors. The different doped materials were used to activate PMS and tested for the ability to degrade tetracycline hydrochloride, sulfadiazine sodium salt, and levofloxacin hydrochloride. The average degradation efficiencies of DD-doped hydrothermal + pyrocarbon (DD-HPBC), TU-doped hydrothermal + pyrocarbon (TU-HPBC), and ST-doped hydrothermal + pyrocarbon (ST-HPBC) were 83.76%, 86.74%, and 93.60%, respectively, all higher than the degradation efficiency of the undoped material. When sodium thiosulfate-doped pyrocarbon (ST-PBC), hydrochar (ST-HBC), and hydrothermal + pyrocarbon (ST-HPBC) were used to activate PMS, the highest degradation efficiencies were achieved, with average rates of 71.59%, 78.22% and 97.20%, respectively. ST-HPBC exhibited the highest concentration of environmentally persistent free radicals (EPFRs), 9.47 × 10 18 spin/g, among all biochar materials. Given this high concentration of EPFRs, use of ST-HPBC to activate PMS resulted in a very high rate of antibiotic degradation, and the concentration of EPFRs was positively correlated with the degradation efficiency. Increase of specific surface area, the thiophene S (-C-S-C-) ratio, and concentration of EPFRs in S-doped biochars promoted the degradation of antibiotics. For PMS activated by biochar, reactive oxygen species (ROS) degraded antibiotics in the order of sulfate radical (SO 4 •- ) > singlet oxygen ( 1 O 2 ) > hydroxyl radical (•OH) > superoxide radical (•O 2 − ). This work provides new insight into the application of S-doped sludge biochar materials.
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INORGANIC CHEMISTRY
·
2021
·
IF 5.165
Yi-Xin Zhang,Yun-Qiao Tang,Zheng Ma,Ming-Yu Hu,Jing Feng,Zhen-Hua Ge
In this study, Cu2Se1–xSx (x = 0.1, 0.3, and 0.5) alloy powders were prepared by the hydrothermal synthesis method. In the subsequent sintering process, the spontaneous in situ phase separation process of the sample forms a two-phase hybrid structure. The generated Cu2S precipitates in the Cu2Se matrix noticeably enhance phonon scattering, which is beneficial for low thermal conductivity without significantly affecting the electrical transport performance. Ultimately, an optimized thermoelectric performance was obtained in Cu2Se0.9S0.1, reaching a peak zT value of 1.43 at 773 K, the optimum value among the Cu–Se–S systems at this temperature.
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SYNTHETIC METALS
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2021
·
IF 3.266
Jiaoyan Shi,Lipeng Wu,Qingya Sun,Fan Wu,Aming Xie
Elemetal doping is an efficient strategy to adjust the microstructue and electronic property of a carbon material, as a result, shows great potential in the design of novel electromagnetic absorption (EMA) materials. In this work, we report an useful strategy to prepare a N,S co-doped carbon (NSC) using TTF-TCNQ as the precusor, and systematically explore its frequency-depedent dielectric and EMA properties. Different N/S ratios can be tuned by the regulation of pyrolitic temperature. The derived NSC exhibits wonderful EMA performance when the pyrolytic temperature is setted to 700 ℃ with loading ratio of 35 wt%. Efficient absorption can be achieved in the frequency range of 6.4–18 GHz. Moreover, it is determined that the efficient absorption bandwidth gets to 6.5 GHz, while the maximal absorption reaches −46 dB. The EMA mechanism of NSC is considered to be mainly contributed by improved impedance matching realized by macropores, enhanced conductance loss caused by well constructed condutive network, and polarization by N,S doping. This research provides a new idea for development of novel carbon materials for EMA applicaion.
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ACS Applied Energy Materials
·
2021
·
IF 6.024
Tao Long,Bin Xu,Yixin Zhao,Hu Liu,Sheng Cheng,Yongyi Zhang,Jiehua Liu,Fancheng Meng
The shuttling effect and sluggish redox kinetics of polysulfides are the main obstacles that restrict the practical application of lithium–sulfur (Li–S) batteries. Herein, in this work, cathode material embedded with bipolar metals Ti and Co prepared by a facile self-assembly process using hollow carbon nanospheres (HCSs), MXene nanosheets, and CoO(OH) has been reported. Due to the strong chemical adsorption and high catalytic activity introduced by the bipolar metal related active sites, the Li–S battery with the HCS@Co–MXene/S cathode shows the lowest charge transfer resistance and the best rate capability compared with HCS/S and HCS@MXene/S cathodes. Moreover, the battery delivers a high initial discharge capacity of 1309 mA h g–1, which maintains at 570 mA h g–1 after 300 cycles at 0.5 C. Even at an elevated discharge current of 1 C, the battery retains a reversible capacity of 728 mA h g–1 over 120 cycles. Therefore, with the embedding of bipolar metals, the current Li–S battery cathode demonstrates superior cycling stability than the reference cathodes. The findings in this work exhibit a promising prospect for facile assembling of the high-performance Li–S battery cathode and the resultant device.
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SENSORS AND ACTUATORS B-CHEMICAL
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2021
·
IF 7.46
Guanhua Chen,Zhengzheng Wang,Mei Deng,Fangbin Xiao,Xuekun Bai,Hengyi Xu
Foodborne pathogenic microorganism pose a serious threat to public health security; thus, constructing quick and sensitive methods for early screening foodborne pathogenic microorganism is necessary for human health. Teicoplanin (Teic) is a broad-spectrum biometric molecule, which can recognize Gram-positive (G + ) bacteria. In this study, using bovine serum albumin (BSA) and PEG 2k as “carrier” and “linker”, respectively. Teic was wired to magnetic beads (MBs) to form the biomimetic dandelion-like magnetic nanoparticles (MBs-PEG-BSA-Teic) to capture Staphylococcus aureus ( S. aureus ) and Listeria monocytogenes ( L. monocytogenes ). The MBs-PEG-BSA-Teic displayed excellent capture ability of S. aureus (> 93%) and L. monocytogenes (> 86%). After separation, the fluorescence probes were added, forming a “sandwich” structural compounds, namely, MBs-PEG-BSA-Teic~bacteria~fluorescence probes. The fluorescence intensity of the probes was measured by a multimode microplate reader. Consequently, this novel method showed high detection sensitivity to target model bacteria, and the detection limit of S. aureus and L. monocytogenes in PBS buffer solution and juice were achieved 10 1 CFU/mL, spinach and ground beef samples were achieved 10 2 CFU/g. The method has easy operation and high sensitivity, and it is less interfered by food matrix or negative bacteria; thus, this method is suitable for early screening G + pathogen in suspected food samples.
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ENERGY & FUELS
·
2021
·
IF 3.605
Zhihui Xu,Xuelei Li,Shishuai Sun,Zepeng Wei,Hongguo Li,Shougen Yin
The synergistic effect of the electrochemical double-layer and pseudocapacitance electrode materials has been extensively used to improve the performance of composite electrodes for supercapacitors (SCs). However, the energy density of SCs is still unsatisfactory for practical utilization. Herein, a C-NiCo2O4/C@Ni–Co–S electrode is ingeniously devised through coupling the interior of 0D/2D carbon-modified NiCo2O4 and the external sheath of Ni–Co–S nanosheets. The 0D carbon quantum dot doping can effectively avoid the agglomeration of NiCo2O4 nanoparticles and improve the electronic conductivity. 2D carbon as the intermediate layer can ameliorate the physical/chemical stability of the electrode. Ni–Co–S nanosheets can improve the area-specific capacitance of the electrode and thus enhance the energy density of the device. As expected, the C-NiCo2O4/C@Ni–Co–S electrode delivers an outstanding specific capacitance of 2396 F g–1 (7.9 F cm–2) at 3 A g–1 and excellent cycling stability (92% after 10 000 cycles). Furthermore, a quasi-solid-state asymmetric supercapacitor (ASC) using C-NiCo2O4/C@Ni–Co–S as positive electrode and active carbon (AC) as negative electrode exhibits a high energy density of 95 Wh kg–1 at 0.9 kW kg–1 and an excellent cycle performance. Our work reveals that this reasonable structure design is very effective for achieving a high-performance positive electrode for practical SC applications.
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Polymer Chemistry
·
2021
·Vol. 12
·期 17
·2598-2605
·
IF 5.582
Xianheng Shi,Min Liu,Lishan Li,Jiandong Zhang,Haiyan Li,Zhihao Huang,Wei Zhang,Zhengbiao Zhang,Nianchen Zhou,Xiulin Zhu
Discrete oligomers are perfect candidates for understanding the structure-dependent properties of polymers. Herein, a series of discrete conjugated oligo(fluorenediacetylene)s (D-oFDAs) with a degree of polymerization (DP) up to 10 were obtained by purification with automated flash column chromatography from polydisperse polymers. It is found that the chain length can affect not only photophysical properties but also crystalline properties. As the DP of D-oFDAs increased, the longer conjugation length caused red shifts in their optical spectra and weaker crystallinity. The effective conjugation length has been extrapolated to be as long as 9 fluorenediacetylene units. Moreover, the oligomers can form uniform films by solution casting for the fabrication of light-emitting diodes, showing that the octamer has the most efficient electroluminescence (EL) properties. When the crystal of the dimer was exposed to 254 nm UV light, only part of the sample was polymerized via a 1,4-addition reaction. Significantly, the simple, scalable and effective strategy provides opportunities to further optimize the structure with diverse blocks and side chains for precisely building macromolecular architectures.
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SEMICONDUCTOR SCIENCE AND TECHNOLOGY
·
2021
·Vol. 36
·期 4
·045025
·
IF 2.352
Xiang Yu Liu,Jin Li
Solar-driven nano-semiconductor catalysts have shown great potential in solving environmental pollution and energy issues. They convert solar energy into chemical energy, release strong oxidizing hydroxyl radicals (OH·), and thoroughly degrade organic pollutants. However, these photocatalysts in turn may also damage some organic carriers. Therefore, we have used graphite phase carbon nitride (g-C3N4) as the isolation layer to prevent the carrier polyester fiber (PET) from being oxidized by zinc oxide (ZnO). ZnO-g-C3N4@PET composite has been prepared by hydrothermal method, photoluminescence results indicated that ZnO-g-C3N4@PET has a low photo-generated charge recombination rate, while g-C3N4 improves the visible light response of the composite and exhibits an obvious photocatalytic enhancement effect. In the experiment of degrading methylene blue (MB), the degradation efficiency of ZnO-g-C3N4@PET composite has been significantly improved compared with ZnO@PET and g-C3N4@PET alone. In addition, the prepared photocatalyst also has good reusability and still maintains a high degradation rate after five cycles of tests. In the end, a possible mechanism and a pathway of photocatalytic degradation of MB were proposed. All in all, this is a feasible way to build a highly efficient, environmentally friendly and sustainable supported photocatalyst.
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