Molecular Catalysis
·
2023
·
IF 4.6
Weikun Chen,Xiao Fu,Xiaoying Liu,Linmin Ye,Youzhu Yuan
N -alkylated piperazines can be synthesized by the thermal catalytic alkylation of piperazine with alkyl halides or alcohols in the presence of supported metal catalysts. However, these processes either discharge large amounts of waste or require harsh conditions. Here, we report the results of N -alkylation of piperazine with lower alcohols (methanol, ethanol, and propanol) without external hydrogen addition at room temperature in the presence of a TiO 2 -supported Pd catalyst (Pd/TiO 2 -P) prepared by photodeposition method. Compared with the catalysts prepared by the conventional chemical reduction or hydrogen reduction, the Pd/TiO 2 -P catalyst showed the highest conversion of piperazine and the best selectivity to N -alkypiperazines. The mechanistic studies indicated that this phenomenon occurs via tandem photocatalytic reactions involving alcohol dehydrgenation to aldehyde, aldehyde condensation with piperazine to enamine, and enamine hydrogenation to N -alkylated piperazines. Considering the experimental results of methanol isotope kinetics, the α-C–H cleavage of methanol to form hydroxymethyl radical (·CH 2 OH) was proven to be the rate-determining step in the N -alkylation reaction of piperazine with low carbon alcohols. The characterization and control experiments revealed that the size of Pd nanoparticles and the valence of Pd species were vital to the reaction. The Pd/TiO 2 -P catalyst with an average of 2.5 ± 0.5 nm Pd particles and approximately 68% Pd 0 species on surfaces presented the highest activity for the photocatalytic tandem reactions of methanol dehydrogenation and enamine hydrogenation.
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JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2022
·
IF 9.965
Chao Liu,Peng-kai Fan,Xiao-qi Xie,Ying-jie Sun,Yan Li,Xiao-jing Wang
Generally, it is important to ameliorate the co-catalyst used in photocatalytic hydrogen evolution reactions (PHERs) to achieve efficient transfer and separation of photogenerated carriers, decrease the surface reaction energy barrier, and hence improve the photocatalytic activity . In this study, N-doped graphite carbon (GC) was introduced in situ to MoO 2 to ensure the presence of well-dispersed active sites, lower the overpotential of hydrogen evolution, and further achieve high conductivity. Then, the MoO 2 /GC composite obtained was used as a co-catalyst of ZnIn 2 S 4 (ZIS) in a PHER, resulting in a great improvement in the photocatalytic activity. Given the metallicity and large work function of MoO 2 /GC, a Schottky interface can form between MoO 2 /GC and ZIS, which accelerates the transmission of photogenerated electrons. As a result, the separation efficiency of photogenerated carriers improves, whereas the surface overpotential of PHERs clearly decreases for ZIS. This study proposes a new idea for exploiting efficient co-catalysts and promotes the wide and heavy use of carbon materials in the field of solar energy conversion .
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FOOD CHEMISTRY
·
2022
·
IF 9.231
Hui Zhangsun,Qinzhi Wang,Zhihao Xu,Jiao Wang,Xiaoshuai Wang,Yijian Zhao,Hui Zhang,Shuang Zhao,Lihua Li,Zhenyu Li,Li Wang
Enhancing catalytic activity is the key to develop electrochemical sensors for monitoring of neonicotinoid such as imidacloprid (IMI), thiamethoxam (THX) and dinotefuran (DNF). Herein, a MOF-derived octahedral NiCu nanoporous carbon composite with abundant N -doped (N/ [email protected] ) was synthesized, which was exploited as electrochemical sensor for neonicotinoid determination. Integrating the synergistic effect of NiCu nanoalloy and the hierarchical porous carbon structure, the N/ [email protected] /GCE significantly promoted the diffusion between electrolyte and active site. Meanwhile, the introduction of polyvinylpyrrolidone (PVP) improved the hydrophilicity and dispersibility of N/ [email protected] , endowing superior electrocatalytic performance for IMI, THX and DNF determination, with linear ranges of 0.5–60, 1–60 and 0.5–60 μM, respectively, and detection limits of 0.017, 0.007 and 0.001 μM. Additionally, the sensor can determine IMI, THX and DNF in apples, tomatoes and potatoes with the recovery rate of 92.1–103.4% and RSD ≤ 4.7%. This study has explored a novel modified electrode material for construction of neonicotinoid sensors.
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CHEMICAL ENGINEERING JOURNAL
·
2022
·
IF 16.744
Jiaoqin Liu,Chengjie Guo,Nannan Wu,Chenguang Li,Ruijuan Qu,Zunyao Wang,Riya Jin,Yina Qiao,Zengdi He,Jing Lu,Xingqiao Feng,Yufan Zhang,Anlong Wang,Jingshuai Gao
In this work, the kinetics and mechanisms of photocatalytic degradation of perfluorooctanoic acid (PFOA) by nitrogen-doped indium trioxide (N-doped In 2 O 3 or NH 4 NO 3 -In 2 O 3 ) under Xe lamp irradiation were systematically investigated. Nitrogen originating from various inorganic and organic nitrogen compounds was doped into In 2 O 3 to examine the catalytic effect. The NH 4 NO 3 -In 2 O 3 catalyst was characterized by SEM , TEM, FT-IR, UV-DRS, BET surface area, XPS, and XRD , and showed the best catalytic performance. After 18 h of irradiation, PFOA was almost completely degraded with addition of 5 mg catalyst, while it was hardly degraded by simulated sunlight alone. The low photocatalytic degradation efficiency of PFOA was observed in different natural waters, which was due to the inhibitory effect of high pH and common anions like SO 4 2− . The calculation results of Materials Studio showed that a shoulder-to-shoulder π system between nitrogen atom and oxygen atom (NO π*) was formed after nitrogen doping into interstitial sites of In 2 O 3 , therefore resulting in a reduction in band gap energy. Occupied NO π* states were responsible for the red shift, while unoccupied NO π* levels restrained the recombination of electrons (e − ) and holes (h + ). Nitrogen doping reduced the excitation energy for electronic transition, and thus accelerated the reaction. According to mass spectrometry analysis, decarboxylation and elimination were still the main photodegradation pathways of PFOA. To the best of our knowledge, this report is the first to explore the reaction mechanisms of PFOA in an N-doped In 2 O 3 /Xe lamp irradiation system.
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Marine Drugs
·
2022
·Vol. 20
·期 2
·86
·
IF 6.085
Jingmin Cui,Xia Ji,Yingqi Mi,Qin Miao,Fang Dong,Wenqiang Tan,Zhanyong Guo
N-2-hydroxypropyltrimethyl ammonium chloride chitosan (HACC), a cationic quaternary ammonium salt polymer exhibiting good solubility in water, is widely used because of its low toxicity and good biocompatibility. Herein, through ion exchange reaction, we preparedN-2-hydroxypropyltrimethyl ammonium chitosan derivatives bearing amino acid Schiff bases with good biological activities. The accuracy of the structures was verified by FT-IR and1H NMR. The antibacterial activity, antifungal activity, and scavenging ability of DPPH radical and superoxide radical of HACC derivatives were significantly improved compared with that of HACC. In particular, HACGM (HACC-potassium 2-((2-hydroxy-3-methoxybenzylidene)amino)acetate) and HACGB (HACC-potassium 2-((5-bromo-2-hydroxybenzylidene)amino)acetate) showed good inhibitory effect on bacteria and fungi, includingStaphylococcus aureus,Escherichia coli,Botrytis cinerea,andFusarium oxysporumf. sp.cubense. The inhibition rate of HACGB onStaphylococcus aureusandEscherichia colicould reach 100% at the concentration of 0.1 mg/mL, and the inhibition rate of HACGM and HACGB onBotrytis cinereaandFusarium oxysporumf. sp.cubensecould also reach 100% at the concentration of 0.5 mg/mL. Improving antimicrobial and antioxidant activities of HACC could provide ideas and experiences for the development and utilization of chitosan derivatives.Keywords:N-2-hydroxypropyltrimethyl ammonium chloride chitosan;amino acid Schiff bases;antimicrobial activity;antioxidant activity
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ELECTROCHIMICA ACTA
·
2022
·
IF 7.336
Ningxiang Wu,Xiao Gu,Shuhao Zhou,Xu Han,Huitao Leng,Panpan Zhang,Pan Yang,Ying Qi,Sheng Li,Jingxia Qiu
Membrane capacitive deionization (MCDI) technology is a promising water quality desalination technology. It is reasonably necessary to find suitable electrode materials with unique properties for high desalination performance. Herein, fish scales (FSs) are selected as precursors for obtaining carbon materials with a hierarchical porous structure with the contributions from hydroxyapatites (HAs) templates, which are naturally contained in the FSs. The characterizations of the derived carbon show that it possesses an ultra-high specific surface area of 3,761.71 m 2 g −1 , a lot of micro/mesopores, natural heteroatomic doping sites and excellent wettability. As a result, it shows an excellent desalination capacity of 29.14 mg g −1 and good electrode regeneration performance, proving that the fish scales-derived carbon is promising for MCDI application.
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ChemSusChem
·
2022
·Vol. 15
·期 6
·e202102642
·
IF 9.14
Lingling Zheng,Yingji Zhao,Hongjuan Zhang,Wei Xia,Jing Tang
Graphical There's no space : Highly dispersed Fe−N x anchored on concave N-doped carbon is synthesized by space-confined strategy. The resulting NC@Fe−N−C exhibits superior oxygen reduction activity, originating from the combination of intrinsic activity and acceleration of mass electron transfer. Carbon-based electrocatalysts with atomically dispersed Fe−N−C display promising performance for oxygen reduction reaction (ORR) amongst non-precious electrocatalysts. Nonetheless, increasing the number and utilization of Fe−N−C active sites is challenging. Designing morphologies and adjusting the pore structure of carbon-based electrocatalysts would boost the mass transfer, enhance the utilization of the active sites, and increase the overall ORR performance. In this work, a concave N-doped carbon cubes structure adorned with highly external Fe−N x was designed and produced by the space-confined induced strategy. The optimal electrocatalyst revealed excellent ORR activity in both alkaline and acidic electrolytes, with half-wave potentials of 0.86 and 0.75 V, respectively. The superior performance arose from its unique concave structure, possessing more accessible active sites with improved intrinsic activity, which holds promising potential for preparing advanced ORR electrocatalysts.
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SCIENCE OF THE TOTAL ENVIRONMENT
·
2022
·
IF 10.753
Qian Zhu,Huiqin Gao,Yiwei Sun,Yujia Xiang,Xiangjing Liang,Andrei Ivanets,Xiaoqin Li,Xintai Su,Zhang Lin
The synergistic effect of heteroatoms is a viable method to enhance the adsorption performance of heavy metal onto carbon-based materials. However, the high cost, complex operation and a lot of pollution from the synthesis process have limited its development. Herein, a facile two-step pyrolysis method is used to prepare in situ N and S doped porous biochar from paper mill sludge for the removal of Cr(VI) from aqueous environment. The NSC-450 sample prepared under the optimum conditions has a large specific surface area of 3336.7 m 2 g −1 , an average pore size of 2.56 nm and a total pore volume of 2.10 cm 3 g −1 , manifesting the excellent adsorption capacity of 356.25 mg g −1 for Cr(VI). The adsorption of Cr(VI) by NSC-450 is consistent with the Langmuir isotherm and pseudo-second-order model, suggesting a spontaneous and endothermic chemisorption process. The analysis results show that the NH, graphitic nitrogen and thiophene structures have a positive effect on converting a large amount of Cr(VI) to Cr(III) by synergistic reduction, indicating obviously facilitating Cr(VI) removal compared to other sites. Therefore, in this material, the strong adsorption mechanism is mainly reductive complexation. Moreover, the effects of real water quality, anions, cations and fulvic acid on the adsorption behavior of Cr(VI) onto the NSC-450 were further investigated. The results demonstrate that the chromium removal rate remains above 82% even in actual electroplating wastewater, suggesting NSC-450 has great practical application prospect. This work offered a feasible method for high-value utilization of sludge, but also provided a novel perspective for the future design of heteroatom-doped carbon materials for promoting to eliminate hexavalent chromium from water environment.
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FUEL
·
2022
·
IF 8.035
Xinru Wu,Xueqin Lei,Shidong Wang,Hongwei Zhang,Qingyan Cui,Xiaojun Bao,Tinghai Wang,Pei Yuan
Isomerization of alkane is one of the most important catalytic processes for producing environmentally friendly gasoline fraction with high octane number. However, the development of non-noble metal based catalysts with high conversion and selectivity towards multi-branched isomerized products is still challenging. Herein, we report that a NiP-Hβ/modified Kaolin catalyst was successfully prepared by ball-milling of amorphous NiP nanoparticles with Hβ/modified Kaolin composites and applied for n-hexane isomerization. The introduction of chemically modified Kaolin with abundant weak-medium acid sites and mesopores not only alleviates the cracking of isomerized products on the strong acid sites on Hβ, but also provides more active sites for the formation of di-branched isomerized products with high octane number. As a result, the NiP-Hβ/modified Kaolin catalyst shows an excellent catalytic performance for n-hexane isomerization in terms of good conversion (78.1%), high selectivity towards mono-branched (75.4%) and di-branched (21.4%) i-C 6 products, and high liquid yield (99.9%). This work paves the way to the development of high performance non-noble metal based catalysts for large scale production of clean gasoline.
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CHEMICAL ENGINEERING JOURNAL
·
2022
·
IF 16.744
Yongsong Ma,Xianglin Liu,Mengyi Tang,Kaifa Du,Huayi Yin,Xuhui Mao,Dihua Wang
Heteroatom-doped carbon materials have been proved as potent catalysts for the remediation of organic contaminants. Herein, molten salt electrolysis (MSE) was employed to convert waste eggshell and Co 3 O 4 into N, P, S tri-doped core–shell catalyst (Co@NPSC), achieving the conversion of waste eggshell into value-added materials. Impressively, Co@NPSC/peroxymonosulfate (PMS) system exhibited an exceptional ultra-high turnover frequency (TOF) value of 83.86 min −1 for sulfamethoxazole (SMX) degradation with a low catalyst dosage of 0.001 g L –1 . Subsequently, density functional theory (DFT) simulation clarified the synergistic essences of catalytic oxidation (i.e., the Co@NPSC catalyst reduced the adsorption energy of PMS molecular on its surface, reduced itself work function, enhanced the length of the O-O bond ( I O-O ) of PMS molecule, and facilitated electron transfer for PMS activation). In addition, both theoretical predictions and acute toxicity assay results indicated that the degradation of SMX equals detoxification. This work provides a new insight into the reutilization of waste eggshell and the design of heteroatom-doped core–shell catalysts.
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JOURNAL OF ELECTROANALYTICAL CHEMISTRY
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2022
·
IF 4.598
Tao Wang,Jing Feng,Qian Liu,Xiaofeng Han,Dongling Wu
Here, a simple and green synthesis process of Fe/N-codoped reduced graphene oxide (Fe-N-C/NG) with high electrocatalytic activity for oxygen reduction reaction (ORR) is reported. The synthesis of 3D porous structure of Fe-N-C/NG composites involves thermal drying the mixture of graphene oxide (GO), iron nitrate and aspartic acid (Asp) directly, follow by pyrolysis the mixture. The Asp is introduced as an environment-friendly nitrogen and carbon source, and the iron nitrate serves as the pore-forming agent and a gas producer that prevents the agglomeration of graphene. The as-prepared Fe-N-C/NG exhibits 3D loose porous structure with larger specific surface area (245 m 2 g - 1 ). The Fe-NC/NG composite exhibits the onset potential of 0.91 V, a half-wave potential (E 1/2 = 0.83 V), low Tafel slope and four-electron selectivity (n = 3.99) in alkaline solution. Furthermore, the stability test manifests the outstanding stability of Fe-NC/NG electrocatalyst and a superior methanol tolerance than Pt/C electrodes. Particularly, when the prepared Fe-NC/NG-3 catalyst is used as an air electrode catalyst in an assembled Zn-air battery, it exhibits a high specific capacity of 848.2 mAh g Zn -1 and displays more stability than Pt/C. This work provides an effective strategy for preparing high ORR and Zn-air battery performance Fe/N-codoped reduced graphene oxide materials.
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CURRENT MICROBIOLOGY
·
2022
·Vol. 79
·期 6
·1-11
·
IF 2.343
Bao Jingjiao,Guo Dengkang,Jin Lei,Li Tiejun,Shi Hui
Vibrio fluvialis is a marine opportunistic pathogen that frequently causes diseases in aquatic animals and humans. V. fluvialis can produce quorum sensing signaling molecules to coordinate cell density-dependent behavioral changes, including N-acyl homoserine lactone (AHL), which acts as a vital mediator of virulence-associated gene expression. Currently, several AHL molecules in V. fluvialis have been detected via biological and physicochemical methods, although different detection approaches have generated diverse AHL profiles. Here, we describe the AHL-producing bacterium, V. fluvialis BJ-1, which was isolated from marine sediments from the East China Sea. V. fluvialis BJ-1 could stimulate AHL-mediated β-galactosidase synthesis of the biosensor Agrobacterium tumefaciens NTL4 (pZLR4) but could not induce violacein production in the AHL reporter strain, Chromobacterium violaceum CV026. This bacterial isolate exhibited strong AHL-producing activity at low cell density; however, the AHL activity declined when population density remained at high levels. Analysis of the AHLs by Ultra-High-Performance Liquid Chromatography tandem Mass Spectrometry demonstrated that V. fluvialis BJ-1 produced five different AHL signaling molecules, including two linear chain AHL products (C 8 - and C 10 -HSL), and three β-carbon-oxidative AHL products (3-O-C 8 -, 3-O-C 10 - and 3-O-C 12 -HSL). Significantly, the present study is the first to accurately define the AHL profile of marine V. fluvialis . In future, the coupling of UHPLC to ESI–MS/MS is expected to be utilized for the accurate determination of AHL profiles in marine Vibrio .
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