OPTICS AND LASER TECHNOLOGY
·
2020
·
IF 3.233
Gulgina Mamtmin,Nuerguli Kari,Renagul Abdurahman,Patima Nizamidin,Abliz Yimit
Optical waveguide (OWG) sensors are widely used in gas detection, and sensitive materials are the key factors affecting sensor performance. Herein, we report on a 5,10,15,20-tetrakis-(4-methoxyphenyl) porphyrin (TMP) deposited optical wave guide (OWG) sensor. The porphyrin solutions with different acidity were deposited on a K + -ion exchanged glass OWG surface by spin coating, to fabricate porphyrin film-coated OWG gas sensing devices. The effects of pH values of the porphyrin solution used to prepare the sensitive film on the sensing properties of these devices were investigated. The gas sensitive performances of these devices in response to analytes were compared. Among them, the sensing devices fabricated using original and acidic solutions of porphyrin exhibited significant responses to sulfide gases and ethanediamine, respectively. The sensing device prepared using an acidic solution has a good response to ethanediamine gas (response and recovery times of the sensor for 1 ppm of EDA (ΔI = 48) are 13 and 38 s, respectively). The RSD of the output light intensity is ±2.84, the signal to noise ratio (S/N) is 5.6. The device prepared using the original solution has an excellent response to sulfide gases (H 2 S, SO 2 ), and can detect low concentration levels (ppm) of sulfide gases. These sensing devices thus have the potential to be used in food quality testing and environmental monitoring.
研究领域:
材料科学
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化学传感器
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环境监测
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产品关联
DOI
高影响因子
KINETICS AND CATALYSIS
·
2024
·Vol. 65
·期 3
·251-260
·
IF 1.3
Yang Zhi,Luo Mingsheng,Liu Qinglong,Li Chenmeng,Wang Yatao,Li Hongjuan,Yao Lifei
Abstract The direct production of higher alcohols from syngas in a single step remains a great challenge. In this work, a series of K and Ni promoted Mo 2 C/Al 2 O 3 catalysts were prepared by impregnation method to enhance the selectivity of Mo 2 C-based catalysts for the one-step conversion of syngas to higher alcohols. The catalysts were continuously tested under the following conditions: 300°C, 3.0 MPa, velocity—11.50 \({\text{Lg}}_{{{\text{Mo}}}}^{{ - 1}}\) h –1 , H 2 /CO ratio of 2. The catalysts promoted with K and Ni demonstrated the highest total alcohol selectivity of 67.7%. Moreover, the selectivity for total C 2+ alcohols reached as high as 56%, with 37% being ethanol. X-ray diffraction (XRD), hydrogen temperature-programmed reduction (H 2 -TPR) and X-ray photoelectron spectroscopy (XPS) characterization data reveal that K can promote the crystallinity of β-Mo 2 C, lower the catalyst reduction temperature and increase the proportion of high-valent Mo on the catalyst surface. In addition, adding Ni as a promoter to the KMo 2 C/Al 2 O 3 catalyst can generate a synergistic effect to further enhance the catalytic activity and the selectivity of higher alcohols.
研究领域:
化学工程
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催化
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材料科学
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产品关联
DOI
高影响因子
Energy Storage Materials
·
2021
·
IF 17.789
Xian-Zhi Zhai,Jin Qu,Juan Wang,Wei Chang,Hong-Jun Liu,Yu-Hao Liu,Hongfu Yuan,Xiaofeng Li,Zhong-Zhen Yu
ABSTRACT Structural unsteadiness and limited electrochemical kinetics upon cycling seriously impede further applications of birnessite cathodes for rechargeable aqueous zinc‑ion batteries (ZIBs), even though they have high voltage platforms and distinctively layered structures for preferable (de)intercalation of zinc ions. Herein, yolk-shell structured K-birnessite (K 0.48 Mn 2 O 4 ·0.49H 2 O)@mesoporous carbon nanospheres (KMOH@C) with rich oxygen vacancies are synthesized for the first time with a two-step diffusion-driven strategy of hydrothermal synthesis followed by etching with KOH. The transport of reaction ions is regulated by surface charge and pore structure of the carbon shells, thus K-birnessite is preciously transferred into the hollow mesoporous carbon (HMC) nanospheres. Furthermore, the etching effect of KOH and the confinement effect of HMC nanospheres generate intercalated K + and abundant oxygen vacancies into KMOH, leading to an excellent electrochemical kinetics. Meanwhile, HMC nanospheres also endow rapid electron/ion transport and stabilize the crystal structure of K-birnessite. Therefore, KMOH@C exhibits superior electrochemical performances with high reversible capacities of 412.7 and 122.2 mA h g ‒1 at 0.5 and 10.0 A g ‒1 than reported cathodes, respectively. Moreover, an exceptional cyclability of 129.6 mA h g ‒1 even after 6000 cycles at 3.0 A g ‒1 is achieved, making the KMOH@C cathode highly competitive for eco-friendly aqueous ZIBs.
研究领域:
材料科学
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电化学
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产品关联
DOI
高影响因子
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
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2020
·
IF 3.085
Junnan Qu,Yi Du,Yibing Feng,Jianyong Wang,Bo He,Minxing Du,Yang Liu,Nan Jiang
A visible-light-responsive hybrid photocatalyst , K-doped g-C 3 N 4 /BiOBr, has been synthesized by K-doped g-C 3 N 4 (K–CN) and BiOBr. The property of photocatalysts was characterized by XRD , FT-IR, TEM, SEM , DRS , PL , EIS and HPLC. The photocatalytic activity of K-doped g-C 3 N 4 /BiOBr was evaluated by degradation of Rhodamine B (RhB) and tetracycline hydrochloride under visible-light irradiation. The K-doped g-C 3 N 4 /BiOBr hybrid photocatalyst which contains K–CN with mass fraction of 20% (20K–CN/BiOBr) shows the best degradation efficiency of RhB. The degradation efficiency of RhB (20 mg/L) can be achieved to 99% and the degradation efficiency of tetracycline hydrochloride by BiOBr decreased with the increase of K-doped g-C 3 N 4 doping. The results of photocurrent and EIS assumed that the tight coupling between K–CN and BiOBr can enhance the separating efficiency of photo-generated carrier. In addition, the capture experiment proof that h + is the primary active substance in the system of reaction and ·OH is the auxiliary active substance. After five degradation experiments, the efficiency of the degradation of Rhodamine B by the sample can still reach 90%, which proves that the samples are stable. A new and efficient method is provided in this work to solve the pollution of organic dyes and antibiotics.
研究领域:
环境科学
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材料科学
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DOI
高影响因子
Nanoscale Research Letters
·
2019
·Vol. 14
·期 1
·1-11
·
IF 3.159
Wang Shuya,Cui Bin,Zhuang Quanchao,Shi Yueli,Zheng Hong
Potassium-ion batteries (KIBs) are favored by researchers because of the unique advantages. In this work, KIB cathode material nano-perovskite K(Mn 0.95 Ni 0.05 )F 3 with concentration gradient was synthesized by EDTA-assisted homogeneous precipitation method for the first time and characterized. The solid solution material was deposited on the multi-walled carbon nanotubes (MWCNTs) to form K(Mn 0.95 Ni 0.05 )F 3 /MWCNT nanocomposites to improve the electron conductivity of the electrode material so as to obtain the excellent electrochemical performance. As expected, the charge and discharge capacities of K(Mn 0.95 Ni 0.05 )F 3 /MWCNTs after the 60th cycle can still reach 106.8 and 98.5 mAh g −1 over the voltage range 4.2–1.2 V vs. K/K + at the current density of 35 mA g −1 , respectively. Electrochemical performance studies showed that solid solution K(Mn 0.95 Ni 0.05 )F 3 had the potential applications as the cathode material for KIBs. Electrochemical impedance spectroscopy (EIS) was used to study the transport and reaction processes of ions at the solid–liquid interface. The main factors affecting electrochemical performance could be analyzed from the Nyquist plot of the EIS test.
研究领域:
材料科学
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电化学
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能源存储
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
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2014
·
IF 2.726
Y.C. Hu,H.Y. Wang,X.W. Wang,G.L. Song,J. Su,Y.W. Cui,H. Ma,F.G. Chang
Ordered double-perovskite oxides of Sr 2− x K x FeMoO 6 (0.00 ⩽ x ⩽ 0.10) are synthesized via sol–gel method. X-ray powder diffraction analysis shows that all the samples have a single phase and exhibit I4/m symmetry. The cation order of Sr 2− x K x FeMoO 6 decreases from 94.4(2)% to 50.4(2)%, indicating that Fe/Mo is in nearly complete disorder. The magnetic property of Sr 2− x K x FeMoO 6 samples depends on temperature under zero-field-cooling (ZFC) and field-cooling (FC) processes at an applied magnetic field of 100 Oe. The thermal irreversibility behavior in the FC and ZFC curves indicates a typical cluster glass behavior in this system. The H / M versus M 2 curves indicate a second-order magnetic transition, resulting in a small variation in magnetic entropy. Antisite defect is the primary reason for the effective paramagnetic moment.
研究领域:
材料科学
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固体物理
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无机化学
·
磁学
✓ 已验证
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
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2022
·
IF 10.753
Tongtong Wang,Jiyong Zheng,Jinjun Cai,Qiangqiang Liu,Xianxia Zhang
To improve the performance of graphitic carbon nitride (g-C 3 N 4 ), a hotly researched metal-free photocatalyst, for better application in the efficient removal of organic pollutants, adsorption synergistically enhanced photocatalysis mechanism was thoroughly explored. Based on KOH pore-forming activated biochar (ACB) and K + doped g-C 3 N 4 (K-gC 3 N 4 ), the novel activated biochar-based K-gC 3 N 4 composite (ACB-K-gC 3 N 4 ) was synthesized via the innovative ultrasonic-milling method. Rhodamine B (RhB), tetracycline (TC), norfloxacin (NOR), and chloramphenicol (CAP) were selected as target pollutants, and the effects of environmental factors, recycling and actual wastewater tests, disinfection effects, and various enhancement strategies were investigated. The results showed that K-gC 3 N 4 was successfully composited with ACB by various characterizations, where the loading mass ratio of 1:2 exhibited the best performance. ACB-K-gC 3 N 4 possessed a larger specific surface area, richer functional groups, suitable band gap (2.29 eV), and broader visible light absorption (~716 nm) than K-gC 3 N 4 . ACB-K-gC 3 N 4 presented effective removal efficiency over K-gC 3 N 4 for four pollutants, in which the removal efficiency of RhB reached 93.26%, and the degradation rate constant of 0.0119 min −1 was four times higher than K-gC 3 N 4 (0.0029 min −1 ). Moreover, ACB-K-gC 3 N 4 was superior to K-gC 3 N 4 in disinfecting S. aureus and E. coli , with a sterilization rate of exceeding 90% for 12 h. The photodegradation activity was dominated by · O 2 − , h + , and · OH, and the mechanisms involved in the three stages. This was attributed to the unique structure and surface properties (defects and persistent free radicals) of ACB, as evidenced by improved adsorption stage and transfer of degradation intermediates, facilitated the generation of active species, accelerated migration of photogenerated electrons, and inhibited photogenerated carriers recombination by the heterojunction . The good reusability and stability, enhancement strategies (blowing air and heating), and satisfactory feasibility for actual wastewater allow ACB-K-gC 3 N 4 possible to promote high-concentration wastewater treatment and disinfection.
研究领域:
环境科学
·
材料科学
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产品关联
DOI
PubMed
高影响因子
International Journal of Nanomedicine
·
2017
·
IF 4.3
Lei Yang,Zhenghai Zhang,Jian Hou,Xin Jin,Zhongcheng Ke,Dan Liu,Mei Du,Xiaobing Jia,Huixia Lv
Ginsenoside compound K (CK) is one of the effective ingredients in antitumor composition of ginsenoside. However, the poor water solubility and significant efflux have limited the widespread clinical use of CK. In this study, preparation of novel CK-loaded d -alpha-tocopheryl polyethylene glycol 1,000 succinate/poly(ethylene glycol)-poly(ε-caprolactone) mixed micelles (CK-M) is discussed to solve the above problems. Particle size, zeta potential, and morphology were characterized using dynamic light scattering and transmission electron microscopy. CK-M are spherical shaped with an average particle size of 53.07±1.31 nm with high drug loading of 11.19%±0.87% and entrapment efficiency of 94.60%±1.45%. Water solubility of CK was improved to 3.78±0.09 mg/mL, which was ~107.35 times higher than free CK. A549 and PC-9 cells were used to evaluate in vitro cytotoxicity and cellular uptake. IC 50 values of CK-M in A549 and PC-9 cells (24 h) were 25.43±2.18 and 18.35±1.90 μg/mL, respectively. Enhanced cellular uptake of CK-M was observed in both cells. Moreover, CK-M promoted tumor cell apoptosis, inhibited tumor cell invasion, metastasis, and efflux through regulation of Bax, Bcl-2, matrix metalloproteinase-2, Caspase-3, and P-glycoprotein. In vivo imaging indicated that CK-M has excellent tumor targeting effect within 24 h, and the relative tumor inhibition rate of CK-M was 52.04%±4.62% compared with control group ( P <0.01). Thus, CK-M could be an appropriate delivery agent for enhanced solubility and antitumor effect of CK.
研究领域:
药学
·
肿瘤学
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纳米技术
·
药物递送系统
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产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Wen Lu,Aimin Wang,Yanyu Zhang,Songyu Ren,Zhongguo Zhang
In this work, an innovative strategy combining vacuum ultraviolet (VUV) and K doping graphite carbon nitride (K-g-C 3 N 4 ) was proposed for antibiotic removal in aqueous. The properties of K-g-C 3 N 4 were systematically characterized by XRD, FT-IR, BET, SEM, UV-vis DRS, and XPS, showing that K-g-C 3 N 4 possessed a larger specific surface and richer functional groups than g-C 3 N 4 . The catalytic efficiency of K-g-C 3 N 4 was investigated for the trimethoprim (TMP) removal under VUV irradiation. Compared with UVC photolysis, VUV photolysis, UVC/g-C 3 N 4 , VUV/g-C 3 N 4 , and UVC/K-g-C 3 N 4 processes, VUV/K-g-C 3 N 4 enhanced the pseudo-first-order reaction rate constant of TMP removal by 2.0–19.7 times and the mineralization rate by 9.0%-38.2%. Electron paramagnetic resonance results and quenching experiments validated that O 2 •- , • OH, 1 O 2 , h + , and e - were engaged in the VUV/K-g-C 3 N 4 process. The fluorescent spectra of O 2 •- -substituted and • OH-substituted products revealed that the K-g-C 3 N 4 greatly enhanced the quantity of O 2 •- and • OH during VUV irradiation. The VUV/K-g-C 3 N 4 system produced marginally more H 2 O 2 and • OH than the UVC/K-g-C 3 N 4 system, confirming that K-g-C 3 N 4 predominantly utilized the UVC and other ultraviolet–visible light emitted by the VUV lamp, with VUV having a minor effect. Furthermore, K-g-C 3 N 4 had exceptional stability and reusability, efficiently degrading various contaminants under VUV irradiation. This work offered a comprehensive insight into VUV/K-g-C 3 N 4 process as a novel approach for antibiotic removal from water.
研究领域:
环境科学
·
材料科学
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产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2018
·
IF 5.116
Jiangping Jing,Zhuoyuan Chen,Chang Feng
Graphitic carbon nitride (g-C 3 N 4 ) usually shows amphoteric property in a neutral solution. In this work, a K&I co-doped g-C 3 N 4 is prepared by simply sintering the mixture of dicyandiamine, KI and I 2 . The K&I co-doping modulates the band structure of g-C 3 N 4 with pulling the Fermi level toward its conduction band minimum. The obtained K&I co-doped g-C 3 N 4 (K&I-C 3 N 4 ) generates positive photocurrents over the whole investigated potential range, exhibiting a typical n-type semiconductor characteristic. Therefore, the K&I co-doping transforms the g-C 3 N 4 from amphoteric to n-type semiconductor. Also, the prepared K&I-C 3 N 4 shows widened light absorption range and enhanced separation efficiency of the photogenerated charge carriers, which results in the dramatically enhanced photoelectrochemical performance.
研究领域:
材料科学
·
光化学
·
半导体物理
✓ 已验证
DOI
高影响因子
JOURNAL OF PHARMACEUTICAL AND BIOMEDICAL ANALYSIS
·
2015
·
IF 2.979
Hui Liu,Yong-Sheng Wang,Xian Tang,Hui-Xian Yang,Si-Han Chen,Hui Zhao,Shan-Du Liu,Yu-Feng Zhu,Xiao-Feng Wang,Yan-Qin Huang
A sensitive, lable-free and low cost fluorescence aptasensor was developed for detecting 8-hydroxy-2′-deoxyguanosine (8-OHdG) by using 8-OHdG aptamer (Apt) as a recognition probe and N-methyl mesoporphyrin IX (NMM) as a reporter. The method is based on the conformational switching of a K + -stabilized G-quadruplex to a 8-OHdG-stabilized one. NMM can selectively bind to K + -stabilized G-quadruplex instead of 8-OHdG-stabilized one. The addition of 8-OHdG in the solution of Apt - K + ions leads to a sharp change in fluorescence intensity, which showed a good linear response toward 8-OHdG concentration ranging from 3.96 nM to 211 nM with a detection limit of 1.19 nM. The relative standard deviation and the recovery were 1.23–3.26% ( n = 11) and 94.8–106.7%, respectively. The proposed aptasensor consists of only an aptamer probe and a specific dye NMM, avoiding the complex and expensive labeling procedure. Thus it is much cheaper and more applicable.
研究领域:
分析化学
·
生物传感器
·
分子诊断
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF POROUS MATERIALS
·
2025
·
IF 3.2
Qian Yi,Jiang Qingqing,Xiang Shimeng,Lu Zhenhao,Xu Xiaowen,Yang Jing,Dai Guoliang,Song Ruifeng,Jiang Ji
Separating CO 2 and N 2 from CH 4 is crucial for energy production and environmental protection. This study showed the rapid synthesis of CHA zeolites with different morphologies using an in situ growth method, without the assistance of organic structure directing agents (OSDA) or fluoride media. The crystallization behavior of CHA zeolites was studied in terms of synthesis gel composition (including water content, silicon and aluminum content, alkalinity and Sr 2+ concentration), synthesis temperature and duration. The results suggested that pure phase CHA zeolite nano-aggregates could be synthesized with broad precursor conditions at 150 °C for only 4 h. Then, K-CHA zeolite was ion-exchanged to Na-CHA and Ca-CHA and the adsorption properties of CHA zeolites with different morphologies and ions were studied. The results suggested that Na-CHA exhibited highest CH 4 , CO 2 and N 2 adsorption capacity and showed higher ideal selectivity for N 2 /H 2 ; Although Ca-CHA zeolites exhibited relative lower CO 2 and CH 4 adsorption capacity, it exhibited the highest ideal selectivity for CO 2 /CH 4 ; Simultaneously, K-CHA zeolite exhibited high CH 4 adsorption capacity and high adsorption separation ability of CH 4 /N 2 . Furthermore, breakthrough experiments have confirmed the practical feasibility of separating CO 2 from CH 4 .
研究领域:
材料科学
·
化学工程
·
吸附与分离
·
分子筛合成
·
气体分离
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）