JOURNAL OF MATERIALS SCIENCE
·
2020
·Vol. 56
·期 7
·4666-4676
·
IF 3.553
Wang Pan,Tian Xuemin,Yan Meng,Yang Boxuan,Hua Zhongqiu
In this study, a catalytic-type combustible gas sensor was fabricated by the screen-printing method. Pt supported catalysts (Pt-HZSM5) were prepared by a wet impregnation method using HZSM5 zeolite as support. It was found that Pt-HZSM5 catalysts have a highly catalytic activity to H 2 and CO at low temperatures and a selectively and fully combustible was observed at only 150 °C. A good dispersion state of Pt nanoparticles on HZSM5 zeolite particles was beneficial for the catalytic oxidization of CO and H 2 . However, a high loading amounts lead to a poor dispersion state and a weak catalytic activity. The thick film sensor based on Pt-HZSM5 catalyst was found to be highly sensitive to combustible gas with a good linearity up to 2% and a limitation of detection (LOD) around 50 ppm. Due to the low operation temperature, a highly selectivity was obtained for CO and H 2 and no cross-sensitivity to interfering gases such as CH 4 and VOCs. It was indicated that the present developed catalytic-type gas sensors could be used for the leakage detection and monitor for H 2 and CO with a low power consumption and a good selectivity.
研究领域:
材料科学
·
化学工程
·
传感器技术
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DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2022
·
IF 7.139
Chao Chen,Xiaohua Deng,Yingjie Deng,Lu An,Yijie Deng,Yuying Zheng,Dai Dang,Xu Yang
Developing high-efficiency bifunctional materials for electro-catalysis and supercapacitors are urgently needed but challenging. Herein, we develop a self-supporting Co–Ni LDH electrode prepared by in-situ growing ZIF-L(Co)@ZIF-L(Co, Ni) on carbon paper followed by a pseudomorphic transformation. The optimized Co–Ni LDH/carbon paper electrodes (CN-2/CP) exhibit excellent electrochemical activity and stability in oxygen evolution reactions (OER) and supercapacitors. The CN-2/CP electrode displays a low overpotential of 230 mV at 10 mA cm −2 and superior stability at 40-h chronopotentiometry for OER. For supercapacitor, the CN-2/CP electrode delivers a high specific capacitance of 1346 F g −1 at 1 A g −1 and maintains a capacitance of 88.5% after 7000 charge/discharge cycles at 20 A g −1 . Based on the physical and chemical characterization results, the high performance originates from the in-situ electrochemical conversion of metal hydroxide , improved conductivity, fast charge transfer at the interface and unique layered cross morphology providing more active sites.
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高影响因子
ChemSusChem
·
2019
·Vol. 12
·期 4
·830-838
·
IF 7.804
Shuai Wang,Haeseong Jang,Jia Wang,Zexing Wu,Xien Liu,Jaephil Cho
Graphical From tannic acid to water splitting : Amorphous Co−P/Co−N−C supported on N, P co-doped porous carbon (Co−P/Co−N−C/NPC) with a large specific surface area and abundant reactive sites is prepared. The material exhibits outstanding catalytic performance for the hydrogen evolution reaction (HER, η =234 mV at 10 mA cm −2 ), oxygen evolution reaction (OER, η =374 mV at 10 mA cm −2 ), and oxygen reduction reaction (ORR, E 1/2 =0.89 V, vs. RHE). It remains a tremendous challenge to develop a low-cost, earth-abundant, and efficient catalyst with multifunctional activities for the hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and oxygen reduction reaction (ORR). Herein, a facile and scalable avenue was developed to prepare amorphous Co−P/Co−N−C supported on N, P co-doped porous carbon (Co−P/Co−N−C/NPC) with a large specific surface area (1462.9 m 2 g −1 ) and abundant reactive sites including Co−P, Co−N and NPC. The prepared electrocatalyst exhibits outstanding catalytic performance for HER ( η =234 mV at 10 mA cm −2 ), OER ( η =374 mV at 10 mA cm −2 ), and ORR ( E 1/2 =0.89 V, vs. reversible hydrogen electrode). Benefiting from the excellent HER performance and outstanding OER activity, the Co−P/Co−N−C/NPC delivers a current density of 10 mA cm −2 for overall water splitting at a cell voltage of 1.59 V, which is comparable with the IrO 2 –Pt/C couple electrode.
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DOI
PubMed
高影响因子
JOURNAL OF SOLID STATE ELECTROCHEMISTRY
·
2014
·Vol. 18
·期 7
·2027-2033
·
IF 2.234
Chen Dongrui,Li Benzhen,Liao Youhao,Lan Hongwei,Lin Haibin,Xing Lidan,Wang Yating,Li Weishan
Three samples, LiNi 0.5 Mn 1.5 O 4 , LiNi 0.4 Mn 1.4 Co 0.2 O 4 , and LiNi 0.4 Mn 1.4 Cr 0.15 Co 0.05 O 4 , were prepared by sol–gel method and characterized by powder X-ray diffraction, Fourier transformed infrared spectroscope, scanning electron microscopy, Brunauer–Emmett–Teller surface area, four-probe resistance, cyclic voltammetry, electrochemical impedance spectroscopy, and charge–discharge test. It is found that the co-doped sample LiNi 0.4 Mn 1.4 Cr 0.15 Co 0.05 O 4 exhibits an improved performance compared with the Co-doped sample LiNi 0.4 Mn 1.4 Co 0.2 O 4 and the undoped sample LiNi 0.5 Mn 1.5 O 4 , especially at elevated temperature. At 25 °C, the discharge capacity of LiNi 0.4 Mn 1.4 Cr 0.15 Co 0.05 O 4 is 130 mAh g −1 at 0.1 C and 103 mAh g −1 at 10 C. At an elevated temperature (55 °C), its 1 C discharge capacity is 136 mAh g −1 and maintains 95.6 % of its initial capacity after 100 cycles. Compared with the reported results of LiNi 0.4 Mn 1.4 Co 0.2 O 4 and LiNi 0.475 Mn 1.475 Co 0.05 O 4 , the co-doped sample LiNi 0.4 Mn 1.4 Cr 0.15 Co 0.05 O 4 , with least content of Co, 0.05, possesses not only the high C-rate capacity but also the structural stability. The mechanism on the electrochemical performance improvement of LiNi 0.5 Mn 1.5 O 4 by the co-doping was discussed.
研究领域:
材料科学
·
电化学
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高影响因子
Nanomaterials
·
2021
·Vol. 11
·期 2
·261
·
IF 5.076
Wendi Zhang,Xiaoming Liu,Man Gao,Hong Shang,Xuanhe Liu
The oxygen reduction reaction (ORR) is a crucial step in fuel cells and metal-air batteries. It is necessary to expand the range of efficient non-precious ORR electrocatalysts on account of the low abundance and high cost of Pt/C catalysts. Herein, we synthesized crystalline cobalt-embedded N-doped carbon nanotubes (Co@CNTs-T) via facile carbonization of Co/Zn metal-organic frameworks (MOFs) with dicyandiamide at different temperatures (t = 600, 700, 800, 900 °C). Co@CNTs- 800 possessed excellent ORR activities in alkaline electrolytes with a half wave potential of 0.846 V vs. RHE (Reversible Hydrogen Electrode), which was comparable to Pt/C. This three-dimensional network, formed by Co@CNTs-T, facilitated electron migration and ion diffusion during the ORR process. The carbon shell surrounding the Co nanoparticles resulted in Co@CNTs-800 being stable as an electrocatalyst. This work provides a new strategy to design efficient and low-cost oxygen catalysts.Keywords:metal-organic frameworks;N-doped carbon;oxygen reduction reaction
研究领域:
材料科学
·
电化学
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DOI
PubMed
高影响因子
Analytical Methods
·
2019
·Vol. 11
·期 13
·1811-1815
·
IF 2.378
Shiwei Liu,Liang Liang,Qixian Zhang,Changpeng Liu,Wei Xing,Xiandui Dong
In this report, a reductive-heat-treated platinum tungsten oxide catalyst was prepared to improve the CO electro-oxidation activity and employed in the electrochemical sensor. Tungsten oxide was proved to be an effective co-catalyst for CO sensing and the strong interaction between platinum and tungsten oxide has been enhanced by the reductive heat treatment. As a result, the significant negative shift of CO oxidation potential was confirmed by an electrochemical characterization. Further, the sensing performance of the as-prepared catalyst was investigated by means of the portable CO sensor device, which showed higher sensitivity, faster response time and good linearity within 50 ppm CO.
研究领域:
材料科学
·
环境科学
·
化学工程
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DOI
高影响因子
Advanced Powder Materials
·
2021
·
IF 0
Xingsheng Hu,Yan Li,Xinxin Wei,Lei Wang,Houde She,Jingwei Huang,Qizhao Wang
The cobalt−carbonate (CoCi)/NiFeOOH double-layer co-catalyst was prepared on bismuth vanadate (BiVO 4 ). Compared with the same type of electrode (Co−Pi/NiFeOOH/BiVO 4 and Co−Sil/NiFeOOH/BiVO 4 ), the photoelectrochemical (PEC) performance of the composite electrode presents the most excellent performance. The Co−Ci/NiFeOOH/BiVO 4 electrode prepared by photoelectric deposition (PED) achieves a photocurrent density of 4.1 mA/cm 2 at 1.23 V vs RHE, and the applied bias photon-current efficiency (ABPE) is up to 0.95%. In addition, with the help of the equivalent circuit fitting in electrochemical impedance spectroscopy (EIS), the charge transfer resistance ( R ct ) of Co−Ci/NiFeOOH/BiVO 4 is only 108.9 Ω, which is 16% that of BiVO 4 . The enhanced PEC performance of Co−Ci/NiFeOOH/BiVO 4 in the double-layer cocatalyst system is attributed to the outstanding advantages of Co−Ci cocatalyst in oxygen vacancy defects, superior to other cobalt-based catalysts in promoting charge transfer and improving the kinetics of water oxidation. This makes Co−Ci co-catalyst become one of the favorable competitors in the field of photoelectric catalysis.
研究领域:
材料科学
·
电化学
·
能源转换与存储
✓ 已验证
DOI
DIAMOND AND RELATED MATERIALS
·
2026
·
IF 5.2
Yuchen Zhang,Yuying Feng,Miao Zhang,Zhiwei Yu,Xian Sun,Li Zhang
The Ni@SNC catalyst was prepared through a two-step pyrolysis-solvothermal method. • Sulfur species selectively etched amorphous carbon layers, exposing more active sites during doping. • Sulfur, as a doping atom, modulated the electronic structure of the active sites and enhanced the CO 2 RR performance. • The Ni@SNC catalyst achieved a maximum FE CO of 94.6%, with a current density of 13.4 mA cm -2 at this point. Utilizing renewable energy to catalyze the reduction of CO 2 into diverse high-value products represents an effective pathway for mitigating carbon emissions. Nickel-based catalysts benefit from natural abundance and low cost. Moreover, their CO 2 activation capability and *CO desorption characteristics can be optimized through rational structural design to modulate the adsorption energy of reaction intermediates. These properties make them viable alternatives to noble metal catalysts. In this study, a two-step method termed “pyrolysis-doping” was employed to synthesize the Ni@SNC catalyst, which consists of small-sized Ni nanoparticles supported on S N co-doped carbon, facilitating efficient electrocatalytic CO 2 reduction reaction (CO 2 RR). In the Ni@SNC structure, the coordination of surface Ni nanoparticles with N generates active sites, while S doping modulates the electronic state of these sites to optimize the adsorption of *COOH and the desorption of *CO. Performance tests indicated that Ni@SNC achieved a maximum CO Faradaic efficiency (FE CO ) of 94.6% at −0.9 V (vs. RHE), with a corresponding CO partial current density (j CO ) of 13.4 mA cm −2 , while exhibiting excellent stability during an extended electrolysis. Various characterizations and experiments have shown that S doping selectively etched the carbon layer, thereby increasing the electrochemically active area (ECSA). Furthermore, S doping modulated the electronic configuration of Ni N sites, enhancing the balance between adsorption and desorption of reaction intermediates. This work thus provides a new design method for creating efficient and stable non-precious metal CO 2 reduction catalysts. Download: Download high-res image (149KB) Download: Download full-size image
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高影响因子
Nature Communications
·
2023
·Vol. 14
·期 1
·1-12
·
IF 16.6
Chen Jianjun,Xiong Shangchao,Liu Haiyan,Shi Jianqiang,Mi Jinxing,Liu Hao,Gong Zhengjun,Oliviero Laetitia,Maugé Françoise,Li Junhua
The spillover of oxygen species is fundamentally important in redox reactions, but the spillover mechanism has been less understood compared to that of hydrogen spillover. Herein Sn is doped into TiO 2 to activate low-temperature (<100 °C) reverse oxygen spillover in Pt/TiO 2 catalyst, leading to CO oxidation activity much higher than that of most oxide-supported Pt catalysts. A combination of near-ambient-pressure X-ray photoelectron spectroscopy, in situ Raman/Infrared spectroscopies, and ab initio molecular dynamics simulations reveal that the reverse oxygen spillover is triggered by CO adsorption at Pt 2+ sites, followed by bond cleavage of Ti-O-Sn moieties nearby and the appearance of Pt 4+ species. The O in the catalytically indispensable Pt-O species is energetically more favourable to be originated from Ti-O-Sn. This work clearly depicts the interfacial chemistry of reverse oxygen spillover that is triggered by CO adsorption, and the understanding is helpful for the design of platinum/titania catalysts suitable for reactions of various reactants.
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高影响因子
JOURNAL OF POLYMER RESEARCH
·
2012
·Vol. 19
·期 11
·1-7
·
IF 1.733
Yu Wei-Na,Liu Shou-Xin,Wang Hong-Mei,Tian Rong
Temperature-responsive P(NIPAM- co -HMAM)- b -PEO- b -P(NIPAM- co -HMAM) triblock copolymers were synthesized by an atomic transfer radical polymerization (ATRP) method without freeze–pump–thaw cycles. The composition, structure, and molecular weight of the synthesized block copolymer were characterized by 1 H NMR and GPC. The phase transitions induced by temperature for different copolymers in dilute aqueous solutions have been studied using transmittance measurements, laser particle size measurements, viscosity analysis, and surface tension measurement, which showed that the HMAM content and the PEO (or PEG) chain length in the synthesized triblock copolymer affects the copolymer’s lower critical solution temperature (LCST). The micellization behavior of each temperature-responsive triblock copolymer was investigated by fluorescence probe measurements and transmission electron microscopy (TEM), which showed that the triblock copolymers form stable micelles above the LCST. The introduction of the HMAM component and the formation of micelles represent the first steps in the development of an injectable gel that forms in situ through chemical and physical crosslinking.
研究领域:
高分子化学
·
生物材料
·
药物递送系统
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高影响因子
RSC Advances
·
2023
·Vol. 13
·期 13
·8901-8914
·
IF 3.9
Xinkuai He,Zhousi Hu,Qingtian Zou,Jingjing Yang,Ruqing Guo,Luye Wu
The preparation of active, stable and low-cost non-noble electrocatalysts for the hydrogen evolution reaction (HER) using the electrochemical water splitting process is crucial for the promotion of sustainable energy. In this study, Co–Ni alloys with various Co contents are prepared using a galvanostatic method and the co-deposition behavior of Co2+ and Ni2+ in ethylene glycol (EG) is reported. These results indicate that the presence of additional Ni2+ species can accelerate the Co–Ni co-deposition process and Co2+ species in the system can inhibit the reduction of Ni2+. Moreover, the two effects are improved with an increase in Ni2+ or Co2+ species concentration in the EG system, respectively. Chronoamperometry records show that the Co–Ni electro-crystallization mechanism is one of 3D instantaneous nucleation and growth. Moreover, the Co–Ni alloy with 59.46 wt% Co exhibits high electrocatalytic activity for HER with an overpotential of 133 mV at 10 mA cm−2 in 1 M KOH due to a high value of electrochemical active surface area (ECSA) (955.0 cm2). Therefore, the Co–Ni alloy electrocatalyst obtained from the EG system could be a promising candidate for practical hydrogen production.
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PubMed
高影响因子
JOURNAL OF DRUG DELIVERY SCIENCE AND TECHNOLOGY
·
2022
·
IF 5.062
Hao Wu,Jia Ma,Shuaiqi Qian,Wenhao Jiang,Yuxi Liu,Jingjuan Li,Zhongcheng Ke,Kai Feng
The co-amorphous system is an efficacious approach in enhancing the solubility and dissolution of insoluble drugs. Several small molecules, such as organic acids, amino acids, and organic amines, are commonly used ligands to prepare co-amorphous systems. In this study, a co-amorphous system of posaconazole (POS), a weakly alkaline insoluble drug, with citric acid (CA) was prepared by the solvent evaporation method. An amorphous solid dispersion (ASD) of POS-VA64 was also prepared for comparison. Powder X-ray diffraction pattern and scanning electron microscopy indicated that POS exists in an amorphous form in the POS-CA and POS-VA64 groups. Fourier-transform infrared spectroscopy showed that an intermolecular hydrogen bonding was formed between POS and CA in the co-amorphous system. The amorphous state of POS exhibited increased solubility and dissolution, and the POS-CA form showed the best solubility and dissolution, which may be attributed to the amorphization and acidic environment provided by CA. In addition, the pharmacokinetic study and stability test of the POS-CA form showed superior performance. Therefore, the rational use of small-molecule ligands to prepare co-amorphous compounds can significantly improve the properties of drugs.
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