Catalysis Science & Technology
·
2021
·Vol. 11
·期 22
·7467-7474
·
IF 6.119
Yangfan Ming,Gang Li
When Cu–TEPA (Cu2+ coordinated with tetraethylenepentamine) is used as a template in the one-pot synthesis of Cu–SSZ-13, Cu2+ will be reduced to Cu0, resulting in a too high Cu content in the product. Herein, by adding iron complexes to the precursor, the reduction of Cu2+ could be inhibited and FeCu–SSZ-13 samples with rational Cu and Fe contents were prepared by a simple one-pot strategy. Although these samples show high activity in the NH3-SCR at low temperature, their high temperature performance is poor due to the lack of strong NH3 adsorption sites such as Brønsted acid sites. Meanwhile, different iron complexes were used as iron sources to synthesize FeCu–SSZ-13, and among them the sample with sodium nitroprusside shows the highest activity. Due to the large ionic radius of K+, it is easily retained which blocks the pores, so the performance of the samples synthesized with a K-type iron source is poorer than that of their Na-type counterparts. Moreover, the activity of the catalyst synthesized with an Fe3+ source is higher than that synthesized with an Fe2+ source because the valence state of Fe sources has a great influence on the Fe chemical state in the catalysts.
研究领域:
催化化学
·
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2021
·
IF 5.316
Yongwei Zhang,Sining Yun,Xinying Qiao,Menglong Sun,Jiaoe Dang,Changwei Dang,Jingjing Yang
Developing high-performance and low-cost catalysts for replacing Pt-based catalysts is a significant challenge for solar cells and water splitting applications. In this work, a bifunctional hybrid catalyst of MnTa 2 O 6 @MPC (MPC: mesh-like bio-based porous carbon) was synthesized, using a co-precipitation approach. Benefiting from the high specific surface area (332.743 m 2 g −1 ), integrating the merits of the electrical conductivity of MPC, the outstanding electrocatalytic ability of MnTa 2 O 6 , and the synergistic effect between MnTa 2 O 6 and MPC, the catalytic activity of MnTa 2 O 6 @MPC was significantly enhanced. To boost the photovoltaic performance of dye-sensitized solar cells, a novel Cu 2+ /Cu + redox mediator and dye (Y123, D35) were adopted for replacing the traditional I 3 - /I - redox mediator and N719 dye, respectively. The resulting advanced solar cell with the Cu 2+ /Cu + redox mediator based on the MnTa 2 O 6 @MPC counter electrode catalyst exhibited a photovoltage of ~0.88 V, and cell efficiencies of 3.41% and 1.92% for the D35 and Y123 dye systems, respectively, which are respectively 16% and 8% higher than that of Pt. MnTa 2 O 6 @MPC also exhibited significant catalytic ability for hydrogen production, yielding a small overpotential of 141.9 mV at a current density of 10 mA cm −2 and a small Tafel slope of 105.0 mV dec −1 in an alkaline medium. This work provides promising guidance for designing bifunctional hybrid electrocatalysts for high-performance new energy devices.
研究领域:
材料科学
·
能源技术
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2022
·
IF 6.371
Ruobing Zhao,Zhuangzhuang Liu,Zhihao Zhang
In this work, copper/reduced graphene oxide (Cu/RGO) mixed powders were produced by using hydrogen-reduction (H 2 reduction) with graphene oxide (GO) and copper oxide powders as raw materials. The Cu/RGO composite was sintered through spark plasma sintering (SPS). The effects of RGO content and sintering conditions on the relative density, hardness and electrical conductivity of the composite were investigated. The results show that the GO and copper oxide powder can be reduced via H 2 reduction when sintered at 500 °C for 8 h. Moreover, as the content of RGO increases from 0 wt% to 0.67 wt%, the hardness and electrical conductivity increases firstly and then decrease. When the content of RGO is 0.33 wt%, the hardness and electrical conductivity of the composite reach the maximum, i.e., 98.6 HV and 80.5% IACS (International Annealed Copper Standard) respectively. The hardness and electrical conductivity are maximum for the composite sintered at 600 °C for 8 h. Further increase in sintering temperature lowers the properties of the composite. The Cu/RGO composites sintered at 600 °C achieved a relative density of 95.56%, with the high hardness of 193.9 HV and electrical conductivity of 89.8% IACS.
研究领域:
材料科学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
Analytical Methods
·
2022
·Vol. 14
·期 27
·2703-2713
·
IF 3.532
Min Wang,Mingzhe Jiang,Xiaochen Liao,Xiao Wang,Wenjing Lai,Pengli Li,Jiajia Li,Chenglin Hong,Yu Qi
The effective amplification of the signal is the prerequisite for the ultrasensitive detection of electrochemical immunosensors. To quantitatively detect alpha-fetoprotein (AFP), we prepared a sandwich-type electrochemical immunosensor. Using a gold nanoparticles (Au NPs) modified glassy carbon electrode (GCE) as the sensing platform and Cu/Cu2O-rGO@Au as the signal label, differential pulse voltammetry (DPV) was used to achieve sensitive detection of AFP. We found that the nanomaterials can undergo electro-oxidation and electro-reduction reactions between Cu(I) and Cu(II) in a buffer solution of pH = 6.0. It is worth mentioning that the incorporation of metals into metal oxide substrates is a new strategy to combine the catalytic activity of metal oxides with the electrical conductivity of metals. Reduced graphene oxide (rGO), which is rich in oxygen-containing groups, can load more Cu/Cu2O and Au NPs and increase the conductivity. The modification of Au NPs makes them have better biocompatibility and conductivity. Under the best detection conditions, the prepared immunosensor realizes the specific and ultrasensitive detection of AFP. The detection range is 0.01–50 ng mL−1 and the limit of detection (LOD) was as low as 0.589 pg mL−1 (S/N = 3); meanwhile it also has good practical application ability. Therefore, this immunosensor provides an important means for the early screening and detection of AFP.
研究领域:
生物医学工程
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MICROCHEMICAL JOURNAL
·
2022
·
IF 5.304
Li Fu,Qingmei Chen,Suqi Deng,Li Jia
An economical and label-free fluorescent sensor was developed for the selective detection of Escherichia coli ( E. coli ) based on the competitive reduction of Cu 2+ in CuFe 2 O 4 magnetic particles (MPs) by E. coli and o -phenylenediamine (OPD). Cu 2+ in CuFe 2 O 4 MPs can oxidize OPD to generate 2,3-diaminophenazine (OPDox) with fluorescent property. The presence of E. coli can weaken the oxidative ability of CuFe 2 O 4 MPs toward OPD owing to the copper reductase activity of NADH dehydrogenase-2 (NDH-2) in E. coli . NDH-2 can reduce Cu 2+ to Cu + , thereby inhibiting the OPD oxidation and resulting in the decrease of the fluorescence of the system. Under the optimum conditions, the fluorescent sensor exhibited a wide linear response to E. coli in the concentration range of 10 3 – 10 6 cfu mL −1 , and the detection limit was calculated to be 5.8 × 10 2 cfu mL −1 . Furthermore, the feasibility of the sensor was verified by successful detection of E. coli in popsicle and swimming pool water samples. More importantly, the sensor utilized the magnetic property of CuFe 2 O 4 MPs to realize the phase separation, thus averting the interference of other impurities in the sample matrix.
研究领域:
分析化学
·
生物技术
·
环境科学
·
微生物学
✓ 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）