scholarly journals Peroxidase-Like Metal-Based Nanozymes: Synthesis, Catalytic Properties, and Analytical Application

2021 ◽  
Vol 11 (2) ◽  
pp. 777
Author(s):  
Olha Demkiv ◽  
Nataliya Stasyuk ◽  
Roman Serkiz ◽  
Galina Gayda ◽  
Marina Nisnevitch ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Noble Metals ◽  
Catalytic Properties ◽  
High Surface ◽  
High Surface Area ◽  
High Sensitivity ◽  
Analytical Application ◽  
Practical Applications ◽  
Self Assembling ◽  
H2o2 Determination

Nanozymes (NZs) are nanostructured artificial enzymes that mimic catalytic properties of natural enzymes. The NZs have essential advantages over natural enzymes, namely low preparation costs, stability, high surface area, self-assembling capability, size and composition-dependent activities, broad possibility for modification, and biocompatibility. NZs have wide potential practical applications as catalysts in biosensorics, fuel-cell technology, environmental biotechnology, and medicine. Most known NZs are mimetics of oxidoreductases or hydrolases. The present work aimed to obtain effective artificial peroxidase (PO)-like NZs (nanoPOs), to characterize them, and to estimate the prospects of their analytical application. NanoPOs were synthesized using a number of nanoparticles (NPs) of transition and noble metals and were screened for their catalytic activity in solution and on electrodes. The most effective nanoPOs were chosen as NZs and characterized by their catalytic activity. Kinetic parameters, size, and structure of the best nanoPOs (Cu/CeS) were determined. Cu/CeS-based sensor for H2O2 determination showed high sensitivity (1890 A·M−1·m−2) and broad linear range (1.5–20,000 µM). The possibility to apply Cu/CeS-NZ as a selective layer in an amperometric sensor for hydrogen-peroxide analysis of commercial disinfectant samples was demonstrated.

scholarly journals Peroxidase-Like Activity of Ferrihydrite and Hematite Nanoparticles for the Degradation of Methylene Blue

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Nicolaza Pariona ◽  
M. Herrera-Trejo ◽  
J. Oliva ◽  
A. I. Martinez
Keyword(s):  
Methylene Blue ◽  
Catalytic Activity ◽  
Surface Area ◽  
Catalytic Properties ◽  
High Surface ◽  
High Surface Area ◽  
Catalytic Process ◽  
Hematite Nanoparticles ◽  
High Crystallinity ◽  
Average Size

The peroxidase-like catalytic properties of 2-line ferrihydrite (2LFh) and hematite nanoparticles (NPs) for the degradation of methylene blue (MB) were studied. It is highlighted that the hematite NPs were prepared from the transformation of the metastable 2LFh NPs. It was found that the 2LFh NPs exhibited poor crystallinity with an average size of 5 nm, while the hematite NPs exhibited high crystallinity with an average size ofca. 100 nm. It was found that the total degradation of MB occurred for hematite NPs, while only a maximum degradation of 69% was possible for the 2LFh NPs. The Michaelis–Menten parameters indicated that the hematite NPs present higher catalytic activity than the 2LFh NPs at basic pH. It was found that the ordered surface of the hematite NPs has a stronger effect for the degradation of MB than its low surface area. It was concluded that the crystal planes of the hematite NPs affect the catalytic process more significantly than the high surface area of 2LFh NPs.

Evaluation of The Catalytic Activity of A High Surface Area, Regular, Porous Solid Formed From The Clusters of Clusters, MII4O[(CO)9Co3CCO2]6, M = Co, Zn

1992 ◽  
Vol 286 ◽  
Author(s):  
Wei Cen ◽  
Thomas P. Fehlner ◽  
Zbigniew Kalenik ◽  
Eduardo E. Wolf
Keyword(s):  
Catalytic Activity ◽  
Surface Area ◽  
Catalytic Properties ◽  
High Surface ◽  
High Surface Area ◽  
Molecular Clusters ◽  
Porous Solid ◽  
Test Reaction ◽  
Solid Materials ◽  
Highly Porous

ABSTRACTThe discrete molecular clusters of clusters, M1140[(CO)9Co3CCO2]6, M = Co, Zn undergo thermolysis with the production of highly porous solid materials. Evaluation of the catalytic properties of these materials has been investigated using the hydrogenation of 1,3- butadiene as a test reaction. These experiments suggest it is the unique structure of the porous materials that is responsible for the high activities and the selectivities observed.

scholarly journals Fabrication of Ni-Based Bimodal Porous Catalyst for Dry Reforming of Methane

Catalysts ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1220
Author(s):  
Linghui Lyu ◽  
Yunxing Han ◽  
Qingxiang Ma ◽  
Shengene Makpal ◽  
Jian Sun ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Noble Metals ◽  
Carbon Deposition ◽  
Physical Adsorption ◽  
High Surface ◽  
High Surface Area ◽  
Dry Reforming ◽  
Dry Reforming Of Methane ◽  
Porous Catalyst ◽  
Temperature Programmed

Dry reforming of methane (DRM) can effectively convert two greenhouse gases into high-valued chemicals, in which the syngas produced by the reaction can be directly used as raw gases for Fischer–Tropsch synthesis and methanol synthesis. Ni-based catalysts for the DRM reaction with comparable initial activity to noble metals are the focus of most researchers, but their poor carbon deposition resistance easily causes their low stability. More importantly, the nickel loading will affect the catalytic activity and carbon deposition resistance of the catalyst. Herein, a series of Ni/Al2O3 catalysts with bimodal pores was prepared and characterized by X-ray diffraction (XRD), N2 physical adsorption–desorption, H2-temperature programmed reduction (H2-TPR), temperature programmed hydrogenation (TPH), Raman, and thermogravimetric analysis (TG). The results show that the interesting bimodal structure catalysts could provide a high surface area and contribute to the mass transfer. Besides, the catalytic performance of the DRM reaction is sensitive to nickel loadings. In this study, the Ni/Al2O3 catalyst with nickel loadings of 6% and 8% exhibited excellent catalytic activity and carbon deposition resistance. These findings will provide a new strategy to design a highly efficient and stable heterogeneous catalyst for industry.

scholarly journals Flower-Shaped C-Dots/Co3O4{111} Constructed with Dual-Reaction Centers for Enhancement of Fenton-Like Reaction Activity and Peroxymonosulfate Conversion to Sulfate Radical

Catalysts ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 135
Author(s):  
Zhibin Wen ◽  
Qianqian Zhu ◽  
Jiali Zhou ◽  
Shudi Zhao ◽  
Jinnan Wang ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Active Site ◽  
High Surface ◽  
High Surface Area ◽  
Reaction Centers ◽  
Organic Radicals ◽  
The Other ◽  
High Catalytic Activity ◽  
High Adsorption ◽  
High Turnover

Novel flower-shaped C-dots/Co3O4{111} with dual-reaction centers were constructed to improve the Fenton-like reaction activity and peroxymonosulfate (PMS) conversion to sulfate radicals. Due to the exposure of a high surface area and Co3O4{111} facets, flower-shaped C-dots/Co3O4{111} could provide more Co(II) for PMS activation than traditional spherical Co3O4{110}. Meanwhile, PMS was preferred for adsorption on Co3O4{111} facets because of a high adsorption energy and thereby facilitated the electron transfer from Co(II) to PMS. More importantly, the Co–O–C linkage between C-dots and Co3O4{111} induced the formation of the dual-reaction center, which promoted the production of reactive organic radicals (R•). PMS could be directly reduced to SO4−• by R• over C-dots. On the other hand, electron transferred from R• to Co via Co–O–C linkage could accelerate the redox of Co(II)/(III), avoiding the invalid decomposition of PMS. Thus, C-dots doped on Co3O4{111} improved the PMS conversion rate to SO4−• over the single active site, resulting in high turnover numbers (TONs). In addition, TPR analysis indicated that the optimal content of C-dots doped on Co3O4{111} is 2.5%. More than 99% of antibiotics and dyes were degraded over C-dots/Co3O4{111} within 10 min. Even after six cycles, C-dots/Co3O4{111} still remained a high catalytic activity.

scholarly journals High surface area nitrogen-functionalized Ni nanozymes for efficient peroxidase-like catalytic activity

PLoS ONE ◽  
2021 ◽  
Vol 16 (10) ◽  
pp. e0257777
Author(s):  
Anuja Tripathi ◽  
Kenneth D. Harris ◽  
Anastasia L. Elias
Keyword(s):  
Catalytic Activity ◽  
Plasma Treatment ◽  
Surface Composition ◽  
Point Of Care ◽  
High Surface ◽  
Effective Means ◽  
High Surface Area ◽  
Catalytic Performance ◽  
Optimal Time ◽  
Ammonia Plasma

Nitrogen-functionalization is an effective means of improving the catalytic performances of nanozymes. In the present work, plasma-assisted nitrogen modification of nanocolumnar Ni GLAD films was performed using an ammonia plasma, resulting in an improvement in the peroxidase-like catalytic performance of the porous, nanostructured Ni films. The plasma-treated nanozymes were characterized by TEM, SEM, XRD, and XPS, revealing a nitrogen-rich surface composition. Increased surface wettability was observed after ammonia plasma treatment, and the resulting nitrogen-functionalized Ni GLAD films presented dramatically enhanced peroxidase-like catalytic activity. The optimal time for plasma treatment was determined to be 120 s; when used to catalyze the oxidation of the colorimetric substrate TMB in the presence of H2O2, Ni films subjected to 120 s of plasma treatment yielded a much higher maximum reaction velocity (3.7⊆10−8 M/s vs. 2.3⊆10−8 M/s) and lower Michaelis-Menten coefficient (0.17 mM vs. 0.23 mM) than pristine Ni films with the same morphology. Additionally, we demonstrate the application of the nanozyme in a gravity-driven, continuous catalytic reaction device. Such a controllable plasma treatment strategy may open a new door toward surface-functionalized nanozymes with improved catalytic performance and potential applications in flow-driven point-of-care devices.

scholarly journals Characterization of Ag:Zno Thin Films and Their Use in Photoelectrocatalytic Degradation Of Methylene Blue (Mb)

2018 ◽  
Vol 22 (2) ◽  
pp. 109-116
Author(s):  
Bhishma Karki ◽  
Jeevan Jyoti Nakarmi ◽  
Rhiddi Bir Singh ◽  
Manish Banerjee
Keyword(s):  
Noble Metals ◽  
Spray Pyrolysis Technique ◽  
High Surface ◽  
High Surface Area ◽  
Nano Particles ◽  
Mixed Metal Oxide ◽  
Design And Synthesis ◽  
In Situ Deposition ◽  
Photoelectrocatalytic Degradation ◽  
Challenges And Opportunities

The synthesis of functional nano-particles via spray pyrolysis technique (SPT), especially those of catalytic nature, has attracted the interests of scientists and engineers, as well as industries. The rapid and high temperature continuous synthesis yields nano-particles with intrinsic features of active catalysts, that is, high surface area and surface energetic. For these reasons, SPT finds applications in various thermally inducible catalytic reactions. However, the design and synthesis of photocatalysts by SPT requires a knowledge set which is different from that established for thermal catalysts. Unknown to many, this has resulted in frustrations to those entering the field unprepared, especially since SPT appears to be an elegant tool in synthesizing oxide nano-particles of any elemental construct. From simple oxide to doped-oxide, and mixed metal oxide to the in situ deposition of noble metals, this Perspective gives an overview on the development of photocatalysts made by SPT in the last decade that led to a better understanding of the design criteria. Various challenges and opportunities are also highlighted; especially those beyond simple metal oxides, which perhaps contain the greatest potential for the exploitation of photocatalysts design by SPT. Journal of Institute of Science and TechnologyVolume 22, Issue 2, January 2018, Page: 109-116

scholarly journals Solid State Electronic Sensors for Detection of Carbon Dioxide

Sensors ◽  
2019 ◽  
Vol 19 (18) ◽  
pp. 3848 ◽  
Author(s):  
Ami Hannon ◽  
Jing Li
Keyword(s):  
Carbon Dioxide ◽  
Iron Oxide ◽  
High Surface ◽  
High Surface Area ◽  
Multiwall Carbon Nanotubes ◽  
High Sensitivity ◽  
Space Applications ◽  
Detection Range ◽  
Ultra Low Power ◽  
Compact Size

Detection of carbon dioxide (CO2) is very important for environmental, health, safety and space applications. We have studied novel multiwall carbon nanotubes (MWCNTs) and an iron oxide (Fe2O3) nanocomposite based chemiresistive sensor for detection of CO2 at room temperature. The sensor has been miniaturized to a chip size (1 cm × 2 cm). Good sensing performance was observed with a wide detection range of CO2 concentrations (100–6000 ppm). Structural properties of the sensing materials were characterized using Field-Emission Scanning Electron Microscopy, Fourier-Transform Infrared and Raman spectroscopies. The greatly improved sensitivity of the composite materials to CO2 can be attributed to the formation of a depletion layer at the p-n junction in an MWCNT/iron oxide heterostructure, and new CO2 gas molecules adhere to the high surface area of MWCNTs due to the concentration gradient. The test results showed that the CO2 sensor possesses fast response, compact size, ultra-low power consumption, high sensitivity and wide dynamic detection range.

scholarly journals An Efficient Electrochemical Sensor Driven by Hierarchical Hetero-Nanostructures Consisting of RuO2 Nanorods on WO3 Nanofibers for Detecting Biologically Relevant Molecules

Sensors ◽  
2019 ◽  
Vol 19 (15) ◽  
pp. 3295 ◽  
Author(s):  
Hyerim Lee ◽  
Yeomin Kim ◽  
Areum Yu ◽  
Dasol Jin ◽  
Ara Jo ◽  
...  
Keyword(s):  
Tungsten Trioxide ◽  
High Surface ◽  
High Surface Area ◽  
High Sensitivity ◽  
Annealing Process ◽  
Electrochemical Sensing ◽  
Biologically Relevant ◽  
Sensing Platform ◽  
Thermal Annealing Process ◽  
Biologically Relevant Molecules

By means of electrospinning with the thermal annealing process, we investigate a highly efficient sensing platform driven by a hierarchical hetero-nanostructure for the sensitive detection of biologically relevant molecules, consisting of single crystalline ruthenium dioxide nanorods (RuO2 NRs) directly grown on the surface of electrospun tungsten trioxide nanofibers (WO3 NFs). Electrochemical measurements reveal the enhanced electron transfer kinetics at the prepared RuO2 NRs-WO3 NFs hetero-nanostructures due to the incorporation of conductive RuO2 NRs nanostructures with a high surface area, resulting in improved relevant electrochemical sensing performances for detecting H2O2 and L-ascorbic acid with high sensitivity.

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