scholarly journals Electrochemical Response of Glucose Oxidase Adsorbed on Laser-Induced Graphene

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1893
Author(s):  
Sónia O. Pereira ◽  
Nuno F. Santos ◽  
Alexandre F. Carvalho ◽  
António J. S. Fernandes ◽  
Florinda M. Costa
Keyword(s):  
Electron Transfer ◽  
Glucose Oxidase ◽  
Ph Dependence ◽  
High Surface ◽  
High Surface Area ◽  
Cost Effective ◽  
Great Promise ◽  
Glucose Detection ◽  
Half Wave ◽  
Electrochemical Transducers

Carbon-based electrodes have demonstrated great promise as electrochemical transducers in the development of biosensors. More recently, laser-induced graphene (LIG), a graphene derivative, appears as a great candidate due to its superior electron transfer characteristics, high surface area and simplicity in its synthesis. The continuous interest in the development of cost-effective, more stable and reliable biosensors for glucose detection make them the most studied and explored within the academic and industry community. In this work, the electrochemistry of glucose oxidase (GOx) adsorbed on LIG electrodes is studied in detail. In addition to the well-known electroactivity of free flavin adenine dinucleotide (FAD), the cofactor of GOx, at the expected half-wave potential of −0.490 V vs. Ag/AgCl (1 M KCl), a new well-defined redox pair at 0.155 V is observed and shown to be related to LIG/GOx interaction. A systematic study was undertaken in order to understand the origin of this activity, including scan rate and pH dependence, along with glucose detection tests. Two protons and two electrons are involved in this reaction, which is shown to be sensitive to the concentration of glucose, restraining its origin to the electron transfer from FAD in the active site of GOx to the electrode via direct or mediated by quinone derivatives acting as mediators.

Template-free synthesis of nanocage-like g-C3N4 with high surface area and nitrogen defects for enhanced photocatalytic H2 activity

2019 ◽  
Vol 7 (10) ◽  
pp. 5324-5332 ◽  
Author(s):  
Mao Wu ◽  
Yansheng Gong ◽  
Tao Nie ◽  
Jin Zhang ◽  
Rui Wang ◽  
...  
Keyword(s):  
Surface Area ◽  
Carbon Nitride ◽  
High Surface ◽  
High Surface Area ◽  
Cost Effective ◽  
Porous Graphitic Carbon ◽  
Graphitic Carbon ◽  
Graphitic Carbon Nitride ◽  
Template Free

Nanocage-like 3D porous graphitic carbon nitride (g-C3N4) with a high surface area and nitrogen defects was successfully prepared via a novel, template-free, cost-effective and hydrothermal-copolymerization route.

scholarly journals Poly (3, 4-ethylene dioxythiophene) Supported Palladium Catalyst prepared by Galvanic Replacement Reaction for Methanol Tolerant Oxygen Reduction

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Pandia Rajathi M ◽  
Sheela Berchmans
Keyword(s):  
Oxygen Reduction ◽  
Direct Methanol Fuel Cells ◽  
High Surface ◽  
High Surface Area ◽  
Cost Effective ◽  
Reduction Reaction ◽  
Partial Substitution ◽  
Galvanic Replacement ◽  
Potential Cycling ◽  
Electrochemical Approach

AbstractHerein, we propose a facile electrochemical approach for the synthesis of Pd loaded poly 3, 4-ethylenedioxythiophene (PEDOT) electrodeposited on glassy carbon electrode (GCE) resulting in high surface area. The catalyst preparation is initiated with EDOT polymerization on GCE surface by electrochemical potential cycling method, followed by the electrodeposition of Cu from a 2 mM solution of CuSO4 in 0.1 M NaClO4 at a constant potential of +0.34 V vs. SHE in the form of Cu nanocubes on the PEDOT surface. Pd-PEDOT catalyst was then prepared by the partial substitution of copper by galvanic displacement with various concentrations of PdCl2. The prepared Pd/PEDOT electrocatalyst is found to be methanol resistant indicating its usefulness as fuel cell cathode. The prepared catalyst supports two electron transfer of oxygen reduction reaction in 0.5 M H2SO4. The effects of Pd and Cu contents and the quantity of PEDOT, mass and specific activities were studied. At a relatively low Pd loading of 0.57 ng/cm2, the Pd/PEDOT should be a cost-effective alternative cathode catalyst for direct methanol fuel cells, DMFCs. This work explains the usefulness of PEDOT as good catalyst supporting material which is prepared by an eco-friendly electrochemical route.

scholarly journals Electro Spun- Nanofibrous Mats: A Modern Wound Dressing Matrix with a Potential of Drug Delivery and Therapeutics

2015 ◽  
Vol 10 (4) ◽  
pp. 155892501501000 ◽  
Author(s):  
Seham Abdelhady ◽  
Khaled M. Honsy ◽  
Mallesh Kurakula
Keyword(s):  
Healing Process ◽  
High Surface ◽  
High Surface Area ◽  
Electrospun Nanofibers ◽  
Cost Effective ◽  
External Agent ◽  
Masking Agents ◽  
Ordinary Time ◽  
Treatment Of Wounds ◽  
Chemical Materials

Nanofibers have emerged as advanced fibers with broad use and potential in biomedical fields in recent decades. The process of healing is an innate immune response towards a pathophysiology such as wound. Ordinary time taken for wound healing is approximately 2–3 days depending upon the chronic state. Air moisture and microbes risk pathological manifestations leading to delayed or incomplete palliate process. An external agent that can provide balanced moisture, increasing cell proliferation with microbial infiltration or anti- bacterial activity, aids to speed the healing process. Apart from these qualities, an ideal material should be simple, cost effective, and repeatable. Nanofibers produced through electrospinning have become a promising strategy in the treatment of wounds. Apart from being simple in application, they are produced from natural or synthetic polymers. Nanofibers exhibit high surface area, nanoporosity, with a potential to load potent drugs or enzymes. Other biomedical applications include use of nanofibers as tissue scaffolds and as masking agents in modern cosmetics. Therefore nanofibers are excellent candidates for wound treatment and management. The current review is an attempt to discuss and present literature about different techniques, chemical materials, and entities used to produce efficient electrospun nanofibers for use in pathological, medicinal, or treatment or management of injury or laceration.

scholarly journals Highly efficient electrocatalytic hydrogen evolution reaction on carbonized porous conducting polymers

2020 ◽  
Vol 24 (11-12) ◽  
pp. 2763-2771
Author(s):  
Abhishek Lahiri ◽  
Guozhu Li ◽  
Frank Endres
Keyword(s):  
Conducting Polymers ◽  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Rational Design ◽  
High Surface ◽  
High Surface Area ◽  
Fine Tuning ◽  
Great Promise ◽  
Copolymer Composition ◽  
Electrochemical Approach

Abstract A rational design of an efficient and inexpensive electrocatalyst for water splitting still remains a challenge. Porous conducting polymers are attractive materials which not only provide a high surface area for electrocatalysis but also absorb light which can be harnessed in photoelectrocatalysis. Here, a novel and inexpensive electrochemical approach is developed to obtain nanoporous conducting copolymers with tunable light absorbance and porosity. By fine-tuning the copolymer composition and upon heat treatment, an excellent electrocatalytic hydrogen evolution reaction (HER) was achieved in alkaline solution with an overpotential of just 77 mV to obtain a current density of 10 mA cm−2. Such an overpotential is remarkably low compared with other reported values for polymers in an alkaline medium. The nanoporous copolymer developed here shows a great promise of using metal-free electrocatalysts and brings about new avenues for exploitation of these porous conducting polymers.

Conventional to Nano-Green Adsorbents for Water Pollution Management - A Review

2014 ◽  
Vol 925 ◽  
pp. 674-678 ◽  
Author(s):  
Md Eaqub Ali ◽  
Mahbub Ullah ◽  
Sharifah Bee Abd Hamid
Keyword(s):  
Water Pollution ◽  
High Surface ◽  
High Surface Area ◽  
Cost Effective ◽  
Chemical Precipitation ◽  
Surface Reactivity ◽  
Pollutant Removal ◽  
Treatment Techniques ◽  
Water Pollution Management ◽  
Important Position

Pure and clean water is a must for living a healthy life. However, the increasing influence of urbanization, industrialization, domestic and agricultural activities, is continuously adding both conventional and newly emerging pollutants to the earth's water bodies, seriously affecting both the terrestrial and aquatic flora and fauna. Thus water pollution has become a major issue in the global perspectives. In the last few decades, numerous methods, such as chemical precipitation, filtration, oxidation, ion exchange treatment and adsorption have been proposed for the purification of contaminated water. Among these methods, adsorption has taken an important position in water purification technology. This is because of its ease of operations, cost-effective maintenance, and availability of adsorbents in various forms with high surface area, porous structure and specific surface reactivity. Instead of having many attractive properties, many adsorbents have failed to achieve a good acceptability at commercial levels. In the recent years, nanotechnology approaches have introduced nanoadsorbent which is capable of removing water pollutants more efficiently. In this review, various water treatment techniques with their shortcomings followed by efficiency of adsorption and nanoadsorbent for pollutant removal are discussed with green chemistry perspectives.

Multimolecular assemblies on high surface area metal oxides and their role in interfacial energy and electron transfer

2018 ◽  
Vol 47 (1) ◽  
pp. 104-148 ◽  
Author(s):  
Jamie C. Wang ◽  
Sean P. Hill ◽  
Tristan Dilbeck ◽  
Omotola O. Ogunsolu ◽  
Tanmay Banerjee ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Metal Oxides ◽  
Surface Area ◽  
Interfacial Energy ◽  
High Surface ◽  
High Surface Area ◽  
Energy And Electron Transfer ◽  
Molecular Components

High surface area metal oxides offer a unique substrate for the assembly of multiple molecular components at an interface.

Cyclic voltammogram on ridge/pore array architectured electrode inspired by butterfly-wings

2015 ◽  
Vol 87 (8) ◽  
pp. 815-825 ◽  
Author(s):  
Xingmei Guo ◽  
Han Zhou ◽  
Di Zhang ◽  
Tongxiang Fan
Keyword(s):  
Electrode Materials ◽  
High Surface ◽  
High Surface Area ◽  
Lateral Diffusion ◽  
Cost Effective ◽  
Hierarchical Architecture ◽  
Cyclic Voltammogram ◽  
Peak Current Density ◽  
Porous Architecture ◽  
Butterfly Wings

AbstractPorous architectured electrodes are intensely investigated for promoting electrochemical performance. Besides the high surface area, mass transport plays an irreplaceable role in the architecture assisting effect, which is, however, far beyond expression due to the complexity and irregularity of various electrode materials. Here, we took advantage of elaborate architectures from butterfly wings and obtained carbon electrode with ridge/pore array hierarchical architecture (ridge/pore-C) using a carbonizing-graphite coating method. A basic one-electron transfer process using the redox couple ferri/ferrocyanide as a benchmark under cyclic voltammetric conditions was conducted. The peak potential separation for ridge/pore-C was decreased by 117 mV compared to its non-architectured counterpart, with obvious enhancement of peak current density, indicating prominent beneficial impact on electrochemical responses. Further finite element simulation demonstrated the additional lateral diffusion within the ridge domain and partial thin layer diffusion within the pore array domain of ridge/pore-C, and simultaneously verified the experimental results. By constructing and investigating the well-organized porous architecture for affecting cyclic voltammogram, this work provides a prototype and cost-effective method for structural design of efficient electrodes by drawing inspiration from nature.

scholarly journals Design and Modeling of Novel Low-Pressure Nanofiltration Hollow Fiber Modules for Water Softening and Desalination Pretreatment

2018 ◽  
Author(s):  
Omar Labban
Keyword(s):  
Hollow Fiber ◽  
Transport Model ◽  
High Surface ◽  
Scale Up ◽  
High Surface Area ◽  
Volume Ratio ◽  
Low Pressure ◽  
System Level ◽  
Great Promise ◽  
Module Design

Given its high surface area to volume ratio and desirable mass transfer characteristics, the hollow fibermodule configuration has been central to the development of RO and UF technologies over the past fivedecades. Recent studies have demonstrated the development of a novel class of low-pressure nanofiltration(NF) hollow fiber membranes with great promise for scale-up implementation. Further progress on large-scaledeployment, however, has been restrained by the lack of an accurate predictive model, to guide module designand operation. Earlier models targeting hollow fiber modules are only suitable for RO or UF. In this work,we propose a new modeling approach suitable for NF based on the implementation of mass and momentumbalances, coupled with a validated membrane transport model based on the extended Nernst-Planck equationto predict module performance at the system-level. Modeling results are validated with respect to syntheticseawater experiments reported in an earlier work. A preliminary module design is proposed, and parametricstudies are employed to investigate the effect of varying key system parameters and elucidate the tradeoffsavailable during design. The model has significant implications for low-pressure nanofiltration, as well ashollow fiber NF module design and operation.

scholarly journals Iron removal from ground water using Egyptian cost-effective clay minerals

2020 ◽  
Vol 3 (1) ◽  
pp. 23
Author(s):  
Hamdy Maamoun Abdel-Ghafar ◽  
ElSayed Abdel-Aal ◽  
Bahgat El_anadouli
Keyword(s):  
High Surface ◽  
High Surface Area ◽  
Chemical Characterization ◽  
Statistical Design ◽  
Cost Effective ◽  
Iron Removal ◽  
Optimum Conditions ◽  
Physical And Chemical Characterization ◽  
Physical And Chemical

Glauconite and kaolin are used as adsorbent materials for iron removal from synthetic solutions. Different concentrations of iron solutions have been prepared (10, 20 and 30 mg/L). Different dose of glauconite and kaolin were added (0.1, 0.55 and 1.0 g). Statistical design was used to determine the optimum conditions of iron adsorption on glauconite and kaolin. It is shown that glauconite has high adsorption for iron reaching to 95% while kaolin has lower adsorption for iron. Physical and chemical characterization of glauconite and kaolin was tested. High surface area of glauconite (19.8 m2/g) compared to kaolin (5.4 m2/g) explains its high removal efficiency. 

Ultrafine oxygen-defective iridium oxide nanoclusters for efficient and durable water oxidation at high current densities in acidic media

2020 ◽  
Vol 8 (46) ◽  
pp. 24743-24751
Author(s):  
Zhipeng Yu ◽  
Junyuan Xu ◽  
Yifan Li ◽  
Bin Wei ◽  
Nan Zhang ◽  
...  
Keyword(s):  
Oxygen Evolution Reaction ◽  
Water Oxidation ◽  
High Surface ◽  
High Surface Area ◽  
Current Collector ◽  
Cost Effective ◽  
High Current ◽  
Acidic Media ◽  
Cost Effective Approach ◽  
Current Densities

Ultrafine IrOx nanoclusters are immobilized on a hydrothermally treated high-surface-area titanium current collector via a simple and cost-effective approach, showing outstanding performance for the oxygen evolution reaction at high current densities in acidic media.

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