scholarly journals Dechlorination of Environmental Contaminants Using a Hybrid Nanocatalyst: Palladium Nanoparticles Supported on Hierarchical Carbon Nanostructures

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Hema Vijwani ◽  
Abinash Agrawal ◽  
Sharmila M. Mukhopadhyay

This paper demonstrates the effectiveness of a new type of hybrid nanocatalyst material that combines the high surface area of nanoparticles and nanotubes with the structural robustness and ease of handling larger supports. The hybrid material is made by fabricating palladium nanoparticles on two types of carbon supports: as-received microcellular foam (Foam) and foam with carbon nanotubes anchored on the pore walls (CNT/Foam). Catalytic reductive dechlorination of carbon tetrachloride with these materials has been investigated using gas chromatography. It is seen that while both palladium-functionalized carbon supports are highly effective in the degradation of carbon tetrachloride, the rate of degradation is significantly increased with palladium on CNT/Foam. However, there is scope to increase this rate further if the wettability of these structures can be enhanced in the future. Microstructural and spectroscopic analyses of the fresh and used catalysts have been compared which indicates that there is no change in density or surface chemical states of the catalyst after prolonged use in dechlorination test. This implies that these materials can be used repeatedly and hence provide a simple, powerful, and cost-effective approach for dechlorination of water.

2020 ◽  
Vol 8 (46) ◽  
pp. 24743-24751
Author(s):  
Zhipeng Yu ◽  
Junyuan Xu ◽  
Yifan Li ◽  
Bin Wei ◽  
Nan Zhang ◽  
...  

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.


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

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.


Catalysts ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1385
Author(s):  
Botagoz Zhuman ◽  
Shaheen Fatima Anis ◽  
Saepurahman ◽  
Gnanapragasam Singravel ◽  
Raed Hashaikeh

Zeolite-based catalysts are usually utilized in the form of a composite with binders, such as alumina, silica, clay, and others. However, these binders are usually known to block the accessibility of the active sites in zeolites, leading to a decreased effective surface area and agglomeration of zeolite particles. The aim of this work is to utilize carbon nanostructures (CNS) as a binding material for nano-zeolite-Y particles. The unique properties of CNS, such as its high surface area, thermal stability, and flexibility of its fibrous structure, makes it a promising material to hold and bind the nano-zeolite particles, yet with a contemporaneous accessibility of the reactants to the porous zeolite structure. In the current study, a nano-zeolite-Y/CNS composite catalyst was fabricated through a ball milling approach. The catalyst possesses a high surface area of 834 m2/g, which is significantly higher than the conventional commercial cracking catalysts. Using CNS as a binding material provided homogeneous distribution of the zeolite nanoparticles with high accessibility to the active sites and good mechanical stability. In addition, CNS was found to be an effective binding material for nano-zeolite particles, solving their major drawback of agglomeration. The nano-zeolite-Y/CNS composite showed 80% conversion for hexadecane catalytic cracking into valuable olefins and hydrogen gas, which was 14% higher compared to that of pure nano-zeolite-Y particles.


2019 ◽  
Vol 7 (10) ◽  
pp. 5324-5332 ◽  
Author(s):  
Mao Wu ◽  
Yansheng Gong ◽  
Tao Nie ◽  
Jin Zhang ◽  
Rui Wang ◽  
...  

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.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Pandia Rajathi M ◽  
Sheela Berchmans

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.


2015 ◽  
Vol 10 (4) ◽  
pp. 155892501501000 ◽  
Author(s):  
Seham Abdelhady ◽  
Khaled M. Honsy ◽  
Mallesh Kurakula

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.


2014 ◽  
Vol 925 ◽  
pp. 674-678 ◽  
Author(s):  
Md Eaqub Ali ◽  
Mahbub Ullah ◽  
Sharifah Bee Abd Hamid

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.


2015 ◽  
Vol 87 (8) ◽  
pp. 815-825 ◽  
Author(s):  
Xingmei Guo ◽  
Han Zhou ◽  
Di Zhang ◽  
Tongxiang Fan

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.


2021 ◽  
Author(s):  
Dang Long Quan ◽  
Phuoc Huu Le

The direct methanol fuel cell (DMFC) is among the most promising alternative energy sources for the near future owing to its advantages of simple construction, compact design, high energy density, and relatively high energy-conversion efficiency. Typically, the electrodes in DMFC is comprised of a Pt-based catalysts supported on great potential of carbon materials such as multi-walled carbon nanotubes (MWCNTs), carbon black (CB), graphene, etc. It is desired to develop an electrode with high surface area, good electrical conductivity and suitable porosity to allow good reactant flux and high stability in the fuel cell environment. This chapter will provide recent advances in Pt-based binary and ternary electrocatalysts on carbon supports for high-performance anodes in DMFC. Through studying the effects of composition-, support-, and shape dependent electrocatalysts, further fundamental understanding and mechanism in the development of anode catalysts for DMFC will be provided in details.


2020 ◽  
Vol 3 (1) ◽  
pp. 23
Author(s):  
Hamdy Maamoun Abdel-Ghafar ◽  
ElSayed Abdel-Aal ◽  
Bahgat El_anadouli

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. 


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