scholarly journals Recent Developments in All-Solid-State Micro-Supercapacitors Based on Two-Dimensional Materials

2020 ◽  
Author(s):  
Minu Mathew ◽  
Sithara Radhakrishnan ◽  
Chandra Sekhar Rout

Owing to their unique features such as high surface area, rich electroactive sites, ultrathin thickness, excellent flexibility and mechanical stability and multiple surface functionalities enables outstanding electrochemical response which provides high energy and power density supercapacitors based on them. Also, the Van der Waals gap between layered 2D materials encourages the fast ion transport with shorter ion diffusion path. 2D materials such as MXenes, graphene, TMDs, and 2D metal–organic frame work, TMOs/TMHs materials, have been described with regard to their electrochemical properties for MSCs. We have summarized the recent progress in MSC based on well-developed 2D materials-based electrodes and its potential outcomes with different architectures including interdigitated pattern, stacked MSC and 3D geometries for on-chip electronics. This chapter provides a brief overview of the recent developments in the field of 2D material based all-solid-state microsupercapacitors (MSCs). A brief note on the MSC device configuration and microfabrication methods for the microelectrodes have been discussed. Taking advantage of certain 2D materials such as 2D MXenes, TMDs, TMOs/TMHs that provide good surface chemistry, tunable chemical and physical properties, intercalation, surface modification (functionalization), heterostructures, phase transformations, defect engineering etc. are beneficial for enhancement in pseudocapacitance as it promotes the redox activity.

2020 ◽  
Vol 16 (4) ◽  
pp. 617-624 ◽  
Author(s):  
Yao Feng ◽  
Ran Wang ◽  
Juanjuan Yin ◽  
Fangke Zhan ◽  
Kaiyue Chen ◽  
...  

Background: 4-nitrophenol (4-NP) is one of the pollutants in sewage and harmful to human health and the environment. Cu is a non-noble metal with catalytic reduction effect on nitro compounds, and.has the advantages of simple preparation, abundant reserves, and low price. Carbon nanotubes (CNT) are widely used for substrate due to their excellent mechanical stability and high surface area. In this study, a simple method to prepare CNT-Cu2O by controlling different reaction time was reported. The prepared nanocomposites were used to catalyze 4-NP. Methods: CNTs and CuCl2 solution were put into a beaker, and then ascorbic acid and NaOH were added while continuously stirring. The reaction was carried out for a sufficiently long period of time at 60°C. The prepared samples were dried in a vacuum at 50°C for 48 h after washing with ethyl alcohol and deionized water. Results: Nanostructures of these composites were characterized by scanning electron microscope and transmission electron microscopy techniques, and the results at a magnification of 200 nanometers showed that Cu2O was distributed on the surface of the CNTs. In addition, X-ray diffraction was performed to further confirm the formation of Cu2O nanoparticles. The results of ultraviolet spectrophotometry showed that the catalytic effect of the compound on 4-NP was obvious. Conclusions: CNTs acted as a huge template for loading Cu2O nanoparticles, which could improve the stability and cycle performance of Cu2O. The formation of nanoparticles was greatly affected by temperature and the appropriate concentration, showing great reducibility for the 4-NP reduction reaction.


Catalysts ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1232
Author(s):  
Simin Arshi ◽  
Mehran Nozari-Asbemarz ◽  
Edmond Magner

Biocatalysts provide a number of advantages such as high selectivity, the ability to operate under mild reaction conditions and availability from renewable resources that are of interest in the development of bioreactors for applications in the pharmaceutical and other sectors. The use of oxidoreductases in biocatalytic reactors is primarily focused on the use of NAD(P)-dependent enzymes, with the recycling of the cofactor occurring via an additional enzymatic system. The use of electrochemically based systems has been limited. This review focuses on the development of electrochemically based biocatalytic reactors. The mechanisms of mediated and direct electron transfer together with methods of immobilising enzymes are briefly reviewed. The use of electrochemically based batch and flow reactors is reviewed in detail with a focus on recent developments in the use of high surface area electrodes, enzyme engineering and enzyme cascades. A future perspective on electrochemically based bioreactors is presented.


1989 ◽  
Vol 111 (3) ◽  
pp. 394-397 ◽  
Author(s):  
M. S. Hossain ◽  
M. Neyman ◽  
W. J. Cook ◽  
A. Z. Gordon

Solid-state electrochemical technology, embodied in the IGR process, is used to reduce nitrogen oxides (NOx) to nitrogen and oxygen, and thereby control NOx emissions from natural gas powered engines. The IGR deNOx process is based on solid-state, flow-through, high surface area, porous oxygen ion conductive ceramic electrolytes. Recent bench-scale experiments conducted for the Gas Research Institute have demonstrated NOx reduction in multicomponent gas streams, the inert portion of which simulate natural gas combustion products. The reduction products were analyzed by in situ gas chromatography to verify NOx reduction rates inferred from electrochemical measurements. IGR process advantages compared with existing NOx control technologies are reviewed.


Nanomaterials ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 297 ◽  
Author(s):  
Jin-Ho Lee ◽  
Soo-jeong Park ◽  
Jeong-Woo Choi

Graphene, a single atom thick layer of two-dimensional closely packed honeycomb carbon lattice, and its derivatives have attracted much attention in the field of biomedical, due to its unique physicochemical properties. The valuable physicochemical properties, such as high surface area, excellent electrical conductivity, remarkable biocompatibility and ease of surface functionalization have shown great potentials in the applications of graphene-based bioelectronics devices, including electrochemical biosensors for biomarker analysis. In this review, we will provide a selective overview of recent advances on synthesis methods of graphene and its derivatives, as well as its application to electrochemical biosensor development. We believe the topics discussed here are useful, and able to provide a guideline in the development of novel graphene and on graphene-like 2-dimensional (2D) materials based biosensors in the future.


2007 ◽  
Vol 2 (2) ◽  
pp. 204-208 ◽  
Author(s):  
Hongbo Guan ◽  
Pei Wang ◽  
Biying Zhao ◽  
Yuexiang Zhu ◽  
Youchang Xie

2016 ◽  
Vol 81 ◽  
pp. 347-364 ◽  
Author(s):  
Dimitris S. Achilias ◽  
Kostas Gerakis ◽  
Dimitrios J. Giliopoulos ◽  
Kostas S. Triantafyllidis ◽  
Dimitrios N. Bikiaris

2014 ◽  
Vol 172 ◽  
pp. 521-532 ◽  
Author(s):  
Patrick R. Unwin

This contribution provides a personal overview and summary of Faraday Discussion 172 on “Carbon in Electrochemistry”, covering some of the key points made at the meeting within the broader context of other recent developments on carbon materials for electrochemical applications. Although carbon electrodes have a long history of use in electrochemistry, methods and techniques are only just becoming available that can test long-established models and identify key features for further exploration. This Discussion has highlighted the need for a better understanding of the impact of surface structure, defects, local density of electronic states, and surface functionality and contamination, in order to advance fundamental knowledge of various electrochemical processes and phenomena at carbon electrodes. These developments cut across important materials such as graphene, carbon nanotubes, conducting diamond and high surface area carbon materials. With more detailed pictures of structural and electronic controls of electrochemistry at carbon electrodes (and electrodes generally), will come rational advances in various technological applications, from sensors to energy technology (particularly batteries, supercapacitors and fuel cells), that have been well-illustrated at this Discussion.


Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 3638 ◽  
Author(s):  
Maurizio Donarelli ◽  
Luca Ottaviano

After the synthesis of graphene, in the first year of this century, a wide research field on two-dimensional materials opens. 2D materials are characterized by an intrinsic high surface to volume ratio, due to their heights of few atoms, and, differently from graphene, which is a semimetal with zero or near zero bandgap, they usually have a semiconductive nature. These two characteristics make them promising candidate for a new generation of gas sensing devices. Graphene oxide, being an intermediate product of graphene fabrication, has been the first graphene-like material studied and used to detect target gases, followed by MoS2, in the first years of 2010s. Along with MoS2, which is now experiencing a new birth, after its use as a lubricant, other sulfides and selenides (like WS2, WSe2, MoSe2, etc.) have been used for the fabrication of nanoelectronic devices and for gas sensing applications. All these materials show a bandgap, tunable with the number of layers. On the other hand, 2D materials constituted by one atomic species have been synthetized, like phosphorene (one layer of black phosphorous), germanene (one atom thick layer of germanium) and silicone (one atom thick layer of silicon). In this paper, a comprehensive review of 2D materials-based gas sensor is reported, mainly focused on the recent developments of graphene oxide, exfoliated MoS2 and WS2 and phosphorene, for gas detection applications. We will report on their use as sensitive materials for conductometric, capacitive and optical gas sensors, the state of the art and future perspectives.


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