Design and construction of low‐cost electrocatalysts with high catalytic activity and long‐term stability is a challenging task in the field of catalysis. Metal‐organic frameworks (MOF) are promising ...candidates as precursor materials in the development of highly efficient electrocatalysts for energy conversion and storage applications. This review starts with a summary of basic concepts and key evaluation parameters involved in the electrochemical water‐splitting reaction. Then, different synthesis approaches reported for the cobalt‐based Zeolitic imidazolate framework (ZIF‐67) and its derivatives are critically reviewed. Additionally, several strategies employed to enhance the electrocatalytic activity and stability of ZIF‐67‐based electrocatalysts are discussed in detail. The present review provides a succinct insight into the ZIF‐67 and its derivatives (oxides, hydroxides, sulfides, selenides, phosphide, nitrides, telluride, heteroatom/metal‐doped carbon, noble metal‐supported ZIF‐67 derivatives) reported for oxygen evolution reaction (OER), hydrogen evolution reaction (HER), and overall water splitting applications. Finally, this review concludes with the associated challenges and the perspectives on developing the best economic, durable electrocatalytic materials.
MOF‐derived electrocatalysts/electrodes have excellent prospects in energy storage and conversion systems. This paper presents an in‐depth review of the application of ZIF‐67‐derived electrocatalysts for OER, HER, and overall water splitting, highlighting experimental and computational results demonstrated in the literature. Recent progress in synthesis routes and strategies used to enhance the electrocatalytic activity of ZIF‐67 derived electrocatalysts is explicitly discussed.
This work demonstrates the synthesis of a switchable single-molecule electrochromic device generated by tethering a viologen onto a poly(ionic liquid) (PIL)
via
an alkyl linker. With the combined ...properties of an electrochromic viologen and an ion conductive PIL in one single molecule, this novel electro-responsive material exhibits multiple functionalities such that it acts both as an electrochrome and an electrolyte.
This work demonstrates the synthesis of a switchable single-molecule electrochromic device generated by tethering a viologen onto a poly(ionic liquid) (PIL)
via
an alkyl linker.
•DMC are commonly used as fuel additive, in electrochemistry and organic synthesis.•This study presents an overview of advances in direct DMC synthesis from CO2 and methanol.•It also summarizes the ...challenges such as necessity of dehydrating agents.•And the uses of various catalysts to address challenges like low yield and thermodynamic limitations.
The present review compiles the recently published literature for the single step dimethyl carbonate (DMC) synthesis from carbon dioxide (CO2) and methanol. The various routes of DMC synthesis are also discussed in short with their advantages and disadvantages in order to distinguish the merits of direct DMC synthesis route. Next, the major applications of DMC such as in electrochemistry, as fuels additive, as solvent and building block in organic synthesis are described. The major problems in the direct DMC synthesis route such as low yield, reaction rate, thermodynamic limitations and hydrolysis of produced DMC are also pointed out. Furthermore, the significance of fabricating an effective dehydrating agent for the removal of water from the reaction is narrated for the enhancement of DMC yield. The type of catalyst materials based on their nature i.e. metal carbonates, tin-based catalysts, metal oxides, organic catalysts and polymer based materials, etc. used for title reaction are separately discussed in details. The varieties of dehydrating agents and their role in DMC production is explained with the help of most recent reported literature.
The involvement of CO
2
as a renewable and abundant feedstock toward a carbon balanced future has led to production of several value-added products. The primary focus in the current effort is to ...assess fixation of CO
2
and epoxides into cyclic carbonates by employing state-of-the-art metal complexes as promising catalytic systems. Our attention is restricted to Earth-abundant metals such as aluminum, cobalt, iron, zinc and few transition metals in association with different ligand skeletons used for the structural construction of the respective complexes. This review sequentially categorizes these complexes and provides a panoramic overview of their selective catalytic activities and mechanistic understandings based on experimental and theoretical evidences.
A series of pyridinium based dicationic C6(Mpy)2, C10(Epy)2, C10(Bpy)2 with traditional counter anions such as Br−, BF4−, PF6− and Tf2N molten salts (ionic liquids) were synthesized. ...1,1(-hexane-1,6-diylbis (3-methylpyridinium) dibromide C6(Mpy)2 (Br)2 used as catalyst for the simple, facile and environmentally benign method for the conversion of carboxylic acids to their corresponding ester. Display omitted
► A set of pyridinium based dicationic ionic liquids were synthesized. ► Dicationic IL C6(Mpy)2 (Br)2 used as catalyst for the esterification of carboxylic acids. ► Reaction carried out under mild reaction conditions and without any additional organic solvent. ► Good yields and high selectivity. ► The dicationic IL recycled and reused.
A series of pyridinium based dicationic C6(Mpy)2, C10(Epy)2, C10(Bpy)2 with traditional counter anions such as Br−, BF4−, PF6− and Tf2N− molten salts (ionic liquids (ILs)) were synthesized. Most of them can be classified as ionic liquids (mp<100°C). Key physicochemical properties, such as melting point, thermal stability and solubility in common solvents were determined. The synthesized dicationic salt 1,1′-hexane-1,6-diylbis (3-methylpyridinium) dibromide tested for the esterification of carboxylic acid derivatives with a variety of alkyl halides in the presence of triethylamine. The esterification was carried out under mild reaction conditions and without any additional organic solvent. The results showed that carboxylic acids were successfully converted into esters with good yields and high selectivity. The produced esters were easily recovered due to immiscibility with the ionic liquid as green reaction medium. The ionic liquid was recycled and reused. Thus, reported dicationic ionic liquid was a promising catalyst for esterification reaction.
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•Spinel type iron cobalt oxide (FeCoO-NF) was successfully grown on Ni-foam.•Composite electrode is binder free with excellent activity for HER and OER.•Water electrolyzer constructed ...using FeCoO-NF reached Id 10mAcm−2 at 1.62V.
Water electrolysis offers an efficient way to store energy derived from renewable sources in the form of hydrogen. However, the practical implication of this technology is hindered by the lack of efficient earth abundant catalyst capable of accelerating both half reaction of water electrolysis. In this regards, herein; we have prepared a highly active composite electrode by depositing hierarchical spinel iron cobalt oxide on the surface of nickel foam. The layered morphology of iron cobalt oxide is ideal for effective transfer of electrolyte and facile dissipation of gaseous product. Moreover, intimate contact between the catalyst and the current collector caused a significant reduction in charge transfer resistance. Consequently, composite electrode displayed enhanced catalytic activity for HER and OER, achieving the benchmark current density of 10mAcm−2 at a low overpotential of 205mV and 244mV respectively. In addition, a two-electrode alkaline water electrolyzer constructed by employing the composite electrode as anode and cathode yielded a current density of 10mAcm−2 at an applied potential of only 1.62V. The long-lasting stability of iron cobalt oxide-Ni foam electrode along with its exceptional catalytic activity makes it a promising alternative to substitute the precious metal catalyst used in commercial water electrolyzer.
In the hospitality sector, it is often believed that giving more power to customers (e.g., “the customer is king”) would enhance the service quality, customer satisfaction, and organizational ...performance. However, it can cause a backlash by excessively elevating the level of the customers’ perceived power, which could result in their power abuse against the employees. Based on the organizational support theory, this research argues that balancing the level of power between the customers and the employees (vs. shifting the power to the customers) can be more effective for improving the perceptions of both the current and the potential employees. The argument is empirically supported by the findings from three studies, which showed that adopting a power-balancing message positively affects the current employees’ perceived organizational support and motivates them to feel obliged to give back to the organization and also potential job applicants’ organizational attraction and the job pursuit intention.
Recent developments on osmotically driven membrane processes (ODMPs), e.g. forward osmosis (FO) and pressure retarded osmosis (PRO), suggest a high viability for clean water and energy production. ...However, membranes used in these processes encounter high internal concentration polarization (ICP), inherent to osmotically driven membranes, which keeps them from delivering optimum performance in terms of water flux. In this study, a nanofiber thin film composite (NTFC) membrane was synthesized. Crosslinked electrospun polyvinyl alcohol (PVA) nanofiber was uniquely found to be a very effective support layer, specifically for FO applications, due to its very low tortuosity, very high porosity and remarkable hydrophilic property. The successfully fabricated composite exhibited a 7–8 times improved FO water flux as compared to a commercially available FO membrane. Ultimately, our membrane displayed a lower structural parameter (S=66±7.9), a measure of ICP condition, compared to previously synthesized NTFC membranes. Based on the performance of our membrane, this hydrophilic nanofiber supported membrane, with further development, has the high potential to be the next-generation FO membrane.
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•Successful polymerization of polyamide on the surface of crosslinked PVA nanofiber substrate•A low, tortuous and very hydrophilic support layer was successfully fabricated.•Water permeability, A, of NC-PVA/PA membrane is 2.4 times higher than HTI-NW membrane.•FO flux of NC-PVA/PA membrane is 7.5 times higher than HTI-NW membrane.•NC-PVA/PA membrane exhibited the lowest S value, 66±7.9μm, in open literature.
In this study, the NiMoO
4
-carbon nanotubes (NiMoO
4
-CNTs) nanocomposite with interesting vertical nanosheet architecture and hierarchical mesoporous surface was synthesized via a simple ...hydrothermal treatment, followed by annealing process. The NiMoO
4
nanoparticles were chemically tailored onto amine functionalized CNT through the reactive –NH
2
group available; this noble electrode design not only resulted to remarkably high specific surface area of 181.88 m
2
g
−1
with numerous numbers of active sites, but also ensured outstanding mechanical and chemical stability that helped retained 91.93% capacity retention even after 5000 continuous cycles at fast scan rate. The fabricated NiMoO
4
-CNT electrode press deposited onto nickel foam substrate obtained specific capacitance of 611.69 F g
−1
and 20.42 W h kg
−1
energy density at 1 A g
−1
current density. Furthermore, the annealing temperature was a critical factor during the synthesis of the modified material as it has direct effect on the structure and crystal phase, as well as to the amount of decomposed CNT; thus, the effect of using low and high annealing temperature towards the electrochemical activity of the modified material was extensively examined. The synthesized materials were investigated by using thermo gravimetric analysis, X-ray diffraction, field emission scanning electron micrographs equipped with energy dispersive X-ray spectrometer, and Brunauer–Emmett–Teller.
Infectious diseases caused by viruses can elevate up to undesired pandemic conditions affecting the global population and normal life function. These in turn impact the established world economy, ...create jobless situations, physical, mental, emotional stress, and challenge the human survival. Therefore, timely detection, treatment, isolation and prevention of spreading the pandemic infectious diseases not beyond the originated town is critical to avoid global impairment of life (e.g., Corona virus disease - 2019, COVID-19). The objective of this review article is to emphasize the recent advancements in the electrochemical diagnostics of twelve life-threatening viruses namely - COVID-19, Middle east respiratory syndrome (MERS), Severe acute respiratory syndrome (SARS), Influenza, Hepatitis, Human immunodeficiency virus (HIV), Human papilloma virus (HPV), Zika virus, Herpes simplex virus, Chikungunya, Dengue, and Rotavirus. This review describes the design, principle, underlying rationale, receptor, and mechanistic aspects of sensor systems reported for such viruses. Electrochemical sensor systems which comprised either antibody or aptamers or direct/mediated electron transfer in the recognition matrix were explicitly segregated into separate sub-sections for critical comparison. This review emphasizes the current challenges involved in translating laboratory research to real-world device applications, future prospects and commercialization aspects of electrochemical diagnostic devices for virus detection. The background and overall progress provided in this review are expected to be insightful to the researchers in sensor field and facilitate the design and fabrication of electrochemical sensors for life-threatening viruses with broader applicability to any desired pathogens.
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•Comprehensive overview of virus diagnosis by analytical/electrochemical approaches.•Summary of electrochemical biosensors for coronaviruses (COVID-19, MERS, SARS).•Rapid POC screening of Influenza, Hepatitis, HIV, HPV, Zika, Dengue and Rotavirus.•Infectious virus detection by immuno/apta/CRISPR based electrochemical sensors.•Perspectives on biofouling, selectivity, multiplex sensing and wireless devices.
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