A series of metal-free N-doped carbon nanotubes (CNTs) are fabricated using an in-situ synthesis and post nitridation treatment. N-doped carbon nanotubes with various defects, nitrogen contents, and nitrogen species are employed as the catalysts for nitrobenzene hydrogenation. The potential active sites of N-doped carbon nanotubes are explored in terms of catalytic performance in nitrobenzene hydrogenation as well as DFT calculations of hydrogen adsorption on carbon nanotubes and nitrogen species. Active and selective hydrogenation of nitrobenzene is achieved over N-doped carbon nanotubes prepared by post nitridation. Pyrrolic-N in the N-doped carbon nanotubes is found to play an active site for nitrobenzene hydrogenation, which is greatly in favor of the chemisorption and dissociation of hydrogen molecules. N-doped carbon nanotubes with pyrrolic-N show an encouraging catalytic hydrogenation activity in nitrobenzene reduction. These findings provide a promising route for the rational design of the metal-free hydrogenation catalysts and the development of carbon nanotube-based materials.

Nitrogen-doped carbon nanotubes as a highly active metal-free catalyst for nitrobenzene hydrogenation

Hazardous gases sensors based on conducting polymer composites: Review

Nowadays, the rapid development and demand of high-performance, lightweight, low cost, portable/wearable electronic devices in electrical vehicles, aerospace, medical systems, etc., strongly motivates researchers towards advanced electrochemical energy storage (EES) devices and technologies. The electrolyte is also one of the most significant components of EES devices, such as batteries and supercapacitors. In addition to rapid ion transport and the stable electrochemical performance of electrolytes, great efforts are required to overcome safety issues due to flammability, leakage and thermal instability. A lot of research has already been completed on solid polymer electrolytes, but they are still lagging for practical application. Over the past few decades, ionic liquids (ILs) as electrolytes have been of considerable interest in Li-ion batteries and supercapacitor applications and could be an important way to make breakthroughs for the next-generation EES systems. The high ionic conductivity, low melting point (lower than 100 °C), wide electrochemical potential window (up to 5–6 V vs. Li+/Li), good thermal stability, non-flammability, low volatility due to cation–anion combinations and the promising self-healing ability of ILs make them superior as “green” solvents for industrial EES applications. In this short review, we try to provide an overview of the recent research on ILs electrolytes, their advantages and challenges for next-generation Li-ion battery and supercapacitor applications.

https://www.mdpi.com/1996-1944/14/11/2942/pdf

Application of Ionic Liquids for Batteries and Supercapacitors.

Accurate monitoring of environmental pollutants has become a primary concern due to rapid progress in the oil industry during recent years. Nanoparticles (NPs) for electrochemical sensing are emerging as crucial tools for pollutant monitoring such as aromatics hydrocarbon, polyphenols, and toxic gases produced by the oil industry. NPs provided increasing the sensitivity and selectivity of the sensor through increasing the surface area, owing to the high surface-to-volume ratios, and a highly active site area so that the molecules could be easily adsorbed on the surface electrode to undergo a redox reaction. This paper presents a comprehensive overview of the latest nanoparticles used for electrochemical sensing. Moreover, some parameters such as sensitivity, selectivity, the limit of detection, including a specific mechanism detection of analyte targets, and response time have been discussed to determine optimum condition for polyphenols, aromatic compounds, and toxic gases detection. Some recent results have been presented and discussed.

Nanoparticles as components of electrochemical sensing platforms for the detection of petroleum pollutants: A review

This work describes the development of an electronic nose (e-nose) based on carbon nanocomposites to detect clove essential oil (CEO), eugenol (EUG), and eugenyl acetate (EUG.ACET). Our e-nose syst...

Electronic Nose Based on Carbon Nanocomposite Sensors for Clove Essential Oil Detection

Polyaniline-multiwalled carbon nanotube (PANI-MWCNT): Room temperature resistive carbon monoxide (CO) sensor

The current study emphasizes the influence of electrochemical active surface area (ECSA) on the electrochemical oxygen evolution reaction (OER) and supercapacitive performances of MnO2-multiwalled carbon nanotube (MC) composites. The best sample exhibits an ECSA of 8.6Â cm2. With the increase of ECSA both OER activity and the supercapacitive performance of the composites increases. The MC composite exhibits a low over potential (0.385 V) for OER activity. The composite displays outstanding catalytic activity for OER in the alkali medium as well as exhibits excellent supercapacitive activity (specific capacitance of 1039 F gâ��1 at a scan rate of 2Â mV sâ��1). An asymmetric supercapacitor has also been developed which shows very high specific capacitance within a wide working potential of 1.8Â V. This device can supply an energy and power density of 60.55 Wh kgâ��1 and 8.45 kW kgâ��1, respectively. The role of ECSA has been investigated in both oxygen evolution and supercapacitive process showing the promise of this multifunctional MnO2-MWCNT composite for both energy storage but also in conversion. Â© 2021 John Wiley & Sons Ltd.

Influence of electrochemical active surface area on the oxygen evolution reaction and energy storage performance of MnO2-multiwalled carbon nanotube composite

In the present investigation, we have design and develop pyridyl-imine capped gold nanoaggregates; fully characterized via various spectroscopic techniques. The photophysical and electrochemical studies revealed that the developed pyridyl-imine capped gold nanoaggregates are proven to be selective sensor for picric acid with remarkable low detection limit within nano-molar concentration (15.0 nM) based on 3σ/K; a common constituent of many powerful explosives. The quenching of fluorescence intensity at λ 357 nm occurs which may ascribe to the electron transfer phenomenon exhibited by the electron rich receptor and emergence of red shift in fluorescence spectroscopy (λem 464 nm) after gradual addition of picric acid; a selective phenomenon towards the most electron deficient nitroaromatic (picric acid) sensing. Additionally, the results obtained for the analysis of spiked samples in real water samples such as river and tap water, show that the developed PA sensor is potentially applicable in the determination of trace PA explosive without any interference.

Gobardhan Lal

Papers

Polyaniline-multiwalled carbon nanotube (PANI-MWCNT): Room temperature resistive carbon monoxide (CO) sensor

Influence of electrochemical active surface area on the oxygen evolution reaction and energy storage performance of MnO2-multiwalled carbon nanotube composite

Tripodal pyridyl-imine capped gold nano-aggregates for selective detection of picric acid in aqueous media