Priyanka H. Maheshwari

Enhanced performance of PEM fuel cell using MWCNT reinforced carbon paper

Porous conducting carbon paper has been identified as one of the most suitable materials to be used as a fuel cell electrode backing. Carbon paper is prepared by the combined process of papermaking followed by composite formation. Experiments have been carried out whereby heat treated multiwalled carbon nanotubes (MWCNTs) are integrated in the sample while keeping the amount of fiber and resin constant. The diminutive magnitudes of these nanostructures are found to have a considerable effect on the electrical and mechanical properties of the carbon paper electrode. The I–V performance of the unit polymer electrolyte membrane (PEM) fuel cell shows a maximum power density of 880 mW cm−2 with 0.05 vol% of MWCNTs, an increase of ∼25% as compared to 700 mW cm−2 obtained using commercially available standard Toray carbon paper tested under similar conditions.

Highly purified CNTs: an exceedingly efficient catalyst support for PEM fuel cell

High performance in PEM fuel cells has been achieved using purified CNTs as catalyst support. Pt/CNT nanocomposites were synthesized by reducing Pt salt on CNTs in the presence of ethylene glycol as solvent and in inert atmosphere. The reactions were carried out using both pristine and purified MWCNTs under different pH and atmospheric conditions. The detailed physical and electrochemical characterization revealed that a highly active catalytic surface could be achieved on reducing Pt on defect-free, purified MWCNTs. A further elaborated mechanism is discussed, which illustrates that reduced Pt nanoparticles form a chelate in the presence of nitrogen at neutral pH. This results in increased stability and enhanced catalytic activity. The I–V performance of a unit PEM fuel cell using the synthesized catalyst (with purified CNTs as catalyst support) showed a peak power density of 818 mW cm−2. The performance repeated in triplicate was found to be consistent and exceptionally high (>80%) in comparison with 448 mW cm−2, the value obtained while employing pristine CNTs as support and tested under similar conditions. Moreover, a novel experimental support was given to confirm the number of electrons involved in the oxygen reduction reaction (ORR) on these highly purified CNT supported catalysts.

Solar powered lithium-ion battery incorporating high performing electrode materials

The development of portable electronic communities requires high performing and high power lithium rechargeable batteries. Herein, we explore a new lithium ion battery combined with a new carbon based anode and cobalt based cathode which delivers an energy output of 280 Wh kg−1 and cycling efficiency of 97% over the investigated 500 cycles (1 C rate) of the lithium ion cell.

Zinc-Supported Multiwalled Carbon Nanotube Nanocomposite: A Synergism to Micronutrient Release and a Smart Distributor To Promote the Growth of Onion Seeds in Arid Conditions

In the current scenario, nanotechnological applications in the agriculture sector showing potential impacts on the improvement of plant growth in terms of protection and safety are at a very nascent stage. The present study deals with the synergistic role of zinc (Zn) and multiwalled carbon nanotubes (MWCNTs) synthesized as a zinc oxide (ZnO)/MWCNT nanocomposite, a prospective applicant to modulate the micronutrient supply and enhance the growth of onion seeds, thereby replacing harmful, unsafe chemical fertilizers. To the best of our knowledge, this is the first report wherein MWCNTs have been envisaged as a micronutrient distributor and a nutrient stabilizer enhancing the growth of onion plant under arid conditions. The growth trend of onion seeds was evaluated in an aqueous medium with varied concentrations of (i) MWCNTs, (ii) zinc oxide nanoparticles, and (iii) ZnO/MWCNT nanocomposites. ZnO/MWCNT nanocomposites with 15 μg/mL concentration displayed the best seedling growth with the maximum number of cells in telophase. A significant growth trend with increased concentration of ZnO/MWCNTs displayed no negative impact on plant growth in contrast to that with the use of MWCNTs. The synergistic impact of Zn nanoparticles and MWCNTs in ZnO/MWCNT nanocomposites on the rate of germination was explained via a mechanism supported by scanning transmission electron microscopy.