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Srivastava G.,Indian Institute of Technology Kanpur | Das A.,Indian Institute of Technology Kanpur | Kusurkar T.S.,Indian Institute of Technology Kanpur | Roy M.,Indian Institute of Technology Kanpur | And 5 more authors.
Materials Express

Iron pyrite (FeS2) is a promising material with plethora of applications ranging from sulfuric acid production to photo-voltaic devices. Interestingly, the proponents of the theory of hydrothermal origin of life on earth argues that FeS2 may have evolved 4.0 billion years ago, and used as an energy source by the earliest evolving life forms on earth. In the present time, bacteria like Thiobacillus ferrooxidans, which survives in the oxygen deficient environments, derives energy solely from FeS2 to maintain its critical biomass. The key question, we addressed in this paper is 'whether higher plants have the ability to derive energy solely from FeS2, just like the way Thiobacillus species does.' To answer this question, we developed a novel, inexpensive, low temperature scheme (<100 °C) for FeS2 synthesis. We characterize FeS2 using X-ray diffraction (XRD), scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM) techniques. Further, we pretreated the chick-pea (Legume) seeds for 12 hours in sterile, double distilled aqueous medium of dispersed FeS2 (80 μg/ml). Following this, we allowed these seeds to grow in sterile, double distilled water for 7 days. At this stage, we observed that FeS2 pre-treated seeds result in significantly healthier plants, with increased dryweight and enhanced sulfur content as compared to the control plants. In summary, a brief FeS2 pre-treatment of the seeds resulted in increased plant biomass. This study has drawn an evolutionary consilience between two diverse life forms in terms of their ability to use a common pre-biotic energy molecule for biomass production. Our results suggest that FeS2 apart from its opto-electronic potential, could also be used as a pro-fertilizer for sustainable agriculture practices. © 2014 by American Scientific Publishers All rights reserved. Source

Dubey A.,Indian Institute of Technology Kanpur | Singh S.K.,Defense Research Development Organization | Tulachan B.,Indian Institute of Technology Kanpur | Roy M.,Institute of Engineering Science and Technology | And 4 more authors.
RSC Advances

Sustainable charge storage devices require materials that are environmentally benign, readily moldable, easily synthesizable, and profitable for applications in the electronics industry. Nano iron pyrite (FeS2) is one such material, which is applicable in diverse areas like photovoltaic devices to seed dressing in agriculture. In this work, we propose an innovative application of nano FeS2viz., as a symmetric charge storage device that is flexible, portable, and lightweight; along with its fabrication details. The device consists of a (H3PO4)/polyvinyl alcohol (PVA) electrolyte gel sandwiched between two similar electrodes made up of FeS2/poly-aniline (PA), upon which graphite sheets are used as current collectors. Electrodes were characterized by XRD, FTIR and SEM. The device was calibrated by cyclic voltammetry and charge-discharge cycle. In its present laboratory prototype form, it powers solid-state electronic devices and electric motors. Further refinements of this device will open up new avenues in the field of sustainable charge storage devices and low power electronics. © The Royal Society of Chemistry 2016. Source

Roy M.,Indian Institute of Technology Kanpur | Meena S.K.,Indian Institute of Technology Kanpur | Singh S.K.,Defense Research Development Organization | Sethy N.K.,Defense Institute of Physiology and Allied Science | And 4 more authors.
Materials Express

This work addresses an interesting, interdisciplinary problem of nature-the mechanism by which animal senses the earth's magnetic field and navigate. Currently there are two existing theories trying to explain, How the animal senses the magnetic field of earth. One theory is based on the presence of biogenic magnetic materials in the body of the animals. Such magnetic materials which are present inside the body, orients itself according to the earth's weak magnetic field and convey the information to the nervous system to develop the navigational map. The second theory is based on a light dependent photochemical reaction. A photochemical reaction leads to the generation of radical pairs, which helps in sensing the weak magnetic field of the earth. In this work, we are proposing a new model of magnetoreception. Unlike the existing radical pair system of magnetoreception, where a light-dependent reaction is essential to generate free radicals, here we show the presence of a large pool of stable carbon-centric free radicals in the nano-domains of the antennae and the wings of silk moth. This stable pool of carbon-centric free radicals is intrinsic in the nano-domains of these anatomical structures and responds to weak magnetic fields similar to that of Earth's (50 μT) even in the absence of light. Hence we are proposing that nocturnal animals in their navigation could utilize such a light independent mechanism. We further observed the presence of ferromagnetic elements (Fe, Ni, Co, Mn) in these structures. In conclusion, we have discussed how carbon centric free radicals along with other ferromagnetic components present in the antennae and the wings of the nocturnal silk moth, might help them to avoid the bats. © 2013 by American Scientific Publishers All rights reserved. Source

Srivastava G.,Indian Institute of Technology Kanpur | Das C.K.,Indian Institute of Technology Kanpur | Das A.,Indian Institute of Technology Kanpur | Singh S.K.,Indian Institute of Technology Kanpur | And 8 more authors.
RSC Advances

Certain nano-materials are known to have plant growth promoting effects, which could find applications in agriculture. We drew inspiration from the nano-factories of deep-sea hydrothermal vents; where iron pyrite nanoparticles serve as fertilizer to sustain chemoautotrophic life forms. We synthesized such iron pyrite nanoparticles in a controlled environment and used them as seed treatment agent (Pro-fertilizer). For us, the term 'pro-fertilizers' represents those materials that cause enhanced plant growth with minimum interference to the soil ecosystem when used for seed treatment. We conducted multi-location field trials on spinach crops, since it is a globally popular crop, consumed as both fresh (salads) and processed food. The spinach seeds were treated for 14 hours in an aqueous suspension of iron pyrite nanoparticle (FeS2 + H2O) and thereafter directly sown in the field setup for the experiment. The control seeds were only treated in water for the same duration and sown directly in the field. After 50 days, the crop yields from iron-pyrite nanoparticle treated seeds and control seeds were evaluated. The plants developed from iron pyrite nanoparticle treated seeds exhibited significantly broader leaf morphology, larger leaf numbers, increased biomass; along with higher concentration of calcium, manganese and zinc in the leaves when compared to the plants developed from control seeds. We further investigated the possible mechanism resulting in the biomass enhancement following seed-treatment. Our results indicate that there is an enhanced breakdown of stored starch in the iron pyrite treated seeds resulting in significantly better growth. This raises the possibility of developing iron pyrite nanoparticles as a commercial seed-treatment agent (pro-fertilizer) for spinach crops. © 2014 The Royal Society of Chemistry. Source

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