5-Jan-2023: New electrolyte found can help better ammonia synthesis

A new aqueous electrolyte that can help make electrochemical ammonia synthesis more efficient will be useful for industries producing green energy or hydrogen.

The electrochemical ammonia synthesis is largely limited by the poor solubility of nitrogen (N2) in the aqueous electrolyte environment as well as the competitive hydrogen evolution reaction. The obstacle faced was that reduction of N2 has actually occurred in the aqueous medium. In an attempt to solve these issues, the “ambient” conditions are mostly overseen. Researchers mostly work on catalyst development, while electrolyte improvisation still remains in infancy. According to a recent report, 90.7 % of the research works related to : Nitrogen reduction reaction (NRR) have focused on the suitable catalyst development, while only 4.7 % have been devoted to work on the electrolytes.

Scientists from Institute of Nano Science and Technology (INST) Mohali, an autonomous institute of Department of Science and Technology (DST), have introduced a new electrolyte called (NaBF4), which not only acts as an N2-carrier in the medium but also works as a full-fledged “co-catalyst” along with active material transition metal-doped nanocarbon (MnN4) to deliver high yield of ammonia (NH3) at absolutely ambient experimental conditions. The high production rate of NH3 approached industrial scale and exceeded almost all the standard catalysts in any other electrolyte medium. The source of NH3 was thoroughly studied and confirmed to be chiefly from the electrochemical reduction of the purged N2 gas (make it N2 saturated electrolyte to convert N2 to NH3.

This research published in the journal PNAS is a novel approach to get through the long-standing issues about the solubility of N2 in aqueous medium and achieve industrial scale production rate of ammonia by NRR at ambient condition.

This work supported by DST SERB brings an user-friendly aqueous electrolyte (NaBF4) which can encourage researchers to work more on aqueous electrolyte designing towards an even improved NRR performance of the electro catalysts. A patent has been filed for this work and the scientists are now working towards making electrolyser for rapid rate of ammonia production at an industrial scale. 

24-Dec-2022: New Artificial Nanostructures for Infrared Absorption Technologies can be useful in Defense, Imaging & Sensing

A new method to confine and absorb infrared (IR) light with GaN nanostructures can help develop highly efficient infrared absorbers, emitters, and modulators that are useful in defense technologies, energy technologies, imaging, sensing, and so on.

GaN, a widely used material for blue light emission, is one of the most advanced semiconductors. Though visible and ultraviolet light applications of GaN have already been realized, with LEDs and laser diodes commercially available, utilization of GaN for IR light harvesting or development of GaN-based IR optical elements is lacking.

Researchers in Bengaluru’s Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR), an autonomous institute of the Department of Science and Technology, have shown for the first time infrared light emission and absorption with GaN nanostructures. Though blue light emission from GaN has been known for some time, and it is used in LEDs, this is the first time that infrared light-matter interactions are demonstrated in GaN. For this demonstration, they have utilized a scientific phenomenon called surface polariton excitations in GaN nanostructures that lead to light-matter interactions at IR spectral range.

Surface polaritons are special modes of electromagnetic waves traveling at the interface of a conductor and an insulator such as air. By altering the morphology and shape of the nanostructures, they are also able to excite plasmon polaritons in GaN, which results in extending the light-matter coupling to further reaches of the electromagnetic spectrum. These polaritons are quasi-particles which have both light and matter characteristics.

To grow these GaN nanostructures, the researchers utilized a specialized material deposition instrument called molecular beam epitaxy in the International Centre for Materials Science in JNCASR. This instrument uses ultra-high vacuum, similar to the conditions of outer space, to grow high-quality material nanostructures with dimensions about 100000 times smaller than the width of a human hair.

Such cutting-edge materials allow the creation of polariton-based devices, which offer several advantages to conventional electronic devices. Polaritonic technologies have attracted a wide range of applications, such as secure high-speed light-based communication (LiFi), next-generation light sources, solar energy converters, quantum computers, and waste-heat converters.

“In the last 25 years, blue LED with GaN has changed our world significantly. While the blue light emission from GaN is well-understood, utilizing GaN for infrared optics is not well-established. Our work demonstrates a novel pathway for utilizing GaN in infrared nanophotonic applications. Importantly, the scientists said that the infrared surface polariton excitations that we have demonstrated can be translated to many other semiconductors as well”. The research has been published in the prestigious journal Nano Letters. The proof of concept of the technology has been demonstrated.

“This work will greatly benefit in addressing the demand for IR sources and detectors for energy, security, imaging, and other applications,” said Dr. Bivas Saha, Assistant Professor at the Jawaharlal Nehru Centre for Advanced Scientific Research.