Indian Institute of Technology Hyderabad (IITH) is a premier institute of science and technology established in 2008. IITH has been consistently ranked in the&nbsp;<a href="https://iith.ac.in/reports/" rel="noopener noreferrer">top 10 institutes</a>&nbsp;in India for Engineering&nbsp;<a href="https://www.nirfindia.org/2021/EngineeringRanking.html" rel="noopener noreferrer" target="_blank">according to NIRF</a>&nbsp;making it one of the most coveted schools for science and technology in the country.

IITH offers&nbsp;<a href="https://iith.ac.in/academics/under-graduate/">undergraduate programs</a>&nbsp;in all the classical engineering disciplines, applied sciences, design, as well as several modern interdisciplinary areas. Students are given a flexibility to explore a broad set of areas, and potentially pursue a minor or double major in a discipline that is not their own. Students who wish to seek a deeper understanding of their own discipline are strongly encouraged to get involved in cutting-edge research with the help of a faculty to mentor them, and earn an Honors in their own field.

The very foundation of IIT Hyderabad is based on&nbsp;<a href="https://iith.ac.in/research/">research and innovation</a>. The vibrant research culture is evident from the number of patents and publications that IITH produces consistently every year. IITH offers&nbsp;<a href="https://iith.ac.in/academics/programmes-offered/">graduate programs</a>&nbsp;at both a masters, and a doctoral level, in several diverse areas. There are separate programs for technology, design, science, and liberal arts. The&nbsp;<a href="https://iith.ac.in/academics/post-graduate/">MTech program</a>&nbsp;is offered in various modes and durations to cater to the ever-growing need of postgraduate level professionals in the country.

IITH encourages and supports&nbsp;<a href="https://iic-iith.netlify.app/index.html" rel="noopener noreferrer" target="_blank">innovation and entrepreneurship</a>&nbsp;at every stage. The minor program in entrepreneurship is open to all students of IITH, and many of the courses are offered by industrialists who are entrepreneurs themselves. There are various&nbsp;<a href="https://iith.ac.in/research/centres-incubators/">innovation centers and incubators</a>&nbsp;that promote entrepreneurship and help mentor young innovators. IITH has been very successful in building tie-ups with leading academic institutions around the globe.

IITH enjoys a very special relationship with Japanese universities and industries that goes beyond academic and research collaborations. In fact, some of the iconic buildings in IITH campus will carry the signature of Japanese architecture.

IITH creates a unique holistic ecosystem for education that offers interactive learning, a very flexible academic structure, cutting-edge research, strong industry collaboration, and entrepreneurship. This is an environment which enables students and faculty to translate their dreams into realities.

IIT Hyderabad

Optical green emitting microresonators with high values of nonlinearity are desired for high optical up-conversion energy storage and lasing applications. Here we report on the synthesis of benzylammonium lead iodide (BALI) perovskite microcrystals made via antisolvent diffusion method. The use of polystyrene (PS) matrix helps the growth of environmentally stable BALI nanocrystals as a result of polymer capping. Optimization of the ratio of BALI-PS during the self-assembly process leads to the formation of defect-free composite microspheres. Further, these BALI crystals act as an active material within the microsphere resonators that display whispering gallery modes (WGM). These WGMs are responsible for high optical storage energy of resonators evidenced by their Q-factor as high as ∼1180. Two-dimensional finite difference time-domain calculation shows the concentration of the electric field near the microspheres boundary within a small mode volume of 1.83 μm3. Remarkably, BALI-PS composite microresonators and their neat crystals exhibit brilliant two-photon luminescence upon excitation by the infrared fundamental radiation. This simplistic microresonators fabrication technique provides a route toward low-cost nonlinear optical microlasers and other optical energy devices useful for various applications. © 2018 American Chemical Society.

Department of Chemistry

World University root node

ACS Applied Energy Materials

High optical energy storage and two-photon luminescence from solution-processed perovskite-polystyrene composite microresonators

An efficient and eco-friendly procedure for the synthesis of highly stable silver (Ag) and gold (Au) nanoparticles (NPs) using phenylalanine conjugated cholic acid (CPhe) in aqueous medium has been developed.These NPs were prepared under natural sunlight irradiation, in which CPhe acts both as self-reducing and capping agent. The size and shape of the NPs were optimized by changing the ratio of the concentration of CPheand Au3+ ions, pH of the solution, sunlight irradiation and reaction time.The optical properties of the nanoparticles (NPs) were studied using UV-visible spectroscopy. Size and morphology of the NPs were analyzed using high resolution transmission electron microscopy (HR-TEM) and dynamic light scattering techniques (DLS) techniques. The interaction of CPhe on the NPs surface were studied by X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FT-IR) spectra.The synthesized Ag and Au NPs solutions were found to be highly stable for more than a year. The prepared NPs were used as probes for highly selective and sensitive detection of heavy metal ions (Hg2+, Cr6+ and Pb2+) by colorimetric in aqueous medium with a detection limit in the range ofnanomolar concentrations. © 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

ChemistrySelect

A Facile Sunlight-Induced Synthesis of Phenylalanine-Conjugated Cholic Acid-Stabilized Silver and Gold Nanoparticles for Colorimetric Detection of Toxic Hg2+, Cr6+ and Pb2+ Ions

Organic micro-heterostructures (MHS) with dual optical emissions are essential to produce miniaturized optical waveguides for wavelength division multiplexing technologies. The bimolecular MHS produced by solution-based bottom-up self-assembly technique often leads to poor surface smoothness, edge imperfection, defects, and unwanted thin films deposits. Conversely, sequential sublimation technique at ambient pressure facilitates effective integration of α-perylene micro-square with dicyanomethylene-2-methyl-6-(p-dimethylaminostyryl) 4H-pyran (DCM) microrods in an epitaxial manner to produce MHS. The obtained DCM/perylene MHS act as optical waveguides to produce red (λmax≈670 nm) or/and yellow (λmax≈607 nm) dual optical outputs via an energy transfer mechanism depending upon the heterostructures geometry and optical excitation positions. The presented dual-color emitting MHS optical waveguides are essential for the integrated nano-photonic and optoelectronic device structures. © 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

Chemistry - An Asian Journal

Vapour-Phase Epitaxial Growth of Dual-Colour-Emitting DCM-Perylene Micro-Heterostructure Optical Waveguides

Single dye based crystalline organic materials displaying molecular packing and conformation-dependent luminescent properties are attractive for opto-electronic and photonic applications. Hence, in this work the opto-structural analysis of two polymorphs (forms I and II) of a well-known coumarin-153 (C-153) dye is presented. Crystal structural analysis based on the syn or anti position of C-β1 and C-β2 carbons adjacent to nitrogen in the julolidyl moieties showed that form I and II polymorphs possess three and two molecular conformers, respectively. Optical excitation of single crystals of forms I and II radiated green and yellow fluorescence (FL) bands, respectively. The presence of different conformers, strong intermolecular π-π stacking, hydrogen bonding interactions, and charge transfer states was attributed to the energetically different emission bands of these polymorphs. Depending on the acetonitrile: water ratio, during self-assembly, C-153 formed polymorphic micro-crystalline rods, tubes and Japanese twin tubes on glass substrates. Analysis of the single-particle Raman spectra and FL life-time values of the rods, tubes and Japanese twin tubes clearly confirmed dissimilar molecular packing within the micro-solids. Single-particle microscopy studies revealed remarkable polymorphism-dependent FL emissions, optical waveguiding, and optical cavity and resonator effects of the rods, tubes and Japanese twin tubes. The yellow emitting hexagonal and rectangular tubes possibly supported whispering-gallery-modes (WGMs) and Fabry-Pèrot (FP) modes, respectively, while the blue-green emitting rods and Japanese twin tubes displayed FP-type cavity modes. Overall this work establishes a simple and economical self-assembly route for the fabrication of C-153 photonic micro-structures displaying polymorphism-dependent emission colours suitable for band-width tunable organic-based micro-lasers, opto-electronic and other polaritonic devices. © 2017 The Royal Society of Chemistry.

Journal of Materials Chemistry C

Polymorphism and microcrystal shape dependent luminescence, optical waveguiding and resonator properties of coumarin-153

Luminescent carbon dots (CDs) are emerging as a potential eco-friendly alternative to standard metal-based semiconductor quantum dots. A solvatothermal method to prepare crystalline, nitrogen-rich, surface-passivated, and rare excitation wavelength-independent green-emitting (λmax ≈ 522 nm in solution and 536 nm in solid) CDs from a pyridine diamine precursor in ethanol solvent is reported here. In comparison to a neat thin film of CDs, a film of CD-doped polystyrene microspheres (PS-CDs) displays a remarkable enhancement of the photoluminescence emission intensity driven by optical cavity effect of the composite microspheres. Apart from downconversion one-photon luminescence, upon excitation with 800 nm femtosecond pulse laser, pure CDs and PS-CDs exhibit enhanced upconversion two-photon luminescence in the range of about 410–580 nm. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Advanced Optical Materials

2D Arrangement of Polymer Microsphere Photonic Cavities Doped with Novel N-Rich Carbon Quantum Dots Display Enhanced One- and Two-Photon Luminescence Driven by Optical Resonances

A facile, one-pot and green method has been developed for the synthesis of silver nanoparticles (AgNPs) using the sodium salt of N-cholyl-l-cysteine (NaCysC) as capping and reducing agent under ambient sunlight irradiation. The synthesized nanoparticles were used for highly selective and sensitive colorimetric detection of Hg2+ in aqueous medium with a limit of detection of about 8 nM. © 2015 The Royal Society of Chemistry.

RSC Advances

Highly selective and sensitive colorimetric detection of Hg(II) ions using green synthesized silver nanoparticles

The present work describes the preparation of gold nanoparticles (AuNPs) under natural sunlight irradiation and their use in colorimetric detection of heavy metal ions. The AuNPs were prepared by an environmentally benign method using N-cholyl-l-valine (NaValC) as a self-reducing as well as stabilizing agent in aqueous medium. The size and shape of the particles were systematically controlled by varying the ratio of NaValC and Au3+ ions. The pH of the solution medium, sunlight irradiation and reaction time also influence the size and shape selectivity. The prepared NPs were thoroughly characterized by using UV-visible spectroscopy, TEM, DLS, EDX, XRD, XPS, FT-IR, cyclic voltammetry and TGA techniques. Natural solar energy acting as a driving force for the generation of AuNPs in aqueous medium makes the process eco-friendly, attractive and economical. As these NPs are highly reactive towards the surrounding environment the prepared AuNPs were effectively utilized for the colorimetric detection of Co2+ and Ni2+ ions in environmental samples. © The Royal Society of Chemistry 2015.

Green synthesis of gold nanoparticles under sunlight irradiation and their colorimetric detection of Ni2+ and Co2+ ions

In this study, we report a simple and green method for the synthesis of l-tyrosine-stabilized silver (AgNPs) and gold nanoparticles (AuNPs) in aqueous medium under ambient sunlight irradiation. The nanoparticles (NPs) are characterized by UV-visible spectroscopy, high-resolution transmission electron microscopy (HR-TEM), Fourier transform infrared spectroscopy (FT-IR), cyclic voltammetry (CV), and dynamic light scattering (DLS) techniques. The size and shape of the metal NPs could be controlled by changing the concentration of the substrate, metal precursors, and pH of the medium. The synthesized AgNPs are found to be highly sensitive to Hg2+ and Mn2+ ions with the detection limit for both ions as low as 16 nM under optimized conditions. However AuNPs are found to be sensitive to Hg2+ and Pb2+ ions with a detection limit as low as 53 and 16 nM, respectively. The proposed method was found to be useful for colorimetric detection of heavy metal ions in aqueous medium. © 2014 American Chemical Society.

ACS Sustainable Chemistry and Engineering

Green synthesized silver and gold nanoparticles for colorimetric detection of Hg2+, Pb2+, and Mn2+ in aqueous medium

One-pot photocatalytic synthesis of 2-substituted benzimidazoles from 2-nitroanilines with different alcohols by combined redox cyclization reaction using TiO 2-P25 is reported. The reaction, when performed with ethanol, gives 2-methylbenzimidazole as a single product. However, in a mixture of ethanol and water (1:1), it gives both 2-methylbenzimidazole and 1-ethyl-2-methylbenzimidazole. The products have been characterized by Fourier transorm-infrared, 1H NMR, 13CNMR, and gas chromatography-mass spectrometry analysis. TiO 2-P25 behaves as a combined redox photocatalyst by reducing 2-nitroaniline and oxidizing alcohols simultaneously under ultraviolet light. Easy product isolation under mild conditions and good yield make this one-pot synthesis ecofriendly. Copyright © Taylor &amp; Francis Group, LLC.

Synthetic Communications

A combined-redox synthesis of 2-alkylbenzimidazoles from 2-nitroanilines by semiconductor photocatalysis

Aqueous solution containing two additives, silver nitrate (AgNO3) and sodium salt of N-cholyl amino acid were irradiated by sunlight for the synthesis of spherical shaped AgNPs without the need for an additional stabilizer or capping agent. Variations of N-cholyl amino acid concentration provided good control over the morphology of the AgNPs, while the carboxylate group of bile salt reduced the Ag+ ions and the amide group binds strongly to the surface of the NPs. The optical properties, morphology of the AgNPs were characterized by UV-visible, transmission electron microscopy (TEM) and dynamic light scattering (DLS) studies. The interaction of N-cholyl amino acid on the AgNPs surface was studied using cyclic voltammetry and FT-IR techniques. The reduction process was completed within 5min and the synthesized AgNPs were stable for more than 6 months. The possible mechanism of N-cholyl amino acid on the reduction and stabilization of AgNPs is also discussed. The antimicrobial activity of N-cholyl amino acid capped AgNPs against Escherichia coli, Staphylococcus aureus and Pseudomonas aeroginosa using Mueller Hinton broth and the antifungal activity against Candida albicans, Candida krusei and Candida tropicalis using RPMI broth were determined by MIC studies as per CLSI guidelines. © 2012 Elsevier B.V.

Colloids and Surfaces B: Biointerfaces

A sunlight-induced rapid synthesis of silver nanoparticles using sodium salt of N-cholyl amino acids and its antimicrobial applications

Silver-loaded TiO2 (Ag-TiO2) and acidic clay (K10 montmorillonite) composite photocatalyst has been successfully applied for the light-induced conversion of o-phenylenediamine (OPD) and its derivatives to substituted benzimidazoles with various alcohols in acetonitrile using UV-A and solar light. The influence of the various photocatalysts, solvents, and substituents on the yield and selectivity of the products has been investigated. The mechanism of photocatalysis is proposed. Loading silver on TiO2 enhances product yield and selectivity both in UV and solar light. In the presence of primary alcohols, 2-aminothiophenol forms only disulfide and hence Ag-TiO2/ clay can be used as a green catalyst for the synthesis of disulfides. © 2010 The Chemical Society of Japan.