Ritu Gupta

Ritu Gupta
Indian Institute of Technology Jodhpur | IITJ · Chemistry Laboratory

Doctor of Philosophy

About

71
Publications
15,551
Reads
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1,575
Citations
Citations since 2017
33 Research Items
1128 Citations
2017201820192020202120222023050100150200
2017201820192020202120222023050100150200
2017201820192020202120222023050100150200
2017201820192020202120222023050100150200
Additional affiliations
June 2021 - June 2021
Indian Institute of Technology Jodhpur
Position
  • Professor (Associate)
August 2015 - June 2021
Indian Institute of Technology Jodhpur
Position
  • Professor (Assistant)
Description
  • Solid State and Materials Chemistry
April 2014 - July 2015
Purdue University
Position
  • PostDoc Position
Education
April 2005 - June 2008
Miranda House
Field of study
  • Chemistry

Publications

Publications (71)
Article
Xylene is one of the representative indoor pollutants, even in ppb levels, that affect human health directly. Due to the non-polar and less reactive nature of xylene, its room temperature detection is challenging. This work demonstrates a metallic tin-doped Sn-SnO2 nanocomposite under controlled pH conditions via a simple solvothermal route. The Sn...
Article
The combinatorial design of sensors has been demonstrated as an effective strategy for rapidly screening sensing materials and optimizing functional parameters for high-performance sensors. In this work, we report the development of room-temperature NO2 sensors based on a SnO2–rGO composite following a componential combination approach. SnO2–rGO is...
Article
Full-text available
Quantum flatland i.e., the family of two dimensional (2D) quantum materials has become increscent and has already encompassed elemental atomic sheets (Xenes), 2D transition metal dichalcogenides (TMDCs), 2D metal nitrides/carbides/carbonitrides (MXenes), 2D metal oxides, 2D metal phosphides, 2D metal halides, 2D mixed oxides, etc. and still new mem...
Article
NiCo2O4 nanoplates supported on conductive carbon substrates were fabricated using printable inks by solution processing and thermolysis of Co and Ni thiolate complex mixture. Uniquely, printed biosensor chip with multiple sensing platforms exhibited uniform signals with high reproduciblity apart from high sensitivity, low LOD, and fast response fo...
Article
Recently, there has been substantial interest in the fluorination of nanomaterial thin films used in various optoelectronic devices for optimum charge transport across semiconducting layers. The discovery of electrophilic fluorinating agents such as Selectfluor® has led to the development of novel methods for fluorination of metal oxides such as ti...
Article
The large-scale fabrication of non-precious metal oxide electrocatalysts with reasonable control over catalytic active surface sites is critical for oxygen evolution reaction (OER). Herein, we report an industrially scalable, dip-coating method for the fabrication of 3D electrodes using Co and Ni thiolate hybrid inks. The solventless thermolysis re...
Article
Full-text available
Fabrication protocols of transparent conducting electrodes (TCEs), including those which produce TCEs of high values of figure of merit, often fail to address issues of scalability, stability, and cost. When it comes to working with high-temperature stable electrodes, one is left with only one and that too, an expensive choice, namely, fluorine-dop...
Article
Full-text available
The disposal of organic waste materials such as polymers is a serious problem to natural ecosystems as some of them can be non-biodegradable and potentially toxic. Thus, there is immense interest in developing processes that convert waste polystyrene into useable carbon. In this work, we developed a unique approach for obtaining graphitic carbon fr...
Article
Full-text available
Transparent electronics continues to revolutionize the way we perceive futuristic devices to be. In this work, we propose a technologically advanced VOC (volatile organic compound) sensor in the form of a thin film transparent display which is fabricated by using fluorinated SnO2 films. A solution processed method for surface fluorination of SnO2 f...
Article
Full-text available
The scalablity and stability of an electrocatalyst is one of the biggest challenge for their practical applicablity. In this context, Co3O4 nanoparticles conformally coated on a light weight, 3D and highly conducting carbon cloth is fabricated using an easily synthesized cobalt hexadecylthiolate complex as ink. This method is especially useful for...
Article
Full-text available
Humidity sensors have gained immense importance as non‐invasive, wearable healthcare devices for personal care as well as disease diagnostics. However, non‐specificity, poor stability at extreme conditions, and low sensitivity of the humidity sensor inhibit its usage as a health monitoring device. In the present study, N−F containing organic molecu...
Article
Monitoring live movements of human body parts is becoming increasingly important in the context of biomedical and human machine technologies. The development of wearable strain sensors with high sensitivity and fast response is critical to addressing this need. In this article, we describe the fabrication of a wearable strain sensor made of a Au mi...
Article
Full-text available
A stretchable and compliant electrode surface of Au metal on polydimethylsiloxane (PDMS) is introduced in this study. A thin layer of Au nanoparticles is thus formed by a simple chemical reduction from aqueous Au salt solution with the AuPDMS gel surface itself acting as a reducing site. Employing the swelling behaviour of PDMS and Au nanoparticles...
Article
Full-text available
he futuristic healthcare technology including glucose sensors demand for wearable components that ought to be transparent and flexible. Ni nanostructures have proven to be highly efficient as an electrocatalyst for glucose sensors. In this study, we explore single source precursors of Ni alkylthiolate, Ni(SR)2 complexes as an active electrode mater...
Article
Photocatalytic activity of low band gap hydrogenated HfO2 doped TiO2 (H-HfO2/TiO2), HfO2 doped TiO2 (HfO2/TiO2) and TiO2 (pristine) were investigated by photocatalytic degradation of five different industrial dyes. The current study envisages the effect of doping hydrogen and HfO2 up on TiO2 for photocatalytic degradation of different chemically st...
Article
Hafnium dioxide (HfO2) nano aggregates are synthesized by sol-gel and hydrothermal route followed by hydrogen annealing at different time duration. The proposed study aims to explore the effect of annealing time on the properties of HfO2 via hydrogen annealing. The current study also envisage the catalytic soot oxidation using HfO2 nano-aggregates....
Article
This paper is a study of ZnO doped TiO2 in various percentages ranging from 0% (undoped) up to 10%. The effect of doping was also observed via the change in morphological, optical, electrical and physical properties of ZnO-TiO2 nanospheres. Hydrothermally grown nanospheres are used for removing contaminants photo-catalytically from waste water and...
Article
Full-text available
Fluorine chemistry has gained tremendous attention in the area of electrochemical energy devices such as lithium ion batteries, fuel cells and solar cells. With the advent of novel fluorinating systems, it is interesting to study the effect of fluorine on the electrochemical characteristics of such energy devices. In this study, an organo‐fluorine...
Article
Full-text available
Fluorinated α-Fe2O3 nanostructures are synthesized via a facile hydrothermal route using Selectfluor™ (F-TEDA) as a fluorinating as well as growth directing agent. The addition of incrementally increasing amount of F-TEDA to Fe precursor under hydrothermal conditions resulted in preferential growth of α-Fe2O3 along (110) orientation with respect to...
Article
Dendritic nanostructures of fluorinated α-Fe2O3 are synthesized using Potassium Ferrocyanide along with Selectfluor™ (F-TEDA), HF, TBABF4, NaF and NH4F as Fe and F precursors respectively in an in-situ hydrothermal process. The choice of sources is based on the nature of fluorine; F-TEDA uniquely acts as a source for electrophilic fluorine while ot...
Article
Scalable Coating of 3D Graphene Architectures: The cover image illustrates the schematic of roll-to-roll printing of nickel hexadecanethiolate ink that can be decomposed under ambient condition to yield NiOxSy as a pseudocapacitive layer. The nickel-based pseudocapacitive layer is conformally coated onto three-dimensional graphitic structures to in...
Article
Ideally, transparent heaters exhibit uniform temperature, fast response time, high achievable temperatures, low operating voltage, stability across a range of temperatures, and high optical transmittance. For metal network heaters, unlike for uniform thin film heaters, all of these parameters are directly or indirectly related to the network geomet...
Research
Full-text available
Hierarchical TiO2/ZnO nanospheres: The cover image shows a schematic of synthesized TiO2 nanospheres and the changes brought about by the incorporation of ZnO. The ZnO/TiO2nanospheres are aggregates of crystallites of ZnO that are uniformly dispersed over TiO2 to make heterojunctions. This study describes the different doping percentages tested wit...
Article
Hierarchical TiO2/ZnO nanospheres: The cover image shows a schematic of synthesized TiO2 nanospheres and the changes brought about by the incorporation of ZnO. The ZnO/TiO2 nanospheres are aggregates of crystallites of ZnO that are uniformly dispersed over TiO2 to make heterojunctions. This study describes the different doping percentages tested wi...
Article
Despite relatively high manufacturing cost, crystalline-Si solar cell continues to hold promising future due to its high energy conversion efficiency and long life. As regards cost, one pertinent issue is the top electrode metallization of textured cell surface, which typically involves screen printing of silver paste. The associated disadvantages...
Article
Agile nanostructure architectures and smart combinations of semiconducting metal oxide materials are key features of high-performing dye-sensitized solar cells (DSSCs). Herein, we synthesize mesoporous solid nanospheres of ZnO–TiO2 with type-II heterojunction and use these as an efficient photoanode material for excellent photoconversion. These pol...
Article
High degree of transparency in devices is considered desirable for futuristic technology. This demands that both the active material and the electrodes are made of transparent materials. In this work, a transparent Pd wire network fabricated using crackle lithography technique over ~ 1 cm(2), with sheet resistance and transmittance of ~ 200 Ω □(-1)...
Article
Black titania (H-TiO2) as a photoanode material has attracted huge attention due to its extremely high optical absorption in the visible region. Herein, black TiO2 doped with HfO2 is demonstrated to possess ~ 45.7 % higher photo-conversion efficiency than H-TiO2 under identically similar conditions. The incorporation of HfO2 nanodots increase the o...
Research
Heater plates or sheets that are visibly transparent have many interesting applications in optoelectronic devices such as displays, as well as in defrosting, defogging, gas sensing and point-of-care disposable devices. In recent years, there have been many advances in this area with the advent of next generation transparent conducting electrodes (T...
Article
Full-text available
Roll and spray coating methods have been employed for the fabrication of highly oxidation resistant transparent and conducting electrodes (TCEs) by a simple solution process using crackle lithography technique. We have spray coated a crackle paint based precursor to produce highly interconnected crackle network on PET rolls mounted on a roll coater...
Article
Full-text available
Rotational reorientation times of a newly synthesized 2,5-bis(phenylethynyl)1,4-bis(dodecyloxy) benzene (DDPE) are experimentally determined in series of n-alkanes by employing steady state and time resolved fluorescence depolarization technique with a view to understand rotational dynamics of large non-polar solute molecule in non-polar solvents a...
Article
Full-text available
Achieving high Raman enhancement (SERS) uniformly over large substrate area has been a major challenge in nanomanufacturing, as enhancement is localized around a plasmonic hotspot and hotspots are not usually spread uniformly over a substrate. Herein, we demonstrate a single-step, scalable method for fabrication of Ag nanohole based SERS substrate...
Article
Achieving high Raman enhancement (SERS) relatively uniform over large substrate area has been a major challenge in nanomanufacturing, as enhancement is localized around a plasmonic hotspot and hotspots are not usually spread uniformly over a substrate. Herein, we demonstrate a single-step, scalable method for fabrication of Ag nanohole based SERS s...
Article
A stable gel of Au nanoparticles in polydimethylsiloxane (PDMS) nanocomposite is prepared by employing the curing agent of PDMS elastomer as a reducing agent for the formation of Au nanoparticles by an in-situ process. The viscoelastic nature of these gels is very sensitive to the Au nanoparticle loading and the synthetic temperature conditions. Ev...
Article
In the quest for indium-tin oxide (ITO)-free photovoltaics and for building integrated as well as automobile roof applications, novel transparent electrodes for both front and back electrodes are required. Here we report the fabrication and integration of submicrometer transparent silver (Ag) and gold (Au) metal network electrodes, which are invisi...
Article
Flexible, semitransparent and robust heating arrays have been designed by grayscale printing as ready-to-use devices for point-of-care application. A perforated Ag mesh is first fabricated with tunable features by controllably varying the toner grayscale value during laser printer on PET. The resistance could be varied between 1 to 2 Ω by tuning th...
Article
Full-text available
Accurate characterization and reporting of organic photovoltaic (OPV) device performance remains one of the important challenges in the field. The large spread among the efficiencies of devices with the same structure reported by different groups is significantly caused by different procedures and equipment used during testing.The presented article...
Article
Full-text available
Highly interconnected crackles were obtained by spreading commercially available low cost crackle wall paint based precursor by the drop coating technique. An interconnected Ag mesh was fabricated by depositing metal over the crackle network followed by the removal of the template. The metal network is well conducting (1 Ω −1) with transmittance of...
Article
A single micro/nanowire network of a metal deposited over a large area on a transparent substrate serves as a transparent conducting electrode with optoelectronic properties that are enhanced in many ways relative to the conventional indium tin oxide films. The wire surface is extremely smooth and the junctions are seamless, thanks to the crackle l...
Article
We present an outdoor interlaboratory stability study of fully printed and coated indium-tin-oxide (ITO)-free polymer solar cell modules in JNCASR Bangalore (India), ECN (Holland), and DTU (Denmark) carried over more than 1 year. The modules comprising a fully printed and coated stack (Ag grid/PEDOT:PSS/ZnO/P3HT:PCBM/PEDOT:PSS/Ag grid) were prepare...
Article
Transparent conducting electrodes (TCEs) have been made on flat, flexible, and curved surfaces, following a crack template method in which a desired surface was uniformly spray-coated with a crackle precursor (CP) and metal (Ag) was deposited by vacuum evaporation. An acrylic resin (CP1) and a SiO2 nanoparticle-based dispersion (CP2) derived from c...
Article
Full-text available
As transparency is becoming a desirable property even in non-optoelectronic devices, there is great impetus given to alternate materials and strategies replacing the conventional ITO. Here we have used transparent Au wire networks as electrodes, obtained from a crackle template method, in a capacitor where an ion gel serves as the dielectric. The t...
Article
A solution-processed silver film is employed in the processing of top-illuminated indium-tin-oxide (ITO)-free polymer solar cells in single- and double-junction (tandem) structures. The nontransparent silver film fully covers the substrate and serves as the bottom electrode whereas a PEDOT:PSS/Ag grid forms the semitransparent top electrode. All la...
Article
Full-text available
We report a highly transparent, low resistant Ag metal network templated from a cracked polymer thin film and its incorporation in an organic solar cell. The performance of this scalable metallic network is comparable to that of conventional ITO electrode. This is a general approach to replace ITO in diverse thin film devices.
Article
Full-text available
A metal (Au) wire network, nearly invisible to the naked eye, has been realized on common substrates such as glass, to serve as a transparent conducting electrode (TCE). The process involves coating a TiO2 nanoparticle dispersion to a film thickness of ~10 μm, which following solvent evaporation, spontaneously forms a crackle network; the film is t...
Article
Full-text available
Virtually unlimited and highly interconnected Cu wire networks have been fabricated on polyethylene terephthalate (PET) substrates with sheet resistance of <5 Ω −1 and transmittance of 75%, as alternatives to the commonly used tin doped indium oxide (ITO) based electrodes. This is a four step process involving deposition of commercially available c...
Article
Full-text available
A simple method for producing patterned Ag electrodes on transparent and flexible substrates is reported. The process makes use of laser printed toner as a sacrificial template for an organic precursor, which upon thermolysis and toner lift off produced highly conducting Ag electrodes. Thus, the process takes only a few minutes without any expensiv...
Article
In this study, we demonstrate that a disposable chip periodically patterned with suitable ligands, an ordinary cellphone camera and a simple pattern recognition software, can potentially be used for quantitative diagnostics. A key factor in this demonstration is the design of a calibration grid around the chip, which, through a contrast transfer pr...
Article
Grayscale (halftone) laser printing is developed as a low-cost and solution processable fabrication method for ITO-free, semi-transparent and conducting Ag electrodes extendable over large area on a flexible substrate. The transmittance and sheet resistance is easily tunable by varying the grayscale value of the color fill between 10% to 20%. The o...
Article
Full-text available
As transparency is becoming a desirable property even in non-optoelectronic devices, there is great impetus given to alternate materials and strategies replacing the conventional ITO. Here we have used transparent Au wire networks as electrodes, obtained from a crackle template method, in a capacitor where an ion gel serves as the dielectric. The t...
Article
As solar cell modules are becoming larger, it is important to pay attention to defects originating from the fabrication process and degradation during operation in the ambient. In this article, a simple method of using computer screen display as a light source to map the photoresponse of the solar cells, is reported. The method requires only a conv...
Article
Full-text available
Polymer solar cell modules were prepared directly on thin flexible barrier polyethylene terephthalate foil. The performance of the modules was found to be scalable from a single cell with an area of 6 cm2 to modules with a total area of up to 186 cm2. The substrate thickness was also explored and the performance was found to be independent of thick...
Article
Nowadays, specifying the quality of a transparent conducting electrode (TCE) using a figure of merit (FoM) is considered nearly mandatory. However, not much attention is paid to the local variations in the FoM itself across the large area of the TCE. This calls for the definition of a local FoM (LFoM), particularly relevant with regard to several n...
Article
Pd grating patterns have been fabricated using the process of micromolding in capillary employing a Pd alkanethiolate precursor, which could be converted to metal in situ by thermolysis. Thus generated Pd grating were uniform in width (~950 nm) and spacing (~450 nm) over millimeter square areas on glass substrates. Importantly, the pattern when use...
Article
Full-text available
Organic fluorescent materials that enable a control of the emission color based on external influence are highly sought after in optoelectronic applications. A simple molecule, a di-methoxy substituted oligo(phenyleneethynylene), whose emission can be precisely tuned by controlling the cooling rate from the melt (1–13 °C min−1 and higher) or by cha...
Patent
Full-text available
A Pd grating of periodicity of 1.5 um comprising of 1um wide nanocrystalline Pd lines has been obtained by a direct micromolding method to serve as Hydrogen sensor element in an optical diffraction set up. The device uses a low power diode laser and a photodetector and works with sensitivity of 20%. The hydrogen sensing action is based on monitorin...
Article
A Pd grating of periodicity of 1.5 μm comprising of 1 μm wide nanocrystalline Pd lines has been obtained by a direct micromolding method to serve as Hydrogen sensor element in an optical diffraction set up. The device uses a low power diode laser and a photodetector and works with sensitivity of∼ 20%. The hydrogen sensing action is based on monitor...
Article
A low density, highly compressible, porous foam of poly(dimethylsiloxane) (PDMS) incorporated with Au nanoparticles (10-50 nm) has been synthesized by using a single-step process with water as a medium. It exhibits high swelling ability (≈600%) against benzene, toluene, ethylbenzene, and xylene (BTEX)-a property that has been exploited in the remov...
Article
Full-text available
A simple, one-step direct micromolding process has been realised to produce highly conducting Pd micro-stripes over large areas on various substrates including flexible polyimide. Under a PDMS micromold, Pd octanethiolate served as a precursor at 250 degrees C, a temperature at which the precursor gets neatly metallised. Thus produced micro-stripes...
Article
AuNP/PDMS nanocomposites have been synthesized in the form of gels, foams, and films with distinctive structure and morphology. A simple in situ process in aqueous medium for the formation of such composite materials is described. The nanoparticles are held firmly within the PDMS while still being chemically accessible to substances soluble in PDMS...

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