Novel, soft synthesis and characterization of calcite thin films on plasma-etched silicon substrates Jyoti Kumari, Pushpendra Kumar, Indrajit Mondal, Anoop Kumar Mukhopadhyay Chemical Physics Impact, 2026 This study reports for the very first time the simple, soft, low-cost synthesis of calcite thin films on 1 (D1), 3 (D2), 5 (D3), and 7 (D4) minutes plasma jet etched p-type Si substrates for futuristic optoelectronic device applications. The calcite (CaCO3) thin films were deposited by a sequential dipping method in 0.2 M Calcium Nitrate and 0.2 M Sodium Hydroxide solutions, followed by appropriate exposure to ambient air for desired carbonization that caused the film formation. The nanometric thin films of thickness about 308, 286, 264, and 242 nm were characterized by several characterization techniques. The optical contact angle measurement confirmed that as the plasma etching time was increased, the substrate became rougher and the surface more hydrophilic. The XRD results confirmed that, depending on etching time 80 to 60 wt.% calcite phase was present in the thin films the rest being the Si phase (20 to 40 wt.%). The FTIR data confirmed the presence of the characteristic surface carbonate radicals and related vibrational bonds in all the thin films. FESEM confirmed the morphology of nanostructured calcite thin films, which gradually grew from assembly of nanoparticles (D1) to nanorods (D2) to nanoplatelets (D3) to nanoflower (D4) for etching times of 1, 3, 5, and 7 min. Finally, the UV–Vis results showed that the optical energy band gap increases with a decrease in crystallite size and an increase in etching time. All the mechanisms behind such tunable microstructure development and the tunable optical energy band gap achievement are explained in terms of the Gibbs Free Energy concept and the quantum confinement effect. Finally, the implications of these novel microstructurally tunable calcite thin films on p-type Si substrate for futuristic optoelectronic device development are suggested.
Effect of synthesis process on the properties of GO/Ca(OH)2 nanocomposite and dye removal efficiency Surendra Singh, Akash, Pushpendra Kumar, Upendra Kulshrestha, Ashok Kumar Sharma, Vipin Kumar, Rahul Singhal Chemical Physics Impact, 2026 In this study, graphene oxide (GO) was synthesized by modified Hummer method and Ca(OH)₂ was synthesized using a hydrothermal route at 180°C for 24 hours. After the synthesis of graphene oxide (GO) and Ca(OH) 2 , the nanocomposites of GO/Ca(OH) 2 were synthesized using two different methodologies, first was chemical-precipitation method (CP) and second was hydrothermal method (HT). The synthesized samples were characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), UV-visible spectroscopy, Brunauer-Emmett-Teller (BET) and Field emission scanning electron microscopy (FESEM) to analyze their crystalline structure, chemical composition, optical properties, surface area and surface morphological study, respectively. The average crystal size was obtained as 100.47, 102.71, and 104.25 nm for Ca(OH)₂, GO/Ca(OH)₂-CP, and GO/Ca(OH)₂-HT, respectively. The optical bandgap for Ca(OH)₂ was found to be 5.726 eV, while the bandgap energy increased for the GO/Ca(OH)₂ nanocomposite material. Morphological studies revealed wrinkled GO sheets, nanoscale Ca(OH) 2 particles, and a well-integrated composite structure with uniformly dispersed Ca(OH) 2 nanoparticles on the GO surface. Further, two types of dyes were selected for the study of wastewater treatment, one of which was a cationic dye Rhodamine-6G (Rh6G) and another was anionic dye Methyl Orange (MO). Rh6G was 97% removed by all the samples due to attractive electrostatic interaction between nanomaterials and Rh6G, and methyl orange was less removed due to repulsive electrostatic interaction. This work uniquely mixed GO and Ca(OH) 2 to develop a hybrid nanocomposite material for cost effective treatment of wastewater.
Hydration-Engineered Widely Interlayered Vanadium Oxide Nanobelts for High-Performance Aqueous Zinc-Ion Batteries Divya Rani, Abhishek Dubey, Bheem Kumar, Mahaveer Singh, A. L. Sharma, A. M. P. Hussain, Kedar Singh, Pushpendra Kumar Batteries and Supercaps, 2026 Aqueous zinc‐ion batteries (AZIBs) have attracted significant attention for large‐scale energy storage due to their intrinsic safety, low cost, and environmental compatibility. However, sluggish Zn 2+ diffusion kinetics and high desolvation energy severely restrict the performance of conventional cathode materials. Herein, we report the scalable low‐temperature hydrothermal synthesis of widely interlayered mixed phase hydrated vanadium oxide nanobelts (V 2 O 5 ·1.6H 2 O/V 2 O 5 ·3H 2 O, HVO) as an efficient cathode for AZIBs. The incorporation of structural water molecules expands the interlayer spacing and forms hydrogen‐bonding networks that facilitate Zn 2+ diffusion and improves reversibility. Moreover, the nanobelt morphology containing surface cracks enhances electrolyte penetration and shortens ion transport pathways. The HVO cathode delivers a high specific capacity of 510 mAh g −1 at 0.1 A g −1 , exhibiting hybrid charge storage behavior involving diffusion‐controlled intercalation and dominant pseudocapacitive contributions. The use of zinc trifluoro methane sulfonate electrolyte promotes the formation of a stable perfluoropolyether‐derived cathode‐electrolyte interphase, improving interfacial stability and suppressing parasitic reactions. Consequently, the electrode retains 74.03% of its capacity after 6000 cycles at 10 A g −1 . Post‐cycling analysis reveals partial transformation into Zn 3 (OH) 2 V 2 O 7 ·2H 2 O due to H + /Zn 2+ co‐intercalation. This study demonstrates the effectiveness of hydration engineering for improving structural stability and ion transport in vanadium oxide cathodes for advanced AZIBs.
Interfacial Engineering of Ti3C2Tx -Protected CsPbBr3 Perovskite Quantum Dots for Enhanced Charge Transport and Superior Hydrogen Evolution Catalysis Priyanka, Avinash Rundla, Bheem Kumar, Mahaveer Singh, Divya Rani, Pushpendra Kumar, Vikash Mishra, Kedar Singh Advanced Sustainable Systems, 2026 Hydrogen from electrochemical water splitting is a green energy carrier, but sluggish HER kinetics necessitate cost‐effective alternatives to insufficient Pt‐based catalysts. In this respect, efficient, low‐cost HER electrocatalysts are crucial for survivable hydrogen production, with inorganic halide perovskites offering variable ionic‐electronic conductivity and processability, while MXene provide complementary benefits of high conductivity and abundant active sites. State‐of‐the‐art engineering strategies and characterization techniques of CsPbBr 3 @Ti 3 C 2 T x hierarchical structure are elucidated, emphasizing how unique crystallographic features and tuneable surface terminations of Ti 3 C 2 T x synergistically augment catalytic activity of pristine CsPbBr 3 perovskite quantum dots (PQDs). Subsequently, experimental and theoretical aspects employing CsPbBr 3 @Ti 3 C 2 T x nanohybrids as efficient HER electrocatalysts are extensively discussed. Electrochemical analysis demonstrated that CsPbBr 3 @Ti 3 C 2 T x delivered a low onset potential of −231.12 mV following Volmer‐Heyrovsky pathway with reduced Tafel slope of 48.04 mV dec −1 , indicative of accelerated HER kinetics. The hierarchical structure flaunted supercilious cycling stability compared to CsPbBr 3 PQDs, with the intensified activity emerging from efficient charge ddeliveryat CsPbBr 3 /Ti 3 C 2 T x interface, ample sites, and low R ct . These experimental examinations are further corroborated by theoretical calculations, disclosing laudatory Gibbs free energy and enriched total density of states. CsPbBr 3 @Ti 3 C 2 T x emerge as lucrative, high‐performance HER electrocatalysts, where Ti 3 C 2 T x reinforced stability and conductivity, offering fa lexible approach for next‐generation energy conversion.
Hydrothermally synthesis Cd(OH)2: a high efficiency catalyst for OER in green hydrogen production Neelam Nagda, Naveen Suthar, Pushpendra Kumar, K. K. Nagaraja, Ajay Saini Discover Applied Sciences, 2026 The development of an OER electrocatalyst that combines remarkable durability with high activity is a major concern in today’s energy transition. This study utilizes a hydrothermal technique to synthesize Cd(OH)2 directly on a nickel foam (NF) substrate for application as an electrocatalyst in the oxygen evolution reaction (OER). The impact of different synthesis temperature on electrocatalytic activity was evaluated, focusing specially on the overpotential needed to reach a current density of 10 mA.cm− 2 in 1 M KOH solution. The X-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM), Fourier transform infrared (FTIR) spectroscopy, and UV-Vis spectroscopy was employed to investigate the crystal structure, surface morphology, functional groups and optical properties of the synthesized Cd(OH)₂ samples, respectively. The catalytic performance of Cd(OH)₂ in water splitting is discussed based on the change in structural, microstructural and optical properties. The outcome demonstrates the high activity of the Cd(OH)2 electrocatalyst in generating. The Cd(OH)2 electrocatalyst show a remarkable performance for OER with low overpotential (358 mV at 10 mA.cm− 2) and low Tafel slope (66 mV.dec− 1) in 1 M KOH.
Quasi-2D Ca2X (X = C, Si, Ge, Sn, Pb) hexagonal intermetallic monolayer compounds: Comprehensive and comparative study on the electronic properties and strong anisotropic photo-response Vipin Kumar, Jin Seog Gwag, Pushpendra Kumar Results in Physics, 2025 • The 2D Ca 2 X (X = C, Si, Ge, Sn, Pb) monolayer compounds were explored for their optoelectronic applications using computational tools. • These materials are indirect bandgap materials, except for Ca 2 C, which exhibits metallic feature. • These materials exhibit strong anisotropic behaviour in response to the polarization directions of the light field. • Their polarization-dependent reflection coefficient indicates that they are useful for antireflective coating materials. Quasi-two-dimensional (2D) materials have garnered significant research interest due to their fascinating physical properties and diverse potential applications across various fields. Here, we investigate the electronic properties and anisotropic photo-response of quasi-2D monolayer hexagonal intermetallic compounds based on ultrathin Ca 2 X (X = group IVA elements) films using computational tools. Electronic investigations indicate that these monolayer compounds are indirect-band-gap semiconductors, except for the Ca 2 C monolayer, which exhibits metallic features. The calculated density of states (both total and projected) for these compounds corroborates the corresponding electronic band structures. The included spin–orbit coupling (SOC) for heavy elements like Sn and Pb exhibits the band splitting in the valence band of Ca 2 Sn and Ca 2 Pb monolayers. The obtained cohesive energy reveals that the Ca 2 C is the most stable structure. However, the structural stability is slightly reduced when the X-atom is moved from top to bottom within group IVA. The investigated materials exhibit strong anisotropic dielectric behavior in response to the polarization directions of the light field (in-plane and out-of-plane). These materials exhibit strong light absorption across the infrared (IR) to visible to low-energy ultraviolet (UV) spectrum. A more intense light absorption is also noticed in the X-ray region. Hence, these are excellent for absorption band-pass and stop filters. The calculated refractive index is the highest for the Ca 2 C monolayer and exhibits an anisotropic dispersion along the x- and z-directions. Moreover, these materials can also be realized as polarization-dependent reflection and transmission band filters, which are useful for antireflective coating materials. The investigated properties indicate that these materials have great potential in numerous optoelectronic device applications.
Influence of Impurity on the Properties of Chemically Synthesized Calcium Hydroxide Department of Physics, Manipal University Jaipur, Jaipur-303007, Rajasthan, India, Harish Harish, Pushpendra Kumar, Department of Physics, Manipal University Jaipur, Jaipur-303007, Rajasthan, India, Jyoti Kumari, Department of Physics, Manipal University Jaipur, Jaipur-303007, Rajasthan, India, Priyanka Phalswal, Nano-chemistry Lab, Department of Applied Chemistry, DIAT, Girinagar, Pune 411025, India, Pawan K. Khanna, Nano-chemistry Lab, Department of Applied Chemistry, DIAT, Girinagar, Pune 411025, India, Amena Salim, Department of Physics, Malaviya National Institute of Technology, Jaipur-302017, India, Rahul Singhal, Department of Physics, Malaviya National Institute of Technology, Jaipur-302017, India, Anoop Kumar Mukhopadhyay, Department of Physics, Manipal University Jaipur, Jaipur-303007, Rajasthan, India, Rajendra P. Joshi, RI Instruments, Innovation India, Haldwani, 263139, Uttarakhand, India Journal of Nano and Electronic Physics, 2021
Studies on nanostructured bilayered semiconductor system in PEC water splitting for hydrogen production Aiche Annual Meeting Conference Proceedings, 2012
Nanostructured ZnO thin film for photoelectrochemical splitting of water: A study on role of electrolytes Aiche Annual Meeting Conference Proceedings, 2011
Nanostructured ZnO thin film for photoelectrochemical splitting of water: A study on role of electrolytes Nanomaterials for Energy Applications Topical Conference at the 2011 Aiche Annual Meeting, 2011
Novel, Soft Synthesis and Characterization of Calcite Thin Films on Plasma-Etched Silicon Substrates J Kumari, P Kumar, I Mondal, AK Mukhopadhyay Chemical Physics Impact, 101061 , 2026 2026
Effect of Synthesis Process on The Properties of GO/Ca (OH) 2 Nanocomposite and Dye Removal Efficiency S Singh, P Kumar, U Kulshrestha, AK Sharma, V Kumar, R Singhal Chemical Physics Impact, 101057 , 2026 2026
Insights into the 2D Janus SiOS monolayer: structural, electronic, and optical properties via first-principles study V Kumar, P Kumar, JS Gwag Physica B: Condensed Matter, 418642 , 2026 2026
Low-temperature hydrothermal synthesis of graphitic carbon nitrate-zinc oxide hybrid and study of its photo-luminescence property P Kumar, D Banerjee, AK Sharma Next Materials 11, 101771 , 2026 2026 Citations: 1
Systems, apparatus, and methods to improve webservers using dynamic load balancers A MISRA, N McDonnell, M Ganguli, E Verplanke, S Palermo, R Shah, ... US Patent 12,556,597 , 2026 2026
Hydrothermally synthesis Cd(OH) 2 : a high efficiency catalyst for OER in green hydrogen production N Nagda, N Suthar, P Kumar, KK Nagaraja, A Saini Discover Applied Sciences , 2026 2026
Tailoring the optoelectronic properties of transition metal-doped octahedrally coordinated silicon dioxide (SiO 2 ) monolayer: V Kumar et al. V Kumar, P Kumar, M Singh Indian Journal of Physics, 1-14 , 2025 2025 Citations: 1
Quasi-2D Ca2X (X= C, Si, Ge, Sn, Pb) hexagonal intermetallic monolayer compounds: Comprehensive and comparative study on the electronic properties and strong anisotropic photo … V Kumar, JS Gwag, P Kumar Results in Physics, 108515 , 2025 2025
Enhanced Corrosion Protection of Mild Steel with Ferrocene-Fortified Graphite Epoxy Coatings M Pandey, S Mehtab, MGH Zaidi, VK Shukla, P Kumar, AK Rai ACS Applied Engineering Materials 3 (11), 4037-4049 , 2025 2025 Citations: 1
Tailoring the electronic properties and optical responses in semiconductor-doped magnesium hydroxide monolayer for optoelectronic applications V Kumar, P Kumar, GK Maurya, JS Gwag International Journal of Modern Physics B 39 (24), 2550231 , 2025 2025
Enhanced adsorption characteristics of different modified biochars derived from biomass pyrolysis for the removal of textile effluents L Kumar, N Chakinala, P Kumar, AG Chakinala Chemical Engineering and Processing-Process Intensification, 110538 , 2025 2025 Citations: 2
Toxic gas adsorption on in-plane monolayer heterostructure of transition metal dichalcogenide: a first-principles study V Kumar, P Kumar, GK Maurya, JS Gwag Journal of the Korean Physical Society 87 (3), 281-291 , 2025 2025
Electro-optical properties of zigzag and armchair transition metal dichalcogenide nanoribbons V Kumar, P Kumar, Akash, JS Gwag Reaction Kinetics, Mechanisms and Catalysis 138 (4), 2151-2162 , 2025 2025
Effect of Ni doping on the properties of Ca (OH) 2 nanoparticles and its application in toxic methylene blue dye removal P Kumar, V Kumar, AK Sharma, AK Mukhopadhyay Results in Physics, 108355 , 2025 2025 Citations: 2
Advances in chemically tailored metal alkoxide as single-source precursors for engineered oxide nanostructures A Saini, D Singh, P Kumar, KK Nagaraja Open Ceramics 22, 100800 , 2025 2025
Enhanced Visible Light Response in Engineered Strontium Iodide Monolayer for Optoelectronic Applications V Kumar, U Kumar, GK Maurya, P Kumar, JS Gwag Applied Science and Convergence Technology 34 (1), 1-11 , 2025 2025
Hydrothermally synthesis Cd (OH) N Nagda, N Suthar, P Kumar, KK Nagaraja, A Saini 2025
A critical review on the active anti-viral metabolites of bioprospecting traditionally used plant species from semi-arid regions of the subcontinent A Naz, A Chowdhury, S Pareek, P Kumar, NK Poddar Journal of Complementary and Integrative Medicine 21 (4), 412-439 , 2024 2024 Citations: 3
Insights into the electronic, optoelectronic, and photocatalytic properties of octahedrally coordinated strontium dichloride (SrCl2) monolayer V Kumar, GK Maurya, P Kumar, JS Gwag Computational Condensed Matter 41, e00971 , 2024 2024 Citations: 3
Dielectric study of shellac composites through varying filler concentrations M Chaparia, N Kumari, A Chaurasia, RK Choubey, P Kumar, UK Dwivedi Reaction Kinetics, Mechanisms and Catalysis 137 (6), 3047-3057 , 2024 2024 Citations: 7
MOST CITED SCHOLAR PUBLICATIONS
Oxygen-Insensitive Nitroreductases: Analysis of the Roles of nfsA and nfsB in Development of Resistance to 5-Nitrofuran Derivatives in Escherichia coli J Whiteway, P Koziarz, J Veall, N Sandhu, P Kumar, B Hoecher, ... Journal of bacteriology 180 (21), 5529-5539 , 1998 1998 Citations: 307
Effect of etching parameter on pore size and porosity of electrochemically formed nanoporous silicon P Kumar, P Huber Journal of Nanomaterials 2007 (1), 089718 , 2007 2007 Citations: 77
Tuning the pore wall morphology of mesoporous silicon from branchy to smooth, tubular by chemical treatment P Kumar, T Hofmann, K Knorr, P Huber, P Scheib, P Lemmens Journal of Applied Physics 103 (2) , 2008 2008 Citations: 59
Effect of silicon crystal size on photoluminescence appearance in porous silicon P Kumar International Scholarly Research Notices 2011 (1), 163168 , 2011 2011 Citations: 57
Effect of HF concentration on physical and electronic properties of electrochemically formed nanoporous silicon P Kumar, P Lemmens, M Ghosh, F Ludwig, M Schilling Journal of Nanomaterials 2009 (1), 728957 , 2009 2009 Citations: 53
Preferred orientation of -hexane crystallized in silicon nanochannels: A combined x-ray diffraction and sorption isotherm study A Henschel, P Kumar, T Hofmann, K Knorr, P Huber Physical Review E—Statistical, Nonlinear, and Soft Matter Physics 79 (3 … , 2009 2009 Citations: 50
Coherent Manipulation of Electron Spins in the Spin Triangle Complex Impregnated <?format ?>in Nanoporous Silicon KY Choi, Z Wang, H Nojiri, J Van Tol, P Kumar, P Lemmens, BS Bassil, ... Physical review letters 108 (6), 067206 , 2012 2012 Citations: 49
Palladium capped samarium thin films as potential hydrogen sensors P Kumar, LK Malhotra Materials chemistry and physics 88 (1), 106-109 , 2004 2004 Citations: 49
Recent progress in gas sensing based on 2D SnS2 and its heterostructure platforms: A review RK Mishra, HJ Choi, JW Ryu, GJ Choi, V Kumar, P Kumar, J Singh, ... Sensors and Actuators A: Physical 365, 114860 , 2024 2024 Citations: 40
Influence of chemical synthesis process on the properties of calcium hydroxide nanoparticles P Kumar, J Kumari, L Kumar, A Salim, R Singhal, AK Mukhopadhyay, ... Materials Today: Proceedings 60, 153-159 , 2022 2022 Citations: 36
Recent advances in ZnO nanostructure as a gas‐sensing element for an acetone sensor: a short review RK Mishra, V Kumar, LG Trung, GJ Choi, JW Ryu, R Bhardwaj, P Kumar, ... Luminescence 38 (7), 1087-1101 , 2023 2023 Citations: 29
Utilization of green reductant Thuja Orientalis for reduction of GO to RGO P Kumar, G Andersson, KM Subhedar, HS Dhami, G Gupta, ... Ceramics International 47 (10), 14862-14878 , 2021 2021 Citations: 28
Detailed investigation on structural, optical, dielectric and magneto-dielectric properties with enhanced magneto-impedance characteristic of NdFeO3 nanoparticles P Yadav, A Pandey, B Khan, R Biswal, A Fahad, P Kumar, MK Singh Materials Chemistry and Physics 309, 128424 , 2023 2023 Citations: 24
Effect of reaction rate on the properties of chemically synthesized calcium hydroxide nanoparticles Harish, P Kumar, B Malhotra, P Phalswal, PK Khanna, A Salim, R Singhal, ... Materials Today: Proceedings , 2020 2020 Citations: 24
Optical properties, dielectric relaxor behavior, impedance and modulus spectroscopy of 0.8 BiFeO3-0.2 CaTiO3 composite B Khan, MK Singh, P Yadav, A Kumar, G Singh, P Kumar Materials Chemistry and Physics 290, 126642 , 2022 2022 Citations: 22
Synthesis, morphological and optical properties of hydrothermally synthesized Bi and Mn co-doped Cu2ZnSnS4 (CZTS) A Pandey, P Yadav, P Kumar, MK Singh Materials Today: Proceedings 82, 85-90 , 2023 2023 Citations: 19
Study of Solution Grown Variable BandGap Pb 1 − x Mn x S Semiconductor Nanoparticle Films RK Joshi, P Kumar, HK Sehgal, A Kanjilal Journal of The Electrochemical Society 153 (10), C707-C712 , 2006 2006 Citations: 19
WS 2 Nanorod as a Remarkable Acetone Sensor for Monitoring Work/Public Places RK Mishra, V Kumar, LG Trung, GJ Choi, JW Ryu, SM Mane, JC Shin, ... Sensors 22 (22), 8609 , 2022 2022 Citations: 18
Synthesis, Characterization, and antibacterial activity of calcium hydroxide nanoparticles against gram‐positive and gram‐negative bacteria Harish, S Kumari, J Parihar, Akash, J Kumari, L Kumar, M Debnath, ... ChemistrySelect 7 (37), e202203094 , 2022 2022 Citations: 17
Nucleation and growth of copper on mesoporous silicon by immersion plating P Kumar, P Huber Journal of Physics D: Applied Physics 40 (9), 2864-2869 , 2007 2007 Citations: 17
GRANT DETAILS
Research Project
Running
As PI Project Title: “The facile and low-cost solution for wastewater treatment based on ceramic nanocomposite materials”, Funding Agency: Science and Engineering Research Board (SERB-DST).
Cost: Rs. 23,00,000/- (October 2023- October 2026)
As PI Project Title: “Layered Double Hydroxides as electrode for Sustainable Green Hydrogen Energy via Water Electrolysis: A Novel Approach for Clean Energy Generation”, Funding Agency: MAHE research board (MRB). Cost: Rs. 4,70,000/- (December 2023- December 2025)
Completed
As PI Project Title: “Novel Calcium Hydroxide-Nanocomposites for Multifunctional Applications”
Cost: Rs. 3,00,000/- Funded by Manipal University Jaipur. (October 2019 – June 2022)
As PI Project Title: “Synthesis of Si nanoparticles from electrochemically prepared porous silicon”
Cost: Rs. 1,00,000/- Funded by Manipal University Jaipur., ( July 2016 – March 2018)
As PI Project Title: Metal hydroxide-graphene oxide nanocomposite materials for wastewater treatment, Cost: Rs. 5,60,000/-, Funding Agency: RI Instruments & Innovation India (May 2020-October 2022).
As Co-PI in International project on “Textile Industries & Ground Water Contamination around Jaipur, India” funded by KWEF-2015, Japan Grant No.: 15P026,
Cost: 3,00,000 YEN, (October 2015- September 2016)
