Materials Chemistry, Catalysis, Renewable Energy, Sustainability and the Environment, Electrochemistry
28
Scopus Publications
1238
Scholar Citations
17
Scholar h-index
19
Scholar i10-index
Scopus Publications
Facet selective engineered TiO2 as photoanode for dye sensitized solar cells Lakshmi Srinivasan, Nisha T Padmanabhan, Honey John, Narayanapillai Manoj, Pramod Gopinath Materials Today Communications, 2026 Dye-sensitized solar cells (DSSCs) often suffer from inefficient charge transport and recombination losses, limiting their power conversion efficiency. Advancing beyond conventional TiO 2 photoanodes requires deliberate control of charge dynamics at the crystallographic level. In this study, anatase TiO 2 nanocrystals with well-defined characteristic facets were used as photoanodes in DSSCs. A hydrothermally modified sol-gel method was used to synthesize these nanocrystals, utilizing cetyltrimethylammonium bromide (CTAB) as a morphology-controlling agent and titanium tetra isopropoxide (TTIP) as a precursor. Under an acidic pH of 3, the process facilitated the effective adherence of CTAB molecules to the high-energy facets of TiO 2 , resulting in crystal growth elongation along specific directions and facet exposures. The photovoltaic conversion efficiency of DSSCs based on nanocrystalline TiO 2 was compared with that of DSSCs utilizing commercial-grade P25 TiO 2 . The remarkable enhancement in photovoltaic activity of nanocrystalline TiO 2 -based DSSCs was attributed to the increased number of active sites for dye adsorption, leading to enhanced light absorption. Furthermore, high-energy facets significantly improved electron mobility and facilitated spatial separation of photogenerated charge carriers. The photoanodes incorporating the as-synthesized TiO 2 nanocrystals as the active layer exhibited an impressive photoconversion efficiency of 6.6%, markedly surpassing the reference photoanode's efficiency. This study underscores that rational crystallographic design of single-component TiO 2 provides a material-intrinsic and potent pathway to optimize the charge transport dynamics to a greater extend in DSSCs.
Advancing hydrogen storage: critical insights to potentials, challenges, and pathways to sustainability Nisha T Padmanabhan, Laura Clarizia, Priyanka Ganguly Current Opinion in Chemical Engineering, 2025 Research in green hydrogen production is advancing through photocatalysis and electrocatalysis, but storage remains a challenge. Promising hydrogen carriers, such as methanol, ammonia, formic acid, liquid organic hydrogen carriers, and metal hydrides, face issues like low hydrogen content and high energy demands. This review highlights innovations in hydrogen storage, focusing on carrier synthesis and photocatalytic hydrogen release for sustainable, energy-efficient solutions. Advancing catalysts, reactors, lifecycle assessments, and economic feasibility is crucial. Hybrid approaches and augmented intelligence are essential for developing cost-effective, high-efficiency storage systems, driving progress toward a sustainable hydrogen economy.
Multifunctional carbonaceous materials derived from tea waste: Towards sustainable solutions for wastewater treatment and hydrogen evolution Amrutha Thomas, Nisha T. Padmanabhan, E.J. Jelmy, Pramod Gopinath, Honey John Cleaner Waste Systems, 2025 The depletion of conventional energy sources and the alarming rise in water contamination underscore the urgent need for advanced materials that can simultaneously address wastewater treatment and hydrogen evolution reactions (HER). While existing materials offer solutions to either wastewater treatment or HER, multifunctional materials have been developed to address both challenges concurrently. Biomass-derived carbonaceous materials, particularly from abundant and sustainable sources like tea waste, present an environmentally friendly, cost-effective solution. This study presents novel, multifunctional nanomaterials derived from tea waste via facile synthesis method including KOH activation of tea waste ashes (GCW), microwave-assisted carbonization (GCOM), and hydrothermal modification (GCOH) of GCW to create materials capable of efficient dye adsorption and excellent HER activity. The FESEM, TEM, XRD, FTIR, Raman spectroscopy, TGA, BET, the XPS techniques were employed to thoroughly examine the morphological and structural properties of the materials. Among the synthesized materials, hydrothermally treated one (GCOH) after KOH activation of tea waste ashes demonstrated the highest adsorption capacity. Specifically, it showed values of 48 mg/g for the cationic dye Methylene Blue (MB) and 43 mg/g for the anionic dye Methyl Orange (MO). Additionally, GCOH exhibited excellent HER activity in an acidic medium, with an onset overpotential of 349 mV (466 mV at 50 mA cm −2 ) and a lower Tafel slope of 128 mV dec −1 . These findings suggest that biomass-derived carbonaceous materials, particularly from tea waste, can serve as dual-functional agents, offering a sustainable approach to addressing critical environmental and energy challenges. • We have synthesized multifunctional carbonaceous materials from tea waste using a facile synthesis method. • The synthesis includes activation of carbonized tea waste, microwave-assisted carbonization & its hydrothermal treatment. • Among the synthesized materials, the hydrothermally treated one (GCOH) shows a superior dye adsorption capacity. • Further, GCOH demonstrates enhanced electrochemical activity for Hydrogen Evolution Reaction.
The rise of borophene Prashant Kumar, Gurwinder Singh, Rohan Bahadur, Zhixuan Li, Xiangwei Zhang, C.I. Sathish, Mercy R. Benzigar, Thi Kim Anh Tran, Nisha T. Padmanabhan, Sithara Radhakrishnan, Jith C Janardhanan, Christy Ann Biji, Ann Jini Mathews, Honey John, Ehsan Tavakkoli, Ramaswamy Murugavel, Soumyabrata Roy, Pulickel M. Ajayan, Ajayan Vinu Progress in Materials Science, 2024 Borophene stands out uniquely among Xenes with its metallic character, Dirac nature, exceptional electron mobility, thermal conductivity, and Young’s moduli—surpassing graphene. Invented in 2015, various methods, including atomic layer deposition, molecular beam epitaxy, and chemical vapor deposition, have successfully been demonstrated to realize substrate-supported crystal growth. Top-down approaches like micromechanical, sonochemical, solvothermal and modified hummer’s techniques have also been employed. Thanks to its high electronic mobility, borophene serves as an active material for ultrafast sensing of light, gases, molecules, and strain. Its metallic behaviour, electrochemical activity, and anti-corrosive nature make it ideal for applications in energy storage and catalysis. It has been proven effective as an electrocatalyst for HER, OER, water splitting, CO2 reduction, and NH3 reduction reactions. Beyond this, borophene has found utility in bioimaging, biosensing, and various biomedical applications. A special emphasis will be given on the borophene nanoarchitectonics i.e. doped borophene and borophene-based hybrids with other 2D materials and nanoparticles and the theoretical understanding of these emerging materials systems to gain more insights on their electronic structure and properties, aiming to manipulate borophene for tailored applications.
Surfactant-Assisted Restructuring of Boron to Borophene: Implications for Enhanced Hydrogen Evolution Sithara Radhakrishnan, Nisha T. Padmanabhan, Ann Jini Mathews, Youhong Tang, T. Santhanakrishnan, Honey John ACS Applied Nano Materials, 2024 Borophene 2D nanosheets of boron and the evolving group III trans-graphene are a potential material for a plethora of applications; however, they have not been well explored due to the ambiguity in their electronic configuration and consequent polymorphism. Here, we introduced liquid-phase treatments utilizing surfactants exfoliating boron to 2D borophene. Poly(ethelyene glycol) (PEG) polymeric chains with neutral characteristics simultaneously with surfactants of cationic and anionic characteristics, respectively, as cetyltrimethylammonium bromide (CTAB) and sodium dodecyl sulfate (SDS) were utilized to constructively engineer a β rhombohedral crystal structure in borophene layers. These engineered borophene layers, on further analyzing their electrochemical performance by hydrogen evolution reactions, showed a heightened efficacy for borophene sheets synthesized in the presence of PEG, characterized by a Tafel slope of 178 mV/dec in a 0.5 M H 2 SO 4 solution. This enhanced performance was intricately linked to the elevated quality of the borophene sheets during PEG-assisted liquid-phase treatment and to the increased accessibility of active sites characterized by the β rhombohedral crystal lattices engineered by PEG polymeric chains.
Exploring the Catalytic Potential of Crystalline β-Ta2O5: From Water Purification to Hydrogen Production NT Padmanabhan, N Manoj, H John Next Research, 101383 , 2026 2026
Facet Selective Engineered TiO2 as photoanode for Dye Sensitized Solar Cells L Srinivasan, NT Padmanabhan, H John, NP Manoj, P Gopinath Materials Today Communications, 114702 , 2026 2026 Citations: 2
ZnO/Mo2TiC2 MXene nanohybrids for enhanced solar-driven photocatalytic degradation of tetracycline and organic pollutants in contaminated water NT Padmanabhan, K Gayathri, RM Thomas, H John Energy & Environmental Sustainability 1 (3), 100042 , 2025 2025 Citations: 54
Advancing hydrogen storage: critical insights to potentials, challenges, and pathways to sustainability NT Padmanabhan, L Clarizia, P Ganguly Current Opinion in Chemical Engineering 48, 101135 , 2025 2025 Citations: 17
Multifunctional carbonaceous materials derived from tea waste: Towards sustainable solutions for wastewater treatment and hydrogen evolution A Thomas, NT Padmanabhan, EJ Jelmy, P Gopinath, H John Cleaner Waste Systems 10, 100233 , 2025 2025 Citations: 3
The rise of borophene P Kumar, G Singh, R Bahadur, Z Li, X Zhang, CI Sathish, MR Benzigar, ... Progress in Materials Science 146, 101331 , 2024 2024 Citations: 82
Analysing the efficacy of TiO2/g-C3N4 nanohybrid electrospun membranes for visible-light photocatalytic water purification NT Padmanabhan, C Sabin, HU Krishnan, M Hrithik, U Mythili, MK Jayaraj, ... Chemical Physics Letters 854, 141547 , 2024 2024 Citations: 7
2D Semiconductors for Environmental Remediation H John, NT Padmanabhan, S Stanly, JC Janardhanan CRC Press , 2024 2024
The Surface Science of 2D Semiconductors: An Introduction MK Kavitha, NT Padmanabhan 2D Semiconductors for Environmental Remediation, 1-23 , 2024 2024 Citations: 6
Controlled reaction dynamics of cellulose: Revealing the dual morphology nanocrystals SR Joseph, JC Janardhanan, NT Padmanabhan, H John, U Mythili Materials Today Sustainability 27, 100860 , 2024 2024 Citations: 2
Surfactant-assisted restructuring of boron to borophene: implications for enhanced hydrogen evolution S Radhakrishnan, NT Padmanabhan, AJ Mathews, Y Tang, ... ACS Applied Nano Materials 7 (11), 12564-12578 , 2024 2024 Citations: 20
Topology structure significance on the applications of morphologically diverse molybdenum disulfide JC Janardhanan, NT Padmanabhan, PJ Jandas, M Sathyan, RM Thomas, ... Journal of Environmental Chemical Engineering 12 (2), 112268 , 2024 2024 Citations: 10
Exploring enhanced interfacial charge separation in ZnO/reduced graphene oxide hybrids on alkaline photoelectrochemical water splitting and photocatalytic pollutant degradation J Louis, NT Padmanabhan, MK Jayaraj, H John Materials Research Bulletin 169, 112542 , 2024 2024 Citations: 43
Directed morphology engineering of 2D MoS2 nanosheets to 1D nanoscrolls with enhanced hydrogen evolution and specific capacitance JC Janardhanan, NT Padmanabhan, PJ Jandas, NV Nayar, N Manoj, ... Journal of Colloid and Interface Science 652, 240-249 , 2023 2023 Citations: 9
Microwave-induced growth of {101̅0} faceted zinc oxide/graphene 2D/2D nanostructures for visible-light photocatalysis and hydrogen evolution reaction J Louis, NT Padmanabhan, MK Jayaraj, H John Journal of Alloys and Compounds 942, 169071 , 2023 2023 Citations: 15
Interface Engineering of 2D NiMOF–MoS 2 Hybrids for Electrocatalytic Hydrogen Evolution JC Janardhanan, NT Padmanabhan, SC Pillai, H John ACS Sustainable Chemistry & Engineering 11 (18), 6890-6902 , 2023 2023 Citations: 26
Antibacterial self-cleaning nylon-11/TiO2nanofiber membranes as triboelectric nanogenerators S Joseph, NT Padmanabhan, J Jose, H John Results in Engineering 17, 100869 , 2023 2023 Citations: 32
HYDROTHERMALLY GROWN ZnO/rGO AND ZnO/PANI NANOHYBRIDS: COMPARATIVE STUDY ON THEIR ELECTRICAL CONDUCTANCE NT Padmanabhan, R Santhosh, A Antony, U Mythili Journal of advanced scientific research 13 (10), 07-11 , 2022 2022 Citations: 3
Recent updates on triboelectric nanogenerator based advanced biomedical technologies: A short review S Radhakrishnan, N Joseph, NP Vighnesh, PJ Sabarinath, J John, ... Results in Engineering 16, 100782 , 2022 2022 Citations: 32
Antibacterial self-cleaning binary and ternary hybrid photocatalysts of titanium dioxide with silver and graphene NT Padmanabhan, RM Thomas, H John Journal of Environmental Chemical Engineering 10 (2), 107275 , 2022 2022 Citations: 40
MOST CITED SCHOLAR PUBLICATIONS
Graphene coupled TiO2 photocatalysts for environmental applications: A review NT Padmanabhan, N Thomas, J Louis, DT Mathew, P Ganguly, H John, ... Chemosphere 271, 129506 , 2021 2021 Citations: 329
Titanium dioxide based self-cleaning smart surfaces: A short review NT Padmanabhan, H John Journal of Environmental Chemical Engineering 8 (5), 104211 , 2020 2020 Citations: 236
The rise of borophene P Kumar, G Singh, R Bahadur, Z Li, X Zhang, CI Sathish, MR Benzigar, ... Progress in Materials Science 146, 101331 , 2024 2024 Citations: 82
Impact of structure, doping and defect-engineering in 2D materials on CO 2 capture and conversion EJ Jelmy, N Thomas, DT Mathew, J Louis, NT Padmanabhan, ... Reaction Chemistry & Engineering 6 (10), 1701-1738 , 2021 2021 Citations: 66
New insights into the efficient charge transfer of ternary chalcogenides composites of TiO2 P Ganguly, M Muscetta, NT Padmanabhan, L Clarizia, A Akande, ... Applied Catalysis B: Environmental 282, 119612 , 2021 2021 Citations: 64
ZnO/Mo2TiC2 MXene nanohybrids for enhanced solar-driven photocatalytic degradation of tetracycline and organic pollutants in contaminated water NT Padmanabhan, K Gayathri, RM Thomas, H John Energy & Environmental Sustainability 1 (3), 100042 , 2025 2025 Citations: 54
Exploring enhanced interfacial charge separation in ZnO/reduced graphene oxide hybrids on alkaline photoelectrochemical water splitting and photocatalytic pollutant degradation J Louis, NT Padmanabhan, MK Jayaraj, H John Materials Research Bulletin 169, 112542 , 2024 2024 Citations: 43
Antibacterial self-cleaning binary and ternary hybrid photocatalysts of titanium dioxide with silver and graphene NT Padmanabhan, RM Thomas, H John Journal of Environmental Chemical Engineering 10 (2), 107275 , 2022 2022 Citations: 40
Morphology engineered spatial charge separation in superhydrophilic TiO2/graphene hybrids for hydrogen production NT Padmanabhan, P Ganguly, SC Pillai, H John Materials Today Energy 17, 100447 , 2020 2020 Citations: 40
Mechanistic insights into CTAB assisted TiO2 crystal growth with largely exposed high energy crystal facets NT Padmanabhan, MK Jayaraj, H John Journal of Environmental Chemical Engineering 6 (4), 5510-5519 , 2018 2018 Citations: 39
Antibacterial self-cleaning nylon-11/TiO2nanofiber membranes as triboelectric nanogenerators S Joseph, NT Padmanabhan, J Jose, H John Results in Engineering 17, 100869 , 2023 2023 Citations: 32
Recent updates on triboelectric nanogenerator based advanced biomedical technologies: A short review S Radhakrishnan, N Joseph, NP Vighnesh, PJ Sabarinath, J John, ... Results in Engineering 16, 100782 , 2022 2022 Citations: 32
Graphene hybridized high energy faceted titanium dioxide for transparent self-cleaning coatings NT Padmanabhan, MK Jayaraj, H John Catalysis Today 348, 63-71 , 2020 2020 Citations: 27
Interface Engineering of 2D NiMOF–MoS 2 Hybrids for Electrocatalytic Hydrogen Evolution JC Janardhanan, NT Padmanabhan, SC Pillai, H John ACS Sustainable Chemistry & Engineering 11 (18), 6890-6902 , 2023 2023 Citations: 26
Surfactant-assisted restructuring of boron to borophene: implications for enhanced hydrogen evolution S Radhakrishnan, NT Padmanabhan, AJ Mathews, Y Tang, ... ACS Applied Nano Materials 7 (11), 12564-12578 , 2024 2024 Citations: 20
Crystal lattice engineering in a screw-dislocated ZnO nanocone photocatalyst by carbon doping J Louis, NT Padmanabhan, MK Jayaraj, H John Materials Advances 3 (10), 4322-4333 , 2022 2022 Citations: 20
Advancing hydrogen storage: critical insights to potentials, challenges, and pathways to sustainability NT Padmanabhan, L Clarizia, P Ganguly Current Opinion in Chemical Engineering 48, 101135 , 2025 2025 Citations: 17
Microwave-induced growth of {101̅0} faceted zinc oxide/graphene 2D/2D nanostructures for visible-light photocatalysis and hydrogen evolution reaction J Louis, NT Padmanabhan, MK Jayaraj, H John Journal of Alloys and Compounds 942, 169071 , 2023 2023 Citations: 15
Topology structure significance on the applications of morphologically diverse molybdenum disulfide JC Janardhanan, NT Padmanabhan, PJ Jandas, M Sathyan, RM Thomas, ... Journal of Environmental Chemical Engineering 12 (2), 112268 , 2024 2024 Citations: 10
Directed morphology engineering of 2D MoS2 nanosheets to 1D nanoscrolls with enhanced hydrogen evolution and specific capacitance JC Janardhanan, NT Padmanabhan, PJ Jandas, NV Nayar, N Manoj, ... Journal of Colloid and Interface Science 652, 240-249 , 2023 2023 Citations: 9