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Item Bi-functional LaMxFe1-xO3 (M = Cu, Co, Ni) for photo-fenton degradation of methylene blue and photoelectrochemical water splitting(Elsevier Ltd, 2023) James, A.; Rodney, J.D.; Rao, L.; Badekai Ramachandra, B.R.; Udayashankar, N.K.Due to growing concern over environmental remediation and the energy crisis, perovskite nanoparticles have gained wide interest in converting solar energy to sustainable fuel and also in degrading organic effluents. Herein, we report the synthesis and bi-functional activity of one-pot-glycine combustion derived LaMxFe1-xO3 (M = Cu, Co, Ni; x = 0, 0.01) for photo-Fenton degradation of Methylene Blue (MB) and photoelectrochemical water splitting. When used as a photocatalyst, with partial substitution of Cu even at a lower concentration, LaCu0.01Fe0.99O3 has exhibited excellent degradation efficiency of 96.4% in 90 min, which is 2.5 times better than the LaFeO3. On the other hand, Co and Ni modified LaFeO3 photocatalysts have demonstrated prominent activities with degradation efficiency of 93.8% and 74.8% respectively within 180 min of visible light irradiation. The retention and reusability analysis showed that LaCu0.01Fe0.99O3 is stable against photo corrosion and remains unchanged after 5 consecutive cycles of MB dye degradation. In addition, LaCu0.01Fe0.99O3 is complimented as a single catalyst for dual functions such as photocatalysis and electrocatalysis, both of which are assisted by visible light. Under illumination, the overpotential (η) improved from 507.6 mV vs RHE (dark) to 498.1 mV vs RHE (light) for O2 evolution and 220.5 mV vs RHE (dark) to 182.8 mV vs RHE (light) for H2 generation respectively. The light response of the catalyst and improvement in activity is validated by the significant enhancement in current density under exposure at both half cycle of chronoamperometry. © 2023 Hydrogen Energy Publications LLCItem Cobalt-doped LaFeO3 for photo-Fenton degradation of organic pollutants and visible-light-assisted water splitting(Springer, 2024) James, A.; Rodney, J.D.; Manojbabu, A.; Joshi, S.; Rao, L.; Badekai Ramachandra, B.R.; Udayashankar, N.K.The increasing demand for clean energy sources and the growing concerns about environmental pollution have led to a significant interest in developing efficient photocatalytic and photoelectrochemical systems. Here, we report the visible-light-induced photo-Fenton catalytic degradation of Methylene Blue (MB) dye over LaFeO3 and LaCo xFe1−xO3 (x = 0.01, 0.05, 0.1) catalysts synthesized via the facile combustion method. The LaCo0.01Fe0.99O3 has significantly enhanced the photo-Fenton catalytic efficiency of LaFeO3 from 67.75 to 93.85% for MB dye removal after 180 min of light irradiation. The rate constants calculated via the pseudo-first-order kinetics mechanism are found to be 0.00532/min for LaFeO3 and 0.01476/min for LaCo0.01Fe0.99O3, respectively. In addition, the most effective LaCo0.01Fe0.99O3 catalyst has demonstrated remarkable degradation performance towards Tetracycline (TC) and Methyl Orange (MO) dye with an efficacy of 93.81% and 69.67%, respectively, indicating its versatility. Further, the pristine and doped LaFeO3 were structurally optimized using DFT, and the computed band gaps were following the experimental data. Interestingly, the same catalyst can be employed as a light-induced electrocatalyst in addition to water treatment by taking advantage of its dual functionality. The LaCo0.01Fe0.99O3 catalyst achieved a benchmark current density of 10 mA/cm2 for H2 evolution at an overpotential of 297 mV vs. RHE which further improved to 190 mV vs. RHE under illumination. This work provides valuable insights on partial Co incorporation at the B-site of LaFeO3 for the development of visible-light-induced photocatalytic and electrocatalytic systems, which is hoped to contribute to the advancement of sustainable energy production and environmental remediation. © 2024, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.Item Mechanistic insights and DFT analysis of bimetal doped styrofoam-like LaFeO3 perovskites with in-built dual redox couples for enhanced Photo-Fenton degradation of Tetracycline(Elsevier B.V., 2024) James, A.; Naik, S.; Rodney, J.D.; Joshi, S.; Udayakumar, U.; Kim, B.C.; Udayashankar, N.K.The rising number of contaminants released into the environment and the inadequacies of traditional wastewater treatment techniques have led to the demand for enhanced oxidation technologies like photo-Fenton. In this study, bimetal co-doped lanthanum orthoferrite (BixLa1-xCuyFe1-yO3 (x = 0, 0.01, 0.05, 0.1; y = 0, 0.01, 0.05, 0.1, 0.15)) based photo-Fenton catalysts with the in-built redox couples Fe3+/Fe2+, Cu2+/Cu+ and oxygen vacancies have been successfully synthesised via a facile one-pot solution combustion route. Systematic studies show that the Bi0.05La0.95Cu0.1Fe0.9O3 (LFOBC) exhibits an optimal photo-Fenton degradation rate of 0.0497/min for Tetracycline (TC) removal, being ∼ 1.8 and ∼ 6.2 times greater than Bi0.05La0.95FeO3 (LFOB) and pristine LaFeO3 (LFO) respectively. DFT analysis confirmed the better adsorption and dissociation of H2O2 on a bimetal co-doped catalyst and identified the electron density difference in LFOBC, which can induce the H2O2 dissociation. A detailed investigation of various influencing reaction parameters is explored. The degradation pathway for the LFOBC catalyst with the toxicological characteristics of each intermediate is analysed. This study presents the Bi0.05La0.95Cu0.1Fe0.9O3 as a potential photocatalyst for enhanced photo-Fenton degradation with excellent efficiency observed for the degradation of various harmful pollutants for environmental remediation. © 2024 Elsevier B.V.Item Investigation of Indium doped Se-Te bulk chalcogenide glasses for electrical switching and phase changing applications(Elsevier Ltd, 2024) Joshi, S.; Rodney, J.D.; James, A.; Behera, P.K.; Udayashankar, N.K.Recently, Metal-doped Se-Te chalcogenides have gained a lot of interest due to their unique capacity for electrical switching, which makes them desirable for electronic applications. This study examines the electrical switching characteristics of bulk Se86−xTe14Inx (0 ≤ x ≤ 6) amorphous alloys produced by the conventional melt-mix-quench process. The samples with an Indium atomic percentage between 2 to 6 exhibited a remarkable transition from a highly resistive to a low resistive state when subjected to an electric field with a current of 1 mA, displaying quick and reversible switching behaviour. The threshold voltage (Vth) significantly dropped from 410.6 V to 49.2 V with an increase in Indium concentration. Additionally, above the specific current threshold, these bulk glasses demonstrated memory-type switching, demonstrating their potential for data storage applications. To comprehend the trend of glass forming ability, thermal stability range and Hruby's glass stability parameters, with their compositional dependency, Differential Scanning Calorimetry (DSC) was utilized. The sample Se80Te14In6 emerged to be the fastest phase-changing material, with a memory switching current threshold of Ith = 1.3 mA and a threshold voltage value of 49.2 V. To study the formation of crystallites in Se-Te-In alloy, X-ray diffraction patterns of pristine glass and the annealed sample were examined. Furthermore, temperature-dependent conductivity investigations showed a sharp rise in conductivity once the process crystallization begins (Tx), and also the threshold voltage (Vth) of the samples decreased linearly with rising temperature. Overall, this study provides valuable insights into the electrical switching behaviour and thermal properties of Se-Te-In chalcogenide glasses, enhancing their suitability in electronic devices. © 2024 Elsevier B.V.Item Exploration of electrode-modulated memory and threshold switching behaviour in Se-Te-Sn thin film devices(Elsevier B.V., 2024) Joshi, S.; Rodney, J.D.; James, A.; Udayashankar, N.K.Due to their potential use in high-density, three-dimensional stackable cross-point array structures, the electrical switching ability of chalcogenide glasses has captured a lot of attention. Herein, the switching behaviour of unique Se86-xTe14Snx (x = 0, 2, 4, 6) chalcogenide glassy alloys in the form of a thin film were investigated. The electrode modulated dual functionality in switching was achieved by employing Aluminium (Al) and Silver (Ag), as top electrodes. The films with Al/Se86-xTe14Snx/Al interface exhibited memory-type switching due to the phase-changing properties of the material. The threshold voltage (Vth) decreased linearly from 12.75 V to 4.2 V at room temperature as Sn concentration in the glass increased. On the other hand, when the top electrode was replaced with Ag, the Ag/Se86-xTe14Snx/Al interface acted as a programmable metallization cell (PMC) showing threshold-switching properties. Ag/Se82Te14Sn4/Al thin film of thickness 200 nm showed promising results as a material for a unidirectional selector, due to the formation of temporary Ag filament inside chalcogenide material. The composition showed high selectivity (∼104), high endurance (>104 cycles), and low threshold voltage (∼1.6 V). The ability of the composition to exhibit electrode-dependent memory and threshold-switching phenomena makes the material an interesting case. © 2024 Elsevier B.V.Item Kinetic Comparison of Photocatalysis with the Photo-Fenton Process on the Removal of Tetracycline Using Bismuth-Modified Lanthanum Orthoferrite Nanostructures(American Chemical Society, 2024) James, A.; Rodney, J.D.; Udayashankar, N.K.In this study, we investigate visible-light-driven photocatalytic and photo-Fenton degradation of tetracycline (TC) using bismuth-impregnated lanthanum orthoferrite (BixLa1-xFeO3 (x = 0, 0.01, 0.05, 0.07)) nanostructures. Bi doping significantly improves the removal of TC, with Bi0.05La0.95FeO3 (LFO-Bi5) exhibiting optimal degradation. In both photocatalysis (PC) and photo-Fenton catalysis (PFC), the reaction follows pseudo-first-order kinetics, with LFO-Bi5 showing rate constants of 0.0065/min for PC and 0.02716/min for PFC, surpassing LaFeO3 by 2.76 and 3.43 times, respectively. The long-term presence of photoexcited carriers in LFO-Bi5 is confirmed through transient PL, TRPL, and EIS studies. The superior degradation capabilities are attributed to radicals in photocatalysis and OH• radicals in photo-Fenton catalysis. The PFC exhibited faster kinetics due to the rapid production of OH• radicals via the Fe-redox cycle and direct dissociation of H2O2 at oxygen vacancies. LFO-Bi5 demonstrates excellent photostability and reusability for up to six consecutive cycles. The degradation pathway and toxicological properties of the intermediates are analyzed, highlighting the potential of LFO-Bi5 catalysts in antibiotic-contaminated water treatment. © 2024 American Chemical Society.Item An insight into noticeable dielectric response and effect of fe doping on photocatalytic efficiency (visible light) of ZnO nanoparticles synthesized through solution precipitation for harmful textile dye degradation(Springer Science and Business Media B.V., 2024) Mahendra, K.; Fernandes, J.M.; James, A.; B.s, N.; Pattar, J.; Sunitha, D.V.; Gopal, K.; Udayashankar, N.K.Iron (Fe)-incorporated zinc oxide (ZnO) nanoparticles (NPs) were synthesized via chemical precipitation technique and studied using powder X-ray diffraction (PXRD), field emission scanning electron microscopy (FESEM), and UV–vis diffuse reflectance spectroscopy. PXRD analysis reveals a hexagonal wurtzite structure for all the synthesized samples. UV–visible measurements demonstrate a reduction in the bandgap of ZnO with an increase in Fe concentration. The ZnO and Fe-incorporated ZnO NPs are studied for the degradation of organic textile dye under visible light irradiation. All the nanoparticles are thoroughly investigated using impedance and dielectric measurements in the frequency range of 20 Hz to 1 MHz. The results obtained are compared, interpreted, and presented in this paper. © The Author(s), under exclusive licence to Springer Nature B.V. 2024.Item Cerium-Modulated Zinc Oxide for enhanced Photoelectrochemical Non-Enzymatic biosensing of Cholesterol: An experimental and First Principle Analysis(Elsevier B.V., 2024) Rao, L.; Rodney, J.D.; Joy, A.; Shivangi Nileshbhai, C.; James, A.; S, S.; Joyline Mascarenhas, F.; Udayashankar, N.K.; Anjukandi, P.; Chul Kim, B.; Badekai Ramachandra, B.R.Herein, we synthesized CexZn1-xO (x = 0.00, 0.01, 0.02, and 0.03) using the wet chemical method. The investigation explores photoelectrochemical (PEC) biosensors for enzyme-free detection of cholesterol, employing Ce0.03Zn0.97O (CZO3)/Nickel Foam (NF) as the active material. The investigation revealed notable enhancements in sensitivity for cholesterol detection, with a recorded activity of 2.812 mA.mM?1.cm?2, marking a twofold increase in comparison to dark mode (1.37 mA.mM?1.cm?2). The Limit of Detection (LOD) was determined to be 17 µM (light) and 28 µM (dark), while the Limit of Quantification (LOQ) was measured at 54 µM (light) and 98 µM (dark) in 0.1 M KOH solution. These findings demonstrate a linear detection range spanning from 80 µM to 2 mM. Ab-initio calculations based on Density Functional Theory (DFT) were carried out on 101 surfaces of both pristine ZnO and CZO3 to understand how the doping affected the pristine ZnO band gap. The findings indicate that CZO3 exhibits superior activity compared to pristine ZnO, underscoring its enhanced performance and potential for sensing application. The CZO3/NF photoelectrochemical (PEC) biosensor displayed notable cyclic stability, retaining 97 % of its performance over a 60-day period. This underscores its potential for reliable and enduring operation in biosensing applications. Additionally, CZO3/NF exhibited robust sensing capabilities when utilized with human serum samples, showcasing consistent performance in both dark and illuminated conditions. © 2024 Elsevier B.V.Item Investigation of ZnO Nanoparticles Synthesized with Different Concentrations of NaOH for Dielectric and Photocatalytic Applications(Springer Science and Business Media Deutschland GmbH, 2025) Mahendra, K.; Fernandes, J.M.; James, A.; Nagaraja, B.S.; Pattar, J.; Udayashankar, N.K.In this study, ZnO nanoparticles are synthesized for photocatalytic and dielectric applications using precipitation technique. The properties of ZnO nanoparticles are investigated for various sodium hydroxide (NaOH) concentrations. The powder X-ray diffraction (PXRD) method is employed to analyse structural properties. PXRD reveals the decrease in cell volume from 47.92 to 47.73 Å and crystallite size varied from 31.96 to 22.53 nm. The scanning electron microscope (SEM) study explained the morphology and EDS measurements revealed the presence of zinc and oxygen distribution on the surface. Further, the particle size is also calculated to be 62.23 nm, 50.16 nm, 46.86 nm and 47.43 nm respectively. The diffuse reflectance spectroscopy (UV-DRS) study indicates that, as NaOH concentration increases, the optical bandgap of the ZnO nanoparticles decreases from 3.25 eV to 3.12 eV. The PL studies revealed blue emission for all ZnO nanoparticles. I–V measurements indicate improved conductivity for higher concentrations of NaOH. A photocatalyst (as synthesized) is examined in the presence of UV radiation for its ability to photodegrade organic pollutants (Methylene Blue dye) with adsorption capacity of 19.7%, 20.3%, 21.48% and 22.97% respectively. The increased adsorption could be due to the increased surface area of the samples. Further, the dielectric properties of the synthesized nanoparticles, including impedance, dielectric constant, conductivity, dielectric loss, and electric modulus is established and examined. © The Tunisian Chemical Society and Springer Nature Switzerland AG 2025.Item Cu- and Bi-codoped LaFeO3-Decorated MXene Nanosheets for Photo-Fenton Catalysis and Hydrogen Evolution(American Chemical Society, 2025) James, A.; Ray, S.; Rodney, J.D.; Carva, K.; Udayashankar, N.K.; Kim, B.C.The increasing release of contaminants into the environment and the demand for sustainable energy solutions have prompted the exploration of advanced oxidation methods such as photo-Fenton and photoelectrochemical water splitting. Herein, hierarchical heterostructures of Cu- and Bi-codoped LaFeO3(Bi0.05La0.95Cu0.1Fe0.9O3) (LFOBC)-decorated Ti3C2(MXene) nanosheets were developed by a low-cost one-pot combustion approach. The optimized LFOBC/Mx-7 (Bi0.05La0.95Cu0.1Fe0.9O3/Ti3C2-7) composite demonstrated superior photo-Fenton degradation of tetracycline (TC), achieving 1.69 times higher efficiency than LFOBC and 10.65 times more efficiency than pristine LaFeO3(LFO). This enhanced performance is attributed to strong interfacial coupling, which suppressed photoexcited carrier recombination, as confirmed by PL, TRPL, EIS, and photocurrent studies. Experimental and theoretical work function analyses revealed band bending and the formation of an Ohmic junction at the interface. Furthermore, a degradation mechanism and a reaction pathway were proposed, and the reduction in toxicity levels was identified. The LFOBC/Mx-7 catalyst also exhibited promising results for H2evolution with an overpotential of 156 mV vs RHE under visible-light illumination, which was 2.37 times less than that of LFOBC. These results, therefore, showcase the LFOBC/Mx composite as a multifunctional photocatalyst for both pollutant degradation and sustainable energy generation. © 2025 American Chemical Society