Faculty Publications
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Item Organic-inorganic hybrid mixed-valent bisphosphonate-polyoxovanadates composites with activated carbon for energy storage applications(Nova Science Publishers, Inc., 2024) Madhusree, J.E.; Banerjee, A.; Mal, S.S.In this book, we discuss the investigation of two different bisphosphonate-functionalized polyoxovanadate compounds for use in electrochemical energy storage applications. The compounds are (NH4)4[H6(VIVO2)(VV2O5)2O3P-C(O)(CH2-2-C5NH4)-PO32].9H2O (m), and (NH4)4[H6(VIVO2)(VV2O5)2O3P-C(O)(CH2-3-C5NH4)-PO32]. 8H2O (n). They have a mixed-valent oxovanadate polyanionic assembly that has two different pyridyl functional groups present on the organic bisphosphonate ligand. Several techniques have been used to characterize composites made from these compounds with activated carbon, including Fourier transform infrared spectroscopy, P-XRD, FESEM, EDX, and surface adsorption-desorption tests. The electrochemical performance of acidic electrolytic solutions containing 0.1 M H2SO4, AC-m, and AC-n electrode materials was investigated. Although the compounds are isotypic mixed-valence polyoxovanadate structures, their electrical behavior varies based on the position of the pyridyl group. AC-n was reported to have the most prominent specific capacitance of 313 F g-1 at a current density of 1 A g-1 in a voltage window of 0-1 V, with exceptional energy and power densities of 43.56 Wh kg-1 and 1999.72 W kg-1, respectively. At the same time, AC-m exhibited a specific capacitance of 212 F g-1 and a specific energy of 29.45 Wh kg-1. By lighting up different LED lights with only 42 mg of carbon clothcoated sample, the composite AC-n electrode displayed exceptional specific power. A further benefit of AC-n nanohybrids is their ability to retain electrochemical performance over time, which suggests long-term stability. © 2024 Nova Science Publishers, Inc. All rights reserved.Item Benzene hydroxylation to phenol with iron impregnated activated carbon catalysts(Elsevier Inc., 2006) Choi, J.-S.; Kim, T.-H.; Choo, K.-Y.; Sung, J.-S.; Saidutta, M.B.; Badekai Ramachandra, B.R.; Rhee, Y.-W.Iron impregnated on activated carbon was used as catalyst for the direct synthesis of phenol from benzene. The effect of Sn addition to the catalyst was studied. The prepared catalysts were characterized by BET, SEM and XRD analysis. The catalyst 5.0Fe/AC showed good activity in the conversion of benzene and addition of Sn seemed to improve the selectivity of phenol in the reaction. © 2006 Elsevier B.V. All rights reserved.Item Removal of Methylene Blue from Aqueous Solution: An Approach of Environmental Friendly Activated Carbon(Springer Science and Business Media Deutschland GmbH info@springer-sbm.com, 2021) Jayaprakash, M.C.; Chaitra, M.; Rai, P.; Venkat Reddy, D.Methylene blue (MB) dye was adsorbed on an adsorbent prepared from cashew nut shell. A batch adsorption study was carried out with variable adsorbent amount, initial dye concentration and contact time. Studies showed that as the contact time increases relatively there will be an increase in the removal of methylene blue from the aqueous solution. There was also a comparative increase in the removal of dye with the increase in dosage of adsorbent. As the concentration of MB dye increased the percentage of removal of MB from the aqueous solution decreased for a given particular dosage. The results indicate that cashew nut shell activated carbon could be employed as a low-cost alternative to commercial activated carbon in the removal of dyes from wastewater. This work offers an economic incentive to the industrial practice for waste management and eco-friendly approach for removal of toxic dyes from textile waste water. © 2021, Springer Nature Switzerland AG.Item From non-renewable waste to activated carbon: A smart move towards sustainable development and environmental protection in a circular economy(Elsevier Ltd, 2025) Patil, S.S.; Kisiela-Czajka, A.M.; Prasad Dasari, H.P.Waste generation is unavoidable as the population grows and globalisation/modernisation occurs. Ineffective garbage management and treatment raise major environmental concerns. This study provides a comprehensive and unique compilation of available knowledge on the potential use of various non-renewable waste materials to produce activated carbon (AC). One document brings together and evaluates the potential for converting hazardous and non-hazardous waste – from industrial and municipal to recyclable and medical waste – into a valuable resource with wide-ranging applications. The appropriately selected conversion method is key to converting waste into a valuable activated carbon product. It must consider both the applicable legal regulations and the key technological parameters that determine the quality and suitability of the final product for a specific application. The numerous carbonisation and activation methods employed to convert waste to AC include hydrothermal, ionothermal, pyrolysis and microwave-assisted methods. AC's elemental composition and functional groups are analysed using elemental analysis, XPS and FTIR. Crystal structure and phase identification are performed via XRD, SEM and TEM. Surface area and porosity are determined using the BET and BJH methods, along with the iodine index. Following the thermal conversion of various waste materials into AC, it is widely used in multiple disciplines, including energy and the environment. AC is used as an adsorbent to effectively remove harmful elements from water, including pharmaceutical contamination, dyes and heavy metals. AC has excellent electrochemical characteristics and is highly efficient in CO2 capture. AC also extracts valuable products such as hydrocarbons, methane and uranium. © 2025 The Author(s)Item The direct conversion of benzene to phenol by hydroxylation with hydrogen peroxide was carried out over various transition metals impregnated on MCM-41 and activated carbon. Copper-, iron-, and vanadium-impregnated on activated carbon gave better yields of phenol when compared to the corresponding reactions using cobalt-, nickel-, manganese-, and titanium-impregnated catalysts. Comparison of the MCM-41 and activated carbon-supported catalysts showed that activated carbon-supported catalysts gave a higher yield of phenol than did the MCM-41-supported catalysts. The activity of the transition metals supported on activated carbon in the production of phenol was V > Fe > Cu; the corresponding activity of the transition metals supported on MCM-41 was Cu > Fe > V. In addition to the role of transition metals in catalyzing the hydroxylation reaction, the hydrophobic nature of the activated carbon surface seems to enhance the performance of these catalysts relative to the MCM-41-supported catalysts.(Benzene hydroxylation to phenol catalyzed by transition metals supported on MCM-41 and activated carbon) Choi, J.-S.; Kim, T.-H.; Saidutta, M.B.; Sung, J.-S.; Kim, K.-I.; Jasra, R.V.; Song, S.-D.; Rhee, Y.-W.2004Item The direct conversion of benzene to phenol by hydroxylation with hydrogen peroxide was carried out over catalyst containing various transition metals impregnated on activated carbon. Iron and vanadium impregnated catalysts gave better yields of phenol compared to copper impregnated catalysts. The activity of transition metals supported on activated carbon catalyst in the production of phenol was V > Fe > Cu. In addition to the role of transition metals in catalyzing the hydroxylation reaction, the hydrophobic nature of the activated carbon surface and also the surface acidity and basicity seems to have enhanced the performance of these catalysts. © 2005 Springer Science + Business Media, Inc.(Transition metals supported on activated carbon as benzene hydroxylation catalysts) Choi, J.-S.; Kim, T.-H.; Choo, K.-Y.; Sung, J.-S.; Saidutta, M.B.; Song, S.-D.; Rhee, Y.-W.2005Item The direct conversion of benzene to phenol by hydroxylation with hydrogen peroxide was carried out over catalysts containing iron impregnated on activated carbon. Iron was impregnated on various surface modified activated carbons. The catalyst that was made by treating activated carbon with nitric acid, that was treated thermally in the presence of nitrogen at 600 °C and impregnated with 5 wt.% iron, gave a phenol yield of 20%. It was found that the synergistic interactions of surface groups and the impregnated iron have enhanced the performance of these catalysts. © 2005 Elsevier B.V. All rights reserved.(Direct synthesis of phenol from benzene on iron-impregnated activated carbon catalysts) Choi, J.-S.; Kim, T.-H.; Choo, K.-Y.; Sung, J.-S.; Saidutta, M.B.; Ryu, S.-O.; Song, S.-D.; Badekai Ramachandra, B.; Rhee, Y.-W.2005Item Activated carbon-polyethylenedioxythiophene composite electrodes for symmetrical supercapacitors(2008) Muthu, M.S.; Bhat, D.K.A symmetrical (p/p) supercapacitor has been fabricated by making use of activated carbon (AC)-poly-ethylenedioxythiophene (PEDPT)-composite electrodes for the first time. The composite electrodes have been prepared via electrochemical deposition of ?-napthalenesulphonate doped PEDPT onto AC electrodes. The characteristics of the electrodes and the fabricated supercapacitor have been investigated using cyclic voltammetry (CV) and AC impedance spectroscopy. The electrodes show a maximum specific capacitance of 158 Fg-1 at a scan rate of 10 mV s_1. This indicates that the in situ electro-polymerization of ethylenedioxythiophene (EDPT) onto AC could improve the performance of carbon electrodes for use in supercapacitors. © 2007 Wiley Periodicals, Inc.Item Studies on the removal of Pb(II) from wastewater by activated carbon developed from Tamarind wood activated with sulphuric acid(2008) Singh, C.K.; Sahu, J.N.; Mahalik, K.K.; Mohanty, C.R.; Mohan, B.R.; Meikap, B.C.The low-cost activated carbon were prepared from Tamarind wood material by chemical activation with sulphuric acid for the adsorption of Pb(II) from dilute aqueous solution. The activated carbon developed shows substantial capacity to adsorb Pb(II) from dilute aqueous solutions. The parameters studied include physical and chemical properties of adsorbent, pH, adsorbent dose, contact time and initial concentrations. The kinetic data were best fitted to the Lagergren pseudo-first-order and pseudo-second order models. The isotherm equilibrium data were well fitted by the Langmuir and Freundlich models. The maximum removal of lead(II) was obtained 97.95% (experimental) and 134.22 mg/g (from Langmuir isotherm model) at initial concentration 40 mg/l, adsorbent dose 3 g/l and pH 6.5. This high uptake showed Tamarind wood activated carbon as among the best adsorbents for Pb(II). © 2007 Elsevier B.V. All rights reserved.Item Biological sulfide oxidation using autotrophic Thiobacillus sp.: Evaluation of different immobilization methods and bioreactors(2009) Ravichandra, P.; Gopal, M.; Jetty, A.Aims: Evaluation of various immobilization methods and bioreactors for sulfide oxidation using Thiobacillus sp. was studied. Methods and Results: Ca-alginate, K-carrageenan and agar gel matrices (entrapment) and polyurethane foam and granular activated carbon (adsorption) efficacy was tested for the sulfide oxidation and biomass leakage using immobilized Thiobacillus sp. Maximum sulfide oxidation of 96% was achieved with alginate matrix followed by K-carrageenan (88%). Different parameters viz. alginate concentration (1%, 2%, 3%, 4% and 5%), CaCl2 concentration (1%, 2%, 3%, 4% and 5%), bead diameter (1, 2, 3, 4 and 5 mm), and curing time (1, 3, 6, 12 and 18 h) were studied for optimal immobilization conditions. Repeated batch experiments were carried out to test reusability of Ca-alginate immobilized beads for sulfide oxidation in stirred tank reactor and fluidized bed reactor (FBR) at different sulfide concentrations. Conclusions: The results proved to be promising for sulfide oxidation using Ca-alginate gel matrix immobilized Thiobacillus sp. for better sulfide oxidation with less biomass leakage. Significance and Impact of the Study: Biological sulfide oxidation is gaining more importance because of its simple operation. Present investigations will help in successful design and operation of pilot and industrial level FBR for sulfide oxidation. © 2009 The Society for Applied Microbiology.