Papers by lagnamayee mohapatra
Materials Today Chemistry
Photocatalysts - New Perspectives
The increasing organic contamination is mainly produced by the widespread industrial, agricultura... more The increasing organic contamination is mainly produced by the widespread industrial, agricultural, and household applications and has become a serious worldwide issue. Therefore, we need to develop sustainable and environmentally friendly technologies to reduce waste detrimental to the environment. A promising approach is known as heterogeneous photocatalysis, inspired by natural photosynthesis. For this purpose, the challenges raised to synthesize appropriate surface nano/microstructured materials with long-term stability and mechanical durability for practical use. The traditional photocatalytic system is diphasic (dependent upon the solid-liquid phase), where the solid-liquid reaction interface depends upon the mass transfer. Especially, the low concentrations of oxygen in water and the slow diffusion rate limit the removal of electrons which decreases the photocatalytic reaction rates even if the presence of high light intensities. Therefore, the work aims to develop novel trip...
Molecules
Carbon-based nanomaterials (CBM) have shown great potential for various environmental application... more Carbon-based nanomaterials (CBM) have shown great potential for various environmental applications because of their physical and chemical properties. The unique hybridization properties of CBMs allow for the tailored manipulation of their structures and morphologies. However, owing to poor solar light absorption, and the rapid recombination of photogenerated electron-hole pairs, pristine carbon materials typically have unsatisfactory photocatalytic performances and practical applications. The main challenge in this field is the design of economical, environmentally friendly, and effective photocatalysts. Combining carbonaceous materials with carbonaceous semiconductors of different structures results in unique properties in carbon-based catalysts, which offers a promising approach to achieving efficient application. Here, we review the contribution of CBMs with different dimensions, to the catalytic removal of organic pollutants from wastewater by catalyzing the Fenton reaction and ...
Journal of Water Process Engineering
Photocatalytic Functional Materials for Environmental Remediation, 2019
Materials Advances, 2020
The significance of this work lies in the promotion of thin carbon paper as well as its treatment... more The significance of this work lies in the promotion of thin carbon paper as well as its treatment (such as the one presented in this work) as electrodes for flow batteries, in particular VRFB reactions.
Chemical Communications, 2019
We report for the first time, the performance of black pearl (BP) carbon as an electrocatalyst in... more We report for the first time, the performance of black pearl (BP) carbon as an electrocatalyst in all-vanadium redox-flow-batteries.
Qatar Foundation Annual Research Conference Proceedings Volume 2016 Issue 1, 2016
Fe-doped ZnO mediated by visible light having composition as Zn 1-x Fe x O (x=0.0, 0.05) have bee... more Fe-doped ZnO mediated by visible light having composition as Zn 1-x Fe x O (x=0.0, 0.05) have been synthesized via sol-gel auto-combustion technique. The thermal and optical properties have been investigated systematically using thrmogravimetric analysis and UV/vis-spectrophotometer, respectively. The doping of Fe 3+ at Zn-site in ZnO helped to reduce its band-gap energy, attributed to the creation of an extra level near band edges. The synthesized materials exhibited enhanced photocatalytic activity in the degradation of methylene blue under visible-light irradiation. Pseudo-first-order rate law has also been applied to understand the reaction kinetics of methylene blue when visiblelight is induced.
Qatar Foundation Annual Research Conference Proceedings Volume 2018 Issue 1, 2018
Catal. Sci. Technol., 2017
Oxo-bridged systems are versatile photo-redox catalysts for environmental decontamination and art... more Oxo-bridged systems are versatile photo-redox catalysts for environmental decontamination and artificial photosynthesis.
J. Mater. Chem. A, 2016
The present review article evaluates the effectiveness and special features of LDH/modified LDH o... more The present review article evaluates the effectiveness and special features of LDH/modified LDH on photocatalytic activities.
Energy Technology, 2017
A triple junction nano structured material consisting of porous exfoliated g-C 3 N 4 nanosheets, ... more A triple junction nano structured material consisting of porous exfoliated g-C 3 N 4 nanosheets, ZnO and ZnCr 2 O 4 was prepared by one pot synthesis method by calcining mixture of urea, thiourea and Zn-Cr LDH at 450˚C. The structural, morphological and optical properties of the prepared nano composites were characterized by various physicochemical techniques. This synthesis process simultaneously makes the material porous, results exfoliated sheets of g-C 3 N 4 and disperses mixed metal oxides on the surface of g-C 3 N 4 due to the slow evolution of significant amount of gases like H 2 O, CO 2 , NH 3 and H 2 S. Dispersion of mixed oxides ZnO and ZnCr 2 O 4 on the surface of g-C 3 N 4 exfoliated nanosheets results a preferable resolution for visible light-induced photocatalytic H 2 and O 2 evolution. An optimal g-C 3 N 4 content (60%) in ZnCr 2 O 4 @ZnO/g-C 3 N 4 nanostructured composite exhibits maximum H 2 (847 µmole/2h) and O 2 (455 µmole/2h) production in the presence of CH 3 OH and AgNO 3 as sacrificial reagents. The apparent conversion efficiency for H 2 evolution and O 2 evolution are 28.01% and 15.0% respectively. The increased photocatalytic activity was attributed to proper alignment in band structure, synergistic effect owing to good coordination between g-C 3 N 4 (Lewis base) and Zn II ions (Lewis acid) and suppression of electron and hole recombination due to the formation of g-C 3 N 4 nanosheets.
European Journal of Inorganic Chemistry, 2017
Herein, we design and successful fabrication of novel Fe-based Mg/Fe Layered double hydroxides (L... more Herein, we design and successful fabrication of novel Fe-based Mg/Fe Layered double hydroxides (LDHs) with different molar ratios (2:1, 3:1, and 4:1) by co-precipitation method. Among all, the prepared Mg/Fe (4:1) LDH sample with high crystallinity and phase purity was further modified by intercalating molybdate anion. The prepared catalysts were subsequently examined their structural, morphological, optical, electrochemical and photocatalytic properties. In comparison with Mg/Fe (4:1) LDH, the photocatalytic activity for degradation of methyl orange (MO) dye was enhanced surprisingly by intercalating molybdate into the interlayer of Mg/Fe (4:1) LDHs following apparent first order kinetics. The radical trapping experiments demonstrate that h + , OH• and O 2-• radicals are the dominant reactive species for pollutant degradation. The highest photocatalytic activity of molybdate intercalated LDH is attributed mainly to the combined effect of layered structure with Oxo-bridged Mg (II)-O-Fe (III) linkage and intercalated molybdate anion which act as the visible light absorption center towards higher wavelength, and can promote charge carrier trapping, as well as hinder the photogenerated
Nanoclay Reinforced Polymer Composites, 2016
Clays have been one of the more important industrial minerals; and with the recent advent of nano... more Clays have been one of the more important industrial minerals; and with the recent advent of nanotechnology, they have found multifarious applications and in each application, nanoclays help to improve the quality of product, economize on the cost and saves environment. The chapter describes key characteristics of nanoclays and their classification on the basis of the arrangement of "sheets" in their basic structural unit "layer". Major groups include kaolin-serpentine, pyrophyllitetalc, smectite, vermiculite, mica and Chlorite. The structural, morphological and physicochemical properties of halloystite and montmorillonite nanoclays, representative of the 1:1 and 2:1 layer groups, respectively, are discussed as well. After briefly introducing the surface modification of clay minerals by modifying or functionalizing their surfaces and their incorporation into polymer matrices to develop polymer/clay nanocomposites, techniques that are being employed to characterize these nanoclays, in general, and the sample preparation for these techniques, in particular, are also reviewed in this chapter.
J. Mater. Chem. A, 2015
Dispersion of exfoliated CN over the surface of exfoliated LDH composite materials, and its photo... more Dispersion of exfoliated CN over the surface of exfoliated LDH composite materials, and its photocatalytic water splitting under visible-light irradiation.
Physical chemistry chemical physics : PCCP, Jan 28, 2014
To harvest solar energy efficiently, a series of Zn/Bi layered double hydroxide (LDH) photocataly... more To harvest solar energy efficiently, a series of Zn/Bi layered double hydroxide (LDH) photocatalysts with different molar ratios of Zn/Bi (2 : 1, 3 : 1, 4 : 1) has been synthesized by a coprecipitation method at constant pH. All the Bi doped LDH samples displayed hydrotalcite-like structure with interlayer carbonate, in which crystallinity decreases as the bismuth content increases. The Zn/Bi (4 : 1) LDH with a small amount of bismuth in the brucite layer and possessing high crystallinity was further modified hydrothermally by intercalating decavanadate and it showed high photochemical stability and photocatalytic activity for the degradation of different organic pollutants for practical applications under solar light irradiation. The structural integrity of the materials has been successfully characterized by studying their structural, morphological, electronic and optical properties by various physico-chemical techniques. The present study provided an insight into oxo-bridged MMCT...
Journal of Materials Chemistry A, 2013
Figure S1. Volume of hydrogen evolution obtained for Ni+Zn/Cr LDH with different catalyst doses f... more Figure S1. Volume of hydrogen evolution obtained for Ni+Zn/Cr LDH with different catalyst doses for 1 h.
The Journal of Physical Chemistry C, 2012
In the present work, a series of Cu−Co/Cr ternary LDHs containing CO 3 2− in the interlayer was p... more In the present work, a series of Cu−Co/Cr ternary LDHs containing CO 3 2− in the interlayer was prepared by coprecipitation method. To investigate the effect of divalent metal ions on the catalytic activity, we vaired Cu/Co atomic ratios, keeping constant the atomic ratio of Cu+Co/Cr (2:1). Several characterization tools, such as powder X-ray diffraction (PXRD), Brunauer−Emmett−Teller surface area, Fourier transform infrared spectroscopy, thermogravimetric analysis, transmission electron microscopy, and UV−vis diffuse reflectance spectroscopy, were employed to study the phase structures, textural, and optical properties of the samples. The PXRD of all samples showed the characteristic pattern of the hydrotalcite without any detectable impurity phases. The expected cell parameter variation was calculated assuming the Vegard's law and proved the ideal atomic arrangement for the cations in the brucite layer. The shifting of the diffraction plane "d110" toward lower angle clearly indicates that Co 2+ is substituted in the brucite layer. The formation of the highest amount of hydroxyl radicals (OH •) on the surface of visible-light illuminated LDHs detected by the luminescence technique using terephthalic acid as probe molecules supports the highest activity LDH-4 with Cu/ Co atomic ratio 0.033 + 0.1 (i.e., 1:3) toward MG degradation. The degradation of malachite green (MG) followed pseudo-firstorder kinetics. The highest photocatalytic activity of LDH4 ascribed to the oxo-bridged system was explained by UV−vis DRS and EPR study.The degradation of MG followed pseudo-first-order kinetics, and the photocatalytic degradation mechanism was also explained in detail.
Separation and Purification Technology, 2012
ABSTRACT Heterogeneous photocatalysis, one of the important steps in advanced oxidative process (... more ABSTRACT Heterogeneous photocatalysis, one of the important steps in advanced oxidative process (AOPs) that was found to be promising for the elimination of toxic organic and inorganic compounds from wastewater. Herein, we reported Zn–Cr-CO3, a novel layered double hydroxide (LDH) for visible-light-driven photo- catalytic degradation of organic chemicals. The physicochemical properties of the synthesized Zn/Cr- CO3 LDH, prepared by co-precipitation method at constant pH, were determined by several techniques such as powder X-ray diffraction (PXRD), Fourier Transform Infrared (FT-IR), thermo gravimetric/differ- ential thermal analysis (TG/DTA), BET surface area, scanning electronic microscope (SEM), transmission electron microscope (TEM) and optical absorption spectra. The photocatalytic degradation studies on xanthene dyes (Rhodamine B, Rhodamine 6G) and substituted phenol (4-chloro 2-nitro phenol) using Zn–Cr-CO3 were reported here for the first time. The kinetic study demonstrated that Zn–Cr-CO3 LDH was an efficient photocatalyst for degradation of organic pollutants. The formation of intermediate oxi- dative species (OH�,O��2 and 1O2) during the photocatalytic reactions were ascertained by using different quenchers and the possible mechanism was proposed.
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Papers by lagnamayee mohapatra