M. Basith - Academia.edu (original) (raw)

Papers by M. Basith

AIP Advances

Here, we report on the structural, vibrational phonon, electrical, and magnetic properties of und... more Here, we report on the structural, vibrational phonon, electrical, and magnetic properties of undoped strontium titanate SrTiO3, Ce doped Sr1−xCexTiO3, and (Ce, Fe) co-doped Sr1−xCexTi1−yFeyO3 samples synthesized through solid state reaction route. The Rietveld refined powder x-ray diffraction analysis confirmed the cubic Pm-3 m phase in our as-synthesized samples. We observed grain size reduction in SrTiO3 from scanning electron micrographs due to the incorporation of Ce and Fe dopants. The sample purity in terms of chemical species identification has been confirmed from energy-dispersive x-ray spectroscopy. The characteristic phonon modes in our samples are identified using room temperature Raman spectroscopy and benchmarked against existing relevant experimental observations. The incorporation of Ce and Fe as substitutional dopants in SrTiO3 unit cell was confirmed from the absence of absorption at 480, 555, 580, and 1635 cm−1 band in Fourier transform infrared spectra. The 3% Ce...

Physical Chemistry Chemical Physics, 2022

B-site ordered Nd2CrFeO6 double perovskite: A thermodynamically stable ferrimagnetic semiconducto... more B-site ordered Nd2CrFeO6 double perovskite: A thermodynamically stable ferrimagnetic semiconductor with a band gap in the visible range predicted by DFT calculations.

AIP Conference Proceedings, 2018

This investigation aims to synthesize an effective photocatalyst for solar hydrogen (H2) fuel pro... more This investigation aims to synthesize an effective photocatalyst for solar hydrogen (H2) fuel production. The polycrystalline ceramic pellets of 10% Ti-doped BiFeO3 (BFTO) were prepared by the conventional solid-state reaction technique. After grinding into micro-meter sized powders, this bulk sample was mixed with isopropanol and the solution was subsequently sonicated using an ultrasonic bath to obtain corresponding BFTO nanoparticles. The structural, morphological and optical properties of the prepared BFTO nanoparticles were then analogized with bulk BFTO sample, undoped bulkBiFeO3 (BFO) sample and undoped BFO nanoparticles. A notable modification in the crystallographic structure of BFTO nanoparticles compared to other samples was observed. The X-ray diffraction patterns of BFTO showed a transition from rhombohedral perovskite structure to orthorhombic as Ti was doped. The impurity phases found in BFO sample decreased significantly in bulk BFTO which further became negligible in BFTO nanoparticles. The images from Field Emission Scanning Electron M icroscope (FESEM) revealed the surface morphology of the BFTO pellets and demonstrated that the BFTO nanoparticles had a uniformly distributed, reduced grain size (range: 60-120 nm, average size: ∼90 nm). The band gap energy of different samples calculated from their Diffused Reflectance Spectra (DRS) confirmed that like the undoped bulk BFO, the bulk and nanoparticles of Ti-doped BiFeO3 can absorb solar radiation with wavelengths ranging from UV to visible region. The BFTO nanoparticles exhibited lower band gap energy compared to other samples which is indicative of its potential as a photocatalyst in solar energy application. The efficiency of the synthesized materials as photocatalysts will be checked to produce hydrogen via water splitting under visible light irradiation.This investigation aims to synthesize an effective photocatalyst for solar hydrogen (H2) fuel production. The polycrystalline ceramic pellets of 10% Ti-doped BiFeO3 (BFTO) were prepared by the conventional solid-state reaction technique. After grinding into micro-meter sized powders, this bulk sample was mixed with isopropanol and the solution was subsequently sonicated using an ultrasonic bath to obtain corresponding BFTO nanoparticles. The structural, morphological and optical properties of the prepared BFTO nanoparticles were then analogized with bulk BFTO sample, undoped bulkBiFeO3 (BFO) sample and undoped BFO nanoparticles. A notable modification in the crystallographic structure of BFTO nanoparticles compared to other samples was observed. The X-ray diffraction patterns of BFTO showed a transition from rhombohedral perovskite structure to orthorhombic as Ti was doped. The impurity phases found in BFO sample decreased significantly in bulk BFTO which further became negligible in BFTO nanoparticles. T...

A comparative study between zinc oxide/graphene-carbon nanotubes (ZnO/Gr-CNTs) nanocomposite and ... more A comparative study between zinc oxide/graphene-carbon nanotubes (ZnO/Gr-CNTs) nanocomposite and ZnO nanoparticles was carried out to investigate their abilities in the degradation of Rhodamine B (RhB) dye. We utilized the Modified Hummer’s method to prepare the graphene oxide (GO) nanosheet. Moreover, Gr-CNTs had been synthesized from GO and multi-walled carbon nanotubes with hydroxyl group (MWCNTs-OH). The hydrothermal method was employed to fabricate the ZnO/Gr-CNTs nanocomposite from ZnO nanoparticles and Gr-CNTs. During the characterization by X-ray Diffraction (XRD), all the significant peaks of ZnO and ZnO/Gr-CNTs were found in the same phase angle. In addition, the final nanocomposite was also characterized by Field Emission Scanning Electron Microscope (FESEM) and Energy Dispersive X-ray Spectroscopy (EDS). Finally, from the dye degradation test, it was apparent that ZnO/Gr-CNTs nanocomposite showed superior dye removal ability compared to the ZnO nanoparticles.

arXiv: Mesoscale and Nanoscale Physics, 2020

A 3-D composite of zinc oxide/graphene carbon nanotubes was fabricated to observe the photocataly... more A 3-D composite of zinc oxide/graphene carbon nanotubes was fabricated to observe the photocatalytic adsorption and hydrogen evolution to prevent water pollution and to find the application in the energy storage system.

Bismuth Ferrite nanoparticles prepared from ceramic pellets doped with Sm and co-doped with Sm-Ti... more Bismuth Ferrite nanoparticles prepared from ceramic pellets doped with Sm and co-doped with Sm-Ti were synthesized by conventional solid state reaction method having the nominal compositions of Bi1-xSmxFe1-yTiyO3 [(i) x=0.03, y=0; (ii) x=0.06, y=0; (iii) x=0.03, y=0.03; (iv) x=0.06, y=0.06]. Using simple cost effective top down ultrasonication technique micrometer-sized powders grounded from these ceramic pellets were mixed with isopropanol to prepare nanoparticles. The structural and morphological analysis of these multiferroic samples were performed using X-Ray Diffraction (XRD) and Scanning Electron Microscope (SEM). XRD patterns confirmed a phase transition from rhombohedral to pseudo tetragonal/orthorhombic symmetry accompanied by small residual of Bi2Fe4O9 and Bi25FeO40 impurity phases with 6% Sm and Ti substitution in BiFeO3. The calculated values of lattice parameters indicated that there was a continual change in lattice constant when Sm and Ti were substituted at Bi-and Fe...

Results in Physics, 2021

We synthesized strontium titanate SrTiO3 (STO), Zr doped Sr1-xZrxTiO3 and (Zr, Ni) co-doped Sr1-x... more We synthesized strontium titanate SrTiO3 (STO), Zr doped Sr1-xZrxTiO3 and (Zr, Ni) co-doped Sr1-xZrxTi1-yNiyO3 samples using solid state reaction technique to report their structural, electrical and magnetic properties. The cubic P m-3m phase of the synthesized samples has been confirmed using Rietveld analysis of the powder X-ray diffraction pattern. The grain size of the synthesized materials was reduced significantly due to Zr doping as well as (Zr, Ni) co-doping in STO. The chemical species of the samples were identified using energy-dispersive X-ray spectroscopy. We observed forbidden first order Raman scattering at 148, 547 and 797 cm −1 which may indicate nominal loss of inversion symmetry in cubic STO. The absence of absorption at 500 cm −1 and within 600-700 cm −1 band in Fourier Transform Infrared spectra corroborates Zr and Ni as substitutional dopants in our samples. Due to 4% Zr doping in Sr0.96Zr0.04TiO3 sample dielectric constant, remnant electric polarization, remnant magnetization and coercivity were increased. Notably, in the case of 4% Zr and 10% Ni co-doping we have observed clearly the existence of both FE and FM hysteresis loops in Sr0.96Zr0.04Ti0.90Ni0.10O3 sample. In this co-doped sample, the remnant magnetization and coercivity were increased by ∼1 and ∼2 orders of magnitude respectively as compared to those of undoped STO. The coexistence of FE and FM orders in (Zr, Ni) co-doped STO might have the potential for interesting multiferroic applications.

Physical Chemistry Chemical Physics, 2021

Hot-injection synthesized CsSnCl3 nanocrystals demonstrated promising morphology, crystallinity a... more Hot-injection synthesized CsSnCl3 nanocrystals demonstrated promising morphology, crystallinity and photocatalytic ability. By employing experimental parameters, electronic band structure was calculated with greater accuracy using DFT simulations.

Ceramics International, 2018

Gd doped Bi 1−x Gd x Mn 2 O 5 (x = 0.00-0.12) ceramics are synthesized via solid state reaction t... more Gd doped Bi 1−x Gd x Mn 2 O 5 (x = 0.00-0.12) ceramics are synthesized via solid state reaction technique and they have been investigated for their structural, morphological, magnetic and electric properties. X-ray diffraction experiments and their corresponding Rietveld refinement confirm that the major phase characteristics of all the compositions are orthorhombic. The morphological studies reveal that the average grain size gradually decreases from ∼ 500 nm to ∼ 200 nm due to Gd substitution. The temperature dependent zero field cooled (ZFC) and field cooled (FC) magnetization curves demonstrate an antiferromagnetic Néel transition at 42 K. Due to the substitution of 4 % Gd, the phase transition remains unaltered, however, both ZFC and FC curves coincide with each other at an applied magnetic field of 500 Oe. The remanent magnetizations and coercive fields are also found to enhance at room temperature due to the substitution of Gd. The polarization vs. electric field hysteresis loops exhibits the ferroelectric behavior of Bi 1−x Gd x Mn 2 O 5 (x = 0.00-0.12) ceramics at room temperature. Gd substitution also results in enhanced stability of the dielectric constant at wide range of high frequencies with significant suppression of low frequency dispersion particularly for 12% Gd doping. Moreover, a correlation among leakage current, remanent polarization, dielectric constant and microstructure has also been observed while investigating the Gd doped BiMn 2 O 5 ceramics.

Journal of Nanophotonics, 2017

Abstract. Accurate determination of a material’s optical band gap lies in the precise measurement... more Abstract. Accurate determination of a material’s optical band gap lies in the precise measurement of its absorption coefficients, either from its absorbance via the Beer–Lambert law or diffuse reflectance spectrum via the Kubelka–Munk function. Absorption coefficients of powder-form nanomaterials calculated from absorbance spectrum do not match those calculated from diffuse reflectance spectrum, implying the inaccuracy of the traditional optical band gap measurement method for such samples. We have modified the Beer–Lambert law and the Kubelka–Munk function with proper approximations for powder-form nanomaterials. Applying the modified method for powder-form nanomaterial samples, both absorbance and diffuse reflectance spectra yield exactly the same absorption coefficients and therefore accurately determine the optical band gap.

Scientific Reports, 2018

A comprehensive comparison between BiFeO 3-reduced graphene oxide (rGO) nanocomposite and Bi 25 F... more A comprehensive comparison between BiFeO 3-reduced graphene oxide (rGO) nanocomposite and Bi 25 FeO 40-rGO nanocomposite has been performed to investigate their photocatalytic abilities in degradation of Rhodamine B dye and generation of hydrogen by water-splitting. The hydrothermal technique adapted for synthesis of the nanocomposites provides a versatile temperature-controlled phase selection between perovskite BiFeO 3 and sillenite Bi 25 FeO 40. Both perovskite and sillenite structured nanocomposites are stable and exhibit considerably higher photocatalytic ability over pure BiFeO 3 nanoparticles and commercially available Degussa P25 titania. Notably, Bi 25 FeO 40-rGO nanocomposite has demonstrated superior photocatalytic ability and stability under visible light irradiation than that of BiFeO 3-rGO nanocomposite. The possible mechanism behind the superior photocatalytic performance of Bi 25 FeO 40-rGO nanocomposite has been critically discussed. High expenses associated with fabrication of complex optoelectronic devices, coupled with their poor conversion efficiency, limits the use of abundant solar energy from the sun 1-5. Besides overcoming these obstacles, the researchers have focused on converting solar energy into a more usable and reproducible form which is also inexpensive to store. Interestingly, substrateless photocatalyst powders suspended in earth-abundant water can absorb the sunlight incident on them and electrochemically split the water molecules to produce hydrogen and oxygen 6,7. Storing the generated hydrogen, a green fuel, is also easy and inexpensive. Furthermore, these photocatalyst powders can be used to degrade different industrial pollutants which are excessively harmful to our environment 8-14. Since photocatalysts have been able to manifest a great potential in the production of hydrogen by splitting water molecules and degradation of environmental pollutants, investigations on their photocatalytic properties have been carried out for both energy-related and environmental applications 12,13,15-17. Metal oxide photocatalysts are being studied extensively for their enhanced catalytic abilities supplemented by highly stable nature under the electrochemical reaction conditions 16,17. An efficient photocatalyst is expected to have a large surface area, superior sensitivity to the visible region of the solar spectrum, appropriate band energetics, and agile carrier transport to inhibit recombination processes 15,17-19. While graphene is not well-suited for optical applications due to the absence of band gap, its enormous surface area and extraordinary transport properties can be used to supplement the photocatalytic abilities of metal oxides 11,14,20-25. Investigations on the in-situ growth of metal oxide nanoparticles on the 2D lattice of graphene have unveiled incredible improvements in morphology, optical sensitivity, adsorption capabilities, and electron transport characteristics over the pristine metal oxide nanoparticles 23-28. Furthermore, engineering the work function of graphene implied that it is capable of modifying the energy bands of a semiconductor by forming heterojunction 29-32. Among numerous metal oxides, the ones belonging to perovskite and sillenite structures have drawn more interest as photocatalysts as they have shown good optical response and great stability 16,17,33-35. Bismuth ferrite (BFO) is one such family of metal oxide that shows both perovskite (BiFeO 3) and sillenite (Bi 25 FeO 40

Materials Research Bulletin, 2018

6% Sm-Ti co-doping induces phase transition SEM analysis of Bulk materials Highlights  Bulk samp... more 6% Sm-Ti co-doping induces phase transition SEM analysis of Bulk materials Highlights  Bulk samples Bi1-xSmxFe1-yTiyO3 were synthesized by solid-state reaction and their corresponding nanoparticles by ultrasonication method.  Structural, ferroelectric and magnetic properties were compared between nanoparticles and their corresponding bulk counterparts.  Structural phase transition of Bi0.94Sm0.06Fe0.94Ti0.06O3 with negligible impurity phases.  Significant reduction of leakage current density in the synthesized nanoparticles. Enhanced ferromagnetic behavior 4  Enhanced ferromagnetic behavior in 6% Sm-Ti co-doped BiFeO3 nanoparticles compared to its corresponding bulk counterparts.

Journal of Alloys and Compounds, 2016

In this investigation, Gd and Mn co-doped Bi 0.85 Gd 0.15 Fe 1-x Mn x O 3 (x=0.0-0.15) nanopartic... more In this investigation, Gd and Mn co-doped Bi 0.85 Gd 0.15 Fe 1-x Mn x O 3 (x=0.0-0.15) nanoparticles have been prepared to report the influence of co-substitution on their structural, optical, magnetic and electrical properties. Due to simultaneous substitution of Gd and Mn in BiFeO 3 , the crystal structure has been modified from rhombohedral (R3c) to orthorhombic (Pn2 1 a) and the Fe-O-Fe bond angle and Fe-O bond length have been changed. For Mn doping up to 10% in Bi 0.85 Gd 0.15 Fe 1-x Mn x O 3 nanoparticles, the saturation magnetization (M s) has been enhanced significantly, however, for a further increase of doping up to 15 %, the M s has started to reduce again. The co-substitution of Gd and Mn in BiFeO 3 nanoparticles also demonstrates a strong reduction in the optical band gap energy and electrical resistivity compared to that of undoped BiFeO 3 .

The Journal of Physical Chemistry C, 2012

The polyaniline (PANI)/TiO2 nanocomposites have been successfully synthesized via a hydrothermal ... more The polyaniline (PANI)/TiO2 nanocomposites have been successfully synthesized via a hydrothermal method and followed by a low-temperature calcination treatment process. We find that such a PANI/TiO2 nanocomposite exhibits higher photocatalytic activity and stability than bare TiO2 and TiO2-xNx toward the liquid-phase degradation of methyl orange (MO) under both UV and visible light (420 nm < λ < 800 nm) irradiation. More noteworthy, the PANI/TiO2 photocatalyst still perform good activity toward MO and 4-chlorophenol (4-CP) under the longer wavelength of light (550 nm < λ < 800 nm). The total organic carbon (TOC) tests show that the mineralization rate of MO and 4-CP over PANI/TiO2 are apparently higher than bare TiO2 under the irradiation of both UV and visible light. The presence of synergic effect between PANI and TiO2 is believed to play an essential role in affecting the photoreactivity. At last, the roles of active species in the photocatalytic process are compared by using different types of active ...

Journal of Applied Physics, 1996

We have studied the electronic and magnetic properties of the Si and Ga substituted Nd2Fe17 compo... more We have studied the electronic and magnetic properties of the Si and Ga substituted Nd2Fe17 compounds by means of first‐principles calculations. The results show that for the Nd2Fe17−xSix (x=1,2,3, and 4) series, the total Fe moments per cell decrease as x increases but the average local Fe moments actually increase up to x=3, except for the 18h site which is the most preferable site for substitution. For Nd2Fe15Ga2, the moments on every Fe site increase. These results are also compared with the earlier calculation on Nd2Fe17−xAlx (x=1,2, and 4). From the spin‐polarized density of states (DOS) and local DOS for Si, Al, and Ga, it is shown that different substituting elements can change the electronic structure of Nd2Fe17 crystal substantially because of the slightly different interactions with the Fe atoms, and the change in the lattice constants. Estimation of Curie temperatures based on the spin‐fluctuation model shows qualitative agreement with experiments.

Materials Science and Engineering: B, 2021

Fabrication of heterogeneous photocatalysts has received increasing research interest due to thei... more Fabrication of heterogeneous photocatalysts has received increasing research interest due to their potential applications for the degradation of organic pollutants in wastewater and evolution of carbon-free hydrogen fuel via water splitting. Here, we report the photodegradation and photocatalytic hydrogen generation abilities of nanostructured LaFeO 3-MoS 2 photocatalyst synthesized by facile hydrothermal technique. Prior to conducting photocatalytic experiments, structural, morphological and optical properties of the nanocomposite were extensively investigated using X-ray diffraction analysis, field emission scanning electron microscopy and UV-visible spectroscopy, respectively. Nanostructured LaFeO 3-MoS 2 photodegraded ∼96% of rhodamine B dye within only 150 minutes which is considerably higher than that of LaFeO 3 and commercial Degussa P25 titania nanoparticles. The LaFeO 3-MoS 2 nanocomposite also exhibited significantly enhanced photocatalytic efficiency in the decomposition of a colorless probe pollutant, ciprofloxacin eliminating the possibility of the dye-sensitization effect. Moreover, LaFeO 3-MoS 2 demonstrated superior photocatalytic activity towards solar hydrogen evolution via water splitting. Considering the band structures and contribution of reactive species, a direct Z-scheme photocatalytic mechanism is proposed to rationalize the superior photocatalytic behavior of LaFeO 3-MoS 2 nanocomposite.

RSC Advances, 2019

Novel few-layer MoS2 nanosheets incorporated α-Fe2O3/ZnO photocatalyst nanocomposite is reported ... more Novel few-layer MoS2 nanosheets incorporated α-Fe2O3/ZnO photocatalyst nanocomposite is reported with high dye degradation and hydrogen evolution ability under solar illumination.