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Papers by john abel mark

Solid State Communications, 2021

Abstract NH3 is a type of foul smelling gas, when breathed beyond a comfortable level, is extreme... more Abstract NH3 is a type of foul smelling gas, when breathed beyond a comfortable level, is extremely hazardous to human health. Developing of room-temperature ammonia sensors are one of the challenging task in research. Manganese ferrites and cobalt doped manganese ferrites nanoparticles were successfully produced in this work, and used as a sensing material for ammonia gas sensor, also getting the better results at room temperature. The synthesized materials were confirmed by various characterization techniques namely XRD, SEM & EDAX, FTIR, and DRS. Three different weight percentage (1, 3, and 5 wt%) of Co is doped with MnFe2O4 nanomaterial and study the optical properties and the ammonia sensing ability comparatively. From that 5 wt% Co: MnFe2O4 nanoparticles shows good sensing percentage of about 75.3 %.

Journal of Cluster Science, 2021

In this work, the Zr doped CuFe2O4 nanoparticles were prepared with different concentrations of z... more In this work, the Zr doped CuFe2O4 nanoparticles were prepared with different concentrations of zirconium ions through the chemical precipitation method. The Zr ion are added as Zr(x wt%):CuFe2(100-xwt%)O4 with (x = 0, 1, 3, 5). The crystal structure and phase were identified by XRD characterization. From the XRD the average crystallite sizes of the synthesized material were calculated and are obtained as 33 nm, 34 nm, 38 nm, and 42 nm. FT-IR characterization was taken to find the functional groups present in the material. The optical properties and corresponding optical band gap were determined by UV-DRS and PL studies. The bandgap was found to be 1.39 eV, 1.56 eV, 1.80 eV, and 1.97 eV for 0%, 1%, 3%, and 5% Zr doped CuFe2O4 nanoparticles respectively. The surface morphology is studied by SEM analysis. EDAX is used for the elemental composition analysis of the prepared materials. Further, the photocatalytic performances were studied with Rose Bengal (RB) and Indigo Carmine (IC) textile dyes. The maximum degradation percentage was obtained as 88% for RB dye and 71% for IC dye with 5wt% Zr doped CuFe2O4 nanoparticles within 120 min. The mineralization of the degraded dye solution was confirmed by the Chemical Oxygen Demand (COD) technique.

Inorganic Chemistry Communications, 2020

Abstract The present work deals with the study of CoFe2O4 and three different concentrations of Z... more Abstract The present work deals with the study of CoFe2O4 and three different concentrations of Zn2+ substituted CoFe2O4 nanoparticles synthesized via a simple co-precipitation method as a sunlight driven photocatalyst. Powder X-ray diffraction studies were taken to preliminary confirmation of crystal structure and crystallite size were found to be is found to be 43 nm, 41 nm, 40 nm, and 37 nm for Znx Co (100-x %)Fe2O4 (x = 3 wt%, 7 wt%, 11 wt%) samples respectively. optical band gap was found to be 1.85 eV, 1.99 eV, 2.08 eV and 2.28 eV Znx Co (100-x %)Fe2O4 (x = 3 wt%, 7 wt%, 11 wt%) samples respectively using diffused reflectance spectroscopy (UV-DRS). The Photoluminescence (PL) study was carried out for crystal defect analysis. Fourier transforms infrared (FTIR) spectroscopy gives the details about the functional group present in the material. Scanning electron microscopy and energy dispersive X-ray spectrum (SEM & EDAX) show the surface morphology and elemental composition of the synthesized material. Rhodamine B (RhB), Methylene Blue (MB) and Crystal Violet (CV) are mineralized by photodegradation using synthesized material was studied.

Research on Chemical Intermediates, 2020

The spinel nickel manganite (NiMn2O4) nanoparticles (NPs) were successfully synthesized through s... more The spinel nickel manganite (NiMn2O4) nanoparticles (NPs) were successfully synthesized through simple co-precipitation method, and their structural, optical, morphological and photocatalytic behavior is examined in this investigation. The powder X-ray diffraction pattern confirms the face-centered cubic spinel structure of the as-prepared sample, and the average crystallite size is found to be 46.27 nm. The absorption spectrum of the material was obtained via diffuse reflectance spectroscopy (UV-DRS), and the bandgap value is calculated using Tauc’s relation as 2.41 eV. Morphological analysis was investigated by using a scanning electron microscope (SEM). From the SEM analysis, the hexagonal cake-like structure was observed from the prepared material and size was achieved around to be 50–100 nm. Furthermore, the photocatalytic behavior of NiMn2O4 (NPs) against organic dyes under direct sunlight was analyzed by using methylene blue, malachite green and Congo red and the efficiency is observed as 92%, 94% and 62%, within 120 min, 60 min and 120 min, respectively.

Physica B: Condensed Matter, 2020

Abstract Cobalt ferrite and nickel doped cobalt ferrite nanoparticles (NPs) was victoriously deve... more Abstract Cobalt ferrite and nickel doped cobalt ferrite nanoparticles (NPs) was victoriously developed through chemical co-precipitation technique. The spinel crystal structure of prepared samples was confirmed by powder X-ray diffraction studies (PXRD) and also the crystalline size was calculated. Optical properties of the samples were analyzed using UV–Visible spectrophotometer and Photoluminescence (PL) studies. The bandgap was calculated using Tauc's plot and is found to be 1.83 eV, 1.92 eV, 2.12 eV, and 2.21eV for pure cobalt ferrite and (3, 7, 11) wt% Ni-doped CoFe2O4 samples respectively. Further, the morphological and the compositional weight percentage (wt %) was examined using a Scanning Electron Microscope (SEM) and Energy Dispersive X-ray spectrum (EDAX) respectively. Towards application, the photocatalytic activity of the synthesized NPs was studied under direct sunlight and the maximum efficiency was obtained as 83.41%, 63.62% and 82.76% for Methylene Blue (MB), Rhodamine B (RhB) and Crystal Violet (CV) respectively.

Materials Research Express, 2019

Physica B: Condensed Matter, 2019

American Journal of Orthodontics, 1961

Conductive materials are formed by implanting high energy ions (30 keV to 300 keV) into rigid bac... more Conductive materials are formed by implanting high energy ions (30 keV to 300 keV) into rigid backboned polymers, such as poly (p-phenylene sulfide); conductivities on the order of 10-³ (ohm-cm)-¹ are demonstrated and the materials remain stable over periods as long as a year.

Mine Water and the Environment, 1994

Zambia Consolidated Copper Mines Ltd. (ZCCM) is planning a substantial increase in ore production... more Zambia Consolidated Copper Mines Ltd. (ZCCM) is planning a substantial increase in ore production in several of their underground mines on the Zambian Copperbelt over the next 10 years. The future production strategy is based on development of productive and economic mining methods through the application of mechanization and backfilling. Mechanization is designed to provide the production capability and the backfilling is designed to reduce water inflow into the mines. A similar trend can be seen in worldwide changes in mining methods from open stoping and sub-level caving to cut-and-fill stoping. Backfill is being employed worldwide, including in Australia, Canada, Sweden, Latin America, Zambia, and the U.S.A. Plans for backfill mining methods are underway for future operations in Chile, Canada, Zambia, and Mexico. The principal reasons for these changes in mining methods are twofold: Increased ore recovery, and Decreased environmental impact. The main difference in the environmental impacts between mining with sub-level caving or open stoping and mining with backfilling methods is the reduction in subsidence or the potential for subsidence. Backfilling reduces ground movements in the rock overlying and adjacent to mine openings as well as subsidence at the surface. Reduced ground movement decreases the number and size of fracture-controlled hydraulic flow paths into a mine and, thereby, the impact of mining on surface and ground water resources. This paper deals with: 1) The impacts caused by open stoping and sub-level caving in comparison to backfilling methods; 2) The approximate impact of backfill on dewatering strategies, and; 3) The environmental benefits of backfiU mining. The differences in mine drainage strategies are supported by case histories from various mines.

International Journal of Mining and Geological Engineering, 1988

Soft rock pillars can be designed by several methods available in the mining literature. All of t... more Soft rock pillars can be designed by several methods available in the mining literature. All of these methods include the effect of shape, or geometry, on the average strength of specimens and pillars. All of the pillar design methods include some measurement of the strength of specimens of the pillar rock. The most common rock specimen strength property measured is the unconfined compressive strength. However, the average strength of triaxially confined rock specimens is much greater than the unconfined specimen strength, which can be more important to pillar strength. The estimation of the strength of a pillar is complicated by the decrease in rock specimen strength with increase in specimen size.

Inorganic Chemistry Communications, 2021

This work is focused on the field of gas sensor for sensing the toxic gases which is highly harmf... more This work is focused on the field of gas sensor for sensing the toxic gases which is highly harmful to environment. The semiconductor metal oxide nanoparticles of manganese ferrites and copper doped manganese ferrite (MnFe2O4 and Cu: MnFe2O4) was successfully developed. The characterization like crystal structure, surface morphology, optical bandgap, elemental composition and functional group analysis for the developed materials were carried out using X-ray Diffraction (XRD), Scanning electron microscope (SEM), Diffused reflectance spectroscopy (DRS), Energy dispersive X-Ray analysis (EDAX) and Fourier Transform (FT-IR) studies respectively. The ammonia gas (NH3) was taken as test gas and the sensitivity of prepared samples were analyzed with different ppm (200-400) of gas molecules at room temperature. The sensing percentage gradually improved with the increase in Cu2+ concentration also with the increase in ppm of the gas. However, the recovery time of the material is increased wi...

Inorganic Chemistry Communications, 2021

Abstract Manganese ferrites (MnFe2O4) and three different weight percentage of nickel doped manga... more Abstract Manganese ferrites (MnFe2O4) and three different weight percentage of nickel doped manganese ferrites (Ni: MnFe2O4) was prepared through a chemical co-precipitation method. The crystal structure, crystallite size, and phase of the prepared materials are determined by X-Ray Diffraction technique (XRD). The average crystallite size was calculated to be 44 nm, 42 nm, 37 nm, and 35 nm for MnFe2O4, Ni1%Mn(x-1%) Fe2O4, Ni3%Mn(x-3%)Fe2O4, and Ni5%Mn(x-5%)Fe2O4, respectively. Fourier Transforms Infrared (FTIR) spectroscopy technique is used to study the functional groups present in the prepared materials. Surface morphology and elemental compositions of the synthesized nanoparticles were examined using Scanning Electron Microscope (SEM) and Energy Dispersive X-ray spectroscopy (EDAX). The gas sensing property of the prepared materials was studied with different ppm of ammonia gas (NH3), and the respective response and recovery time was calculated.

Physica B: Condensed Matter, 2021

Abstract The tetragonal spinel Cobalt manganite (CoMn2O4) nanoparticles (NPs) were prepared succe... more Abstract The tetragonal spinel Cobalt manganite (CoMn2O4) nanoparticles (NPs) were prepared successfully via the co-precipitation route. The crystal structure and phase purity was primarily confirmed by the PXRD pattern. The optical band gap of the prepared CoMn2O4 NPs was found to be 1.70 and 2.0 eV. The morphological analysis of CoMn2O4 NPs was carried out by SEM images. The EDX spectrum gives the elemental composition of the prepared CoMn2O4 NPs. The FTIR and PL spectrum gives details of the functional groups and crystal defects presents in the synthesized sample. Magnetic property of the prepared sample was analyzed using Vibrating Sample Magnetometer (VSM). The photocatalytic activity of the CoMn2O4 NPs was performed against the organic dyes such as Methylene Blue (MB), Malachite Green (MG) and Congo Red (CR) under direct sunlight. The degradation efficiency was achieved to be 87.80%, 79.43% and 52.78% respectively for MG, MB, and CR dyes.

Inorganic Chemistry Communications, 2021

Abstract The Fe2O3@MgO, Fe2O3@Mn2O3, and Fe2O3@Co3O4 nanocomposites were developed using a two-po... more Abstract The Fe2O3@MgO, Fe2O3@Mn2O3, and Fe2O3@Co3O4 nanocomposites were developed using a two-pot wet chemical procedure. The structure and the phase were confirmed using the Powder X-Ray diffraction tool (PXRD). The optical properties of the prepared materials were analyzed using Photoluminescence (PL) and Diffuse Reflectance Spectroscopy (DRS) technique. Surface morphology and elemental composition of the prepared samples were studied by Scanning Electron Microscope (SEM) and Energy Dispersive X-Ray Spectroscopy (EDAX). The porosity and the surface area of the materials were studied by Brunauer–Emmett–Teller (BET) analysis. The functional group present in the prepared material is analyzed by Fourier transforms IR analysis (FT-IR). The photocatalytic analysis was done using Methylene Blue (MB), Rhodamine B (RhB) and Phenol. Further the mineralizations of the pollutants are studied by COD experiment and also the radical scavenger experiments are carried out.

Journal of the Iranian Chemical Society

Copper doped Zinc Oxide nanoparticles were synthesized using co-precipitation method. The structu... more Copper doped Zinc Oxide nanoparticles were synthesized using co-precipitation method. The structural optical, antibacterial activities were studied and compared with those of ZnO: Cu and the bare ZnO nanoparticles. XRD studies confirmed that all the prepared nanoparticles have hexagonal wurtzite structure of ZnO without any secondary phase after doping and the particle size was found to be within the range between 30 and 44 nm. By W–H (Williamson–Hall methods) analysis the strain occurred in ZnO and Cu: ZnO samples were calculated. UV–vis absorption spectra of the samples show sharp absorption edges around 290 nm. Optical absorption analysis of samples shows a red shift in the absorption band edge in Cu: ZnO nano-powders. The constituents of composites presence in Cu: ZnO samples were confirmed by FTIR data. The antibacterial activity of synthesized un-doped and Cu doped ZnO nano powders was studied using disc diffusion technique against both gram positive (S. aurous) and gram negative (E. coli) bacteria, which revealed the enhanced activity of Cu doped ZnO with increasing content of the doping agent. The catalytic activity of the prepared samples was analyzed with RhB (Rhodamine B) textile dye and 97% of efficiency was achieved for 5 wt% Cu doped ZnO nanoparticles within 6 min at pH 9.

Solid State Communications, 2021

Abstract NH3 is a type of foul smelling gas, when breathed beyond a comfortable level, is extreme... more Abstract NH3 is a type of foul smelling gas, when breathed beyond a comfortable level, is extremely hazardous to human health. Developing of room-temperature ammonia sensors are one of the challenging task in research. Manganese ferrites and cobalt doped manganese ferrites nanoparticles were successfully produced in this work, and used as a sensing material for ammonia gas sensor, also getting the better results at room temperature. The synthesized materials were confirmed by various characterization techniques namely XRD, SEM & EDAX, FTIR, and DRS. Three different weight percentage (1, 3, and 5 wt%) of Co is doped with MnFe2O4 nanomaterial and study the optical properties and the ammonia sensing ability comparatively. From that 5 wt% Co: MnFe2O4 nanoparticles shows good sensing percentage of about 75.3 %.

Journal of Cluster Science, 2021

In this work, the Zr doped CuFe2O4 nanoparticles were prepared with different concentrations of z... more In this work, the Zr doped CuFe2O4 nanoparticles were prepared with different concentrations of zirconium ions through the chemical precipitation method. The Zr ion are added as Zr(x wt%):CuFe2(100-xwt%)O4 with (x = 0, 1, 3, 5). The crystal structure and phase were identified by XRD characterization. From the XRD the average crystallite sizes of the synthesized material were calculated and are obtained as 33 nm, 34 nm, 38 nm, and 42 nm. FT-IR characterization was taken to find the functional groups present in the material. The optical properties and corresponding optical band gap were determined by UV-DRS and PL studies. The bandgap was found to be 1.39 eV, 1.56 eV, 1.80 eV, and 1.97 eV for 0%, 1%, 3%, and 5% Zr doped CuFe2O4 nanoparticles respectively. The surface morphology is studied by SEM analysis. EDAX is used for the elemental composition analysis of the prepared materials. Further, the photocatalytic performances were studied with Rose Bengal (RB) and Indigo Carmine (IC) textile dyes. The maximum degradation percentage was obtained as 88% for RB dye and 71% for IC dye with 5wt% Zr doped CuFe2O4 nanoparticles within 120 min. The mineralization of the degraded dye solution was confirmed by the Chemical Oxygen Demand (COD) technique.

Inorganic Chemistry Communications, 2020

Abstract The present work deals with the study of CoFe2O4 and three different concentrations of Z... more Abstract The present work deals with the study of CoFe2O4 and three different concentrations of Zn2+ substituted CoFe2O4 nanoparticles synthesized via a simple co-precipitation method as a sunlight driven photocatalyst. Powder X-ray diffraction studies were taken to preliminary confirmation of crystal structure and crystallite size were found to be is found to be 43 nm, 41 nm, 40 nm, and 37 nm for Znx Co (100-x %)Fe2O4 (x = 3 wt%, 7 wt%, 11 wt%) samples respectively. optical band gap was found to be 1.85 eV, 1.99 eV, 2.08 eV and 2.28 eV Znx Co (100-x %)Fe2O4 (x = 3 wt%, 7 wt%, 11 wt%) samples respectively using diffused reflectance spectroscopy (UV-DRS). The Photoluminescence (PL) study was carried out for crystal defect analysis. Fourier transforms infrared (FTIR) spectroscopy gives the details about the functional group present in the material. Scanning electron microscopy and energy dispersive X-ray spectrum (SEM & EDAX) show the surface morphology and elemental composition of the synthesized material. Rhodamine B (RhB), Methylene Blue (MB) and Crystal Violet (CV) are mineralized by photodegradation using synthesized material was studied.

Research on Chemical Intermediates, 2020

The spinel nickel manganite (NiMn2O4) nanoparticles (NPs) were successfully synthesized through s... more The spinel nickel manganite (NiMn2O4) nanoparticles (NPs) were successfully synthesized through simple co-precipitation method, and their structural, optical, morphological and photocatalytic behavior is examined in this investigation. The powder X-ray diffraction pattern confirms the face-centered cubic spinel structure of the as-prepared sample, and the average crystallite size is found to be 46.27 nm. The absorption spectrum of the material was obtained via diffuse reflectance spectroscopy (UV-DRS), and the bandgap value is calculated using Tauc’s relation as 2.41 eV. Morphological analysis was investigated by using a scanning electron microscope (SEM). From the SEM analysis, the hexagonal cake-like structure was observed from the prepared material and size was achieved around to be 50–100 nm. Furthermore, the photocatalytic behavior of NiMn2O4 (NPs) against organic dyes under direct sunlight was analyzed by using methylene blue, malachite green and Congo red and the efficiency is observed as 92%, 94% and 62%, within 120 min, 60 min and 120 min, respectively.

Physica B: Condensed Matter, 2020

Abstract Cobalt ferrite and nickel doped cobalt ferrite nanoparticles (NPs) was victoriously deve... more Abstract Cobalt ferrite and nickel doped cobalt ferrite nanoparticles (NPs) was victoriously developed through chemical co-precipitation technique. The spinel crystal structure of prepared samples was confirmed by powder X-ray diffraction studies (PXRD) and also the crystalline size was calculated. Optical properties of the samples were analyzed using UV–Visible spectrophotometer and Photoluminescence (PL) studies. The bandgap was calculated using Tauc's plot and is found to be 1.83 eV, 1.92 eV, 2.12 eV, and 2.21eV for pure cobalt ferrite and (3, 7, 11) wt% Ni-doped CoFe2O4 samples respectively. Further, the morphological and the compositional weight percentage (wt %) was examined using a Scanning Electron Microscope (SEM) and Energy Dispersive X-ray spectrum (EDAX) respectively. Towards application, the photocatalytic activity of the synthesized NPs was studied under direct sunlight and the maximum efficiency was obtained as 83.41%, 63.62% and 82.76% for Methylene Blue (MB), Rhodamine B (RhB) and Crystal Violet (CV) respectively.

Materials Research Express, 2019

Physica B: Condensed Matter, 2019

American Journal of Orthodontics, 1961

Conductive materials are formed by implanting high energy ions (30 keV to 300 keV) into rigid bac... more Conductive materials are formed by implanting high energy ions (30 keV to 300 keV) into rigid backboned polymers, such as poly (p-phenylene sulfide); conductivities on the order of 10-³ (ohm-cm)-¹ are demonstrated and the materials remain stable over periods as long as a year.

Mine Water and the Environment, 1994

Zambia Consolidated Copper Mines Ltd. (ZCCM) is planning a substantial increase in ore production... more Zambia Consolidated Copper Mines Ltd. (ZCCM) is planning a substantial increase in ore production in several of their underground mines on the Zambian Copperbelt over the next 10 years. The future production strategy is based on development of productive and economic mining methods through the application of mechanization and backfilling. Mechanization is designed to provide the production capability and the backfilling is designed to reduce water inflow into the mines. A similar trend can be seen in worldwide changes in mining methods from open stoping and sub-level caving to cut-and-fill stoping. Backfill is being employed worldwide, including in Australia, Canada, Sweden, Latin America, Zambia, and the U.S.A. Plans for backfill mining methods are underway for future operations in Chile, Canada, Zambia, and Mexico. The principal reasons for these changes in mining methods are twofold: Increased ore recovery, and Decreased environmental impact. The main difference in the environmental impacts between mining with sub-level caving or open stoping and mining with backfilling methods is the reduction in subsidence or the potential for subsidence. Backfilling reduces ground movements in the rock overlying and adjacent to mine openings as well as subsidence at the surface. Reduced ground movement decreases the number and size of fracture-controlled hydraulic flow paths into a mine and, thereby, the impact of mining on surface and ground water resources. This paper deals with: 1) The impacts caused by open stoping and sub-level caving in comparison to backfilling methods; 2) The approximate impact of backfill on dewatering strategies, and; 3) The environmental benefits of backfiU mining. The differences in mine drainage strategies are supported by case histories from various mines.

International Journal of Mining and Geological Engineering, 1988

Soft rock pillars can be designed by several methods available in the mining literature. All of t... more Soft rock pillars can be designed by several methods available in the mining literature. All of these methods include the effect of shape, or geometry, on the average strength of specimens and pillars. All of the pillar design methods include some measurement of the strength of specimens of the pillar rock. The most common rock specimen strength property measured is the unconfined compressive strength. However, the average strength of triaxially confined rock specimens is much greater than the unconfined specimen strength, which can be more important to pillar strength. The estimation of the strength of a pillar is complicated by the decrease in rock specimen strength with increase in specimen size.

Inorganic Chemistry Communications, 2021

This work is focused on the field of gas sensor for sensing the toxic gases which is highly harmf... more This work is focused on the field of gas sensor for sensing the toxic gases which is highly harmful to environment. The semiconductor metal oxide nanoparticles of manganese ferrites and copper doped manganese ferrite (MnFe2O4 and Cu: MnFe2O4) was successfully developed. The characterization like crystal structure, surface morphology, optical bandgap, elemental composition and functional group analysis for the developed materials were carried out using X-ray Diffraction (XRD), Scanning electron microscope (SEM), Diffused reflectance spectroscopy (DRS), Energy dispersive X-Ray analysis (EDAX) and Fourier Transform (FT-IR) studies respectively. The ammonia gas (NH3) was taken as test gas and the sensitivity of prepared samples were analyzed with different ppm (200-400) of gas molecules at room temperature. The sensing percentage gradually improved with the increase in Cu2+ concentration also with the increase in ppm of the gas. However, the recovery time of the material is increased wi...

Inorganic Chemistry Communications, 2021

Abstract Manganese ferrites (MnFe2O4) and three different weight percentage of nickel doped manga... more Abstract Manganese ferrites (MnFe2O4) and three different weight percentage of nickel doped manganese ferrites (Ni: MnFe2O4) was prepared through a chemical co-precipitation method. The crystal structure, crystallite size, and phase of the prepared materials are determined by X-Ray Diffraction technique (XRD). The average crystallite size was calculated to be 44 nm, 42 nm, 37 nm, and 35 nm for MnFe2O4, Ni1%Mn(x-1%) Fe2O4, Ni3%Mn(x-3%)Fe2O4, and Ni5%Mn(x-5%)Fe2O4, respectively. Fourier Transforms Infrared (FTIR) spectroscopy technique is used to study the functional groups present in the prepared materials. Surface morphology and elemental compositions of the synthesized nanoparticles were examined using Scanning Electron Microscope (SEM) and Energy Dispersive X-ray spectroscopy (EDAX). The gas sensing property of the prepared materials was studied with different ppm of ammonia gas (NH3), and the respective response and recovery time was calculated.

Physica B: Condensed Matter, 2021

Abstract The tetragonal spinel Cobalt manganite (CoMn2O4) nanoparticles (NPs) were prepared succe... more Abstract The tetragonal spinel Cobalt manganite (CoMn2O4) nanoparticles (NPs) were prepared successfully via the co-precipitation route. The crystal structure and phase purity was primarily confirmed by the PXRD pattern. The optical band gap of the prepared CoMn2O4 NPs was found to be 1.70 and 2.0 eV. The morphological analysis of CoMn2O4 NPs was carried out by SEM images. The EDX spectrum gives the elemental composition of the prepared CoMn2O4 NPs. The FTIR and PL spectrum gives details of the functional groups and crystal defects presents in the synthesized sample. Magnetic property of the prepared sample was analyzed using Vibrating Sample Magnetometer (VSM). The photocatalytic activity of the CoMn2O4 NPs was performed against the organic dyes such as Methylene Blue (MB), Malachite Green (MG) and Congo Red (CR) under direct sunlight. The degradation efficiency was achieved to be 87.80%, 79.43% and 52.78% respectively for MG, MB, and CR dyes.

Inorganic Chemistry Communications, 2021

Abstract The Fe2O3@MgO, Fe2O3@Mn2O3, and Fe2O3@Co3O4 nanocomposites were developed using a two-po... more Abstract The Fe2O3@MgO, Fe2O3@Mn2O3, and Fe2O3@Co3O4 nanocomposites were developed using a two-pot wet chemical procedure. The structure and the phase were confirmed using the Powder X-Ray diffraction tool (PXRD). The optical properties of the prepared materials were analyzed using Photoluminescence (PL) and Diffuse Reflectance Spectroscopy (DRS) technique. Surface morphology and elemental composition of the prepared samples were studied by Scanning Electron Microscope (SEM) and Energy Dispersive X-Ray Spectroscopy (EDAX). The porosity and the surface area of the materials were studied by Brunauer–Emmett–Teller (BET) analysis. The functional group present in the prepared material is analyzed by Fourier transforms IR analysis (FT-IR). The photocatalytic analysis was done using Methylene Blue (MB), Rhodamine B (RhB) and Phenol. Further the mineralizations of the pollutants are studied by COD experiment and also the radical scavenger experiments are carried out.

Journal of the Iranian Chemical Society

Copper doped Zinc Oxide nanoparticles were synthesized using co-precipitation method. The structu... more Copper doped Zinc Oxide nanoparticles were synthesized using co-precipitation method. The structural optical, antibacterial activities were studied and compared with those of ZnO: Cu and the bare ZnO nanoparticles. XRD studies confirmed that all the prepared nanoparticles have hexagonal wurtzite structure of ZnO without any secondary phase after doping and the particle size was found to be within the range between 30 and 44 nm. By W–H (Williamson–Hall methods) analysis the strain occurred in ZnO and Cu: ZnO samples were calculated. UV–vis absorption spectra of the samples show sharp absorption edges around 290 nm. Optical absorption analysis of samples shows a red shift in the absorption band edge in Cu: ZnO nano-powders. The constituents of composites presence in Cu: ZnO samples were confirmed by FTIR data. The antibacterial activity of synthesized un-doped and Cu doped ZnO nano powders was studied using disc diffusion technique against both gram positive (S. aurous) and gram negative (E. coli) bacteria, which revealed the enhanced activity of Cu doped ZnO with increasing content of the doping agent. The catalytic activity of the prepared samples was analyzed with RhB (Rhodamine B) textile dye and 97% of efficiency was achieved for 5 wt% Cu doped ZnO nanoparticles within 6 min at pH 9.