The Experts below are selected from a list of 5678937 Experts worldwide ranked by ideXlab platform
Amitava Patra - One of the best experts on this subject based on the ideXlab platform.
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Photophysical Properties of Doped Carbon Dots (N, P, and B) and Their Influence on Electron/Hole Transfer in Carbon Dots–Nickel (II) Phthalocyanine Conjugates
The Journal of Physical Chemistry C, 2014Co-Authors: Monoj Kumar Barman, Bikash Jana, Santanu Bhattacharyya, Amitava PatraAbstract:Doping in carbon nanomaterial with various hetero atoms draws attention due to their tunable properties. Herein, we have synthesized nitrogen containing carbon dots [C-dots (N)], phosphorus co-doped nitrogen containing carbon dots [C-dots (N, P)], and boron co-doped nitrogen containing carbon dots [C-dots (N, B)]; and detailed elemental analysis has been unveiled by X-ray photoelectron spectroscopy (XPS) measurements. Our emphasis is given to understand the effect of doping on the photophysical behavior of carbon dots by using steady-state and time-resolved spectroscopy. Nitrogen containing carbon dots have quantum yield (QY) of 64.0% with an average decay time of 12.8 ns. Photophysical properties (radiative decay rate and average decay time) are found to be increased for phosphorus Co-Doping carbon dots due to extra electron incorporation for n-type doping (phosphorus dopant) to carbon dots which favors the radiative relaxation pathways. On the contrary, boron (p-type dopant) Co-Doping with nitrogen cont...
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photophysical properties of doped carbon dots n p and b and their influence on electron hole transfer in carbon dots nickel ii phthalocyanine conjugates
Journal of Physical Chemistry C, 2014Co-Authors: Monoj Kumar Barman, Bikash Jana, Santanu Bhattacharyya, Amitava PatraAbstract:Doping in carbon nanomaterial with various hetero atoms draws attention due to their tunable properties. Herein, we have synthesized nitrogen containing carbon dots [C-dots (N)], phosphorus co-doped nitrogen containing carbon dots [C-dots (N, P)], and boron co-doped nitrogen containing carbon dots [C-dots (N, B)]; and detailed elemental analysis has been unveiled by X-ray photoelectron spectroscopy (XPS) measurements. Our emphasis is given to understand the effect of doping on the photophysical behavior of carbon dots by using steady-state and time-resolved spectroscopy. Nitrogen containing carbon dots have quantum yield (QY) of 64.0% with an average decay time of 12.8 ns. Photophysical properties (radiative decay rate and average decay time) are found to be increased for phosphorus Co-Doping carbon dots due to extra electron incorporation for n-type doping (phosphorus dopant) to carbon dots which favors the radiative relaxation pathways. On the contrary, boron (p-type dopant) Co-Doping with nitrogen cont...
Monoj Kumar Barman - One of the best experts on this subject based on the ideXlab platform.
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Photophysical Properties of Doped Carbon Dots (N, P, and B) and Their Influence on Electron/Hole Transfer in Carbon Dots–Nickel (II) Phthalocyanine Conjugates
The Journal of Physical Chemistry C, 2014Co-Authors: Monoj Kumar Barman, Bikash Jana, Santanu Bhattacharyya, Amitava PatraAbstract:Doping in carbon nanomaterial with various hetero atoms draws attention due to their tunable properties. Herein, we have synthesized nitrogen containing carbon dots [C-dots (N)], phosphorus co-doped nitrogen containing carbon dots [C-dots (N, P)], and boron co-doped nitrogen containing carbon dots [C-dots (N, B)]; and detailed elemental analysis has been unveiled by X-ray photoelectron spectroscopy (XPS) measurements. Our emphasis is given to understand the effect of doping on the photophysical behavior of carbon dots by using steady-state and time-resolved spectroscopy. Nitrogen containing carbon dots have quantum yield (QY) of 64.0% with an average decay time of 12.8 ns. Photophysical properties (radiative decay rate and average decay time) are found to be increased for phosphorus Co-Doping carbon dots due to extra electron incorporation for n-type doping (phosphorus dopant) to carbon dots which favors the radiative relaxation pathways. On the contrary, boron (p-type dopant) Co-Doping with nitrogen cont...
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photophysical properties of doped carbon dots n p and b and their influence on electron hole transfer in carbon dots nickel ii phthalocyanine conjugates
Journal of Physical Chemistry C, 2014Co-Authors: Monoj Kumar Barman, Bikash Jana, Santanu Bhattacharyya, Amitava PatraAbstract:Doping in carbon nanomaterial with various hetero atoms draws attention due to their tunable properties. Herein, we have synthesized nitrogen containing carbon dots [C-dots (N)], phosphorus co-doped nitrogen containing carbon dots [C-dots (N, P)], and boron co-doped nitrogen containing carbon dots [C-dots (N, B)]; and detailed elemental analysis has been unveiled by X-ray photoelectron spectroscopy (XPS) measurements. Our emphasis is given to understand the effect of doping on the photophysical behavior of carbon dots by using steady-state and time-resolved spectroscopy. Nitrogen containing carbon dots have quantum yield (QY) of 64.0% with an average decay time of 12.8 ns. Photophysical properties (radiative decay rate and average decay time) are found to be increased for phosphorus Co-Doping carbon dots due to extra electron incorporation for n-type doping (phosphorus dopant) to carbon dots which favors the radiative relaxation pathways. On the contrary, boron (p-type dopant) Co-Doping with nitrogen cont...
Zhigong Zheng - One of the best experts on this subject based on the ideXlab platform.
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Magnetic behavior of Co-Mn co-doped ZnO nanoparticles
Journal of Magnetism and Magnetic Materials, 2014Co-Authors: Xinzhong Liu, Zhigong ZhengAbstract:Abstract Here, we report on systematic studies of the magnetic properties of Co and Mn co-doped ZnO nanoparticles prepared by a sol–gel technique. The effect of the concentration of the doping ions on the magnetic properties of Co and Mn co-doped ZnO nanoparticles is presented. X-ray diffraction characterizations (XRD) of co-doped ZnO nanoparticles are all wurtzite structure. The Zn 0.96 Co 0.02 Mn 0.02 O nanoparticles and Zn 0.94 Co 0.02 Mn 0.04 O nanoparticles display ferromagnetic behavior at room temperature. Superconducting quantum interference device (SQUID) magnetometer figures show that with the concentration of the Mn ions increased, the saturation magnetic moment ( M s ) increased, and the magnetic is probably due to the Co-Doping of the Mn ions. Our results demonstrate that the Mn ions doping concentration play an important role in the ferromagnetic properties of Co–Mn co-doped ZnO nanoparticles at room temperature.
Sajjad Ali - One of the best experts on this subject based on the ideXlab platform.
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Theoretical investigation of optoelectronic and magnetic properties of Co-doped ZnS and (Al, Co) co-doped ZnS
Computational Materials Science, 2020Co-Authors: Muhammad Sheraz Khan, Lijie Shi, Bingsuo Zou, Sajjad AliAbstract:Abstract In this work, electronic, magnetic and optical properties of Co-doped and (Co, Al) co-doped ZnS have been studied using the first principles technique based on density functional theory (DFT). The non-spin polarized state of ZnS changes to spin-polarized state when doping with Co. The Co ions interact antiferromagnetically which can be discussed on the basis of the super-exchange mechanism. The additional electron introduced by Al Co-Doping changes the magnetic order from antiferromagnetic to ferromagnetic state. Moreover, optical properties such as dielectric functions, reflectivity, absorption coefficients and transmissivity for undoped ZnS, Co; ZnS and (Co, Al); ZnS were also discussed. We found that the optical absorption edges shift to lower energy after Co doping in ZnS. After Al Co-Doping in Co; ZnS, a new peak is observed in infrared region. Thus, we found all curves of optical properties are broadened after Co doping and (Co, Al) Co-Doping in ZnS. The correlation between the magnetic coupling and intra-band d-d transition was also investigated and we found that d-d (4T1-6A1) transition peak for AFM coupled Co ions is higher than that for FM coupled Co ions, which is in line with theoretical and experimental observations. The improved optical and magnetic results indicate that (Co, Al) co-doped ZnS can be used as a promising candidate for photonic and spintronic devices in the future.
Joaquim Carlos Gomes Esteves Da Silva - One of the best experts on this subject based on the ideXlab platform.
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Preparation, characterization, and photocatalytic activity under UV and visible light of Co, Mn, and Ni mono-doped and (P,Mo) and (P,W) co-doped TiO_2 nanoparticles: a comparative study
Environmental Science and Pollution Research, 2019Co-Authors: Abderrahim El Mragui, Ikram Daou, Omar Zegaoui, Joaquim Carlos Gomes Esteves Da SilvaAbstract:In this work, TiO_2-based nanomaterials have been successfully synthesized by doping TiO_2 with Co, Mn, and Ni and by Co-Doping it with (P,Mo) or (P,W). The structural, optical, and morphological properties of the synthesized nanomaterials have been investigated using various techniques such as XRD, FTIR spectroscopy, UV-vis diffuse reflectance spectroscopy, XPS, and SEM-EDS. The obtained results showed that the crystalline structure of the doped TiO_2-based nanomaterials depends strongly on the nature of the doping ions. The obtained band gap energy of TiO_2 co-doped with (P,Mo) changes to a level below the band gap energy of TiO_2 anatase indicating a high ability to absorb visible light. The obtained photocatalytic activity results of methyl orange degradation showed that, under visible light, the mono-doping of TiO_2 with Co and its Co-Doping with (P,Mo) or (P,W) improve significantly the photocatalytic activity of TiO_2 in comparison with undoped TiO_2. The activity order obtained under UV-A irradiation for the used photocatalysts is TiO_2 > > 1%Ni-TiO_2 > 1%Co-TiO_2 > 30%(P,Mo)-TiO_2 ≈ 30%(P,W)TiO_2 > 1%Mn-TiO_2 while under visible light, it is 1%Co-TiO_2 > 30%(P,Mo)-TiO_2 > 30%(P,W)TiO_2 ≈ TiO_2 > 1%Ni-TiO_2 > 1%Mn-TiO_2. The high photocatalytic activity observed for these samples could be the result of a synergetic effect of the high visible light absorption capacity and the low recombination rate of photoexcited electrons and holes.