TY  - JOUR
AU  - Sandoval, Stefania
AU  - Kepić, Dejan P.
AU  - Perez del Pino, Angel
AU  - Gyorgy, Eniko
AU  - Gomez, Andres
AU  - Pfannmoeller, Martin
AU  - Tendeloo, Gustaaf Van
AU  - Ballesteros, Belen
AU  - Tobias, Gerard
PY  - 2018
UR  - http://pubs.acs.org/doi/10.1021/acsnano.8b01638
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/7933
AB  - The electronic and optical properties of two-dimensional layered materials allow the miniaturization of nanoelectronic and optoelectronic devices in a competitive manner. Even larger opportunities arise when two or more layers of different materials are combined. Here, we report on an ultrafast energy efficient strategy, using laser irradiation, which allows bulk synthesis of crystalline single-layered lead iodide in the cavities of carbon nanotubes by forming cylindrical van der Waals heterostructures. In contrast to the filling of van der Waals solids into carbon nanotubes by conventional thermal annealing, which favors the formation of inorganic nanowires, the present strategy is highly selective toward the growth of monolayers forming lead iodide nanotubes. The irradiated bulk material bearing the nanotubes reveals a decrease of the resistivity as well as a significant increase in the current flow upon illumination. Both effects are attributed to the presence of single-walled lead iodide nanotubes in the cavities of carbon nanotubes, which dominate the properties of the whole matrix. The present study brings in a simple, ultrafast and energy efficient strategy for the tailored synthesis of rolled-up single-layers of lead iodide (i.e., single-walled PbI2 nanotubes), which we believe could be expanded to other two-dimensional (2D) van der Waals solids. In fact, initial tests with ZnI2 already reveal the formation of single-walled ZnI2 nanotubes, thus proving the versatility of the approach.
T2  - ACS Nano
T1  - Selective Laser-Assisted Synthesis of Tubular van der Waals Heterostructures of Single-Layered PbI 2 within Carbon Nanotubes Exhibiting Carrier Photogeneration
VL  - 12
IS  - 7
SP  - 6648
EP  - 6656
DO  - 10.1021/acsnano.8b01638
ER  - 

@article{
author = "Sandoval, Stefania and Kepić, Dejan P. and Perez del Pino, Angel and Gyorgy, Eniko and Gomez, Andres and Pfannmoeller, Martin and Tendeloo, Gustaaf Van and Ballesteros, Belen and Tobias, Gerard",
year = "2018",
abstract = "The electronic and optical properties of two-dimensional layered materials allow the miniaturization of nanoelectronic and optoelectronic devices in a competitive manner. Even larger opportunities arise when two or more layers of different materials are combined. Here, we report on an ultrafast energy efficient strategy, using laser irradiation, which allows bulk synthesis of crystalline single-layered lead iodide in the cavities of carbon nanotubes by forming cylindrical van der Waals heterostructures. In contrast to the filling of van der Waals solids into carbon nanotubes by conventional thermal annealing, which favors the formation of inorganic nanowires, the present strategy is highly selective toward the growth of monolayers forming lead iodide nanotubes. The irradiated bulk material bearing the nanotubes reveals a decrease of the resistivity as well as a significant increase in the current flow upon illumination. Both effects are attributed to the presence of single-walled lead iodide nanotubes in the cavities of carbon nanotubes, which dominate the properties of the whole matrix. The present study brings in a simple, ultrafast and energy efficient strategy for the tailored synthesis of rolled-up single-layers of lead iodide (i.e., single-walled PbI2 nanotubes), which we believe could be expanded to other two-dimensional (2D) van der Waals solids. In fact, initial tests with ZnI2 already reveal the formation of single-walled ZnI2 nanotubes, thus proving the versatility of the approach.",
journal = "ACS Nano",
title = "Selective Laser-Assisted Synthesis of Tubular van der Waals Heterostructures of Single-Layered PbI 2 within Carbon Nanotubes Exhibiting Carrier Photogeneration",
volume = "12",
number = "7",
pages = "6648-6656",
doi = "10.1021/acsnano.8b01638"
}

Sandoval, S., Kepić, D. P., Perez del Pino, A., Gyorgy, E., Gomez, A., Pfannmoeller, M., Tendeloo, G. V., Ballesteros, B.,& Tobias, G.. (2018). Selective Laser-Assisted Synthesis of Tubular van der Waals Heterostructures of Single-Layered PbI 2 within Carbon Nanotubes Exhibiting Carrier Photogeneration. in ACS Nano, 12(7), 6648-6656.
https://doi.org/10.1021/acsnano.8b01638

Sandoval S, Kepić DP, Perez del Pino A, Gyorgy E, Gomez A, Pfannmoeller M, Tendeloo GV, Ballesteros B, Tobias G. Selective Laser-Assisted Synthesis of Tubular van der Waals Heterostructures of Single-Layered PbI 2 within Carbon Nanotubes Exhibiting Carrier Photogeneration. in ACS Nano. 2018;12(7):6648-6656.
doi:10.1021/acsnano.8b01638 .

Sandoval, Stefania, Kepić, Dejan P., Perez del Pino, Angel, Gyorgy, Eniko, Gomez, Andres, Pfannmoeller, Martin, Tendeloo, Gustaaf Van, Ballesteros, Belen, Tobias, Gerard, "Selective Laser-Assisted Synthesis of Tubular van der Waals Heterostructures of Single-Layered PbI 2 within Carbon Nanotubes Exhibiting Carrier Photogeneration" in ACS Nano, 12, no. 7 (2018):6648-6656,
https://doi.org/10.1021/acsnano.8b01638 . .

TY  - JOUR
AU  - Kepić, Dejan P.
AU  - Sandoval, Stefania
AU  - Perez del Pino, Angel
AU  - Gyorgy, Eniko
AU  - Cabana, Laura
AU  - Ballesteros, Belen
AU  - Tobias, Gerard
PY  - 2017
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/1358
AB  - N-doped reduced graphene oxide (RGO) has been prepared in bulk form by laser irradiation of graphene oxide (GO) dispersed in an aqueous solution of ammonia. A pulsed Nd:YAG laser with emission wavelengths in the infrared (IR) 1064 nm, visible (Vis) 532 nm, and ultraviolet (UV) 266 nm spectral regions was employed for the preparation of the N-doped RGO samples. Regardless of the laser energy employed, the resulting material presents a higher fraction of pyrrolic nitrogen compared to nitrogen atoms in pyridinic and graphitic coordination. Noticeably, whereas increasing the laser fluence of UV and Vis wavelengths results in an increase in the total amount of nitrogen, up to 4.9 at.% (UV wavelength at 60 mJ cm(-2) fluence), the opposite trend is observed when the GO is irradiated in ammonia solution through IR processing. The proposed laser-based methodology allows the bulk synthesis of N-doped reduced graphene oxide in a simple, fast, and cost efficient manner.
T2  - ChemPhysChem
T1  - Nanosecond Laser-Assisted Nitrogen Doping of Graphene Oxide Dispersions
VL  - 18
IS  - 8
SP  - 935
EP  - 941
DO  - 10.1002/cphc.201601256
ER  - 

@article{
author = "Kepić, Dejan P. and Sandoval, Stefania and Perez del Pino, Angel and Gyorgy, Eniko and Cabana, Laura and Ballesteros, Belen and Tobias, Gerard",
year = "2017",
abstract = "N-doped reduced graphene oxide (RGO) has been prepared in bulk form by laser irradiation of graphene oxide (GO) dispersed in an aqueous solution of ammonia. A pulsed Nd:YAG laser with emission wavelengths in the infrared (IR) 1064 nm, visible (Vis) 532 nm, and ultraviolet (UV) 266 nm spectral regions was employed for the preparation of the N-doped RGO samples. Regardless of the laser energy employed, the resulting material presents a higher fraction of pyrrolic nitrogen compared to nitrogen atoms in pyridinic and graphitic coordination. Noticeably, whereas increasing the laser fluence of UV and Vis wavelengths results in an increase in the total amount of nitrogen, up to 4.9 at.% (UV wavelength at 60 mJ cm(-2) fluence), the opposite trend is observed when the GO is irradiated in ammonia solution through IR processing. The proposed laser-based methodology allows the bulk synthesis of N-doped reduced graphene oxide in a simple, fast, and cost efficient manner.",
journal = "ChemPhysChem",
title = "Nanosecond Laser-Assisted Nitrogen Doping of Graphene Oxide Dispersions",
volume = "18",
number = "8",
pages = "935-941",
doi = "10.1002/cphc.201601256"
}

Kepić, D. P., Sandoval, S., Perez del Pino, A., Gyorgy, E., Cabana, L., Ballesteros, B.,& Tobias, G.. (2017). Nanosecond Laser-Assisted Nitrogen Doping of Graphene Oxide Dispersions. in ChemPhysChem, 18(8), 935-941.
https://doi.org/10.1002/cphc.201601256

Kepić DP, Sandoval S, Perez del Pino A, Gyorgy E, Cabana L, Ballesteros B, Tobias G. Nanosecond Laser-Assisted Nitrogen Doping of Graphene Oxide Dispersions. in ChemPhysChem. 2017;18(8):935-941.
doi:10.1002/cphc.201601256 .

Kepić, Dejan P., Sandoval, Stefania, Perez del Pino, Angel, Gyorgy, Eniko, Cabana, Laura, Ballesteros, Belen, Tobias, Gerard, "Nanosecond Laser-Assisted Nitrogen Doping of Graphene Oxide Dispersions" in ChemPhysChem, 18, no. 8 (2017):935-941,
https://doi.org/10.1002/cphc.201601256 . .

TY  - JOUR
AU  - Cabana, Laura
AU  - Ke, Xiaoxing
AU  - Kepić, Dejan P.
AU  - Oro-Sole, Judith
AU  - Tobias-Rossell, Ester
AU  - Tendeloo, Gustaaf Van
AU  - Tobias, Gerard
PY  - 2015
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/712
AB  - Purification and shortening of carbon nanotubes have attracted a great deal of attention to increase the biocompatibility and performance of the material in several applications. Steam treatment has been employed to afford both purification and shortening of multi-walled carbon nanotubes (MWCNTs). Steam removes the amorphous carbon and the graphitic particles that sheath catalytic nanoparticles, facilitating their removal by a subsequent acidic wash. The amount of metal impurities can be reduced in this manner below 0.01 wt.%. The length distribution of MWCNTs after different steam treatment times (from 1 h to 15 h) was assessed by box plot analysis of the electron microscopy data. Samples with a median length of 0.57 mu m have been prepared with the reported methodology while preserving the integrity of the tubular wall structure. (C) 2015 Elsevier Ltd. All rights reserved.
T2  - Carbon
T1  - The role of steam treatment on the structure, purity and length distribution of multi-walled carbon nanotubes
VL  - 93
SP  - 1059
EP  - 1067
DO  - 10.1016/j.carbon.2015.06.027
ER  - 

@article{
author = "Cabana, Laura and Ke, Xiaoxing and Kepić, Dejan P. and Oro-Sole, Judith and Tobias-Rossell, Ester and Tendeloo, Gustaaf Van and Tobias, Gerard",
year = "2015",
abstract = "Purification and shortening of carbon nanotubes have attracted a great deal of attention to increase the biocompatibility and performance of the material in several applications. Steam treatment has been employed to afford both purification and shortening of multi-walled carbon nanotubes (MWCNTs). Steam removes the amorphous carbon and the graphitic particles that sheath catalytic nanoparticles, facilitating their removal by a subsequent acidic wash. The amount of metal impurities can be reduced in this manner below 0.01 wt.%. The length distribution of MWCNTs after different steam treatment times (from 1 h to 15 h) was assessed by box plot analysis of the electron microscopy data. Samples with a median length of 0.57 mu m have been prepared with the reported methodology while preserving the integrity of the tubular wall structure. (C) 2015 Elsevier Ltd. All rights reserved.",
journal = "Carbon",
title = "The role of steam treatment on the structure, purity and length distribution of multi-walled carbon nanotubes",
volume = "93",
pages = "1059-1067",
doi = "10.1016/j.carbon.2015.06.027"
}

Cabana, L., Ke, X., Kepić, D. P., Oro-Sole, J., Tobias-Rossell, E., Tendeloo, G. V.,& Tobias, G.. (2015). The role of steam treatment on the structure, purity and length distribution of multi-walled carbon nanotubes. in Carbon, 93, 1059-1067.
https://doi.org/10.1016/j.carbon.2015.06.027

Cabana L, Ke X, Kepić DP, Oro-Sole J, Tobias-Rossell E, Tendeloo GV, Tobias G. The role of steam treatment on the structure, purity and length distribution of multi-walled carbon nanotubes. in Carbon. 2015;93:1059-1067.
doi:10.1016/j.carbon.2015.06.027 .

Cabana, Laura, Ke, Xiaoxing, Kepić, Dejan P., Oro-Sole, Judith, Tobias-Rossell, Ester, Tendeloo, Gustaaf Van, Tobias, Gerard, "The role of steam treatment on the structure, purity and length distribution of multi-walled carbon nanotubes" in Carbon, 93 (2015):1059-1067,
https://doi.org/10.1016/j.carbon.2015.06.027 . .