TY  - JOUR
AU  - Bjelajac, Anđelika
AU  - Petrović, Rada
AU  - Popović, Maja
AU  - Rakočević, Zlatko Lj.
AU  - Socol, Gabriel
AU  - Mihailescu, Ion N.
AU  - Janaćković, Đorđe T.
PY  - 2019
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/8589
AB  - The ∼60 nm wide and ∼2 μm long TiO2 nanotubes were obtained by anodization of Ti films sputtered on F-doped tin oxide glass. For N-doping the samples were annealed in ammonia atmosphere. The effect of pre- and post-annealing in air on the nature and amount of incorporated N was studied by X-ray photoelectron spectroscopy. By measuring the absorption spectra of the obtained samples and interpreting the corresponding Tauc plots it was shown that the sample annealed just in ammonia showed the highest visible light absorption even after sputtering cleaning and a decrease of N amount from 3.8% to 1%. Pre and/or post annealing in air led to smaller amount of incorporated N, that caused less pronounced absorption enhancement and smaller band gap narrowing compared to the sample annealed only in ammonia. By fitting of N 1 s line, the contribution that was assigned to substitutional N was detected only in the samples that did not sustained post-annealing. The study showed that post-annealing in air might lead to partial conversion of N atoms in TiO2 to oxidized nitrogen species that are easily removed with sputtering. It is also possible that substitutional nitrogen was suppressed by oxygen from air to move to interstitial site. Weakly bonded NOx surface species, which are cleaned away by sputtering, can be removed by post-annealing in air. Those surface species could act as sensitizers and when their amounts are reduced, the core absorption properties, as a result of interstitial incorporation of N in TiO2 structure, were revealed. Much lower visible light sensitization was achieved in the case of pre-annealed sample in comparison to sample without pre-annealing, regardless the same quantity and type of incorporated nitrogen.
T2  - Thin Solid Films
T1  - Doping of TiO2 nanotubes with nitrogen by annealing in ammonia for visible light activation: Influence of pre- and post-annealing in air
VL  - 692
SP  - 137598
DO  - 10.1016/j.tsf.2019.137598
ER  - 

@article{
author = "Bjelajac, Anđelika and Petrović, Rada and Popović, Maja and Rakočević, Zlatko Lj. and Socol, Gabriel and Mihailescu, Ion N. and Janaćković, Đorđe T.",
year = "2019",
abstract = "The ∼60 nm wide and ∼2 μm long TiO2 nanotubes were obtained by anodization of Ti films sputtered on F-doped tin oxide glass. For N-doping the samples were annealed in ammonia atmosphere. The effect of pre- and post-annealing in air on the nature and amount of incorporated N was studied by X-ray photoelectron spectroscopy. By measuring the absorption spectra of the obtained samples and interpreting the corresponding Tauc plots it was shown that the sample annealed just in ammonia showed the highest visible light absorption even after sputtering cleaning and a decrease of N amount from 3.8% to 1%. Pre and/or post annealing in air led to smaller amount of incorporated N, that caused less pronounced absorption enhancement and smaller band gap narrowing compared to the sample annealed only in ammonia. By fitting of N 1 s line, the contribution that was assigned to substitutional N was detected only in the samples that did not sustained post-annealing. The study showed that post-annealing in air might lead to partial conversion of N atoms in TiO2 to oxidized nitrogen species that are easily removed with sputtering. It is also possible that substitutional nitrogen was suppressed by oxygen from air to move to interstitial site. Weakly bonded NOx surface species, which are cleaned away by sputtering, can be removed by post-annealing in air. Those surface species could act as sensitizers and when their amounts are reduced, the core absorption properties, as a result of interstitial incorporation of N in TiO2 structure, were revealed. Much lower visible light sensitization was achieved in the case of pre-annealed sample in comparison to sample without pre-annealing, regardless the same quantity and type of incorporated nitrogen.",
journal = "Thin Solid Films",
title = "Doping of TiO2 nanotubes with nitrogen by annealing in ammonia for visible light activation: Influence of pre- and post-annealing in air",
volume = "692",
pages = "137598",
doi = "10.1016/j.tsf.2019.137598"
}

Bjelajac, A., Petrović, R., Popović, M., Rakočević, Z. Lj., Socol, G., Mihailescu, I. N.,& Janaćković, Đ. T.. (2019). Doping of TiO2 nanotubes with nitrogen by annealing in ammonia for visible light activation: Influence of pre- and post-annealing in air. in Thin Solid Films, 692, 137598.
https://doi.org/10.1016/j.tsf.2019.137598

Bjelajac A, Petrović R, Popović M, Rakočević ZL, Socol G, Mihailescu IN, Janaćković ĐT. Doping of TiO2 nanotubes with nitrogen by annealing in ammonia for visible light activation: Influence of pre- and post-annealing in air. in Thin Solid Films. 2019;692:137598.
doi:10.1016/j.tsf.2019.137598 .

Bjelajac, Anđelika, Petrović, Rada, Popović, Maja, Rakočević, Zlatko Lj., Socol, Gabriel, Mihailescu, Ion N., Janaćković, Đorđe T., "Doping of TiO2 nanotubes with nitrogen by annealing in ammonia for visible light activation: Influence of pre- and post-annealing in air" in Thin Solid Films, 692 (2019):137598,
https://doi.org/10.1016/j.tsf.2019.137598 . .

TY  - JOUR
AU  - Bjelajac, Anđelika
AU  - Đokić, Veljko R.
AU  - Petrović, Rada
AU  - Bundaleski, Nenad
AU  - Socol, Gabriel
AU  - Mihailescu, Ion N.
AU  - Rakočević, Zlatko Lj.
AU  - Janaćković, Đorđe T.
PY  - 2017
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/1786
AB  - A process of obtaining N-doped TiO2 nanotubes sensitized by CdS nanoparticles is presented, including detailed characterizations performed along the synthesis. Transparent TiO2 films consisting of nanotubes, 2.5 mu m long and of similar to 60 nm inner diameter, were obtained after anodization of a titanium film deposited onto FTO glass substrate. N-doping was achieved by annealing of TiO2 film in ammonia. X-ray Photoelectron Spectroscopy measurements showed that nitrogen was substitutionally incorporated in the TiO2 matrix, with the N:Ti concentration ratio of 1:100. The doping changed the optical properties of the material in such a way that the absorption edge was shifted from 380 nm to 507 nm, as observed from diffuse reflectance spectra. The influence of the microwave (MW) irradiation on the synthesized CdS quantum dots and their optical properties was investigated. It was shown that the diameter of CdS nanoparticles was increased due to releasing of S-2-ions from dimethyl sulfoxide (DMSO) as a consequence of the MW treatment. The (N)TiO2 films were then used as substrates for matrix assisted pulsed laser deposition of the CdS quantum dots with DMSO as a matrix. The laser parameters for the deposition were optimized in order to preserve the nanotubular structure open, the latter being an important feature of this type of photoanode. The structure obtained under optimized conditions has an additional absorption edge shift, reaching 603 nm.
T2  - Ceramics International
T1  - Absorption boost of TiO2 nanotubes by doping with N and sensitization with CdS quantum dots
VL  - 43
IS  - 17
SP  - 15040
EP  - 15046
DO  - 10.1016/j.ceramint.2017.08.029
ER  - 

@article{
author = "Bjelajac, Anđelika and Đokić, Veljko R. and Petrović, Rada and Bundaleski, Nenad and Socol, Gabriel and Mihailescu, Ion N. and Rakočević, Zlatko Lj. and Janaćković, Đorđe T.",
year = "2017",
abstract = "A process of obtaining N-doped TiO2 nanotubes sensitized by CdS nanoparticles is presented, including detailed characterizations performed along the synthesis. Transparent TiO2 films consisting of nanotubes, 2.5 mu m long and of similar to 60 nm inner diameter, were obtained after anodization of a titanium film deposited onto FTO glass substrate. N-doping was achieved by annealing of TiO2 film in ammonia. X-ray Photoelectron Spectroscopy measurements showed that nitrogen was substitutionally incorporated in the TiO2 matrix, with the N:Ti concentration ratio of 1:100. The doping changed the optical properties of the material in such a way that the absorption edge was shifted from 380 nm to 507 nm, as observed from diffuse reflectance spectra. The influence of the microwave (MW) irradiation on the synthesized CdS quantum dots and their optical properties was investigated. It was shown that the diameter of CdS nanoparticles was increased due to releasing of S-2-ions from dimethyl sulfoxide (DMSO) as a consequence of the MW treatment. The (N)TiO2 films were then used as substrates for matrix assisted pulsed laser deposition of the CdS quantum dots with DMSO as a matrix. The laser parameters for the deposition were optimized in order to preserve the nanotubular structure open, the latter being an important feature of this type of photoanode. The structure obtained under optimized conditions has an additional absorption edge shift, reaching 603 nm.",
journal = "Ceramics International",
title = "Absorption boost of TiO2 nanotubes by doping with N and sensitization with CdS quantum dots",
volume = "43",
number = "17",
pages = "15040-15046",
doi = "10.1016/j.ceramint.2017.08.029"
}

Bjelajac, A., Đokić, V. R., Petrović, R., Bundaleski, N., Socol, G., Mihailescu, I. N., Rakočević, Z. Lj.,& Janaćković, Đ. T.. (2017). Absorption boost of TiO2 nanotubes by doping with N and sensitization with CdS quantum dots. in Ceramics International, 43(17), 15040-15046.
https://doi.org/10.1016/j.ceramint.2017.08.029

Bjelajac A, Đokić VR, Petrović R, Bundaleski N, Socol G, Mihailescu IN, Rakočević ZL, Janaćković ĐT. Absorption boost of TiO2 nanotubes by doping with N and sensitization with CdS quantum dots. in Ceramics International. 2017;43(17):15040-15046.
doi:10.1016/j.ceramint.2017.08.029 .

Bjelajac, Anđelika, Đokić, Veljko R., Petrović, Rada, Bundaleski, Nenad, Socol, Gabriel, Mihailescu, Ion N., Rakočević, Zlatko Lj., Janaćković, Đorđe T., "Absorption boost of TiO2 nanotubes by doping with N and sensitization with CdS quantum dots" in Ceramics International, 43, no. 17 (2017):15040-15046,
https://doi.org/10.1016/j.ceramint.2017.08.029 . .