Different approaches for enhancing photocatalytic properties of TiO2:Au thin films deposited by DC sputtering
Само за регистроване кориснике
2019
Аутори
Pjević, DejanPeruško, Davor
Savić, Tatjana
Novaković, Mirjana
Popović, Maja
Potočnik, Jelena
Petrović, Suzana
Конференцијски прилог (Објављена верзија)
Метаподаци
Приказ свих података о документуАпстракт
INTRODUCTION: Titanium dioxide (TiO2) thin films showed as promising materials for photocatalytic degradation of pollutants in water under irradiation of UV-light. It is favorable material for photocatalytic processes because of its non-toxicity, high photosensitivity, large band gap and stability. One of the way to increase efficiency of TiO2 thin films is by doping and coating with metals. Metal-doped TiO2 can reduce electron-hole recombination and increase hydroxyl radical concentration on the surface of TiO2, resulting in increase in the photocatalytic activity1. In studies of J.M.Jung at al.1 with Au-buffered TiO2 thin films and V. S. Mohite et al.2 with doped TiO2 thin films showed that this systems have enhanced photocatalytic activity in comparison to pure TiO2 thin films. Also recent study3 showed that Au doped TiO2 thin films are great candidates beside photocatalysis for enhancing visible light water splitting. EXPERIMENTAL STUDY TiO2 and TiO2:Au thin films were obtained by ...DC magnetron sputtering of Ti target with Ar ions in O2 atmosphere. In the case of doped TiO2 thin films with Au, three different systems were deposited for comparison (fig.1): Buffering Au layer into the TiO2 layer (b), subsurface buffering of Au with island formation of Au on the surface and etching the surface of TiO2 layer by HF and applying Au nanoparticles on the surface. Annealing of the samples was performed in air and N2 atmospheres on 600 °C for better crystallinity and release of defects. For structural analyses XRD, XPS, TEM and SEM methods were used, while for optical characterization UV/Vis method was used. The photo-degradation rate was measured using Rhodamine B which simulated pollutant. Fig. 1: Experimental setup. RESULTS AND DISCUSSION Structural analysis has shown that as deposited films have amorphous-like structures, while post-deposition thermal annealing in air for 3 hours inducted significantly better crystallinity in thin films with anatase phase dominating. SEM analysis showed the presence of 10 nm Au buffered layer in crystalline structure of TiO2 and also on the surface. Optical measurements showed shift of the absorbance edge in UV/Vis spectra toward visible light wavelengths. Presence of metal dopant in the structure probably has induced some new energy sites in the region of TiO2 energy gap. Analysis of the binding energy in the corresponding XPS spectra showed that deposited films have good stoichiometry of TiO2. At binding energies of 530 eV where O1s line is present there is broadening toward higher energies and can be attributed to surface hydroxyl group. Presence of this group on the surface of the films is favorable for photo-degradation processes. CONCLUSION Obtained TiO2 thin films after deposition were amorphous-like structured, and after annealing on 600 °C anatase phase dominates in the structure. All Au doped TiO2 thin films showed better photo-degradation rates then pure TiO2. Presence of the gold clusters on the surface of the thin film showed of significant importance. Future work will be concentrated on understanding mechanisms of different Au doping sites in TiO2 crystal structure on its photocatalytic activity.
Извор:
ANM 2019 : Advanced Nano Materials 2019 : Book of abstracts, 2019Напомена:
- Advanced Nano Materials 2019 : Book of abstracts; July 17-19, Portugal
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Институција/група
VinčaTY - CONF AU - Pjević, Dejan AU - Peruško, Davor AU - Savić, Tatjana AU - Novaković, Mirjana AU - Popović, Maja AU - Potočnik, Jelena AU - Petrović, Suzana PY - 2019 UR - https://vinar.vin.bg.ac.rs/handle/123456789/11901 AB - INTRODUCTION: Titanium dioxide (TiO2) thin films showed as promising materials for photocatalytic degradation of pollutants in water under irradiation of UV-light. It is favorable material for photocatalytic processes because of its non-toxicity, high photosensitivity, large band gap and stability. One of the way to increase efficiency of TiO2 thin films is by doping and coating with metals. Metal-doped TiO2 can reduce electron-hole recombination and increase hydroxyl radical concentration on the surface of TiO2, resulting in increase in the photocatalytic activity1. In studies of J.M.Jung at al.1 with Au-buffered TiO2 thin films and V. S. Mohite et al.2 with doped TiO2 thin films showed that this systems have enhanced photocatalytic activity in comparison to pure TiO2 thin films. Also recent study3 showed that Au doped TiO2 thin films are great candidates beside photocatalysis for enhancing visible light water splitting. EXPERIMENTAL STUDY TiO2 and TiO2:Au thin films were obtained by DC magnetron sputtering of Ti target with Ar ions in O2 atmosphere. In the case of doped TiO2 thin films with Au, three different systems were deposited for comparison (fig.1): Buffering Au layer into the TiO2 layer (b), subsurface buffering of Au with island formation of Au on the surface and etching the surface of TiO2 layer by HF and applying Au nanoparticles on the surface. Annealing of the samples was performed in air and N2 atmospheres on 600 °C for better crystallinity and release of defects. For structural analyses XRD, XPS, TEM and SEM methods were used, while for optical characterization UV/Vis method was used. The photo-degradation rate was measured using Rhodamine B which simulated pollutant. Fig. 1: Experimental setup. RESULTS AND DISCUSSION Structural analysis has shown that as deposited films have amorphous-like structures, while post-deposition thermal annealing in air for 3 hours inducted significantly better crystallinity in thin films with anatase phase dominating. SEM analysis showed the presence of 10 nm Au buffered layer in crystalline structure of TiO2 and also on the surface. Optical measurements showed shift of the absorbance edge in UV/Vis spectra toward visible light wavelengths. Presence of metal dopant in the structure probably has induced some new energy sites in the region of TiO2 energy gap. Analysis of the binding energy in the corresponding XPS spectra showed that deposited films have good stoichiometry of TiO2. At binding energies of 530 eV where O1s line is present there is broadening toward higher energies and can be attributed to surface hydroxyl group. Presence of this group on the surface of the films is favorable for photo-degradation processes. CONCLUSION Obtained TiO2 thin films after deposition were amorphous-like structured, and after annealing on 600 °C anatase phase dominates in the structure. All Au doped TiO2 thin films showed better photo-degradation rates then pure TiO2. Presence of the gold clusters on the surface of the thin film showed of significant importance. Future work will be concentrated on understanding mechanisms of different Au doping sites in TiO2 crystal structure on its photocatalytic activity. C3 - ANM 2019 : Advanced Nano Materials 2019 : Book of abstracts T1 - Different approaches for enhancing photocatalytic properties of TiO2:Au thin films deposited by DC sputtering UR - https://hdl.handle.net/21.15107/rcub_vinar_11901 ER -
@conference{ author = "Pjević, Dejan and Peruško, Davor and Savić, Tatjana and Novaković, Mirjana and Popović, Maja and Potočnik, Jelena and Petrović, Suzana", year = "2019", abstract = "INTRODUCTION: Titanium dioxide (TiO2) thin films showed as promising materials for photocatalytic degradation of pollutants in water under irradiation of UV-light. It is favorable material for photocatalytic processes because of its non-toxicity, high photosensitivity, large band gap and stability. One of the way to increase efficiency of TiO2 thin films is by doping and coating with metals. Metal-doped TiO2 can reduce electron-hole recombination and increase hydroxyl radical concentration on the surface of TiO2, resulting in increase in the photocatalytic activity1. In studies of J.M.Jung at al.1 with Au-buffered TiO2 thin films and V. S. Mohite et al.2 with doped TiO2 thin films showed that this systems have enhanced photocatalytic activity in comparison to pure TiO2 thin films. Also recent study3 showed that Au doped TiO2 thin films are great candidates beside photocatalysis for enhancing visible light water splitting. EXPERIMENTAL STUDY TiO2 and TiO2:Au thin films were obtained by DC magnetron sputtering of Ti target with Ar ions in O2 atmosphere. In the case of doped TiO2 thin films with Au, three different systems were deposited for comparison (fig.1): Buffering Au layer into the TiO2 layer (b), subsurface buffering of Au with island formation of Au on the surface and etching the surface of TiO2 layer by HF and applying Au nanoparticles on the surface. Annealing of the samples was performed in air and N2 atmospheres on 600 °C for better crystallinity and release of defects. For structural analyses XRD, XPS, TEM and SEM methods were used, while for optical characterization UV/Vis method was used. The photo-degradation rate was measured using Rhodamine B which simulated pollutant. Fig. 1: Experimental setup. RESULTS AND DISCUSSION Structural analysis has shown that as deposited films have amorphous-like structures, while post-deposition thermal annealing in air for 3 hours inducted significantly better crystallinity in thin films with anatase phase dominating. SEM analysis showed the presence of 10 nm Au buffered layer in crystalline structure of TiO2 and also on the surface. Optical measurements showed shift of the absorbance edge in UV/Vis spectra toward visible light wavelengths. Presence of metal dopant in the structure probably has induced some new energy sites in the region of TiO2 energy gap. Analysis of the binding energy in the corresponding XPS spectra showed that deposited films have good stoichiometry of TiO2. At binding energies of 530 eV where O1s line is present there is broadening toward higher energies and can be attributed to surface hydroxyl group. Presence of this group on the surface of the films is favorable for photo-degradation processes. CONCLUSION Obtained TiO2 thin films after deposition were amorphous-like structured, and after annealing on 600 °C anatase phase dominates in the structure. All Au doped TiO2 thin films showed better photo-degradation rates then pure TiO2. Presence of the gold clusters on the surface of the thin film showed of significant importance. Future work will be concentrated on understanding mechanisms of different Au doping sites in TiO2 crystal structure on its photocatalytic activity.", journal = "ANM 2019 : Advanced Nano Materials 2019 : Book of abstracts", title = "Different approaches for enhancing photocatalytic properties of TiO2:Au thin films deposited by DC sputtering", url = "https://hdl.handle.net/21.15107/rcub_vinar_11901" }
Pjević, D., Peruško, D., Savić, T., Novaković, M., Popović, M., Potočnik, J.,& Petrović, S.. (2019). Different approaches for enhancing photocatalytic properties of TiO2:Au thin films deposited by DC sputtering. in ANM 2019 : Advanced Nano Materials 2019 : Book of abstracts. https://hdl.handle.net/21.15107/rcub_vinar_11901
Pjević D, Peruško D, Savić T, Novaković M, Popović M, Potočnik J, Petrović S. Different approaches for enhancing photocatalytic properties of TiO2:Au thin films deposited by DC sputtering. in ANM 2019 : Advanced Nano Materials 2019 : Book of abstracts. 2019;. https://hdl.handle.net/21.15107/rcub_vinar_11901 .
Pjević, Dejan, Peruško, Davor, Savić, Tatjana, Novaković, Mirjana, Popović, Maja, Potočnik, Jelena, Petrović, Suzana, "Different approaches for enhancing photocatalytic properties of TiO2:Au thin films deposited by DC sputtering" in ANM 2019 : Advanced Nano Materials 2019 : Book of abstracts (2019), https://hdl.handle.net/21.15107/rcub_vinar_11901 .