scholarly journals PENGARUH PENAMBAHAN CO-DOPING Mg/La TERHADAP KARAKTERISASI TiO2 SEBAGAI FOTOELEKTRODA

2021 ◽  
Vol 9 (1) ◽  
pp. 79-86
Author(s):  
Mursal Mursal ◽  
◽  
Nurul Azmi ◽  
Ismail Ismail ◽  
◽  
...  

The effect of Mg/La co-doping addition on the caracteristics of TiO2 as photoelectrode have been studied. This study aims to investigate the effect of Mg/La co-doping concentration on the characteristics of TiO2. This study aims investigate the effect of Mg/La co-doping concentration on the characteristics of TiO2. Mg/La was varied from 0% mol, 0.4 / 0.6% mol, and 0.6 / 0.4% mol. Synthesis of TiO2 co-doping Mg/La was done by sol gel method. The resulting of powder pure TiO2 and co-doping Mg/La was made to paste, and was deposited on a glass substrate with a size of 2.5 x 2.5 cm and sintered at 600°C for 1 hour. Mg / La co-doped TiO2 layers were characterized using XRD, UV-Vis, and FTIR spectrometers. The results showed that TiO2 was the mos dominan phase appeared in pure TiO2 sample. The phase of MgO, MgTiO3, Mg2TiO4, and La2O3 were found in Mg/La co-doped TiO2 samples. The crystal size of Mg/La co-doped TiO2 was varied from 8.85 to 7.70 nm. In this research, we obtained that the energy gap was varied from 3.52 to 3.5 eV depent on co-dopant concentration. FTIR measurement showed groups of Ti-O, Ti-O-Ti, Ti-O-O, and H-O.

2010 ◽  
Vol 177 ◽  
pp. 54-57 ◽  
Author(s):  
Li Na Meng ◽  
Wen Yuan Xu ◽  
Ting Xu

Co doped TiO2 nanoparticles and thin films were prepared from Ti(OC4H9)4 by sol-gel method. The influence of Co-doping and its content on the crystallite structure and phase composition of TiO2 was systematically investigated by SEM and XRD, the precursor was analysed by TGA. The photocatalytic activity of nanocomposites was investigated in the photocatalytic degradation of methyl orange. The results indicated that the inhibitory effect of Co-doping on the phase transformation of TiO2 from anatase to rutile receded obviously when the calcination temperature was changed to 650°C from 550°C. Under the ultraviolet light radiation, the favourite Co-doping concentration was 1% and the obtained Co doped TiO2 thin films exhibited higher photocatalytic activity than nanoparticles and pure TiO2 in the photodegradation of methyl orange.


Catalysts ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 235
Author(s):  
Hayette Benkhennouche-Bouchene ◽  
Julien G. Mahy ◽  
Cédric Wolfs ◽  
Bénédicte Vertruyen ◽  
Dirk Poelman ◽  
...  

TiO2 prepared by a green aqueous sol–gel peptization process is co-doped with nitrogen and zirconium to improve and extend its photoactivity to the visible region. Two nitrogen precursors are used: urea and triethylamine; zirconium (IV) tert-butoxide is added as a source of zirconia. The N/Ti molar ratio is fixed regardless of the chosen nitrogen precursor while the quantity of zirconia is set to 0.7, 1.4, 2, or 2.8 mol%. The performance and physico-chemical properties of these materials are compared with the commercial Evonik P25 photocatalyst. For all doped and co-doped samples, TiO2 nanoparticles of 4 to 8 nm of size are formed of anatase-brookite phases, with a specific surface area between 125 and 280 m2 g−1 vs. 50 m2 g−1 for the commercial P25 photocatalyst. X-ray photoelectron (XPS) measurements show that nitrogen is incorporated into the TiO2 materials through Ti-O-N bonds allowing light absorption in the visible region. The XPS spectra of the Zr-(co)doped powders show the presence of TiO2-ZrO2 mixed oxide materials. Under visible light, the best co-doped sample gives a degradation of p-nitrophenol (PNP) equal to 70% instead of 25% with pure TiO2 and 10% with P25 under the same conditions. Similarly, the photocatalytic activity improved under UV/visible reaching 95% with the best sample compared to 50% with pure TiO2. This study suggests that N/Zr co-doped TiO2 nanoparticles can be produced in a safe and energy-efficient way while being markedly more active than state-of-the-art photocatalytic materials under visible light.


Author(s):  
Min Sun ◽  
Wenbo Hou ◽  
Juncheng Liu ◽  
Lifang Nie

The Li+ co-doped Y2O3: Ho3+/Yb3+ films were prepared with sol-gel method and spin-coating technique. The effects of Li+ on the structure and luminescent properties of the films were investigated. The results show the grain size increased first and then decreased with the increase of Li+ doping concentration. The crystal size of particles composing the film got the maximum value when Li+ concentration took 4 mol%. As Li+ doping concentration increased, the optical transmittance of the Y2O3: Ho3+/Yb3+ film improved at first then reduced and got the maximum at 3 mol%. Excited with a 980-nm laser, there were two green emissions in the up-conversion emission spectra, one centered at 535 nm, the other at 550 nm, which ascribed to the 5F4→5I8 and 5S2→5I8 transitions of Ho3+, respectively. The up-conversion luminescence intensity also increased firstly and then decreased with the Li+ doping concentration increase, and got the highest value at 2 mol%.


2018 ◽  
Vol 280 ◽  
pp. 43-49
Author(s):  
Zi Neng Ng ◽  
Kah Yoong Chan

Zinc oxide (ZnO) has gained worldwide attention due to its direct wide band gap and large exciton binding energy, which are important properties in the application of emerging optoelectronic devices. By doping ZnO with donor elements, a combination of good n-type conductivity and good transparency in the visible and near UV range can be achieved. Co-doping ZnO with several types of dopants is also beneficial in improving the electronic properties of ZnO films. To the best of our knowledge, the fundamental properties of gallium-tin (Ga-Sn) co-doped ZnO (GSZO) films were rarely explored. In this work, we attempt to coat GSZO films on glass substrates via sol-gel spin-coating method. The Ga-Sn co-doping ratio was fixed at 1:1 and the concentration of the dopants was varied at 0.5, 1.0, 1.5, and 2 at.% with respect to the precursor. The AFM image show granular features on the morphology of all GSZO films. All samples also exhibit a preferential c-axis orientation as detected by XRD. The XRD indicates higher crystal quality and larger crystallite size on GSZO thin films at 2.0 at.% and agrees well with the AFM results. However, the transparency and optical band-gap of the GSZO thin films degrade with higher co-doping concentration. The best electrical properties were achieved at co-doping concentration of 1 at.% with conductivity and carrier density of 7.50 × 10-2S/cm and 1.37 × 1016cm-3, respectively. At 1.0 at.% co-doping concentration, optimal optical transmittance and electrical properties were achieved, making it promising in the application of optoelectronics.


Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 3874 ◽  
Author(s):  
Abderrahim El Mragui ◽  
Yuliya Logvina ◽  
Luís Pinto da Silva ◽  
Omar Zegaoui ◽  
Joaquim C.G. Esteves da Silva

Pure TiO2 and Fe- and Co-doped TiO2 nanoparticles (NPs) as photocatalysts were synthesized using wet chemical methods (sol-gel + precipitation). Their crystalline structure and optical properties were analyzed using X-ray diffraction (XRD), Raman spectroscopy and Fourier-transform infrared (FTIR) spectroscopy, ultraviolet-visible light (UV-Vis) diffuse reflectance spectroscopy (DRS), and photoluminescence (PL) spectroscopy. The photocatalytic activity of the synthesized nanoparticles was evaluated through degradation of carbamazepine (CBZ) under UV-A and visible-light irradiations. The XRD and Raman analyses revealed that all synthesized nanomaterials showed only the anatase phase. The DRS results showed that the absorption edge was blue-shifted for Fe-doped TiO2 NPs. The decrease in charge recombination was evidenced from the PL investigation for both Co-doped and Fe-doped TiO2 nanomaterials. An enhancement in photocatalytic degradation of carbamazepine in aqueous suspension under both UV-A light and visible-light irradiations was observed for Fe-doped Titania NPs by comparison with pure TiO2. These results suggest that the doping cations could suppress the electron/hole recombination. Therefore, the photocatalytic activity of TiO2-based nanomaterials was enhanced.


2012 ◽  
Vol 430-432 ◽  
pp. 1048-1051 ◽  
Author(s):  
Li Lin ◽  
Xue Jun Zhang ◽  
Gu Qing Xiao ◽  
Xing Xiong

Cerium and nitrogen co-doped TiO2 nanocrystals were synthesized by a simple sol-gel process, using tetrabutyl titanate as the raw materials with (NH4)2Ce(SO4)3 and urea as ion donors. The co-doped TiO2 nanoparticles were characterized by X-ray diffraction and transmission electro microscopy. The photodegradation of glyphosate has been investigated in aqueous suspensions of doped TiO2 under visible irradiation. The results exhibit a higher thermal stability of anatase than pure TiO2.The uniform test results show the optimal conditions: nCe/nTi nN/nTi and calcining temperature was 0.08,0.01 and 800°C. The highest degradation rate for co-doped TiO2 show five times photocatalytic activity of Degussa P25.


2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Jungang Li ◽  
Chaoqian Zhao ◽  
Chun Liu ◽  
Zhenyu Wang ◽  
Zeming Ling ◽  
...  

Abstract Background The bone regeneration of artificial bone grafts is still in need of a breakthrough to improve the processes of bone defect repair. Artificial bone grafts should be modified to enable angiogenesis and thus improve osteogenesis. We have previously revealed that crystalline Ca10Li(PO4)7 (CLP) possesses higher compressive strength and better biocompatibility than that of pure beta-tricalcium phosphate (β-TCP). In this work, we explored the possibility of cobalt (Co), known for mimicking hypoxia, doped into CLP to promote osteogenesis and angiogenesis. Methods We designed and manufactured porous scaffolds by doping CLP with various concentrations of Co (0, 0.1, 0.25, 0.5, and 1 mol%) and using 3D printing techniques. The crystal phase, surface morphology, compressive strength, in vitro degradation, and mineralization properties of Co-doped and -undoped CLP scaffolds were investigated. Next, we investigated the biocompatibility and effects of Co-doped and -undoped samples on osteogenic and angiogenic properties in vitro and on bone regeneration in rat cranium defects. Results With increasing Co-doping level, the compressive strength of Co-doped CLP scaffolds decreased in comparison with that of undoped CLP scaffolds, especially when the Co-doping concentration increased to 1 mol%. Co-doped CLP scaffolds possessed excellent degradation properties compared with those of undoped CLP scaffolds. The (0.1, 0.25, 0.5 mol%) Co-doped CLP scaffolds had mineralization properties similar to those of undoped CLP scaffolds, whereas the 1 mol% Co-doped CLP scaffolds shown no mineralization changes. Furthermore, compared with undoped scaffolds, Co-doped CLP scaffolds possessed excellent biocompatibility and prominent osteogenic and angiogenic properties in vitro, notably when the doping concentration was 0.25 mol%. After 8 weeks of implantation, 0.25 mol% Co-doped scaffolds had markedly enhanced bone regeneration at the defect site compared with that of the undoped scaffold. Conclusion In summary, CLP doped with 0.25 mol% Co2+ ions is a prospective method to enhance osteogenic and angiogenic properties, thus promoting bone regeneration in bone defect repair.


2016 ◽  
Vol 4 (2) ◽  
pp. 407-415 ◽  
Author(s):  
Nicholas P. Chadwick ◽  
Emily N. K. Glover ◽  
Sanjayan Sathasivam ◽  
Sulaiman N. Basahel ◽  
Shaeel A. Althabaiti ◽  
...  

Combinatorial AACVD has achieved the production of various niobium/nitrogen co-doped TiO2 materials in a single film. The co-doping concentrations have been correlated with functional properties.


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