Characterization of a highly efficient N-doped TiO<sub>2</sub> photocatalyst prepared via factorial design

Borges, Karen Araújo; Santos, Lidiaine Maria dos; Paniago, R.; Neto, N.M. Barbosa; Schneider, Jenny; Bahnemann, Detlef W.; Patrocínio, Antonio Otávio T.; Machado, Antônio Eduardo da Hora

doi:10.1039/c6nj00704j

Cited by 27 publications

(12 citation statements)

References 74 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The pseudo first-order apparent rate constant ( k , min −1 ) related to the discoloration of MB, an approximate measure of the photocatalytic activity ( Borges et al, 2016 ) was determined from the regression curve ln (Cn/Co) vs. irradiation time ( França et al, 2016 ).…”

Section: Methodsmentioning

confidence: 99%

Immobilized TiO₂ on glass spheres applied to heterogeneous photocatalysis: photoactivity, leaching and regeneration process

Cunha

Kuznetsov

Achete

et al. 2018

PeerJ

View full text Add to dashboard Cite

Heterogeneous photocatalysis using titanium dioxide as catalyst is an attractive advanced oxidation process due to its high chemical stability, good performance and low cost. When immobilized in a supporting material, additional benefits are achieved in the treatment. The purpose of this study was to develop a simple protocol for impregnation of TiO2-P25 on borosilicate glass spheres and evaluate its efficiency in the photocatalytic degradation using an oxidizable substrate (methylene blue), in a Compound Parabolic Concentrator (CPC) reactor. The assays were conducted at lab-scale using radiation, which simulated the solar spectrum. TiO2 leaching from the glass and the catalyst regeneration were both demonstrated. A very low leaching ratio (0.03%) was observed after 24 h of treatment, suggesting that deposition of TiO2 resulted in good adhesion and stability of the photocatalyst on the surface of borosilicate. This deposition was successfully achieved after calcination of the photocatalyst at 400 °C (TiO2-400 °C). The TiO2 film was immobilized on glass spheres and the powder was characterized by scanning electron microscopy (SEM), X-ray diffraction and BET. This characterization suggested that thermal treatment did not introduce substantial changes in the measured microstructural characteristics of the photocatalyst. The immobilized photocatalyst degraded more than 96% of the MB in up to 90 min of reaction. The photocatalytic activity decreased after four photocatalytic cycles, but it was recovered by the removal of contaminants adsorbed on the active sites after washing in water under UV-Vis irradiation. Based on these results, the TiO2-400 °C coated on glass spheres is potentially a very attractive option for removal of persistent contaminants present in the environment.

show abstract

Section: Methodsmentioning

confidence: 99%

Immobilized TiO₂ on glass spheres applied to heterogeneous photocatalysis: photoactivity, leaching and regeneration process

Cunha

Kuznetsov

Achete

et al. 2018

PeerJ

View full text Add to dashboard Cite

show abstract

“…The doping of TiO 2 with metal ions can bring a desired decrease in E bg , but a metal ion itself may serve as an additional recombination center of the charge carriers, resulting in suppressed redox processes on the surface [12]. Concerning the non-metal element doped titania photocatalysts, the modification of TiO 2 nanostructures using a nitrogen dopant represents a promising method to shift photoactivity to the visible region, as shown in numerous previous studies [13][14][15].…”

Section: Introductionmentioning

confidence: 96%

EPR Investigations of G-C3N4/TiO2 Nanocomposites

et al. 2018

View full text Add to dashboard Cite

Abstract:The g-C 3 N 4 /TiO 2 nanopowders prepared by the annealing of melamine and TiO 2 P25 at 550 • C were investigated under dark and upon UV or visible-light photoactivation using X-and Q-band electron paramagnetic resonance (EPR) spectroscopy. The EPR spectra of powders monitored at room temperature and 100 K showed the impact of the initial loading ratio of melamine/TiO 2 on the character of paramagnetic centers observed. For the photocatalysts synthesized using a lower titania content, the paramagnetic signals characteristic for the g-C 3 N 4 /TiO 2 nanocomposites were already found before exposure. The samples annealed using the higher TiO 2 loading revealed the photoinduced generation of paramagnetic nitrogen bulk centers (g-tensor components g 1 = 2.005, g 2 = 2.004, g 3 = 2.003 and hyperfine couplings from the nitrogen A 1 = 0.23 mT, A 2 = 0.44 mT, A 3 = 3.23 mT) typical for N-doped TiO 2 . The ability of photocatalysts to generate reactive oxygen species (ROS) upon in situ UV or visible-light photoexcitation was tested in water or dimethyl sulfoxide by EPR spin trapping using 5,5-dimethyl 1-pyrroline N-oxide. The results obtained reflect the differences in photocatalyst nanostructures caused by the differing initial ratio of melamine/TiO 2 ; the photocatalyst prepared by the high-temperature treatment of melamine/TiO 2 wt. ratio of 1:3 revealed an adequate photoactivity in both spectral regions.

show abstract

“…Notwithstanding, feasible strategies may be adopted in harvesting the visible solar light. Among these, non-metal (e.g., N, C, S) (Cesano et al, 2008 ; Borges et al, 2016 ; Cravanzola et al, 2017 ) and metal doping (Uddin et al, 2008 ; Wang and Jing, 2014 ), sensitizer molecules (Yang et al, 2015 ), or quantum dots (Frame and Osterloh, 2010 ; Uddin et al, 2014 ) firmly anchored at the surface of the semiconductor or the formation of hybrid interfaces based on 2D materials (i.e., graphene, TMDs) (Bubnova, 2016 ), have been proposed as solutions. In this regard, several studies have demonstrated that single or few-stacked layers and/or small nanoparticles of 2D systems (i.e., graphene, TMDs) can be obtained from graphite and other bulk materials by adopting a top-down approach via the mechanical/chemical exfoliation (Coleman et al, 2011 ) or fragmentation (Muscuso et al, 2015 ) processes.…”

Section: Introductionmentioning

confidence: 99%

Carbon Domains on MoS2/TiO2 System via Catalytic Acetylene Oligomerization: Synthesis, Structure, and Surface Properties

et al. 2017

View full text Add to dashboard Cite

Carbon domains have been obtained at the surface of a MoS2/TiO2 (Evonik, P25) system via oligomerization and cyclotrimerization reactions involved in the interaction of the photoactive material with acetylene. Firstly, MoS2 nanosheets have been synthesized at the surface of TiO2, via sulfidation of a molybdenum oxide precursor with H2S (bottom-up method). Secondly, the morphology and the structure, the optical and the vibrational properties of the obtained materials, for each step of the synthesis procedure, have been investigated by microscopy and spectroscopy methods. In particular, transmission electron microscopy images provide a simple tool to highlight the effectiveness of the sulfidation process, thus showing 1L, 2L, and stacked MoS2 nanosheets anchored to the surface of TiO2 nanoparticles. Lastly, in-situ FTIR spectroscopy investigation gives insights into the nature of the oligomerized species, showing that the formation of both polyenic and aromatic systems can be taken into account, being their formation promoted by both Ti and Mo catalytic sites. This finding gives an opportunity for the assembly of extended polyenic, polyaromatic, or mixed domains firmly attached at the surface of photoactive materials. The presented approach, somehow different from the carbon adding or doping processes of TiO2, is of potential interest for the advanced green chemistry and energy conversion/transport applications.

show abstract

Characterization of a highly efficient N-doped TiO₂ photocatalyst prepared via factorial design

Abstract: The preparation of a highly efficient N-doped TiO2 photocatalyst was optimized by factorial design and the resulting powder was fully characterized.

Cited by 27 publications

References 74 publications

Immobilized TiO₂ on glass spheres applied to heterogeneous photocatalysis: photoactivity, leaching and regeneration process

Immobilized TiO₂ on glass spheres applied to heterogeneous photocatalysis: photoactivity, leaching and regeneration process

EPR Investigations of G-C3N4/TiO2 Nanocomposites

Carbon Domains on MoS2/TiO2 System via Catalytic Acetylene Oligomerization: Synthesis, Structure, and Surface Properties

Contact Info

Product

Resources

About

Characterization of a highly efficient N-doped TiO2 photocatalyst prepared via factorial design

Abstract: The preparation of a highly efficient N-doped TiO2 photocatalyst was optimized by factorial design and the resulting powder was fully characterized.

Cited by 27 publications

References 74 publications

Immobilized TiO2 on glass spheres applied to heterogeneous photocatalysis: photoactivity, leaching and regeneration process

Immobilized TiO2 on glass spheres applied to heterogeneous photocatalysis: photoactivity, leaching and regeneration process

EPR Investigations of G-C3N4/TiO2 Nanocomposites

Carbon Domains on MoS2/TiO2 System via Catalytic Acetylene Oligomerization: Synthesis, Structure, and Surface Properties

Contact Info

Product

Resources

About

Characterization of a highly efficient N-doped TiO₂ photocatalyst prepared via factorial design

Immobilized TiO₂ on glass spheres applied to heterogeneous photocatalysis: photoactivity, leaching and regeneration process

Immobilized TiO₂ on glass spheres applied to heterogeneous photocatalysis: photoactivity, leaching and regeneration process