Graphene-TiO2 hybrids for photocatalytic aided removal of VOCs and nitrogen oxides from outdoor environment

Tobaldi, David Maria; Dvoranová, Dana; Lajaunie, Luc; Rožman, Nejc; Figueiredo, Bruno R.; Seabra, M.P.; Škapin, Andrijana Sever; Calvino, José J.; Brezová, Vlasta; Labrincha, J.A.

doi:10.1016/j.cej.2020.126651

Cited by 125 publications

(31 citation statements)

References 81 publications

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“…Several investigations on the photocatalytic ability of TiO 2 have been reported for different uses, including organic pollutants degradation and air cleaning etc. ( Mir et al, 2012 ; Umar et al, 2012 ; Umar et al, 2016 ; Tobaldi et al, 2021 ). However, overall, the photocatalysts have some disadvantages such as cost-effectiveness, low efficiency, high recombination and requires UV-radiation.…”

Section: Introductionmentioning

confidence: 99%

Synthesis, Characterization, and Photocatalytic Activities of Graphene Oxide/metal Oxides Nanocomposites: A Review

et al. 2021

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Sustainable water processing techniques have been extensively investigated and are capable of improving water quality. Among the techniques, photocatalytic technology has shown great potential in recent years as a low cost, environmentally friendly and sustainable technology. However, the major challenge in the industrial development of photocatalyst technology is to develop an ideal photocatalyst which must have high photocatalytic activity, a large specific surface area, harvest sunlight and shows recyclability. Keeping these views, the present review highlighted the synthesis approaches of graphene/metal oxide nanocomposite, characterization techniques and their prominent applications in photocatalysis. Various parameters such as photocatalyst loading, structure of photocatalyst, temperature, pH, effect of oxidizing species and wavelength of light were addressed which could affect the rate of degradation. Moreover, the formation of intermediates during photo-oxidation of organic pollutants using these photocatalysts is also discussed. The analysis concluded with a synopsis of the importance of graphene-based materials in pollutant removal. Finally, a brief overview of the problems and future approaches in the field is also presented.

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Section: Introductionmentioning

confidence: 99%

Synthesis, Characterization, and Photocatalytic Activities of Graphene Oxide/metal Oxides Nanocomposites: A Review

et al. 2021

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“…Fortunately, selective catalytic reduction (SCR) is an effective method (Busca et al, 1998) for the reduction of NO, with several metal oxides like TiO2 (Liu et al, 2018), CeO2 (Zhang et al, 2015;Tang et al, 2016), Fe2O3 (Yu et al, 2021) researched to obtain good reactive activity under working condition. For VOCs in traditional combustion process, several techniques like chemical adsorption (Yang et al, 2019;Li et al, 2020), photochemical degradation (Tobaldi et al, 2021) are adopted effectively to remove organic air pollutants from flue gas, among which catalytic combustion is considered to be the most efficient way for VOCs abatement (Li et al, 2019;Wang et al, 2019). However, as widely accepted for most power plant only soluble VOCs is removed in wet technology, most of hydrophobic VOCs still remain to be released into atmosphere without…”

Section: Introductionmentioning

confidence: 99%

Simultaneous Catalytic Removal of VOCs and NOx with the Dual-layered Catalyst of CoCeOx and V2O5/TiO2

Zhang

et al. 2021

Aerosol Air Qual. Res.

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NO and volatile organic compounds (VOCs) are ones of exhaust with high irritation and toxicity, thus it is very necessary to develop a catalyst that can simultaneously remove them. In this study, a type of dual-layered catalyst has been prepared by combining CoCeOx and V2O5/TiO2 as different functional layers. The dual-layered catalyst was tested under NO, NH3, propane and the mixing atmosphere, achieving great NOx removal efficiency and good propane degradation under wide range temperature window. It is presented that NO conversion could reach 100% at 225 °C and kept more than 80% at 175-300 °C, while VOCs degradation reached 80% above 260 °C. Moreover, the dual-layered catalyst with different construction is surveyed to reveal the mechanism included in this special construction. It is supposed that V2O5/TiO2 layer possesses rich acid sites which adsorbs NH3 as an ammonia buffer part and CoCeOx layer provides good oxidizing ability to oxidize NO and propane. The combination moderates the competitive adsorption between NH3 and propane which is the initial obstacle for multiple pollutants removal.

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“…[7][8][9] Titania has been well-studied in photocatalytic process, and the development in photocatalytic materials was the most important research focus. [10,11] Rare earth doping was Since GTO-nZ composites contained 90% GTO and only 10% HZSM-5, the zeolite was covered with a thick GTO layer, and HZSM-5 particles could not be figured out in the images. For the same reason, there was nearly no difference in the surface morphologies of GTO-nZ composites.…”

Section: Introductionmentioning

confidence: 99%

“…Titania has been well‐studied in photocatalytic process, and the development in photocatalytic materials was the most important research focus. [ 10,11 ] Rare earth doping was an effective method to improve light absorption property of some kinds of materials, [ 12,13 ] and rare earth doping into titania could significantly enhanced the efficiency on organic pollutant degradation. [ 14,15 ] Titanate is another well‐studied photocatalyst for organic pollutant degradation.…”

Section: Introductionmentioning

confidence: 99%

Effects of ZSM‐5 Treatment on the Properties of Gd₂Ti₂O₇‐nHZSM‐5 Composites for RBR‐X3B Degradation

Jiao

Zhang

2021

Part & Part Syst Charact

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an effective method to improve light absorption property of some kinds of materials, [12,13] and rare earth doping into titania could significantly enhanced the efficiency on organic pollutant degradation. [14,15] Titanate is another well-studied photocatalyst for organic pollutant degradation. [16][17][18][19][20] Wastewater treatment efficiency depended on the activity of photocatalyst, and modification of the materials could lead to an improved activity or to meet special requirements of a wastewater treatment process. Some different types of materials were used to prepare composite materials with greatly enhanced activities. [21][22][23] Photocatalysts were also prepared in the supported forms for a better waterphotocatalyst separation after treatment. [24][25][26] However, the supported photocatalyst in a flat surface usually had weaker activity than powders. Alternatively, photocatalyst was supported on porous zeolites. The obtained powders could be easily separated from the treated water, and a very interesting finding was an improved activity of photocatalyst in the supported form. HZSM-5 was used to prepare TiO 2 -zeolite and titanatezeolite composites in our previous works. [27][28][29] Degradation efficiencies of the photocatalysts were significantly enhanced after supporting.The properties of titanate-zeolite composite apparently depended on the properties of zeolite. Since HZSM-5 zeolite was prepared from Na-type ZSM-5 in a hydrochloric acid solution, the properties of HZSM-5 depended on hydrochloric acid solution concentration. In this work, Gd 2 Ti 2 O 7 -nHZSM-5 composite was prepared to study the influences of hydrochloric acid solution concentration on the characterization results and on the performance of Gd 2 Ti 2 O 7 -nHZSM-5 composite. Results and Discussions Surface Images of GTO and GTO-nZThe surface morphologies of GTO and GTO-nZ composites are presented in Figure 1. The sol-gel synthesized GTO had an irregular shape, and the particle size coluld be larger than 10 µm. Some small particles were along with the big ones because the materials were ground after calcination. Gd 2 Ti 2 O 7 -nHZSM-5 (GTO-nZ) composites are prepared using HZSM-5 zeolite via a sol-gel route. The hydrochloric acid concentration in zeolite treatment can affect the properties of GTO-nZ composites. GTO has a typical pyrochlore phase Gd 2 Ti 2 O 7 , and HZSM-5 zeolite does not have noticeable influences on GTO crystal formation. The bandgap energies are 3.77, 3.73, 3.67, 3.65, and 3.64 eV for GTO-nZ composites when hydrochloric acid concentration is 0, 0.2, 0.3, 0.5, and 1 mol L −1 , respectively. The isotherms of GTO-nZ composites are classified as IUPAC type IV of mesoporous material, while the adsorbed nitrogen quantities on GTO-nZ composites are much larger than the nitrogen quantity on GTO. The small amount of HZSM-5 zeolite can improve the porosity of GTO in the composites, and the surface area of GTO in the composites is significantly enlarged. The hydrochloric acid concentration has an apparent influence on the ...

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Graphene-TiO2 hybrids for photocatalytic aided removal of VOCs and nitrogen oxides from outdoor environment

Abstract: Graphical abstract

Cited by 125 publications

References 81 publications

Synthesis, Characterization, and Photocatalytic Activities of Graphene Oxide/metal Oxides Nanocomposites: A Review

Synthesis, Characterization, and Photocatalytic Activities of Graphene Oxide/metal Oxides Nanocomposites: A Review

Simultaneous Catalytic Removal of VOCs and NOx with the Dual-layered Catalyst of CoCeOx and V2O5/TiO2

Effects of ZSM‐5 Treatment on the Properties of Gd₂Ti₂O₇‐nHZSM‐5 Composites for RBR‐X3B Degradation

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Graphene-TiO2 hybrids for photocatalytic aided removal of VOCs and nitrogen oxides from outdoor environment

Abstract: Graphical abstract

Cited by 125 publications

References 81 publications

Synthesis, Characterization, and Photocatalytic Activities of Graphene Oxide/metal Oxides Nanocomposites: A Review

Synthesis, Characterization, and Photocatalytic Activities of Graphene Oxide/metal Oxides Nanocomposites: A Review

Simultaneous Catalytic Removal of VOCs and NOx with the Dual-layered Catalyst of CoCeOx and V2O5/TiO2

Effects of ZSM‐5 Treatment on the Properties of Gd2Ti2O7‐nHZSM‐5 Composites for RBR‐X3B Degradation

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Effects of ZSM‐5 Treatment on the Properties of Gd₂Ti₂O₇‐nHZSM‐5 Composites for RBR‐X3B Degradation