Effects of surface roughness and light scattering on the activation of TiO2 on mortar photocatalytic process

Dantas, Sérgio Roberto Andrade; Romano, Roberto; Vittorino, Fúlvio; Loh, Kai

doi:10.1016/j.conbuildmat.2020.121421

Cited by 11 publications

(9 citation statements)

References 25 publications

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“…In addition, it was reported that the surface roughness and texture of a material can also influence its light absorption capabilities. Hence, the light absorption ability of the Z-PAgT-5 material could have increased because of its rougher surface, as illustrated in the above SEM result (Figure 3) (Roberto Andrade Dantas et al, 2021). The obtained results suggested the Z-PAgT-5 catalyst with improved light absorption may have increased photonic activation for effective pollutant removal in wastewater.…”

Section: Optical Propertiesmentioning

confidence: 76%

Synthesis and characterization of 3D-zeolite–modified TiO2-based photocatalyst with synergistic effect for elimination of organic pollutant in wastewater treatment

Liu

Sun

et al. 2022

Front. Environ. Sci.

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In this work, zeolite, a porous material with a 3D network structure, was introduced as the carrier to support P/Ag/Ag2O/Ag3PO4/TiO2 (PAgT) composite for synthesizing the 3D-zeolite–modified photocatalyst (Z-PAgT). In this combination, zeolite with strong adsorbability can pre-adsorb and condense organic compounds onto the catalyst surface, thereby helping to speed up the photocatalytic reaction. In the present study, to determine the optimum mass ratio of zeolite to photocatalyst, various samples containing different zeolite additions (0 wt%, 5 wt%, 10 wt%, and 25 wt%) were prepared using the hydrothermal method, respectively. The physical–chemical properties of the as-prepared samples were systematically characterized by different analytical techniques, including XRD, FTIR, SEM, BET, EDX, UV-Vis, and PL. The results revealed that the obtained Z-PAgT-5 sample possessed relatively higher crystallinity, smaller crystalline size, larger specific surface area, narrow band gap, and lower generated electron-hole recombination rate. The photocatalytic degradation of rhodamine B (Rh B) in aqueous suspension has been employed to evaluate the photocatalytic activity of the as-prepared photocatalysts with simulated solar light as an irradiation source. The results showed that Z-PAgT-5 performed the highest photodegradation efficiency, and its degradation rate constant (kapp) (0.188 min−1) is much higher than that of Z-PAgT-0 (0.132 min−1), Z-PAgT-10 (0.050 min−1), Z-PAgT-25 (0.037 min−1), and pure zeolite (0.003 min−1). This super photocatalytic activity of Z-PAgT-5 toward Rh B degradation can be ascribed to the synergistic effect between the 3D-zeolite and PAgT photocatalyst, which made the hybrid zeolite-photocatalyst material possess good adsorption and photodegradation properties. In addition, repetitive experiments demonstrated that the improved Rh B degradation efficiency of Z-PAgT-5 was well maintained even after five recycling runs without any obvious decrease. Hence, the obtained results indicated that Z-PAgT-5 material can be used as a potential photocatalyst for treating organic pollutants during wastewater environmental remediation.

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Section: Optical Propertiesmentioning

confidence: 76%

Synthesis and characterization of 3D-zeolite–modified TiO2-based photocatalyst with synergistic effect for elimination of organic pollutant in wastewater treatment

Liu

Sun

et al. 2022

Front. Environ. Sci.

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“…Following a different approach to measure surface roughness, Dantas et al [52] used an optical profilometer (as a noncontact method), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) elemental mapping to characterize mortar surfaces that received different treatments of TiO 2 -either in powder (added in the cement matrix) or in suspension (commercial solutions and suspensions prepared by the authors). The results showed that microroughness does not directly affect TiO 2 activation but can enhance dirt adhesion, potentially hindering TiO 2 activation.…”

Section: Methods and Tests To Evaluate Surface Roughnessmentioning

confidence: 99%

“…Cement was replaced with a rutile nano-TiO 2 at quantities of 0%, 2%, 4%, 6%, 8% and 10% by weight Dantas et al [52] Roughness was set to vary according to the type of TiO 2 used Different compositions using white Portland cement, dolomite, polypropylene microfibers and TiO 2…”

Section: Overview Of the Existing Researchmentioning

confidence: 99%

See 1 more Smart Citation

TiO2-Based Mortars for Rendering Building Envelopes: A Review of the Surface Finishing for Sustainability

Bersch,

Picanço Casarin,

Maia

et al. 2023

Sustainability

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Building envelopes coated with TiO2-based mortars benefit from depolluting, antibiological and self-cleaning effects. Therefore, photocatalytic renders are allies in the quest for sustainability in the built environment, potentially combatting atmospheric pollution, enhancing durability and reducing maintenance needs. Surface finishing characteristics of the renders influence their photocatalytic efficiency and esthetic and functional properties. In this context, this study reviews the existing literature, focusing on proven surface-affecting parameters, the surface and color of TiO2-based mortars, to explore their impacts on photoactive behavior. The incorporation of TiO2 within an additional surface layer and its mixture into the mortar in bulk were observed for surface roughness. Mainly the addition of TiO2 during casting was identified in colored mortars. Generally, a moderate surface roughness led to better photoactivity; microroughness affected self-cleaning by facilitating dirt deposition. The interaction between the surface roughness and the photocatalytic layer affected the water contact angle, regarding superhydrophilicity or superhydrophobicity. The photoactivity of colored mortars with TiO2 depended on the color and amount of the added pigments, which influenced electron–hole recombination, physically occupied active sites or, on the other hand, led to a higher formation of reactive radicals. Surface finishing can thus be designed to enhance the photoactivity of TiO2-based mortars, which is fundamental for current climate concerns and emphasizes the need for life cycle assessments and environmental protection.

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“…A rougher surface results in better adsorption, as there is a larger surface area. In addition, a rougher surface could enhance photocatalytic activity by increasing light absorptivity because of more contact points with incident light [25,26]. Another reason is that TiO 2 is an n-type semiconductor that has photocatalytic activity but is limited by electron-hole recombination, while NiO, a p-type semiconductor, is coupled with TiO 2 creating a type-II p-n heterojunction [27] in the BLF catalyst.…”

Section: Photocatalytic Degradationmentioning

confidence: 99%

Photocatalytic Degradation of Acid Orange 7 by NiO-TiO2/TiO2 Bilayer Film Photo-Chargeable Catalysts

et al. 2023

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Photocatalysis as an eco-friendly technology has the potential to achieve the Sustainable Development Goals (SDGs). However, an improvement of conventional photocatalysts is necessary to overcome their limitations such as slow kinetics, wavelength for excitation, and environmental restrictions. In particular, the development of a photocatalyst that can operate even in the absence of light is constantly conducted, and a photo-chargeable photocatalyst could be one of the answers. In this paper, a heterojunction composed of TiO2 and NiO-TiO2 bilayer film photocatalyst (BLF) was prepared. The effect of the synthesis conditions of the NiO-TiO2 layer on the photocatalytic properties was investigated. Photocatalytic degradation measurements were conducted with an acid orange 7 (AO7) solution under light and dark conditions. The highest degradation BLF was synthesized at a NiO loading of 52% and calcination temperature of 300 °C. The prepared sample showed about five-fold greater photocatalytic activity of 48% in AO7 degradation after 8 h compared to an ordinary TiO2 film (9%) under light conditions. Moreover, under dark conditions it exhibited 13.6% degradation, while the naked layers of TiO2 and NiO-TiO2 showed no degradation. The proposed mechanism suggested that photocatalysis in the dark was possible due to the stabilization of photogenerated holes by anionic intercalation during illumination.

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Effects of surface roughness and light scattering on the activation of TiO2 on mortar photocatalytic process

Cited by 11 publications

References 25 publications

Synthesis and characterization of 3D-zeolite–modified TiO2-based photocatalyst with synergistic effect for elimination of organic pollutant in wastewater treatment

Synthesis and characterization of 3D-zeolite–modified TiO2-based photocatalyst with synergistic effect for elimination of organic pollutant in wastewater treatment

TiO2-Based Mortars for Rendering Building Envelopes: A Review of the Surface Finishing for Sustainability

Photocatalytic Degradation of Acid Orange 7 by NiO-TiO2/TiO2 Bilayer Film Photo-Chargeable Catalysts

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