A sustainable and green chlorophyll/TiO2:W composite supported on recycled plastic bottle caps for the complete removal of Rhodamine B contaminant from drinking water
“…The standard error calculations are demonstrated in Table S2 . It was found that the lowest activity was detected in the presence of p-BQ indicating the radicals were the most producible reactive species in the photodegradation of RB using the as-fabricated QAD/TiO 2 nanoparticles, as reported earlier in similar works 19 , 24 . Figure 9 The effect of scavengers on the RB photodegradation% in 150 min ( a ) and the corresponding 1st order plots ( b ) using QAD/TiO 2 photocatalyst under UV-A irradiation (experimental parameters: [Cat] = 1 g/L, pH 4, [RB] = 1 × 10 –5 M, [Scavenger] = 1 × 10 –5 M).…”
Section: Mechanism Of the Enhanced Performance Of Qad/tiosupporting
confidence: 73%
“…Similarly, M. Sedghi 22 et al investigated the effect of TCPP to enhance the TiO 2 /Al and shift its response to the visible region; however, the achieved RB removal % was only 29.19%. E. Valadez-Renteria et al 24 employed green chlorophyll as an efficient photosensitizer to TiO 2 :W composite that efficiently degraded RB dye, but ~20% reduction in the activity was observed after the 3rd cycle. Zyoud et al 23 synthesized Anthocyanin-sensitized TiO 2 nanoparticles for the efficient photodegradation of phenazopyridine under solar simulated light that achieve high degradation% (> 90%); however, the degradation% was declined to about 55% after the second use because of the loss of the photosensitizer.…”
Water pollution is one of the global threats severely affecting our planet and human health. Organic textile dyes are one of the common organic water pollutants that are presentient to degradation by traditional physical methods. Semiconductor-assisted photocatalysis is considered a green, efficient, and sustainable technology for wastewater treatment. To maximize the efficient utilization of solar radiation, it is of pivotal significance to explore novel organic molecules to be employed as efficient dye sensitizers for wide-bandgap semiconductors to extend their performance to the Visible-light region. Hence, in this work, we are proposing the design and synthesis of novel structures of QAD molecule as a dye photosensitizer with extended visible light absorptivity due to the extended π–π/n–π conjugations, to promote the performance of TiO2 nanoparticles to the visible-light region and enhance the charge separation. The physicochemical characterizations confirmed the successful synthesis of QAD, TiO2, and QAD/TiO2 samples with the proposed structures. The anchoring of QAD molecules on the surface of TiO2 caused a substantial improvement in the optical characteristics of TiO2 as well as overcoming its common drawbacks by decreasing its bandgap energy to 2.6 eV, a remarkable reduction of PL intensity indicating reducing the e–h recombination and enhancing the charge separation, and creation of efficient visible light-harvesting antenna in the range of 400–600 nm. Besides, the QAD/TiO2 sample achieved a 3-fold enhancement in the observed rate constant of the photodegradation of Rhodamine B dye compared to the bare TiO2. The parameters affecting the photodegradation process were optimized and the sample displayed outstanding stability after 4 consecutive cycles. Finally, the effect of the scavengers was investigated and $${\mathrm{O}}_{2}^{\cdot -}$$
O
2
·
-
was proposed to be the most reactive species and the mechanism of the enhancement was suggested based on the electron injection from the QAD’s HOMO level to the TiO2’s CB. Finally, this work opens the door for various studies for the investigation of the proposed structures or similar structures in various photocatalytic/biomedical applications.
“…The standard error calculations are demonstrated in Table S2 . It was found that the lowest activity was detected in the presence of p-BQ indicating the radicals were the most producible reactive species in the photodegradation of RB using the as-fabricated QAD/TiO 2 nanoparticles, as reported earlier in similar works 19 , 24 . Figure 9 The effect of scavengers on the RB photodegradation% in 150 min ( a ) and the corresponding 1st order plots ( b ) using QAD/TiO 2 photocatalyst under UV-A irradiation (experimental parameters: [Cat] = 1 g/L, pH 4, [RB] = 1 × 10 –5 M, [Scavenger] = 1 × 10 –5 M).…”
Section: Mechanism Of the Enhanced Performance Of Qad/tiosupporting
confidence: 73%
“…Similarly, M. Sedghi 22 et al investigated the effect of TCPP to enhance the TiO 2 /Al and shift its response to the visible region; however, the achieved RB removal % was only 29.19%. E. Valadez-Renteria et al 24 employed green chlorophyll as an efficient photosensitizer to TiO 2 :W composite that efficiently degraded RB dye, but ~20% reduction in the activity was observed after the 3rd cycle. Zyoud et al 23 synthesized Anthocyanin-sensitized TiO 2 nanoparticles for the efficient photodegradation of phenazopyridine under solar simulated light that achieve high degradation% (> 90%); however, the degradation% was declined to about 55% after the second use because of the loss of the photosensitizer.…”
Water pollution is one of the global threats severely affecting our planet and human health. Organic textile dyes are one of the common organic water pollutants that are presentient to degradation by traditional physical methods. Semiconductor-assisted photocatalysis is considered a green, efficient, and sustainable technology for wastewater treatment. To maximize the efficient utilization of solar radiation, it is of pivotal significance to explore novel organic molecules to be employed as efficient dye sensitizers for wide-bandgap semiconductors to extend their performance to the Visible-light region. Hence, in this work, we are proposing the design and synthesis of novel structures of QAD molecule as a dye photosensitizer with extended visible light absorptivity due to the extended π–π/n–π conjugations, to promote the performance of TiO2 nanoparticles to the visible-light region and enhance the charge separation. The physicochemical characterizations confirmed the successful synthesis of QAD, TiO2, and QAD/TiO2 samples with the proposed structures. The anchoring of QAD molecules on the surface of TiO2 caused a substantial improvement in the optical characteristics of TiO2 as well as overcoming its common drawbacks by decreasing its bandgap energy to 2.6 eV, a remarkable reduction of PL intensity indicating reducing the e–h recombination and enhancing the charge separation, and creation of efficient visible light-harvesting antenna in the range of 400–600 nm. Besides, the QAD/TiO2 sample achieved a 3-fold enhancement in the observed rate constant of the photodegradation of Rhodamine B dye compared to the bare TiO2. The parameters affecting the photodegradation process were optimized and the sample displayed outstanding stability after 4 consecutive cycles. Finally, the effect of the scavengers was investigated and $${\mathrm{O}}_{2}^{\cdot -}$$
O
2
·
-
was proposed to be the most reactive species and the mechanism of the enhancement was suggested based on the electron injection from the QAD’s HOMO level to the TiO2’s CB. Finally, this work opens the door for various studies for the investigation of the proposed structures or similar structures in various photocatalytic/biomedical applications.
“…The choice of thiazine dye in photocatalysis is multifaceted, considering factors like absorption wavelength, environmental impact, and overall performance. Rhodamine B and Toluidine Blue, despite moderate photocatalytic activity, may find applications in scenarios where a balance between performance and environmental impact is critical (Hamza et al, 2023;Valadez-Renteria et al, 2022). Furthermore, continuous exploration and understanding of the chemical structures and properties of thiazine dyes will contribute to the optimization of photocatalytic processes and the development of sustainable environmental technologies.…”
Section: Electrolyte Systems Redox Mediatorsmentioning
The emerging field of using titanium dioxide (TiO2)-based photosensitizers for enhancing photocatalytic removal of thiazine dyes such as methylene blue (MB) from water has long been recognized for its exceptional photocatalytic properties, making it an attractive material for environmental remediation and energy conversion. However, its wide bandgap limits its responsiveness to visible light. As such, the utilization of TiO2-based photosensitizers for the removal of thiazine dyes, presents a promising avenue for diverse applications. In addressing the dual challenges of environmental pollution and harnessing sustainable energy sources, this review focuses on the removal of thiazine dyes from water and their subsequent application as photosensitizers for TiO2 materials. Thiazine dyes, ubiquitous in industrial effluents, pose environmental concerns due to their persistence and potential toxicity. Conversely, this innovative approach involves employing TiO2 materials as photocatalysts, utilizing the unique properties of thiazine dyes to enhance light absorption. Studies have shown that beyond the conventional role of thiazine dyes as colorants, they can serve as effective photosensitizers when coupled with TiO2. This tandem not only facilitates the elimination of thiazine dyes, such as MB, from water but also augments the improvement of the photocatalytic performance of TiO2 materials. The synergy between dye sensitizers and TiO2 enhances the overall efficiency of processes like dye degradation and water splitting. Dye sensitizers, acting as light energy absorbers, can efficiently transfer this energy to TiO2, thereby promoting electron transfer and generating reactive oxygen species (ROS). These ROS, in turn, initiate chemical reactions, rendering dye sensitizers valuable in applications such as wastewater treatment, solar energy conversion, and environmental remediation. As such, it is crucial to acknowledge the potential drawbacks associated with thiazine dyes, including toxicity and non-biodegradability. Consequently, careful consideration must be given to thiazine dye application and disposal. Therefore, this review manuscript delves into the comprehensive exploration of TiO2-based photosensitizers, shedding light on their efficacy in various photocatalytic processes for thiazine dye removal.
“…Figure 3 presents a schematic representation of a typical photocatalytic process based on chlorophyll-sensitized TiO 2 . Among the pollutants usually degraded, we can cite dyes such as methylene blue [19] and rhodamine B [51,59]. However, given that the molecules of these dyes are also able to absorb visible photons and donate electrons to TiO 2 , it is necessary to carefully consider the contribution of the dye molecules being degraded to accurately assess the improvement produced by the addition of chlorophyll to titanium dioxide [19,51].…”
Section: Chlorophyll-modified Tio 2 As Photocatalystmentioning
Recent studies have shown that chlorophyll sensitization can improve the performance of semiconductors like TiO2 in photocatalytic reactions and light-harvesting technologies, such as solar cells. Faced with the search for renewable energy sources and sustainable technologies, the application of this natural pigment has been gaining prominence. The present work addresses some of the main possibilities of chlorophyll-TiO2 combination, presenting the most relevant aspects affecting chlorophyll extraction and TiO2 sensitization.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
