Kinetics of TiO2 photochromic response in different hole scavenging solvents

Eglı̅tis, Raivis; Zukuls, Anzelms; Viter, Roman; Šutka, Andris

doi:10.1039/d0pp00079e

Cited by 18 publications

(12 citation statements)

References 31 publications

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“…79 Moreover, considering the role of ethanol as a hole scavenger justifies the improvement of the reaction yield when it is used as the solvent. 80…”

Section: Resultsmentioning

confidence: 99%

An efficient CuO/rGO/TiO₂photocatalyst for the synthesis of benzopyranopyrimidine compounds under visible light irradiation

2022

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“…79 Moreover, considering the role of ethanol as a hole scavenger justifies the improvement of the reaction yield when it is used as the solvent. 80…”

Section: Resultsmentioning

confidence: 99%

An efficient CuO/rGO/TiO₂photocatalyst for the synthesis of benzopyranopyrimidine compounds under visible light irradiation

2022

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“…Significant absorption was observed from the visible to near-infrared region and even to thermal blackbody radiation regime. We have also shown that, for undoped TiO 2 , changing the surrounding medium (solvent) as well as adding hole-scavenging additives can increase the photochromic response …”

Section: Introductionmentioning

confidence: 80%

Strong, Rapid, and Reversible Photochromic Response of Nb Doped TiO₂ Nanocrystal Colloids in Hole Scavenging Media

Eglı̅tis

Joost

Zukuls

et al. 2020

ACS Appl. Mater. Interfaces

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Understanding photochromicity is essential for developing new means of modulating the optical properties and optical response of materials. Here, we report on the synthesis and exciting new photochromic behavior of Nb5+ doped TiO2 nanoparticle colloids (NCs). We find that, in hole scavenging media, Nb5+ doping significantly improves the photochromic response time of TiO2 nanoparticles. In the infrared regime, Nb-doped TiO2 NCs exhibit 1 order of magnitude faster photoresponse kinetics than the pristine TiO2. Enhanced photochromic response is observed in the visible light regime as well. The transmittance of Nb-doped TiO2 NCs drops to 10% in less than 2 min when irradiated by UV-light in the 500 nm range. The photochromic reaction is fully reversible. The physical origin of the high reaction rate is the high Nb5+ concentration. As a donor dopant, Nb5+ builds up a significant positive charge in the material, which leads to highly efficient electron accumulation during the UV irradiation and results in a rapid photoresponse. EPR experiments identify a new defect type from Nb5+ doping, which alters the physical mechanisms available for transmittance modulation. Our new NCs are economic to synthesize and highly suitable for switchable photochromic applications, e.g., smart windows for modulating visible light and infrared transmittance in built-environments.

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“…A similar increase in change rate was also observed for other wavelengths. The rate constant increase can be attributed to effective photogenerated hole scavenging properties of ethanol [14]. A further increase in the EtOH content above 30% shows a decrease on the both the absolute transmittance change as well as the change rate (Figure S11).…”

Section: Photochromic Responsementioning

confidence: 97%

“…The accumulated electrons are reduced by the oxidation products of ethanol, that were created during UV irradiation in reaction with photogenerated hole. It has been previously shown, that photodoped TiO 2 can be used to reduce aldehydes to alcohols [39][40][41][42][43]. The recovery time depending on composition and wavelength ranged from 195 to 500 min.…”

Section: Recoverymentioning

confidence: 99%

“…Anatase TiO 2 is most attractive photochromic material among other TMOs material due to non-toxicity, elemental abundancy and strong photoresponse [10]. The photochromic response of anatase TiO 2 can be modified either by changing the hole scavenger [14] or doping [15]. Strong photochromic response from TiO 2 has been demonstrated mainly for colloids so far.…”

Section: Introductionmentioning

confidence: 99%

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Photochromic TiO2/PEGDA organogels

Eglı̅tis

Šutka

2022

Photochem Photobiol Sci

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Photochromic materials can be used for modulation of the visible and infrared light transmittance for providing privacy or energy saving by blocking the heat. Titanium dioxide (TiO 2 ) nanoparticles has been well reported as a promising photochromic material. However, a high photochromic response from TiO 2 can be observed only when the nanoparticles are dispersed in a strong photogenerated hole scavenger at a liquid state, but polymer composites are less responsive due to lack of hole scavenging capability. However, it is intricate to apply suspensions in real window devices because of possible leaking. Here, we describe the preparation of TiO 2 quantum dot (QD)-based gels from polyethylene glycol diacrylate (PEGDA), N,N-Dimethylformamide (DMF), and ethanol (EtOH). Photochromic gels with TiO 2 contents (1-5 volume%) show performance comparable to their colloidal counterparts with capable of photodarkening within 30 min with a transmittance change ranging from 35.8 to 84.5% at 550 nm. These gels were capable of fully recovering the initial transmittance when not exposed to ultraviolet (UV) light within 3-8 h. The photochromic gel systems with ethanol shows reasonable stability by decreasing in transmittance recovery only by less than 10% in 10 cycles. A potential application for the developed photochromic gels can be photochromic windows.

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Kinetics of TiO2 photochromic response in different hole scavenging solvents

Abstract:
TiO₂ nanoparticle colloids in hole scavenging media exhibit a reversible photochromic response in a broad wavelength range. The response kinetics is strongly dependent on the hole scavenging power.

Cited by 18 publications

References 31 publications

An efficient CuO/rGO/TiO₂photocatalyst for the synthesis of benzopyranopyrimidine compounds under visible light irradiation

An efficient CuO/rGO/TiO₂photocatalyst for the synthesis of benzopyranopyrimidine compounds under visible light irradiation

Strong, Rapid, and Reversible Photochromic Response of Nb Doped TiO₂ Nanocrystal Colloids in Hole Scavenging Media

Photochromic TiO2/PEGDA organogels

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Kinetics of TiO2 photochromic response in different hole scavenging solvents

Abstract: TiO2 nanoparticle colloids in hole scavenging media exhibit a reversible photochromic response in a broad wavelength range. The response kinetics is strongly dependent on the hole scavenging power.

Cited by 18 publications

References 31 publications

An efficient CuO/rGO/TiO2photocatalyst for the synthesis of benzopyranopyrimidine compounds under visible light irradiation

An efficient CuO/rGO/TiO2photocatalyst for the synthesis of benzopyranopyrimidine compounds under visible light irradiation

Strong, Rapid, and Reversible Photochromic Response of Nb Doped TiO2 Nanocrystal Colloids in Hole Scavenging Media

Photochromic TiO2/PEGDA organogels

Contact Info

Product

Resources

About

Abstract:
TiO₂ nanoparticle colloids in hole scavenging media exhibit a reversible photochromic response in a broad wavelength range. The response kinetics is strongly dependent on the hole scavenging power.

An efficient CuO/rGO/TiO₂photocatalyst for the synthesis of benzopyranopyrimidine compounds under visible light irradiation

An efficient CuO/rGO/TiO₂photocatalyst for the synthesis of benzopyranopyrimidine compounds under visible light irradiation

Strong, Rapid, and Reversible Photochromic Response of Nb Doped TiO₂ Nanocrystal Colloids in Hole Scavenging Media