Facile formation of black titania films using an atmospheric-pressure plasma jet

Sener, M. Emre; Quesada-Cabrera, Raúl; Parkin, Ivan P.; Caruana, Daren J.

doi:10.1039/d1gc03646g

Cited by 7 publications

(4 citation statements)

References 30 publications

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“…Hence, obtaining strong light absorption in ultrathin semiconductors has been of great scientific and technological interest for many years, making it one of the essential aspects for the efficient generation of photocarriers, as well as the development of ultrafast optoelectronic devices − and surface-active photocatalysts. , However, ultrathin films of many naturally occurring semiconductor materials provide only limited freedom for controlling the spectral location and magnitude of light absorption, since their intrinsic optical properties are fixed . In contrast, ultrathin metasurfaces constructed from two-dimensional subwavelength arrays of semiconductor structures have shown tremendous potential for concentrating and controlling light on the nanoscale, positioning them as an ideal toolkit for engineering the light absorption in catalytic materials. − Indeed, recent examples have shown that such artificial materials can increase the internal quantum efficiency of semiconductors and metals when shaping them into catalytic metasurfaces. , …”

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confidence: 99%

Catalytic Metasurfaces Empowered by Bound States in the Continuum

Weber

Bienek

et al. 2022

ACS Nano

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Photocatalytic platforms based on ultrathin reactive materials facilitate carrier transport and extraction but are typically restricted to a narrow set of materials and spectral operating ranges due to limited absorption and poor energy-tuning possibilities. Metasurfaces, a class of 2D artificial materials based on the electromagnetic design of nanophotonic resonators, allow optical absorption engineering for a wide range of materials. Moreover, tailored resonances in nanostructured materials enable strong absorption enhancement and thus carrier multiplication. Here, we develop an ultrathin catalytic metasurface platform that leverages the combination of loss-engineered substoichiometric titanium oxide (TiO2–x ) and the emerging physical concept of optical bound states in the continuum (BICs) to boost photocatalytic activity and provide broad spectral tunability. We demonstrate that our platform reaches the condition of critical light coupling in a TiO2–x BIC metasurface, thus providing a general framework for maximizing light–matter interactions in diverse photocatalytic materials. This approach can avoid the long-standing drawbacks of many naturally occurring semiconductor-based ultrathin films applied in photocatalysis, such as poor spectral tunability and limited absorption manipulation. Our results are broadly applicable to fields beyond photocatalysis, including photovoltaics and photodetectors.

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confidence: 99%

Catalytic Metasurfaces Empowered by Bound States in the Continuum

Weber

Bienek

et al. 2022

ACS Nano

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“…In addition, the weak absorption in the 400-500 nm visible region can be attributed to the sub-band-gap light absorption caused by the oxygen vacancies at the band tail. 31 Fig. 3b shows a schematic diagram of the vertical structure of the STO/TiO 2 device, with FTO and In as the bottom electrode and top electrode, respectively.…”

Section: Resultsmentioning

confidence: 99%

“…In addition, the weak absorption in the 400–500 nm visible region can be attributed to the sub-band-gap light absorption caused by the oxygen vacancies at the band tail. 31…”

Section: Resultsmentioning

confidence: 99%

Regulated self-powered photoresponse properties and irradiance-adaptable behavior in ferroelectric SrTiO₃/TiO₂ heterojunction photodetectors

Gao

Shi

et al. 2023

J. Mater. Chem. C

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“…However, the process needs a vacuum chamber and pump, with expensive costs and complicated operation. Atmospheric pressure (AP) plasma has also been used to prepare black TiO 2 and has shown high hydrogenation efficiency, reducing equipment and handling costs [25]. In our previous work [26], TiO 2 coated on Ni foam was successfully hydrogenated by RF AP He/H 2 plasma within a short time (5 min).…”

Section: Introductionmentioning

confidence: 99%

The effects of radio frequency atmospheric pressure plasma and thermal treatment on the hydrogenation of TiO₂ thin film

Wang

et al. 2023

Plasma Sci. Technol.

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The effects of radio frequency (RF) atmospheric pressure (AP) He/H2 plasma and thermal treatment on the hydrogenation of TiO2 thin films were investigated and compared in this work. The color of the original TiO2 film changes from white to black after being hydrogenated in He/H2 plasma at 160 W (gas temperature ~ 381 °C) within 5 min. While the color of the thermal treated TiO2 film did not change obviously even in pure H2 or He/H2 atmosphere with higher temperature (470 °C) and longer time (30 min). This indicated that a more effective hydrogenation reaction happened through RF AP He/H2 plasma than through pure H2 or He/H2 thermal treatment. The color change of TiO2 film was measured based on CIE L*a*b* color space system. Hydrogenated TiO2 film displayed improved visible light absorbance with plasma power. The morphology of the cauliflower-like nanoparticles of the TiO2 film surface remained unchanged after plasma process. X-ray photoelectron spectroscopy (XPS) results showed that the content of Ti3+ species and Ti-OH bonds in the plasma hydrogenated black TiO2 increased comparing with the thermal treated TiO2. X-ray diffraction (XRD) patterns and Raman spectra indicated that plasma would destroy crystal structure of TiO2 surface layer, while thermal annealing would increase the overall crystallinity. The different trends of XRD and Raman results suggested that plasma modification on TiO2 surface layer is more drastic than on its inner layer, which was also consistent with transmission electron microscopy (TEM) results. Optical emission spectra (OES) results suggest that numerous active species were generated in RF He/H2 plasma, while there were not any peaks detected in thermal processing. A possible mechanism about TiO2 hydrogenation process by plasma has been proposed. Numerous active species were generated in the bulk plasma region, accelerated in the sheath region, and bumped toward TiO2 film, which will react with TiO2 surface to form oxygen vacancies and disordered layers. This leads to the tailoring of the band gap of black TiO2 and causes its light absorption to extend into the visible region.

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Facile formation of black titania films using an atmospheric-pressure plasma jet

Abstract: A rapid atmospheric-pressure pulsed helium/hydrogen plasma jet method for conversion of TiO2 films into defective, black TiO2 is demonstrated.

Cited by 7 publications

References 30 publications

Catalytic Metasurfaces Empowered by Bound States in the Continuum

Catalytic Metasurfaces Empowered by Bound States in the Continuum

Regulated self-powered photoresponse properties and irradiance-adaptable behavior in ferroelectric SrTiO₃/TiO₂ heterojunction photodetectors

The effects of radio frequency atmospheric pressure plasma and thermal treatment on the hydrogenation of TiO₂ thin film

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Facile formation of black titania films using an atmospheric-pressure plasma jet

Abstract: A rapid atmospheric-pressure pulsed helium/hydrogen plasma jet method for conversion of TiO2 films into defective, black TiO2 is demonstrated.

Cited by 7 publications

References 30 publications

Catalytic Metasurfaces Empowered by Bound States in the Continuum

Catalytic Metasurfaces Empowered by Bound States in the Continuum

Regulated self-powered photoresponse properties and irradiance-adaptable behavior in ferroelectric SrTiO3/TiO2 heterojunction photodetectors

The effects of radio frequency atmospheric pressure plasma and thermal treatment on the hydrogenation of TiO2 thin film

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Regulated self-powered photoresponse properties and irradiance-adaptable behavior in ferroelectric SrTiO₃/TiO₂ heterojunction photodetectors

The effects of radio frequency atmospheric pressure plasma and thermal treatment on the hydrogenation of TiO₂ thin film