Nanostructured TiO2 Microrods with 3D Nanovoids for Green Photocatalysis - PEC Water Splitting

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F44555601%3A13420%2F19%3A43895158" target="_blank" >RIV/44555601:13420/19:43895158 - isvavai.cz</a>

Výsledek na webu

<a href="https://www.cambridge.org/core/journals/microscopy-and-microanalysis/article/plasmonicphotonic-hybrids-by-freezecasting-ag-decorated-1d-and-2d-tio2-hollow-patterned-nanostructures-for-green-photocatalysis/56C300ADF73F2DE62B906AF8425E2504" target="_blank" >https://www.cambridge.org/core/journals/microscopy-and-microanalysis/article/plasmonicphotonic-hybrids-by-freezecasting-ag-decorated-1d-and-2d-tio2-hollow-patterned-nanostructures-for-green-photocatalysis/56C300ADF73F2DE62B906AF8425E2504</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1017/S1431927619011413" target="_blank" >10.1017/S1431927619011413</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Nanostructured TiO2 Microrods with 3D Nanovoids for Green Photocatalysis - PEC Water Splitting

Popis výsledku v původním jazyce

Titanium dioxide (TiO2) has been studied for several decades due to its versatility for a diverse range of applications. TiO2 is robust, thermally stable, non-toxic, as well as inexpensive. One-dimensional (1D) TiO2 nanostructures have attracted attention because of their unique optical and electronic properties.The first study of photoelectrochemical (PEC) water splitting on TiO2 was reported in 1972 by Fujishima and Honda showed that TiO2 photoanode exhibits outstanding PEC properties, whichmay be utilized for the conversion of solar energy into chemical energy. It was known that TiO2 could not be used in the visible light region and could only split water under UV light irradiation. The large band gap (3.0 - 3.2 eV) is the reason why TiO2 is transparent across the entire visible spectral range. The efficient photocatalysts which could produce electron-hole pairs under VIS light irradiation should be developed because VIS light occupied 43% of sunlight. Novel nanostructures with dense-stacked nanocavities inside 1DTiO2 have been prepared, which present excellent photocatalytic and PEC properties. Recently was observed [2] that the photocatalytic activity of 1D-bicrystalline nanoribbons with alternate structure of TiO2(B) and anatase under visible light irradiation was due to the formation of nanocavities inside the TiO2 nanocrystals. The research revealed that TiO2(B) with nanocavities exhibited a narrow band gap and improved its absorbance coefficient in the UV region. An enhanced optical absorption induced by dense nanovoids inside titania nanorods was also reported by Han et al. The molar absorption coefficient of TiO2 nanorods with nanovoids was found to be about 25% higher than that of TiO2 without nanovoids. Our group has recently reported an environmental friendly, smart and unexpensive preparation method for the synthesis of 1DTiO2 microrods (MRs) in aqueous media starting with hydrated titanyl sulfate crystals (TiOSO4.2H2O). The method is based on the extraction of sulfate ions from the TiOSO4 crystals and their replacement with hydroxyl groups in aqueous ammonia solution leaving the TiMINUS SIGN O framework intact. Heat treatment process (from 500 to 950 oC) causes the evaporation of nanoconfined water which hollowing out empty spaces inside the 1DTiO2 MRs. The self-assemble nanovoids along certain crystallographic directions of anatase NCs were confirmed by STEM and EELS study. The nanovoids with size ranging from 5 to 78 nm in both, length and width, and depth of about 9 nm (Fig. 1e) are responsible for the possibilities of applying 1DTiO2 in the photoelectrochemistry as a stable working electrodes. We are concerned with the nanovoid phenomenon as governed by the evaporation of ice (water) and found that the as-created dense 3D nanovoids enhanced significantly the electrochemical properties of TiO2, thereby providing a new approach to increase the reactivity of 1DTiO2 MRs for use in the PEC cell for water splitting. The incorporation of Ag, Au or Cu nanoscale particles could make a promising future for 1DTiO2 MRs to be applied in the PEC systems.

Název v anglickém jazyce

Nanostructured TiO2 Microrods with 3D Nanovoids for Green Photocatalysis - PEC Water Splitting

Popis výsledku anglicky

Titanium dioxide (TiO2) has been studied for several decades due to its versatility for a diverse range of applications. TiO2 is robust, thermally stable, non-toxic, as well as inexpensive. One-dimensional (1D) TiO2 nanostructures have attracted attention because of their unique optical and electronic properties.The first study of photoelectrochemical (PEC) water splitting on TiO2 was reported in 1972 by Fujishima and Honda showed that TiO2 photoanode exhibits outstanding PEC properties, whichmay be utilized for the conversion of solar energy into chemical energy. It was known that TiO2 could not be used in the visible light region and could only split water under UV light irradiation. The large band gap (3.0 - 3.2 eV) is the reason why TiO2 is transparent across the entire visible spectral range. The efficient photocatalysts which could produce electron-hole pairs under VIS light irradiation should be developed because VIS light occupied 43% of sunlight. Novel nanostructures with dense-stacked nanocavities inside 1DTiO2 have been prepared, which present excellent photocatalytic and PEC properties. Recently was observed [2] that the photocatalytic activity of 1D-bicrystalline nanoribbons with alternate structure of TiO2(B) and anatase under visible light irradiation was due to the formation of nanocavities inside the TiO2 nanocrystals. The research revealed that TiO2(B) with nanocavities exhibited a narrow band gap and improved its absorbance coefficient in the UV region. An enhanced optical absorption induced by dense nanovoids inside titania nanorods was also reported by Han et al. The molar absorption coefficient of TiO2 nanorods with nanovoids was found to be about 25% higher than that of TiO2 without nanovoids. Our group has recently reported an environmental friendly, smart and unexpensive preparation method for the synthesis of 1DTiO2 microrods (MRs) in aqueous media starting with hydrated titanyl sulfate crystals (TiOSO4.2H2O). The method is based on the extraction of sulfate ions from the TiOSO4 crystals and their replacement with hydroxyl groups in aqueous ammonia solution leaving the TiMINUS SIGN O framework intact. Heat treatment process (from 500 to 950 oC) causes the evaporation of nanoconfined water which hollowing out empty spaces inside the 1DTiO2 MRs. The self-assemble nanovoids along certain crystallographic directions of anatase NCs were confirmed by STEM and EELS study. The nanovoids with size ranging from 5 to 78 nm in both, length and width, and depth of about 9 nm (Fig. 1e) are responsible for the possibilities of applying 1DTiO2 in the photoelectrochemistry as a stable working electrodes. We are concerned with the nanovoid phenomenon as governed by the evaporation of ice (water) and found that the as-created dense 3D nanovoids enhanced significantly the electrochemical properties of TiO2, thereby providing a new approach to increase the reactivity of 1DTiO2 MRs for use in the PEC cell for water splitting. The incorporation of Ag, Au or Cu nanoscale particles could make a promising future for 1DTiO2 MRs to be applied in the PEC systems.

Druh

J_ost - Ostatní články v recenzovaných periodicích

CEP obor

—

OECD FORD obor

21001 - Nano-materials (production and properties)

Projekt

—

Návaznosti

V - Vyzkumna aktivita podporovana z jinych verejnych zdroju

Rok uplatnění

2019

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Microscopy and Microanalysis

ISSN

1431-9276

e-ISSN

1435-8115

Svazek periodika

2019

Číslo periodika v rámci svazku

25(S2)

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

2

Strana od-do

2136-2137

Kód UT WoS článku

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EID výsledku v databázi Scopus

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