The Origin of Visible Light Absorption in Chalcogen Element (S, Se, and Te)-Doped Anatase TiO2 Photocatalysts

2010 ◽  
Vol 114 (15) ◽  
pp. 7063-7069 ◽  
Author(s):  
Jian Wei Zheng ◽  
Atreyee Bhattcahrayya ◽  
Ping Wu ◽  
Zhong Chen ◽  
James Highfield ◽  
...  
Keyword(s):  
Visible Light ◽  
Light Absorption ◽  
Anatase Tio2 ◽  
Tio2 Photocatalysts ◽  
Visible Light Absorption

Nanostructured anatase TiO2 densified at high pressure as advanced visible light photocatalysts

2015 ◽  
Vol 14 (9) ◽  
pp. 1685-1693 ◽  
Author(s):  
Giovanni Carini Jr. ◽  
Francesco Parrino ◽  
Giovanni Palmisano ◽  
Gabriele Scandura ◽  
Ilaria Citro ◽  
...  
Keyword(s):  
High Pressure ◽  
Visible Light ◽  
Light Absorption ◽  
Anatase Tio2 ◽  
Structural Defects ◽  
Visible Light Absorption ◽  
Acetaldehyde Production

Uniaxial high pressure up to 2.1 GPa on anatase TiO2 nanopowders induces structural defects, increases visible light absorption and enhances acetaldehyde production.

scholarly journals New insight into effects of 4d transition metals doping on the photocatalytic activities of anatase TiO2(101) surface

2020 ◽  
Author(s):  
Yuehong Ren ◽  
Qingzhen Han ◽  
Qiaozhi Su ◽  
Jie Yang ◽  
Yuehong Zhao ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Light Absorption ◽  
Interband Transition ◽  
Energy Bands ◽  
Tio2 Photocatalysts ◽  
Visible Light Absorption ◽  
Photocatalytic Activities ◽  
Metal Phase Transition ◽  
Insight Into

Aiming at improving the visible-light photocatalytic activities of TiO2(101) surface (TiOS) we make an in-dept study on the TiOS doped with 4d transition metal (TM) atoms. It is shown that the 4d TM dopings can not only produce new impurity energy bands in the bandgap but also result in the semiconductor-metal phase transition. Consequently, the visible-light absorption is strongly strengthened due to the dopings of Y, Zr, Nb, Mo, and Ag, while it is only weakly improved for Tc, Ru, Rh, Pd, and Cd dopings. The improvement in visible-light absorption can be attributed to the intraband or interband transition of electrons. Moreover, the photocatalytic activities are explored, and we find Y and Ag dopings can effectively enhance the photocatalytic activity of TiOS. Thus the mechanism of improving photocatalytic activity of TiOS has been clearly addressed, which is beneficial to further experimental and theoretical researches on TiO2 photocatalysts.

scholarly journals Hydrogen treated anatase TiO2: a new experimental approach and further insights from theory

2016 ◽  
Vol 4 (7) ◽  
pp. 2670-2681 ◽  
Author(s):  
Manan Mehta ◽  
Nisha Kodan ◽  
Sandeeep Kumar ◽  
Akshey Kaushal ◽  
Leonhard Mayrhofer ◽  
...  
Keyword(s):  
Visible Light ◽  
Ab Initio ◽  
Light Absorption ◽  
Photoelectron Spectroscopy ◽  
Experimental Approach ◽  
Anatase Tio2 ◽  
Hydrogen Annealing ◽  
Visible Light Absorption ◽  
X Ray

Vacuum hydrogen annealing of TiO2 leads to increased visible light absorption. The origin thereof was revealed by ab initio calculations and X-ray photoelectron spectroscopy.

Solvothermal synthesis and visible light absorption of anatase TiO2

2015 ◽  
Vol 145 ◽  
pp. 332-335 ◽  
Author(s):  
Jingzhong Zhao ◽  
Weiqiang Xing ◽  
Yang Li ◽  
Kathy Lu
Keyword(s):  
Visible Light ◽  
Light Absorption ◽  
Solvothermal Synthesis ◽  
Anatase Tio2 ◽  
Visible Light Absorption

Impact of Rutile Fraction on TiO2 Visible-Light Absorption and Visible-Light-Induced Photocatalytic Activity

2018 ◽  
Author(s):  
David Maria Tobaldi ◽  
Luc Lajaunie ◽  
ana caetano ◽  
nejc rozman ◽  
Maria Paula Seabra ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Light Absorption ◽  
Solid Phase ◽  
Diffraction Method ◽  
Band Alignment ◽  
Quantitative Phase Analysis ◽  
Transmission Microscopy ◽  
Visible Light Absorption ◽  
X Ray

<div>Titanium dioxide is by far the most utilised semiconductor material for photocatalytic applications. Still, it is transparent to visible-light. Recently, it has been proved that a type-II band alignment for the rutile−anatase mixture would improve its visible-light absorption.</div><div>In this research paper we thoroughly characterised the real crystalline and amorphous phases of synthesised titanias – thermally treated at different temperatures to get distinct ratios of anatase-rutile-amorphous fraction – as well as that of three commercially available photocatalytic nano-TiO2. </div><div>The structural characterisation was done via advanced X-ray diffraction method, namely the Rietveld-RIR method, to attain a full quantitative phase analysis of the specimens. The microstructure was also investigated via an advanced X-ray method, the whole powder pattern modelling. These methods were validated combining advanced aberration-corrected scanning transmission microscopy and high-resolution electron energy-loss spectroscopy. The photocatalytic activity was assessed in the liquid- and gas-solid phase (employing rhodamine B and 4-chlorophenol, and isopropanol, respectively, as the organic substances to degrade) using a light source irradiating exclusively in the visible-range.</div><div>Optical spectroscopy showed that even a small fraction of rutile (2 wt%) is able to shift to lower energies the apparent optical band gap of an anatase-rutile mixed phase. But is this enough to attain a real photocatalytic activity promoted by merely visible-light?</div><div>We tried to give a reply to that question.</div><div>Photocatalytic activity results in the liquid-solid phase showed that a high surface hydroxylation led to specimen with superior visible light-induced catalytic activity (i.e. dye and ligand-to-metal charge transfer complexes sensitisation effects). That is: not photocatalysis <i>sensu-strictu</i>.</div><div>On the other hand, the gas-solid phase results showed that a higher amount of the rutile fraction (around 10 wt%), together with less recombination of the charge carriers, were more effective for an actual photocatalytic oxidation of isopropanol.</div>

Sign in / Sign up

Export Citation Format

Share Document