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 ◽  
...  

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

2010 ◽  
Vol 114 (15) ◽  
pp. 7063-7069 ◽  
Author(s):  
Jian Wei Zheng ◽  
Atreyee Bhattcahrayya ◽  
Ping Wu ◽  
Zhong Chen ◽  
James Highfield ◽  
...  

2016 ◽  
Vol 4 (7) ◽  
pp. 2670-2681 ◽  
Author(s):  
Manan Mehta ◽  
Nisha Kodan ◽  
Sandeeep Kumar ◽  
Akshey Kaushal ◽  
Leonhard Mayrhofer ◽  
...  

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.


2015 ◽  
Vol 145 ◽  
pp. 332-335 ◽  
Author(s):  
Jingzhong Zhao ◽  
Weiqiang Xing ◽  
Yang Li ◽  
Kathy Lu

Author(s):  
David Maria Tobaldi ◽  
Luc Lajaunie ◽  
ana caetano ◽  
nejc rozman ◽  
Maria Paula Seabra ◽  
...  

<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>


2019 ◽  
Vol 2 (10) ◽  
pp. 7518-7526 ◽  
Author(s):  
Hanggara Sudrajat ◽  
Mitsunori Kitta ◽  
Nobuyuki Ichikuni ◽  
Hiroshi Onishi

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