Energy States of a Core-Shell Metal Oxide Photocatalyst Enabling Visible Light Absorption and Utilization in Solar-to-Fuel Conversion of Carbon Dioxide

2016 ◽  
Vol 6 (14) ◽  
pp. 1600583 ◽  
Author(s):  
Dong Ki Lee ◽  
Ji Il Choi ◽  
Gyu Heon Lee ◽  
Yong-Hoon Kim ◽  
Jeung Ku Kang
Keyword(s):  
Carbon Dioxide ◽  
Metal Oxide ◽  
Visible Light ◽  
Light Absorption ◽  
Core Shell ◽  
Fuel Conversion ◽  
Visible Light Absorption ◽  
Energy States

Boosting Visible Light Absorption of Metal-Oxide-Based Phototransistors via Heterogeneous In–Ga–Zn–O and CH3NH3PbI3 Films

2018 ◽  
Vol 10 (15) ◽  
pp. 12854-12861 ◽  
Author(s):  
Young Jun Tak ◽  
Dong Jun Kim ◽  
Won-Gi Kim ◽  
Jin Hyeok Lee ◽  
Si Joon Kim ◽  
...  
Keyword(s):  
Metal Oxide ◽  
Visible Light ◽  
Light Absorption ◽  
Visible Light Absorption

Impact of surface hydroxylation in MgO-/SnO-nanocluster modified TiO2 anatase (101) composites on visible light absorption, charge separation and reducibility.

2017 ◽  
Author(s):  
Michael Nolan ◽  
Stephen Rhatigan
Keyword(s):  
Metal Oxide ◽  
Visible Light ◽  
Light Absorption ◽  
Charge Separation ◽  
Density Functional ◽  
Visible Range ◽  
Hydroxyl Groups ◽  
Visible Light Absorption ◽  
Tio2 Anatase ◽  
The Impact

Surface modification with metal oxide nanoclusters has emerged as a candidate for the enhancement of the photocatalytic activity of titanium dioxide. An increase in visible light absorption and the suppression of charge carrier recombination are necessary to improve the efficiency. We have studied Mg<sub>4</sub>O<sub>4</sub> and Sn<sub>4</sub>O<sub>4</sub> nanoclusters modifying the (101) surface of anatase TiO<sub>2</sub> using density functional theory corrected for on-site Coulomb interactions (DFT + U). Such studies typically focus on the pristine surface, free of the point defects and surface hydroxyls present in real surfaces. We have also examined the impact of partial hydroxylation of the anatase surface on a variety of outcomes such as nanocluster adsorption, light absorption, charge separation and reducibility. Our results indicate that the modifiers adsorb strongly at the surface, irrespective of the presence of hydroxyl groups, and that modification extends light absorption into the visible range while enhancing UV activity. Our model for the excited state of the heterostructures demonstrates that photoexcited electrons and holes are separated onto the TiO<sub>2</sub> surface and metal oxide nanocluster respectively. Comparisons with bare TiO<sub>2</sub> and other TiO<sub>2</sub>-based photocatalyst materials are presented throughout.<br>

ZnO/ZnSxSe1−x core/shell nanowire arrays as photoelectrodes with efficient visible light absorption

2012 ◽  
Vol 101 (7) ◽  
pp. 073105 ◽  
Author(s):  
Zhenxing Wang ◽  
Xueying Zhan ◽  
Yajun Wang ◽  
Muhammad Safdar ◽  
Mutong Niu ◽  
...  
Keyword(s):  
Visible Light ◽  
Light Absorption ◽  
Nanowire Arrays ◽  
Core Shell ◽  
Visible Light Absorption

Impact of surface hydroxylation in MgO-/SnO-nanocluster modified TiO2 anatase (101) composites on visible light absorption, charge separation and reducibility.

2017 ◽  
Author(s):  
Michael Nolan ◽  
Stephen Rhatigan
Keyword(s):  
Metal Oxide ◽  
Visible Light ◽  
Light Absorption ◽  
Charge Separation ◽  
Density Functional ◽  
Visible Range ◽  
Hydroxyl Groups ◽  
Visible Light Absorption ◽  
Tio2 Anatase ◽  
The Impact

Surface modification with metal oxide nanoclusters has emerged as a candidate for the enhancement of the photocatalytic activity of titanium dioxide. An increase in visible light absorption and the suppression of charge carrier recombination are necessary to improve the efficiency. We have studied Mg<sub>4</sub>O<sub>4</sub> and Sn<sub>4</sub>O<sub>4</sub> nanoclusters modifying the (101) surface of anatase TiO<sub>2</sub> using density functional theory corrected for on-site Coulomb interactions (DFT + U). Such studies typically focus on the pristine surface, free of the point defects and surface hydroxyls present in real surfaces. We have also examined the impact of partial hydroxylation of the anatase surface on a variety of outcomes such as nanocluster adsorption, light absorption, charge separation and reducibility. Our results indicate that the modifiers adsorb strongly at the surface, irrespective of the presence of hydroxyl groups, and that modification extends light absorption into the visible range while enhancing UV activity. Our model for the excited state of the heterostructures demonstrates that photoexcited electrons and holes are separated onto the TiO<sub>2</sub> surface and metal oxide nanocluster respectively. Comparisons with bare TiO<sub>2</sub> and other TiO<sub>2</sub>-based photocatalyst materials are presented throughout.<br>

Anomalous infrared and visible light absorption and local structure of Ag–Au core/shell nanoparticles

2011 ◽  
Vol 103 (1) ◽  
pp. 81-88 ◽  
Author(s):  
Y. Suzuki ◽  
M. Yamamoto ◽  
T. Saito ◽  
T. Miyanaga ◽  
S. Ohwada ◽  
...  
Keyword(s):  
Visible Light ◽  
Light Absorption ◽  
Local Structure ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
Visible Light Absorption ◽  
Core Shell Nanoparticles

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>

Double Doping of NaTaO3 Photocatalysts with Lanthanum and Manganese for Strongly Enhanced Visible-Light Absorption

2019 ◽  
Vol 2 (10) ◽  
pp. 7518-7526 ◽  
Author(s):  
Hanggara Sudrajat ◽  
Mitsunori Kitta ◽  
Nobuyuki Ichikuni ◽  
Hiroshi Onishi
Keyword(s):  
Visible Light ◽  
Light Absorption ◽  
Visible Light Absorption ◽  
Double Doping
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