A hybrid DFT based investigation of the photocatalytic activity of cation–anion codoped SrTiO3 for water splitting under visible light

2014 ◽  
Vol 16 (44) ◽  
pp. 24527-24535 ◽  
Author(s):  
Brindaban Modak ◽  
K. Srinivasu ◽  
Swapan K. Ghosh
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Band Gap ◽  
Water Splitting ◽  
Band Alignment ◽  
Trapping Center

The effect of cation (Mo or W) and anion (N) codoping in different proportion has been explored to improve the photocatalytic activity of SrTiO3 under visible light. Codoping in 1 : 2 ratio has been found to be more effective due to reduction in band gap without introducing local trapping center and also for maintaining appropriate band alignment.

Overall water splitting using (oxy)nitride photocatalysts

2006 ◽  
Vol 78 (12) ◽  
pp. 2267-2276 ◽  
Author(s):  
Kazuhiko Maeda ◽  
Kentaro Teramura ◽  
Nobuo Saito ◽  
Yasunobu Inoue ◽  
Hisayoshi Kobayashi ◽  
...  
Keyword(s):  
Solid Solution ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Band Gap ◽  
Water Splitting ◽  
Electronic Configuration ◽  
Oxide Nanoparticles ◽  
Visible Light Region ◽  
Overall Water Splitting ◽  
Light Region

Oxynitride photocatalysts with d10 electronic configuration are presented as effective non-oxide catalysts for overall water splitting. Germanium nitride (β-Ge3N4) having a band gap of 3.8-3.9 eV modified with RuO2 nanoparticles as a cocatalyst is shown to achieve stoichiometric decomposition of H2O into H2 and O2 under UV irradiation (λ > 200 nm). A novel solid solution of GaN and ZnO, (Ga1-xZnx)(N1-xOx), with a band gap of 2.4-2.8 eV (depending on composition) achieves overall water splitting under visible light (λ > 400 nm) when loaded with an appropriate cocatalyst. The narrower band gap of the solid solution is attributed to the bonding between Zn and N atoms at the top of the valence band. The photocatalytic activity of (Ga1-xZnx)(N1-xOx) for overall water splitting is strongly dependent on both the cocatalyst and the crystallinity and composition of the material. The quantum efficiency of (Ga1-xZnx)(N1-xOx) with Rh and Cr mixed-oxide nanoparticles is 2-3 % at 420-440 nm, which is the highest reported efficiency for overall water splitting in the visible-light region.

Two-dimensional van der Waals heterostructure CdO/PtSe2: promising visible light photocatalyst for overall water splitting

2020 ◽  
Vol 22 (42) ◽  
pp. 24662-24668
Author(s):  
Wei Zhang ◽  
Weixiao Ji
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Water Splitting ◽  
Band Alignment ◽  
Type Ii ◽  
Two Dimensional ◽  
Promising Candidate ◽  
Visible Light Photocatalyst ◽  
Van Der Waals Heterostructure ◽  
Visible Light Photocatalytic

The superior visible-light photocatalytic activity and type-II band alignment with built-in electric field make CdO/PtSe2 a promising candidate for water-splitting.

Improving visible light photocatalytic activity of NaNbO3: a DFT based investigation

RSC Advances ◽  
2016 ◽  
Vol 6 (93) ◽  
pp. 90188-90196 ◽  
Author(s):  
Brindaban Modak ◽  
Pampa Modak ◽  
Swapan K. Ghosh
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Band Gap ◽  
Hydrogen Evolution ◽  
Water Splitting ◽  
Valence Band ◽  
Visible Light Photocatalytic Activity ◽  
Visible Light Photocatalytic

The unique characteristics of the (W, N) dopant pair is that it reduces the band gap of NaNbO3 mainly by elevation of valence band maxima, which is very much crucial for photocatalyst for hydrogen evolution through water splitting.

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>

scholarly journals Strain-tunable band alignment and band gap of GaSe/WTe2 heterojunction for water splitting and light-emitting

2021 ◽  
pp. 104605
Author(s):  
Qingyi Feng ◽  
Hongxiang Deng ◽  
Hongdong Yang ◽  
Shasha Ke ◽  
Haifeng Lv ◽  
...  
Keyword(s):  
Band Gap ◽  
Water Splitting ◽  
Band Alignment ◽  
Light Emitting

Visible light-driven novel g-C3N4/NiFe-LDH composite photocatalyst with enhanced photocatalytic activity towards water oxidation and reduction reaction

2015 ◽  
Vol 3 (36) ◽  
pp. 18622-18635 ◽  
Author(s):  
Susanginee Nayak ◽  
Lagnamayee Mohapatra ◽  
Kulamani Parida
Keyword(s):  
Photocatalytic Activity ◽  
Composite Materials ◽  
Visible Light ◽  
Water Splitting ◽  
Visible Light Irradiation ◽  
Water Oxidation ◽  
Reduction Reaction ◽  
Light Irradiation ◽  
Composite Photocatalyst ◽  
Visible Light Driven

Dispersion of exfoliated CN over the surface of exfoliated LDH composite materials, and its photocatalytic water splitting under visible-light irradiation.

Enhanced visible-active photocatalytic behaviors observed in Mn-doped BiFeO3

2018 ◽  
Vol 32 (17) ◽  
pp. 1850185 ◽  
Author(s):  
Yun-Hui Si ◽  
Yu Xia ◽  
Ya-Yun Li ◽  
Shao-Ke Shang ◽  
Xin-Bo Xiong ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Band Gap ◽  
Diffuse Reflectance Spectroscopy ◽  
X Ray Diffraction ◽  
Electron Hole ◽  
X Ray ◽  
Mn Doped ◽  
Hole Recombination ◽  
Narrow Band Gap Semiconductors

A series of BiFeO3 and BiFe[Formula: see text]Mn[Formula: see text]O3 (x = 0, 0.02, 0.04, 0.06, 0.08, 0.10) were synthesized by a hydrothermal method. The samples were characterized by X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy (EDS) and UV–Vis diffuse reflectance spectroscopy, and their photocatalytic activity was studied by photocatalytic degradation of methylene blue in aqueous solution under visible light irradiation. The band gap of BiFeO3 was significantly decreased from 2.26 eV to 1.90 eV with the doping of Mn. Furthermore, the 6% Mn-doped BiFeO3 photocatalyst exhibited the best activity with a degradation rate of 94% after irradiation for 100 min. The enhanced photocatalytic activity with Mn doping could be attributed to the enhanced optical absorption, increment of surface reactive sites and reduction of electron–hole recombination. Our results may be conducive to design more efficient photocatalysts responsive to visible light among narrow band gap semiconductors.

Quantum dots in photocatalytic applications: efficiently enhancing visible light photocatalytic activity by integrating CdO quantum dots as sensitizers

2017 ◽  
Vol 19 (36) ◽  
pp. 24915-24927 ◽  
Author(s):  
A. H. Reshak
Keyword(s):  
Quantum Dots ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Band Gap ◽  
Visible Light Irradiation ◽  
Photocatalytic Performance ◽  
Optical Band Gap ◽  
Visible Light Active ◽  
Photocatalytic Applications ◽  
Visible Light Photocatalytic

The amalgamation of a wide optical band gap photocatalyst with visible-light-active CdO quantum dots (QDs) as sensitizers is one of the most efficient ways to improve photocatalytic performance under visible light irradiation.

Efficient Strategy to Enhance the Photocatalytic Activity of Ir-doped SrTiO3 : A Hybrid DFT Approach

2022 ◽  
Author(s):  
Brindaban Modak
Keyword(s):  
Photocatalytic Activity ◽  
Band Gap ◽  
Water Splitting ◽  
Band Gap Engineering ◽  
Photocatalytic Water Splitting ◽  
Efficient Strategy

Photocatalytic water splitting using sunlight is one of the most promising approaches to produce hydrogen, for which an increasing focus has been directed towards band gap engineering of the existing...

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