Photocatalytic and water-splitting properties of TiO2 and Ag–TiO2 films in the visible 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.

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Defect-rich decorated TiO2 nanowires for super-efficient photoelectrochemical water splitting driven by visible light

Energy & Environmental Science ◽

10.1039/c5ee01615k ◽

2015 ◽

Vol 8 (11) ◽

pp. 3363-3373 ◽

Cited By ~ 61

Author(s):

Md Anisur Rahman ◽

Samad Bazargan ◽

Saurabh Srivastava ◽

Xiongyao Wang ◽

Marwa Abd-Ellah ◽

...

Keyword(s):

Visible Light ◽

Water Splitting ◽

Conversion Efficiency ◽

Photoelectrochemical Water Splitting ◽

Visible Light Region ◽

Tio2 Nanowires ◽

High Conversion Efficiency ◽

Splitting Property ◽

Onset Potential ◽

Light Region

Defect-rich 1D TiO2 nanostructures show excellent photoelectrochemical water splitting property in the visible light region with a low onset potential of 0.3 V vs. RHE and a remarkably high conversion efficiency of 3.6%.

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Preparation of Surface-Modified TiO2 Nanoflower Film as Efficient Visible-Active Photocatalysts

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.214.406 ◽

2011 ◽

Vol 214 ◽

pp. 406-411 ◽

Cited By ~ 2

Author(s):

Ya Hui Wu ◽

Ming Ce Long ◽

Chao Chen ◽

Wei Min Cai

Keyword(s):

Visible Light ◽

Hydrothermal Process ◽

Amorphous Film ◽

Tio2 Films ◽

Titanium Metal ◽

Visible Light Region ◽

Light Region ◽

N Doping ◽

Novel Method ◽

Surface Modified

The TiO2 films were synthesized on Ti substrates by a novel method. Titanium metal was directly oxidized by hydrogen peroxide to generate a rough amorphous film and then hydrothermal process transformed the film to crystalline nanoflower TiO2 film. The obtained film can be modified by calcination with urea and the modified film can keep the nanoflower structure. According to the XPS data, the urea-induced modification is surface-modification rather than N-doping. Compared to the un-modified film, the response scope of the modified film extends to the visible light region. Photocatalytic activity of films were investigated by degrading methyl orange (MO) under visible light. As a result, 47% of MO was decomposed by modified film in 3 hours.

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