Promotion mechanism of -OH groups intercalation for NOx purification on BiOI photocatalyst

Nanoscale ◽  
2021 ◽  
Author(s):  
Weiping Yang ◽  
Qin Ren ◽  
Fengyi Zhong ◽  
Yanxia Wang ◽  
Jielin Wang ◽  
...  
Keyword(s):  
Absorption Band ◽  
Band Structure ◽  
Visible Light ◽  
Light Absorption ◽  
Photocatalytic Efficiency ◽  
Visible Light Absorption ◽  
Oh Groups ◽  
Layered Oxide ◽  
Promotion Mechanism

Bismuth oxyiodide (BiOI) is one of the traditional layered oxide photocatalyst that performs wide visible-light absorption band owning to appropriate band structure. Nevertheless, the photocatalytic efficiency is immensely prohibited according...

Carrier Engineering of Zr-mediated Ta3N5 Film as Efficient Photoanode for Solar Water Splitting

2021 ◽  
Author(s):  
Xin Zou ◽  
Xueyang Han ◽  
Chengxiong Wang ◽  
Yunkun Zhao ◽  
Chun Du ◽  
...  
Keyword(s):  
Band Structure ◽  
Visible Light ◽  
Water Splitting ◽  
Light Absorption ◽  
Photoelectrochemical Water Splitting ◽  
Promising Candidate ◽  
Visible Light Absorption ◽  
Solar Water ◽  
Solar Water Splitting

Ta3N5 is regarded as a promising candidate material with adequate visible light absorption and band structure for photoelectrochemical water splitting. However, the performance of Ta3N5 is severely limited by the...

The Photocatalytic Properties of Fe3+ and N Co-Doped TiO2 Micro/Nanofiber Film for Dye Waste Water Decomposition

2011 ◽  
Vol 356-360 ◽  
pp. 853-856 ◽  
Author(s):  
Qiao Zhen Yu ◽  
Xiang Jun Jin ◽  
Shao Yang Li ◽  
Lei Wang ◽  
Kun Long Liang
Keyword(s):  
Waste Water ◽  
Visible Light ◽  
Light Absorption ◽  
Oxygen Demand ◽  
Photocatalytic Efficiency ◽  
Energy Dispersion Spectroscopy ◽  
Visible Light Absorption ◽  
X Ray ◽  
Nano Fiber ◽  
Co Doped

To obtain a TiO2photocatalyst with high photocatalytic efficiency under visible irradiation and good reusability, the Fe3+and N co-doped TiO2micro/nano fiber films were fabricated by electrospinning and calcinations. The morphologies and structures of the resulting samples were analyzed by scanning electron microscopy (SEM), x-ray diffraction and x-ray energy dispersion spectroscopy (EDS). The absorbance and chemical oxygen demand (COD) were characterized respectively by UV–visible spectrophotometer and COD Rapid Tester. The results show that the Fe3+and N co-doped TiO2micro/nano fiber had a multi-porous structure with an average diameter of about 45 to 506 nm. The crystalinity degrees, visible light absorption of these films were affected by the dosage of Fe3+and N co-doping (DFN). Moreover, these films exhibited high photocatalytic activity for the degradation of dye waste water under sunlight and it was related to DFN. As DFN was 0.5 %, it has highest crystalinity degree, largest visible light absorption and highest photocatalytic efficiency on dye waste water. The decolor rate of the dye waste water was as high as 67.6 % and its COD decreased from 2800±200 to 236.40 ± 15.61, when the photocatalytic time was only 3 h.

scholarly journals An Unusual Strong Visible-Light Absorption Band in Red Anatase TiO2Photocatalyst Induced by Atomic Hydrogen-Occupied Oxygen Vacancies

2018 ◽  
Vol 30 (6) ◽  
pp. 1704479 ◽  
Author(s):  
Yongqiang Yang ◽  
Li-Chang Yin ◽  
Yue Gong ◽  
Ping Niu ◽  
Jian-Qiang Wang ◽  
...  
Keyword(s):  
Absorption Band ◽  
Visible Light ◽  
Light Absorption ◽  
Atomic Hydrogen ◽  
Oxygen Vacancies ◽  
Visible Light Absorption

SrNbO2N as a Water-Splitting Photoanode with a Wide Visible-Light Absorption Band

2011 ◽  
Vol 133 (32) ◽  
pp. 12334-12337 ◽  
Author(s):  
Kazuhiko Maeda ◽  
Masanobu Higashi ◽  
Bhavin Siritanaratkul ◽  
Ryu Abe ◽  
Kazunari Domen
Keyword(s):  
Absorption Band ◽  
Visible Light ◽  
Water Splitting ◽  
Light Absorption ◽  
Visible Light Absorption

Sn-Based Perovskite with a Wide Visible-Light Absorption Band Assisted by Hydride Doping

2021 ◽  
Author(s):  
Masashi Nakamura ◽  
Hiroshi Watanabe ◽  
Hirofumi Akamatsu ◽  
Kotaro Fujii ◽  
Masatomo Yashima ◽  
...  
Keyword(s):  
Absorption Band ◽  
Visible Light ◽  
Light Absorption ◽  
Visible Light Absorption

Eliminating the isolated states from the band structure of doped TiO2: A first principle study

2020 ◽  
Vol 34 (34) ◽  
pp. 2050388
Author(s):  
Matiullah Khan ◽  
Zeng Yi
Keyword(s):  
Band Structure ◽  
Visible Light ◽  
Fermi Level ◽  
Band Gap ◽  
Conduction Band ◽  
Light Absorption ◽  
Structure Modification ◽  
Visible Light Absorption ◽  
Oxidation Reduction ◽  
Clear Band

Band structure of anatase [Formula: see text] could be modified by doping foreign atoms. With ab-initio calculations, considering praseodymium, nitrogen and gadolinium as potential dopants, some mono-, co- and tri-doped models are introduced. The structure modification due to each model is compared with a standard [Formula: see text] system. Pr doping reduced the band gap of [Formula: see text] by introducing Pr 4f states below the conduction band, and the Fermi level appears below the conduction band minimum. The addition of nitrogen in Pr-doped [Formula: see text] pushed back the Fermi level to its intrinsic position while reducing the band gap. The tri-doped system comprising of Pr, N and Gd as dopants provided a populated band gap. The impurity states associated with Gd appeared in the middle of the band gap. The density of states analysis reveals that Pr 4f states change the location of N 2p states in the band structure. Instead of appearing as isolated states, the N 2p states are mixed with O 2p states while the Pr 4f states are coupled with the Ti 3d states in Pr, N-[Formula: see text]. The Pr, N, Gd tri-doped [Formula: see text] system provided strong visible light absorption due to the stepwise transition of electrons by Gd f states. While providing reasonable visible light absorption, the Pr, N-[Formula: see text] is expected to provide strong visible light photoactivity due to the clear band gap. Due to the absence of isolated states, the generated photo-excited carriers would be efficiently utilized in the oxidation/reduction processes.

ChemInform Abstract: SrNbO2N as a Water-Splitting Photoanode with a Wide Visible-Light Absorption Band.

ChemInform ◽  
2011 ◽  
Vol 42 (49) ◽  
pp. no-no
Author(s):  
Kazuhiko Maeda ◽  
Masanobu Higashi ◽  
Bhavin Siritanaratkul ◽  
Ryu Abe ◽  
Kazunari Domen
Keyword(s):  
Absorption Band ◽  
Visible Light ◽  
Water Splitting ◽  
Light Absorption ◽  
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>

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