scholarly journals Cover Feature: Spectroscopic Characterisation of a Bio‐Inspired Ni‐Based Proton Reduction Catalyst Bearing a Pentadentate N 2 S 3 Ligand with Improved Photocatalytic Activity (Chem. Eur. J. 13/2020)

2020 ◽  
Vol 26 (13) ◽  
pp. 2763-2763
Author(s):  
Philipp Gotico ◽  
Dooshaye Moonshiram ◽  
Cunming Liu ◽  
Xiaoyi Zhang ◽  
Régis Guillot ◽  
...  
2020 ◽  
Vol 26 (13) ◽  
pp. 2859-2868 ◽  
Author(s):  
Philipp Gotico ◽  
Dooshaye Moonshiram ◽  
Cunming Liu ◽  
Xiaoyi Zhang ◽  
Régis Guillot ◽  
...  

Catalysts ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1302
Author(s):  
Maria Drosou ◽  
Fotios Kamatsos ◽  
George Ioannidis ◽  
Athanasios Zarkadoulas ◽  
Christiana A. Mitsopoulou ◽  
...  

The tetrahedral copper(I) diimine complex [Cu(pq)2]BF4 displays high photocatalytic activity for the H2 evolution reaction with a turnover number of 3564, thus representing the first type of a Cu(I) quinoxaline complex capable of catalyzing proton reduction. Electrochemical experiments indicate that molecular mechanisms prevail and DFT calculations provide in-depth insight into the catalytic pathway, suggesting that the coordinating nitrogens play crucial roles in proton exchange and hydrogen formation.


2014 ◽  
Vol 5 ◽  
pp. 360-364 ◽  
Author(s):  
Jun Fang ◽  
Lisha Yin ◽  
Shaowen Cao ◽  
Yusen Liao ◽  
Can Xue

Pt@TiO2 core–shell nanostructures were prepared through a hydrothermal method. The dye-sensitization of these Pt@TiO2 core–shell structures allows for a high photocatalytic activity for the generation of hydrogen from proton reduction under visible-light irradiation. When the dyes and TiO2 were co-excited through the combination of two irradiation beams with different wavelengths, a synergic effect was observed, which led to a greatly enhanced H2 generation yield. This is attributed to the rational spatial distribution of the three components (dye, TiO2, Pt), and the vectored transport of photogenerated electrons from the dye to the Pt particles via the TiO2 particle bridge.


2018 ◽  
Author(s):  
Anastasia Vogel ◽  
Mark forster ◽  
Liam Wilbraham ◽  
Charlotte Smith ◽  
Alexander Cowan ◽  
...  

<p>Conjugated ladder polymers (cLaPs) are introduced as organic semiconductors for photocatalytic hydrogen evolution from water under sacrificial conditions. Starting from a linear conjugated polymer (cLiP1), two ladder polymers are synthesized via post-polymerization annulation and oxidation techniques to generate rigidified, planarized materials bearing dibenzo[<i>b</i>,<i>d</i>]thiophene (<b>cLaP1</b>) and dibenzo[<i>b</i>,<i>d</i>]thiophene sulfone subunits (<b>cLaP2</b>). The high photocatalytic activity of <b>cLaP1</b> (1307 μmol h<sup>−1</sup> g<sup>−1</sup>) in comparison to <b>cLaP2</b> (18 μmol h<sup>−1</sup> g<sup>−1</sup>) under broadband illumination (λ >295 nm) in presence of a hole-scavenger is attributed to a higher yield of long-lived charges (µs–ms timescale), as evidenced by transient absorption spectroscopy. Additionally, <b>cLaP1</b> has a larger overpotential for proton reduction and thus an increased driving force for the evolution of hydrogen under sacrificial conditions.</p>


2018 ◽  
Author(s):  
Anastasia Vogel ◽  
Mark forster ◽  
Liam Wilbraham ◽  
Charlotte Smith ◽  
Alexander Cowan ◽  
...  

<p>Conjugated ladder polymers (cLaPs) are introduced as organic semiconductors for photocatalytic hydrogen evolution from water under sacrificial conditions. Starting from a linear conjugated polymer (cLiP1), two ladder polymers are synthesized via post-polymerization annulation and oxidation techniques to generate rigidified, planarized materials bearing dibenzo[<i>b</i>,<i>d</i>]thiophene (<b>cLaP1</b>) and dibenzo[<i>b</i>,<i>d</i>]thiophene sulfone subunits (<b>cLaP2</b>). The high photocatalytic activity of <b>cLaP1</b> (1307 μmol h<sup>−1</sup> g<sup>−1</sup>) in comparison to <b>cLaP2</b> (18 μmol h<sup>−1</sup> g<sup>−1</sup>) under broadband illumination (λ >295 nm) in presence of a hole-scavenger is attributed to a higher yield of long-lived charges (µs–ms timescale), as evidenced by transient absorption spectroscopy. Additionally, <b>cLaP1</b> has a larger overpotential for proton reduction and thus an increased driving force for the evolution of hydrogen under sacrificial conditions.</p>


2018 ◽  
Vol 18 (3) ◽  
pp. 81-91 ◽  
Author(s):  
C. Lalhriatpuia

Nanopillars-TiO2 thin films was obtained on a borosilicate glass substrate with (S1) and without (S2) polyethylene glycol as template. The photocatalytic behaviour of S1 and S2 thin films was assessed inthe degradation of methylene blue (MB) dye from aqueous solution under batch reactor operations. The thin films were characterized by the SEM, XRD, FTIR and AFM analytical methods. BET specific surface area and pore sizes were also obtained. The XRD data confirmed that the TiO2 particles are in its anatase mineral phase. The SEM and AFM images indicated the catalyst is composed with nanosized pillars of TiO2, evenly distributed on the surface of the substrate. The BET specific surface area and pore sizes of S1 and S2 catalyst were found to be 5.217 and 1.420 m2/g and 7.77 and 4.16 nm respectively. The photocatalytic degradation of MB was well studied at wide range of physico-chemical parameters. The effect of solution pH (pH 4.0 to 10.0) and MB initial concentration (1.0 to 10.0 mg/L) was extensively studied and the effect of several interfering ions, i.e., cadmium nitrate, copper sulfate, zinc chloride, sodium chloride, sodium nitrate, sodium nitrite, glycine, oxalic acid and EDTA in the photocatalytic degradation of MB was demonstrated. The maximum percent removal of MB was observed at pH 8.0 beyond which it started decreasing and a low initial concentration of the pollutant highly favoured the photocatalytic degradation using thin films and the presence of several interfering ions diminished the photocatalytic activity of thin films to some extent. The overall photocatalytic activity was in the order: S2 > S1 > UV. The photocatalytic degradation of MB was followed the pseudo-first-order rate kinetics. The mineralization of MB was studied with total organic carbon measurement using the TOC (total organic carbon) analysis.


MRS Advances ◽  
2020 ◽  
Vol 5 (61) ◽  
pp. 3141-3152
Author(s):  
Alma C. Chávez-Mejía ◽  
Génesis Villegas-Suárez ◽  
Paloma I. Zaragoza-Sánchez ◽  
Rafael Magaña-López ◽  
Julio C. Morales-Mejía ◽  
...  

AbstractSeveral photocatalysts, based on titanium dioxide, were synthesized by spark anodization techniques and anodic spark oxidation. Photocatalytic activity was determined by methylene blue oxidation and the catalytic activities of the catalysts were evaluated after 70 hours of reaction. Scanning Electron Microscopy and X Ray Diffraction analysis were used to characterize the catalysts. The photocatalyst prepared with a solution of sulfuric acid and 100 V presented the best performance in terms of oxidation of the dye (62%). The electric potential during the synthesis (10 V, low potential; 100 V, high potential) affected the surface characteristics: under low potential, catalyst presented smooth and homogeneous surfaces with spots (high TiO2 concentration) of amorphous solids; under low potential, catalyst presented porous surfaces with crystalline solids homogeneously distributed.


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