New pyridinium based ionic dyes for the hydrogen evolution reaction

Photocatalytic H2 Production from Water by Metal‐free Dye‐sensitized TiO2 Semiconductors: The Role and Development Process of Organic Sensitizers

“…However, no more H 2 was produced after 1 h, hence the durability of such ionic dye needs to be further studied. [51] Most of the D-π-A dyes investigated have only single anchoring group. Sung Kyu Choi et al studied the effect of changing the number of anchoring group on the corresponding H 2 producing performances.…”

“…In photocatalytic H 2 evolution experiment, the Pt‐TiO 2 ‐PS3 catalyst gave a TON of 407 in 1 h, being a pretty good record among all the metal‐free dyes. However, no more H 2 was produced after 1 h, hence the durability of such ionic dye needs to be further studied [51] …”

“…Structure of dye PS3, and the H 2 production plots of Pt-TiO 2 -PS3 was not given in the original literature. Reproduced from Ref [51]…”

Enzyme-Inspired Synthetic Proton Relays Generate Fast and Acid-Stable Cobalt-Based H2 Production Electrocatalysts

“…The presence of the hydrogen-bonding network in the primary coordination sphere generated by oximes is crucial for catalytic H 2 evolution activity displayed by cobaloximes . However, only a few of them were reported to be active under aqueous conditions because of their instability and poor solubility in water. − Catalytic properties of cobalt–diimine complexes were regulated by the proper choice of axial ligand containing variable N-donor groups such as pyridine, − imidazole, aniline, pyrazine, and their derivatives. , In the past few years, direct correlation of cobaloxime catalytic efficiency with the electronic effects of N-donor group substituents were investigated in detail. , A wide range of functional groups were linked through the axial pyridine spacer to improve catalytic efficiency, water solubility, and long term stability of cobaloximes. ,,,− However, most of these cobaloximes could be only examined for photocatalytic and electrocatalytic H 2 production from an organic medium because of their instability under pure aqueous conditions.…”

Photosensitive Hybrid Nanostructured Materials: The Big Challenges for Sunlight Capture

“…Other phenothiazine-and carbazole-based dyes were designed for the same application [60], including a D-π-A-π-A photosensitizer, with benzothiadiazole as auxiliary electron withdrawing unit [61], and, in particular, a dibenzopyrromethene (BODIPY)-conjugated phenothiazine, which gave Pt/TiO 2 high activity up to near-infrared (NIR) region [62]. Different types of photoactive compounds can be included in the design of a dye with specific structure: some D-A-π-A perylene dyes, featuring cyanoacrylic acid and dicyanomethylene rhodamine as the acceptor/anchoring group, combined with a N-annulated perylene donor and a quinoxaline auxiliary acceptor [63]; two triphenylamine-benzimidazole-based dyes bound on TiO 2 , with Cu 2 WS 4 nanocubes as an alternative water splitting co-catalyst to Pt [64]; a particular composite dye, consisting of π-conjugated indoline-rhodanine with a chlorophyll derivative, which induced panchromatic absorption in the visible range, efficient electron transfer, and prolonged stability [65]; a series of dyes with triphenylamine donor, vinyltiophene bridge, and a cationic pyridinium acceptor (cationic D-π-A photosensitizers) [66]. A superior H 2 evolution rate was recently reached with a thioalkyl-substituted tetrathiafulvalene dye on mesoporous TiO 2 [67].…”