Synthesis and characterization of structured interfaces for hydrogen generation. Study of an N,N'-dialkyl-4,4'-bipyridinium redox polymer/palladium catalyst system

Polymer-Attached Catalysts

“…Such catalysts assist the photochemical production of hydrogen from EDTA solution [126]. Another example is provided by the photoelectrochemical production of hydrogen by p-type semiconducting photocathodes whose surface had been modified by poly(N,N'-dialkyl-4,4'-bipyridinium) (PQ2+)n to which a PtO or PdO colloidal catalyst had been attached [127]. To enable the attachment of PdO to the (PQ2+)n polymer, the Br-counterions of the latter were replaced by PdC14 2 -via an ion-exchange reaction and the Pd 2 + ions reduced by a reducing agent such as H2 , photoirradiation, or an electrochemical method.…”

“…Poly(vinylpyrrolidone)-protected colloidal rhodium catalysts have been prepared by refluxing solutions of RhCl3 in alcohols [127), the particle size altering with the conditions of preparation. Such colloidal rhodium catalysts influence the hydrogenation of olefins, where the catalytic activity observed increased with a decrease in the particle size of the catalyst.…”

Construction of Mono- and Multimolecular Layers with Electron Transfer Mediation Function and Catalytic Activity for Hydrogen Evolution on a Hydrogen-Terminated Si(111) Surface via Si−C Bond

“…Pt modification was performed following the procedure reported before as shown in Schemes 1-3. [54][55][56][57][58][59] The V 2+ -or EBTEA-Si(111) substrate was placed in a 10 mM K 2 PtCl 4 aqueous solution for 10 min to ion exchange the halide ions of the viologen groups (Scheme 1, step iii) or EBTEA (Scheme 2, step ii) by PtCl 4 2-. PtCl 4 2-was reduced to Pt to yield a Pt-V 2+ -Si(111) (Scheme 1, step iv) or Pt-EBTEA-Si(111) surface (Scheme 2, step iii) by keeping the substrate in a H 2 -saturated water for 20 min.…”

“…48,49 To provide a solution to these problems, various groups used polymer layers with electron mediator groups and catalytic metal particles to modify the semiconductor surfaces. [50][51][52][53][54][55][56][57][58][59] Recently, we briefly demonstrated that an organic monolayer with viologen terminal group bonded on hydrogen-terminated n-and p-type Si(111) surfaces via a Si-C bond acted as electron transfer mediator and improved the electrochemical hydrogen evolution reaction rate in the dark and under illumination, respectively. 60 Nakato and colleagues also showed that the stability of the Si photoelectrode for I -oxidation was improved by Pt/alkyl monolayer modification.…”

Hydrogen Generation from Irradiated Semiconductor-Liquid Interfaces

“…143,[181][182][183][184]561,562 An early study also considered n-type Si as a photoanode with a protective SnO 2 layer to prevent it from undergoing corrosion. 563 Ruthenium oxide layers have also been studied, 564 this time on p-Si surfaces.…”