Organic heterojunction photocathodes for optimized photoelectrochemical hydrogen peroxide production

Abstract

This work demonstrates that high performance and stable photocathodes for H2O2 evolution can be easily fabricated from semiconductive organic pigments.

Water‐Soluble Organic Dyes as Molecular Photocatalysts for H2O2 Evolution

“…Sustainable Syst. [18] Comparing catalytic behavior of organic solid-state materials versus their organometallic and inorganic cousins, it is clear that the one particular catalytic transformation where fully organic materials have stood out is the reduction of oxygen to hydrogen peroxide. [27,28] A critical conclusion that our present work underscores is that purely organic dyes can be highly selective for a different catalytic transformation: oxygen reduction to peroxide.…”

“…This finding is surprising in so far as clearly the mechanism behind the reduction is not the same as the two-electron process catalyzed favorably by organic solid-state semiconductors. [18] Comparing catalytic behavior of organic solid-state materials versus their organometallic and inorganic cousins, it is clear that the one particular catalytic transformation where fully organic materials have stood out is the reduction of oxygen to hydrogen peroxide. In the case of homogeneous dye molecules, the model of semiconductor catalysis does not hold, yet the selectivity for hydrogen peroxide remains.…”

“…The cornerstone in the peroxide energy cycle is photogeneration via a catalyzed reaction of solar irradiation with oxygen and water. [16][17][18] On the other hand, a fundamental obstacle in all these examples is related to the fact that only the surface of the particle, exposed to the electrolyte, can actively participate in the photo(electro) catalytic process. Photocatalysts are used in the form of suspensions of particles varying in size from tens of micrometers to a few nanometers.…”

“…[3,15] Molecular organic semiconductors, in addition, can be used to produce photocathodes offering high faradaicyield peroxide-generating photoelectrochemical cells. [16][17][18] On the other hand, a fundamental obstacle in all these examples is related to the fact that only the surface of the particle, exposed to the electrolyte, can actively participate in the photo(electro) catalytic process. The part of the material making up the particle core is inactive.…”

Organic electronic materials for hydrogen peroxide production

“…The experiment shows crucial role of the oxygen diffusion on the photocurrent value, especially prominent for well-performing systems. For currents below 100 µA/cm 2 stirring has no impact on its value156 . Published by The Royal Society of Chemistry.…”