Water Oxidation with Cobalt‐Loaded Linear Conjugated Polymer Photocatalysts

TL;DR

Scientists developed new polymer materials that can split water into oxygen using light and cobalt, with improved efficiency due to better light absorption and particle dispersibility.

Contribution

The first linear conjugated polymer photocatalysts loaded with cobalt are demonstrated for efficient water oxidation.

Findings

Oxygen evolution rates are higher than in related organic materials.

Fast oxidative quenching of excitons minimizes recombination in the presence of an electron scavenger.

Abstract

The first examples of linear conjugated organic polymer photocatalysts that produce oxygen from water after loading with cobalt and in the presence of an electron scavenger are reported. The oxygen evolution rates, which are higher than for related organic materials, can be rationalized by a combination of the thermodynamic driving force for water oxidation, the light absorption of the polymer, and the aqueous dispersibility of the relatively hydrophilic polymer particles. We also used transient absorption spectroscopy to study the best performing system and we found that fast oxidative quenching of the exciton occurs (picoseconds) in the presence of an electron scavenger, minimizing recombination.

Ten linear conjugated organic polymer photocatalysts are presented for water oxidation in the presence of an electron scavenger. The results can be explained by a combination of factors, such as thermodynamic driving force, light absorption, and dispersibility of the relatively hydrophilic polymer particles. Transient absorption spectroscopy was used to study the charge‐carrier dynamics.

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