An “Artificial Leaf”: A Dream or a Viable Energy Provision Concept?

• Published in: Energy Materials pp. 123 - 143
• Main Author: Bandarenka, Aliaksandr S.
• Format: Book Chapter
• Language: English
• Published: United Kingdom CRC Press 2022; Taylor & Francis Group
• Edition: 1
• Subjects: Metal Chalcogenides; Photosystem II; Hydrogen Evolution Reaction; Photogenerated Electrons; RHE; Redox Mediators; Water Splitting; Hydrogen Evolution; Schematic Energy Diagram; Photogenerated Electron Hole Pair; Photocatalytic Water Splitting; Photocatalyst Particle; Hydrogen generation; Evolution Reaction; Photocatalytic Materials; Photocatalysts; Band Gap; Proton Coupled Electron Transfer; Moderate Band Gap; Conduction Band; Artificial Photosynthesis; Photoelectrochemical Water Splitting; Artificial Leaf; Cocatalysts; Aqueous Electrolyte; Antibonding Molecular Orbital; Valence Band; Electron Hole Pairs; semiconductor materials
• ISBN: 0367458101; 0367457369; 9780367457365; 9780367458102
• DOI: 10.1201/9781003025498-7

In this section, a motivation for the “artificial leaf” concept to produce hydrogen fuel is given. In the beginning, a rationale for the simplifications compared to the natural systems is provided based on different approaches involving semiconductor materials or immobilized biological and organic objects. Afterward, the focus is mainly set on the use of semiconductors to generate hydrogen fuel with sunlight. The importance of semiconductor stability under illumination is the subject of the following discussion. Definitions of the terms photocatalysts and cocatalysts are given. Furthermore, mechanistic insights on how charge separation occurs in photocatalysts are provided. Subsequently, approaches for identifying photocatalyst areas, which are responsible for the separation of the photogenerated electrons and holes, are described. Challenges in the engineering of photocatalysts for one-step photoexcitation systems are discussed. As an alternative, two-step photoexcitation systems are also considered.