Heterogene molekulare Systeme für eine photokatalytische CO₂‐Reduktion mit Wasseroxidation

Abstract

Die künstliche Photosynthese, mit einer CO2‐Reduktion zu Chemikalien und Brennstoffen und einer Wasseroxidation unter Verwendung von Sonnenlicht als Energiequelle, ahmt die natürliche Photosynthese in Grünpflanzen nach. Es ist davon auszugehen, dass diese Technologie eine bedeutende Rolle in unserer zukünftigen Energieversorgung haben wird. Aufgrund der hohen Quantenausbeute und der einfachen Manipulierbarkeit bieten heterogene molekulare Photosysteme auf der Basis von Metallkomplexen eine vielversprechende Plattform für eine effiziente Umwandlung von Solarenergie. Dieser Aufsatz beschreibt jüngste Entwicklungen bei der Heterogenisierung solcher Photokatalysatoren. Wir stellen aktuelle Ansätze vor, mit denen die Nachteile einer geringen Beständigkeit und einer unbequemen praktischen Anwendung von homogenen molekularen Systemen überwunden werden sollen, und wir diskutieren die Kopplung der photokatalytischen CO2‐Reduktion mit der Wasseroxidation durch molekulare Vorrichtungen.

Thin Heterojunctions and Spatially Separated Cocatalysts To Simultaneously Reduce Bulk and Surface Recombination in Photocatalysts

“…Theconstruction of aheterojunction is an effective method. [6] Heterojunctions can be formed between two kinds of semiconductors with staggered band structures.For instance,Liu [7] and co-workers have constructed an In 2 O 3 /TiO 2 heterojunction, and observed enhanced charge separation. However, charges separated by the heterogeneous interface would still suffer from severe recombination when transferred to the surface if their diffusion length is smaller than the depth of the heterojunction.…”

Hybrid Photoelectrochemical Water Splitting Systems: From Interface Design to System Assembly

“…Besides, the ligand that is more easily protonated is preferred for water reduction, while water‐ or oxo‐based ligands is beneficial for water oxidation. In addition to experimental procedures, theoretical calculation (e.g., density functional theory calculations) can provide guidance for the rational design of molecular catalyst in the view of the structure optimization, physicochemical property determination and catalytic cycling demonstration for high‐performance water splitting 108,171–175…”

“…The hybrid PEC system approach can also be applied to other chemical conversion reactions including CO 2 reduction 171,176–180. Although encouraging progress has been made in the past few years, working examples for water splitting or CO 2 reduction are still largely at the lab‐scale level, far from large‐scale application.…”

“…In addition to experimental procedures, theoretical calculation (e.g., density functional theory calculations) can provide guidance for the rational design of molecular catalyst in the view of the structure optimization, physicochemical property determination and catalytic cycling demonstration for high-performance water splitting. [108,[171][172][173][174][175] Except for photoelectrode and molecular catalyst design, the interface design must be well established in the hybrid systems to ensure high activity and stability for PEC water splitting. It is clear that the linkage between the photoelectrode and molecular catalyst greatly determines interface charge transfer and PEC performance.…”

“…The hybrid PEC system approach can also be applied to other chemical conversion reactions including CO 2 reduction. [171,[176][177][178][179][180] Although encouraging progress has been made in the past few years, working examples for water splitting or CO 2 reduction are still largely at the lab-scale level, far from large-scale application. Thanks to the increasing interest and continuing advances in this area, hybrid PEC systems may well emerge as a promising approach for high-efficiency, low-cost solar fuel conversion in the future.…”