Photodriven heterogeneous charge transfer with transition-metal compounds anchored to TiO₂semiconductor surfaces

Abstract

A critical review of light-driven interfacial charge-transfer reactions of transition-metal compounds anchored to mesoporous, nanocrystalline TiO2 (anatase) thin films is described. The review highlights molecular insights into metal-to-ligand charge transfer (MLCT) excited states, mechanisms of interfacial charge separation, inter- and intra-molecular electron transfer, and interfacial charge-recombination processes that have been garnered through various spectroscopic and electrochemical techniques. The relevance of these processes to optimization of solar-energy-conversion efficiencies is discussed (483 references).

A Hybrid Photocatalytic System Comprising ZnS as Light Harvester and an [Fe2S2] Hydrogenase Mimic as Hydrogen Evolution Catalyst

“…[9] For semiconductor/complex systems, the process of electron transfer from the excited state of dye molecules to the conduction band of semiconductors has been extensively studied in dye-sensitized solar cells (DSSCs). [10] The process of electron transfer from photoexcited semiconductors to complexes, which is the reverse of the process in DSSCs, is predicted to be on the same time scale as, or even faster than, that in DSSCs. [11] Fast electron transfer from the semiconductor to the complex may be beneficial for a high efficiency of hybrid photocatalyst systems composed of a semiconductor as light-harvester and a biomimetic complex as H 2 evolution catalyst.…”

Spatial separation of photogenerated electrons and holes among {010} and {110} crystal facets of BiVO4

“…C harge separation has a key role in determining solar energy conversion efficiency of semiconductor-based systems for producing solar electricity and solar fuels through solar cells [1][2][3][4] , photoelectrocatalysis [5][6][7][8] and photocatalysis [9][10][11][12][13] . As a key step in energy conversion, electron-hole pairs generated by light absorption need to be separated and transferred to the surface of the semiconductors 1,9,[14][15][16][17] .…”

“…As a key step in energy conversion, electron-hole pairs generated by light absorption need to be separated and transferred to the surface of the semiconductors 1,9,[14][15][16][17] . Hence, an in-depth understanding of charge separation within semiconductors is desirable for the construction of an efficient solar energy conversion system.…”

Injection Kinetics and Electronic Structure at the N719/TiO2 Interface Studied by Means of Ultrafast XUV Photoemission Spectroscopy

“…1 Following the invention of nanostructured dye-sensitized solar cell by Grätzel and O'Regan, 2 considerable efforts have been made to investigate fundamental processes induced by light in this devices. Among various combinations of the sensitizer and semiconductor materials, the ruthenium-based dye complexes, such as Ru(dcbpyH) 2 (NCS) 2 (N3) and its salt (Bu 4 N) 2 Ru(dcbpyH) 2 (NCS) 2 (N719), exhibit high efficiency (close to unity) of the HET mechanism in the visible range of the solar spectrum.…”