“Plug and Play” Photosensitizer–Catalyst Dyads for Water Oxidation

Abstract

We present a simple and easy-to-scale synthetic method to plug common organic photosensitizers into a cyanide-based network structure for the development of photosensitizer-water oxidation catalyst (PS-WOC) dyad assemblies for the photocatalytic water oxidation process. Three photosensitizers, one of which absorbs red light similar to P680 in photosystem II, were utilized to harvest different regions of the solar spectrum. Photosensitizers are covalently coordinated to CoFe Prussian blue structures to prepare PS-WOC dyads. All dyads exhibit steady water oxidation catalytic activities throughout a 6 h photocatalytic experiment. Our results demonstrate that the covalent coordination between the PS and WOC group not only enhances the photocatalytic activity but also improves the robustness of the organic PS group. The photocatalytic activity of "plug and play" dyads relies on several structural and electronic parameters, including the position of the energy levels of the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) of the PS with respect to the HOMO level of the catalytic site, the intensity and wavelength of the absorption band of the PS, and the number of catalytic sites.

Rational design of an acceptor–chromophore–relay–catalyst tetrad assembly for water oxidation

“…Therefore, the photocatalytic oxygen evolution activities of the proposed compounds are studied in 0.1 M PBS at pH 7 containing the catalyst and the sacrificial electron scavenger (ES), persulfate, under 1 sun (100 mW cm À2 ) irradiation. 16 13,17 We also…”

“…The organic chromophore [SF] and the acceptor group [F OH ] exhibit distinct peaks within the 1640 cm À1 to 700 cm À1 region, primarily associated with the stretching vibrations of C-C and C-N rings. 13 [F OH ] displays three prominent peaks at 1592 cm À1 , 1430-1376 cm À1 range, and 1062 cm À1 , corresponding to CQC, C-OH, and C-O bonds, respectively. 14 [SF], on the other hand, shows peaks at 1610 cm À1 and 1410 cm À1 , predominantly attributed to the presence CQN bonds and C-H vibrations of the methyl groups, respectively.…”

“…Thus, the electronically enhanced [F OH –SF–Fe–Co] reaches the highest TOF and TON values among the reported PB based photocatalytic systems. 13,17 We also constructed the band energy diagram for [F OH –SF–Fe–Co] to elucidate the effect of F OH group on the catalytic process (Fig. S5, ESI†).…”

Degenerate and non-degenerate two-photon absorption of coumarin dyes

“…[1][2][3] Coumarin, along with its derivatives, are applicable to cell staining, 4,5 useful as fluorescence probes, [6][7][8] and can act as efficient sensitizers for solar cells. [9][10][11] However, as fluorescent dyes, their one-photon absorption (1PA) properties are well understood, but there remains questions to be answered for multi-photon absorption in the coumarins.…”

Hybrid CuFe–CoFe Prussian Blue Catalysts on BiVO4 for Enhanced Charge Separation and Injection for Photoelectrochemical Water Oxidation

“…In contrast, cobalt sites are surrounded by a combination of nitrogen atoms of cyanide groups and water molecules, making them suitable catalytic centers for the water oxidation process. Coupling PB with an appropriate photosensitizer and/or a semiconductor to use them in the light-driven water oxidation process is the general approach due to the poor photocurrent efficiency of PBs. ,− In such a design, the valence band of the semiconductor should be located at lower energy than the highest occupied molecular orbital (HOMO) level of the PB for an efficient charge transfer. Goberna-Ferron and co-workers studied a catalyst screening of PB with various metals (Mn–Fe, Fe–Fe, Co–Fe, Ni–Fe, Cu–Fe, Mn–Co, Fe–Co, and Co–Co) for the photocatalytic water oxidation process in the presence of a ruthenium photosensitizer.…”