A Visible‐Light Harvesting System for CO₂ Reduction Using a Ru^II–Re^I Photocatalyst Adsorbed in Mesoporous Organosilica

Abstract

A photocatalytic system for CO2 reduction exhibiting visible-light harvesting was developed by preparing a hybrid consisting of a supramolecular metal complex as photocatalyst and periodic mesoporous organosilica (PMO) as light harvester. A RuII–ReI binuclear complex (Ru–Re) with methylphosphonic acid anchor groups was adsorbed on acridone or methylacridone embedded in the walls of PMO mesochannels to yield the hybrid structure. The embedded organic groups absorbed visible light, and the excitation energy was funneled to the Ru units. The energy accumulation was followed by electron transfer and catalytic reduction of CO2 to CO on the Re unit. The light harvesting of these hybrids enhanced the photocatalytic CO evolution rate by a factor of up to ten compared with that of Ru–Re adsorbed on mesoporous silica without a light harvester.

Recent progress on advanced design for photoelectrochemical reduction of CO2 to fuels

“…In addition, a p-type sulfide semiconductor (Cu 2 ZnSn(S,Se) 4 , i.e., CZTSSe) with a narrow band gap was also modified by Ru complex [34]. The modified CZTSSe photocathode demonstrated a similar enhancement for CO 2 reduction, achieving 0.49 mmol L It is worth mentioning that Ishitani group have recently developed a novel metal complex consisting of both Re and Ru elements [133]. The Ru(II)-Re(I) supramolecular metal complex exhibited superior performance for CO 2 reduction to Re and Ru single metal complexes.…”

Heterogene molekulare Systeme für eine photokatalytische CO2‐Reduktion mit Wasseroxidation

“…[52] Als heterogene photokatalytische Systeme zum Aufbau einer künstlichen Photosynthese haben PMO einige Vorteile:1 )Photokatalytische Spezies kçnnen präzise in den Porenraum eingebracht werden, in den die Lichtenergie geleitet wird. [246] In diesem System (Abbildung 12 c) wurde ein zweikerniger Ru II -Re I -Komplex (Ru-Re) mit Methylphosphonsäure-Ankergruppen auf PMO-Mesokanäle gepfropft, in deren Wänden Acridon oder Methylacridon eingebettet war. Inagaki et al stellten ein neues Konzept fürd ie Verbesserung der photokatalytischen CO 2 -Reduktion eines Re I -Komplexes vor, der in die Mesokanäle von Bp-PMO mit Biphenyl-Chromophoren im Netzwerk platziert wurde.…”

Energyless CO₂ Absorption, Generation, and Fixation Using Atmospheric CO₂

“…12,13) CCS involves the capture of CO 2 using chemical absorbent (i.e., monoethanolamine, MEA 1 etc.) [14][15][16][17][18][19][20] in highdensity areas, such as industrial facilities and power stations, and transporting CO 2 to deep subsurface rock formations or the bottom of the ocean via pipelines.…”

“…In contrast, APSs use solar light and a metal catalyst. In this approach, CO 2 is transformed into HCO 2 H 12) or CO, 13) whereby the products can be converted to sources of energy (such as methanol). The use of this system is more valuable than CCS from an economic perspective; however, APSs have been shown to work only when high concentrations of CO 2 (>1 atm) are present.…”

“…The concentrations were monitored every 30 min. ) and 13 C-NMR (δ 164.8), absorbed CO 2 would be transformed into carbonate. The plausible structure of 7 was shown in Fig.…”