Photocatalytic CO2 reduction with aminoanthraquinone organic dyes

Abstract

The direct utilization of solar energy to convert CO2 into renewable chemicals remains a challenge. One essential difficulty is the development of efficient and inexpensive light-absorbers. Here we show a series of aminoanthraquinone organic dyes to promote the efficiency for visible light-driven CO2 reduction to CO when coupled with an Fe porphyrin catalyst. Importantly, high turnover numbers can be obtained for both the photosensitizer and the catalyst, which has not been achieved in current light-driven systems. Structure-function study performed with substituents having distinct electronic effects reveals that the built-in donor-acceptor property of the photosensitizer significantly promotes the photocatalytic activity. We anticipate this study gives insight into the continued development of advanced photocatalysts for solar energy conversion.

Exfoliation of a Two-Dimensional Metal–Organic Framework for Enhanced Photocatalytic CO2 Reduction

“…Photocatalytic CO 2 reduction converts CO 2 into high-value-added chemicals such as CO, CH 4 , CH 3 OH, or C 2 H 4 driven by light energy. This process has been proposed as one of the most ideal methods for CO 2 conversion and “carbon-neutral” economy. − Semiconductor materials − and photoactive molecules − have been developed as photocatalysts for CO 2 reduction. Due to the difficulty in balancing light-harvesting and catalytic functionalities in a single material, integrated systems that contain two or more functional components have also been intensively studied in recent years. , It is optimal to construct such integrated systems with atomic-scale structure precision, which will allow performance improvement by structure-designing and fine-tailoring.…”

Visible-light-promoted CO2 oxidative 1,2-thiosulfonylation of styrenes with sodium sulfinates and thiophenols

“…Initially, the photocatalyst Ru(phen) 3 2+ gives the excited state *Ru(phen) 3 2+ under visible light irradiation. Then Fe III species is reduced to Fe 0 species by the excited *Ru(phen) 3 2+ , 15 affording Ru(phen) 3 3+ which is reduced by the sacrificial electron donor R 2 SO 2 − , with the radical A R 2 SO 2 ˙ released. Meanwhile, CO 2 is reduced to CO and CH 4 through the catalytic cycle (Fe III to Fe 0 cycle, proceeding with Fe I and Fe II species as seen in previous reports, 15 Scheme 1c).…”

“…Then the highly reactive CO 2 ˙ − couples with protons for a multi-electron transfer reaction, which occurs almost instantaneously to generate reduction products C x H y O z . Homogeneous photocatalytic CO 2 reduction systems (Scheme 1b) 15 are usually composed of three substances: a photosensitizer (PS), catalyst (M), and sacrificial donor (SD). The photocatalytic CO 2 reduction is a cyclic system, where the PS gives the excited state PS* under visible light irradiation.…”

Construction of Single Ni Atom-Immobilized ZIF-8 with Ordered Hierarchical Pore Structures for Selective CO2 Photoreduction

“…Reducing the atmospheric concentration of carbon dioxide (CO 2 ) for mitigating the greenhouse effect is crucial as it is emitted excessively due to the combustion of fossil fuels. − The solar-light-driven conversion of CO 2 into valuable derivatives, including CO, CH 4 , and HCOOH, is among the most promising CO 2 conversion pathways. − However, the photocatalytic reduction of CO 2 is currently inefficient because the extremely stable chemical bonds of CO 2 (CO, 750 kJ mol –1 ) caused difficulty of CO 2 adsorption and activation and competitive reactions of water reduction in the aqueous phase. , It is evident that the hydrogen evolution reaction (HER) is more favorable thermodynamically due to the less negative redox potential required through a comparison of the reduction reaction process for CO 2 to CO and water to hydrogen (CO 2 + 2H + + 2e – → CO + H 2 O, E 0 = −0.52 V vs NHE or 2H + + 2e – → H 2 , E 0 = −0.42 V vs NHE). − Furthermore, the water-insoluble CO 2 molecules pose a greater challenge in terms of contacting the catalyst compared to the water molecules, which exacerbates the over-reaction of water decomposition and leads to the low efficiency of CO 2 reduction. − Therefore, enhancing the adsorption and activation of CO 2 while suppressing the occurrence of HER during photocatalytic CO 2 reduction are viable approaches for improving both the catalytic activity and selectivity of CO 2 reduction.…”