Three‐Phase Photocatalysis for the Enhanced Selectivity and Activity of CO₂ Reduction on a Hydrophobic Surface

Abstract

The photocatalytic CO2 reduction reaction (CRR) represents a promising route for the clean utilization of stranded renewable resources, but poor selectivity resulting from the competing hydrogen evolution reaction (HER) in aqueous solution limits its practical applicability. In the present contribution a photocatalyst with hydrophobic surfaces was fabricated. It facilitates an efficient three‐phase contact of CO2 (gas), H2O (liquid), and catalyst (solid). Thus, concentrated CO2 molecules in the gas phase contact the catalyst surface directly, and can overcome the mass‐transfer limitations of CO2, inhibit the HER because of lowering proton contacts, and overall enhance the CRR. Even when loaded with platinum nanoparticles, one of the most efficient HER promotion cocatalysts, the three‐phase photocatalyst maintains a selectivity of 87.9 %. Overall, three‐phase photocatalysis provides a general and reliable method to enhance the competitiveness of the CRR.

Graphitic carbon nitride and polymers: a mutual combination for advanced properties

“…Very recently, hydrophobic polymer grafted g-C 3 N 4 was employed as a three-phase photocatalyst for enhanced selectivity and activity of CO 2 reduction. 97 Hydrophobic 1H,1H,2H,2H-perfluorodecanethiol was utilized to modify poly(glycidyl methacrylate) (PGMA) grafted on CM (pDFe-PGMA/CM) via thiol-epoxy addition reaction. Subsequently, an in situ photoloading method was applied for loading Pt on the pDFe-PGMA/CM surface.…”

Enhanced catalytic reaction at an air–liquid–solid triphase interface

“…Among the different strategies for tackling this problem, a simple solution by constructing an air-liquid-solid triphase reaction interface has been proposed. 42 Fig. 3c shows that an efficient triphase contact of CO 2 (air phase), H 2 O (liquid phase), and the catalyst (solid phase) is formed by modifying polymeric carbon nitride nanosheets with a hydrophobic polymer (with/ without Pt nanoparticle loading).…”

“…The note Â40 means the value of this column shown here is reduced by 40 times. Reproduced with permission from ref 42,. Copyright 2019 Wiley-VCH.…”

Metal-organic framework membranes with single-atomic centers for photocatalytic CO2 and O2 reduction

“…In nature, solar energy is harnessed by photosynthesis and stored in fossil fuels through extremely slow geochemical fossilization processes. Resembling the functionalities of green leaves, interdisciplinary researchers have developed various photosynthetic systems across the natural-artificial spectrum [1][2][3][4][5][6][7][8] . Although a solar-to-electric energy conversion rate of over 20% can be achieved by inorganic photovoltaic devices 9 , abiotic photosynthetic systems that can fix naturally abundant permanent gases (e.g.…”

“…Although a solar-to-electric energy conversion rate of over 20% can be achieved by inorganic photovoltaic devices 9 , abiotic photosynthetic systems that can fix naturally abundant permanent gases (e.g. CO2, O2) into value-added liquid fuels still face challenges in productivity and selectivity 6,10 . The synergistic catalyst and reaction interface design strategy is urgently needed but not yet fully established for enabling efficient photoreduction of permanent gas at the gas-liquid-solid three-phase boundary with water as proton donors.…”