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Silanization processes with perfluoroalkyl silanes have been demonstrated to be effective in developing advanced materials with many functional properties, including hydrophobicity, water repellency, and self-cleaning properties. However, practical industrial applications of perfluoroalkyl silanes are limited by their extremely high cost. On the basis of our recent work on photoredox catalysis for amidation with perfluoroalkyl iodides, its application for surface chemical modification on filter paper, as an illustrative example, has been developed and evaluated. Before photocatalytic amidation, the surface is functionalized with amine functional groups by silanization with 3-(trimethoxysilyl)propylamine. All chemically modified surfaces have been fully characterized by attenuated total reflection infrared (ATR-IR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy with energy-dispersive spectroscopy (SEM-EDS), and three-dimensional (3D) profiling to confirm the successful silanization and photocatalytic amidation. After surface modification of the filter papers with perfluoroalkanamide, they show high water repellency and hydrophobicity with contact angles over 120°. These filter papers possess high wetting selectivity, which can be used to effectively separate the organic and aqueous biphasic mixtures. The perfluoroalkanamide-modified filter papers can be used for separating organic/aqueous biphasic mixtures over many cycles without lowering the separating efficiency, indicating their reusability and excellent durability.

A series of carbene-containing dicarbonyl Re(I) bipyridyl complexes with metal-to-ligand charge transfer (MLCT) transitions in the visible region have been synthesized. Most of these complexes are highly selective and efficient photocatalysts capable of using visible light for CO2reduction to CO. The activities of single- and two-component photocatalytic systems based on a series of carbene-containing dicarbonyl Re(I) bipyridyl complexes as photocatalysts and photosensitizers have been investigated. Importantly, the CO yields and turnover numbers (TONs) can be further enhanced significantly in the two-component photocatalytic systems. A detailed study suggests that the deactivations of these photocatalyses arise from the photodegradation of the photosensitizers or photocatalysts. The results suggest that efficient and robust rhenium-based two-component photocatalytic systems can be developed by combining an active rhenium(I) catalyst, which does not strongly absorb the excitation light, for activating CO2together with a highly photostable photosensitizer with strong absorptivity for harvesting excitation light.