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Abstract

Sunlight is widely used by plants to produce chemical energy fundamental for all life, process that also serves as an inspiration for science. Recently, light-harvesting semiconductor materials, here carbon nitrides, have been widely used in photochemistry to catalyze reactions under visible light illumination. We exploited photoactive carbon nitride thin films as metal-free platform for one-step photo-grafting-from polymers on the surface. Here, we observe photoswitchable wetting properties of polystyrene grafted carbon nitride, which are independent of any classical photoswitchable groups. Dense and thick polymer brush formation with tunable thickness (up to 700 nm) was obtained, allowing for tailor surface properties. Furthermore, exploiting the reciprocal insolubility of water-dimethylacrylamide and pentane-styrene solutions, we provide a general method for synthesis of centimeter-scale pCN-based Janus asymmetric films. It is thought that the simple experimental design based on cheap and common chemicals provides a novel dimension of carbon nitride materials with advanced surface properties.