Metal-free, robust, and regenerable 3D graphene-organics aerogel with high and stable photosensitization efficiency

- A generalized method of fabricating robust and metal-free graphene-dyes 3D aerogel photocatalysts is developed.
- 3D aerogels show higher dye-sensitized activity and long-term stability than powder systems.
- The photoactivity of aerogels can be regenerated easily by replenishing fresh dyes.
- Advantages of the 3D aerogels over their powder counterparts are disclosed.
- The work opens a new doorway to designing novel metal-free visible light photocatalysts.

The design of efficient visible-light-driven photocatalysts that use low-cost and earth-abundant materials with easy recyclability is a significant and enduring theme for solar energy conversion with practical applications. Here we report a facile and generalized synthesis of metal-free 3D macroscopic graphene-organics aerogels in which the organic dyes as photosensitizers are spatially confined and distributed in the graphene framework. This 3D bulk aerogel with an interconnected conductive porous structure displays fast spatial separation and transportation of photogenerated charge carriers, high adsorptivity of target reactants, and efficient visible-light-driven photocatalytic activity, as well as easy separability and recyclability from the reaction medium. In addition, such a bulk aerogel manifests excellent regenerability via simple replenishment of fresh dyes, which guarantees the long-term photoactivity of the 3D aerogel. This universal approach for fabricating 3D graphene-organics aerogels is expected to open a new vista for constructing a novel type of metal-free and robust visible-light photocatalysts for artificial photoredox, as well as offering a generic way to improve the photosensitization efficiency of traditional organic dyes.

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