Extraordinary sensitizing effect of co-doped carbon nanodots derived from mate herb: Application to enhanced photocatalytic degradation of chlorinated wastewater compounds under visible light

•Carbon nanodots containing N and P as co-dopants are retrieved from natural sources.•Doping contents strongly influences the optical response of the carbon dots and their sensitizing effect on titania supports.•Excellent photodegradation rates of 2,4-dichlorophenol are achieved under visible-light irradiation.

The present work investigates the role of two types of carbon nanodots (CNDs) as novel sensitizers of TiO2 to create a visible-light driven photo-catalyst that is not only efficient for solar-driven pollution abatement, but also inexpensive, durable and environmentally-friendly. Two widely available green organic precursors, the Argentinean herb Mate and the Stevia plant have been selected as the carbogenic source to thermally induce the formation of different types of CNDs with different levels of N and P doping and tunable photoluminescence response in the UV-vis-near infrared (NIR) ranges. These CNDs have been successfully assembled with TiO2 to form heterogeneous photocatalysts that are highly active in the visible-light and NIR- driven photodegradation of 2,4-dichlorophenol (2,4-DCP), a persistent chlorinated organic compound present in numerous pesticide formulations.

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