Facile synthesis of self-nitrogen-doped carbon spheres for high-efficient photocatalytic CO2 reduction to CO

Abstract

In this work, self-nitrogen-doped carbon microsphere photocatalysts were prepared by hydrothermal and carbonation pyrolysis with first application in photocatalytic CO2 reduction. Coupled with relevant characterization, nitrogen-doped carbon microspheres were successfully prepared and the introduction of nitrogen significantly improved the photogenerated charge separation efficiency and CO2 photoreduction to CO activity, leading to the highest photocatalytic reduction activity with a CO yield of 185.71 μmol g−1 (9 h) under simulated sunlight irradiation. More importantly, its performance remains at about 98 % after ten consecutive cycle tests, indicating the excellent active stability of self-nitrogen-doped carbon spheres. Possible mechanisms for photocatalytic reduction and the role of nitrogen in photocatalytic adsorption and reduction processes are analyzed and proposed. The research provides novel strategies for the design of bifunctional catalysts that offer robust adsorption and efficient reduction, enabling the sustainable conversion of CO2.