Porous nitrogen-rich g-C3N4 nanotubes for efficient photocatalytic CO2 reduction

Abstract

The conversion of carbon dioxide (CO2) into fuels and valuable chemicals using solar energy is a promising method for reducing CO2 emissions and solving energy supply issues. However, the development of inexpensive, efficient and metal-free materials for photocatalytic CO2 reduction is challenging. Herein, we report a facile supramolecular self-assembly strategy for the preparation of porous nitrogen-rich graphitic carbon nitride (g-C3N4) nanotubes with Lewis basicity and a large surface area, which are beneficial for the adsorption of CO2 and, consequently, the enhancement of the photocatalytic CO2 reduction activity. The metal-free porous nitrogen-rich g-C3N4 nanotubes catalyst exhibits a superior visible-light-induced CO2-to-CO conversion rate of 103.6 μmol g−1 h−1, which is 17 and 15 times higher than those of bulk g-C3N4 (6.1 μmol g−1 h−1) and P25-TiO2 (7.1 μmol g−1 h−1), respectively, and exceeds the performance of most metal-free photocatalysts. This work provides new insights into the synthesis of functional groups-modified g-C3N4 with a unique structure for effective photocatalytic CO2 reduction.