Ultrathin origami accordion-like structure of vacancy-rich graphitized carbon nitride for enhancing CO2 photoreduction

Retaining the ultrathin structure of two-dimensional materials is very important for stabilizing their catalytic performances. However, aggregation and restacking are unavoidable, to some extent, due to the van der Waals interlayer interaction of two-dimensional materials. Here, we address this challenge by preparing an origami accordion structure of ultrathin two-dimensional graphitized carbon nitride (oa-C3N4) with rich vacancies. This novel structured oa-C3N4 shows exceptional photocatalytic activity for the CO2 reduction reaction, which is 8.1 times that of the pristine C3N4. The unique structure not only prevents restacking but also increases light harvesting and the density of vacancy defects, which leads to modification of the electronic structure, regulation of the CO2 adsorption energy, and a decrease in the energy barrier of the carbon dioxide to carboxylic acid intermediate reaction. This study provides a new avenue for the development of stable high-performance two-dimensional catalytic materials.