Theoretical design and experimental study of pyridine-incorporated polymeric carbon nitride with an optimal structure for boosting photocatalytic CO2 reduction

Abstract

Herein, pyridine-incorporated polymeric carbon nitride (PCN) was explored for boosting photocatalytic CO2 reduction. First, theoretical calculations were performed on PCN models with pyridine molecules located at different positions to determine the optimal structure of pyridine-incorporated PCN with the lowest total energy, smallest bandgap, and most efficient CO2 adsorption and activation processes. Subsequently, pyridine-incorporated PCN with the optimal structure was prepared experimentally by copolymerizing urea and 2-aminopyridine (AP). A high CO evolution rate with a selectivity of 99.6% was achieved by combining CN-5%AP with a Co(bpy)2 co-catalyst, which resulted an apparent quantum efficiency of 2.86% at λ = 420 nm. The high performance of pyridine-incorporated PCN mainly originated from its strong CO2 adsorption ability and facilitation of the CO2-to-CO reduction reaction. This work paves the way for the precise design and preparation of photocatalysts with high CO2 reduction efficiency.