2D/3D g-C3N4/BiOI heterostructure catalyst for efficient and robust photocatalytic NO removal

Abstract

Developing visible light responsive photocatalysts with strong light capture ability for catalytic NO removal is of great significance. In this work, we coupled the narrow-gap semiconductor BiOI with graphite-like carbon nitride (g-C3N4) to construct 2D/3D heterostructure and applied it for efficient photocatalytic elimination of NO under visible light irradiation. At relative humidity (RH) of 15 %, g-C3N4/BiOI achieves remarkable NO removal activity (80.5 %) under a gas hourly space velocity (GHSV) of 1,740,000 mL h−1 g−1. Outstanding durability was realized that the NO removal efficiency of g-C3N4/BiOI after 6 consecutive runs. Even at high RH of 50 % and 80 %, g-C3N4/BiOI still exhibited excellent NO removal performances of 80.3 % and 78.5 %, respectively. The heterostructure of g-C3N4/BiOI endowed the enhanced light harvesting, efficient charge separation and rapid charge transfer, which enables sufficient superoxide radicals (O2−) production to improve the efficiency and strengthen the durability of photocatalytic NO removal. This work provides insights into the rational design of heterostructure photocatalyst toward air purification.