Graphene quantum dots/BiOCl visible-light active photocatalyst for degradation of NO

Abstract

This work focuses on modifying BiOCl using graphene quantum dots (GQDs) via a semi-solvothermal method. The formed composites (GQDs/BOC) nanomaterials have enhanced catalytic activity in NO photocatalysis. Multiple characterizations are performed on the prepared GQDs/BOC to describe their crystallization, morphology, and photoelectric characteristics. In addition, photocatalyst activity of GQDs/BOC nanocomposites are assessed by treating 30–32 ppm of NO under visible-light illumination. Within 1 h of photocatalytic NO degradation, GQDs30/BOC behaves the best. Its conversion rate of NO reaches 81.42 % and the DeNOx index is 0.55; they are 1.81 and 2.20 times higher than the counterparts of BiOCl, respectively. The addition of GQDs increases the specific surface area of the BiOCl catalyst, improves the absorption of visible light, accelerates photogenerated carrier transport and inhibits their recombination. These roles of GQDs improve photocatalytic performance. The analysis of the degradation of NO by GQDs/BOC is explored experimentally and theoretically. GQDs in the GQDs/BOC composites are confirmed to act as electron acceptors. In addition, GQDs30/BOC retains excellent catalytic activity after four cycles of testing, evidencing good stability.