Preparation and photo-assisted catalytic reduction properties of silver nanoparticles/potassium-doped graphitic carbon composites

In this paper, silver nanoparticles (AgNPs) were prepared using water-soluble chitosan (WSC) as both the reducing agent and the stabilizer simultaneously. The potassium-doped graphitic carbon nitride (CN K ) photocatalysts were prepared via thermal polymerization of melamine and KOH in the atmosphere. The AgNPs/CN K composite was prepared using an ultrasonic method, and its microstructure and composition were characterized using scanning electron microscope (SEM) and Energy dispersive X-ray spectroscopy (EDS). The photo-assisted catalytic reduction performance of the AgNPs/CN K composite was investigated using the 4-nitrophenol (4-NP) reduction reaction as a model system. The effects of preparation conditions of the AgNPs/CN K composite were systematically examined. When the mass ratio of KOH to melamine in the AgNPs/CN K composite was 1.5:20, the conversion (%) of 4-NP reached 98.2% after 20 minutes of photo-assisted catalytic reduction, with a reaction rate constant k of 0.2432 min −1 .