Production of Pd nanoparticles embedded on micro-sized chitosan/graphitic carbon nitride hybrid spheres for treatment of environmental pollutants in aqueous medium

Abstract

The presence of various organic contaminants such as toxic nitro compounds and dyes in water/wastewater poses a major problem for the environment and human health. Therefore, the treatments of these pollutants are of vital importance. For this aim, a novel heterogeneous catalyst system, in which Pd nanoparticles were immobilized on micro sized chitosan-g-C3N4 hybrid spheres was developed, and its nano-sized structure was confirmed by SEM, EDS, XRD, FT-IR, TG and TEM analyses (Pd-CS-g-C3N4). Then the catalytic potential of Pd-CS-g-C3N4 was evaluated against the reduction of various organic pollutants such as 4-nitro toluene (4-NT), 2-nitroanilin (2-NA), 4-nitroanilin (4-NA), 4-nitrophenol (4-NP), 3-nitrophenol (3-NP), 4-nitro-o-phenylenediamine (4-NPD), 4-nitrobenzoic acid (4-NBA), 4-nitrobenzaldehyde (4-NBZA), methyl orange (MO), methylene blue (MB), congo red (CR), and methyl red (MR) in aqueous solution at room temperature by using NaBH4. The catalytic performance tests showed that Pd-CS-g-C3N4 nanocatalyst effectively catalyzed both nitro compound and organic dye reductions within very short reaction time. Furthermore, Pd-CS-g-C3N4 nanocatalyst was reused many times by preserving both its chemical structure and activity.