Nitrogen-Rich and Porous Graphitic Carbon Nitride Nanosheet-Immobilized Palladium Nanoparticles as Highly Active and Recyclable Catalysts for the Reduction of Nitro Compounds and Degradation of Organic Dyes

Abstract

In the present study, we have successfully synthesized nitrogen-rich graphitic carbon nitride (g-C3N4) nanosheets by a simple direct thermal polymerization approach. The synthesized g-C3N4 nanosheets were exfoliated using HCl to make their surface a few nanometers thick. The ultrathin surface was achieved by simply mixing g-C3N4 in 3 M HCl. After that, palladium nanoparticles were uniformly immobilized on the surface of g-C3N4. The synthesized materials were characterized by various physiochemical techniques such as X-ray diffraction, energy-dispersive X-ray spectroscopy, and Fourier transform infrared spectroscopy. Information about morphology and size was obtained through transmission electron microscopy and scanning electron microscopy. The Brunauer-Emmett-Teller surface area, pore volume, and pore diameter were determined using nitrogen adsorption-desorption measurements. The prepared material (Pd/g-C3N4) was utilized as an efficient catalyst for the reduction of hazardous nitroarenes and degradation of organic dyes. The catalyst could be easily recovered through centrifugation and then could be reused multiple times for the further catalytic cycles with a little loss in its catalytic activity. The work presented here illustrates the sustainable anchoring of metal nanoparticles over the surface of nitrogen-rich g-C3N4 nanosheets and could be utilized for different types of catalytic reactions.