Palladium nanoparticles decorated on functionalized graphitic carbon nitride as an efficient and retrievable nanocatalyst for organic dye degradation and hydrogen peroxide sensing

The impact of synthetic organic dyes on the quality and aesthetics of water stresses the need for an effective method of treating dye-contaminated wastewater. In this study, we report the synthesis, characterization and catalytic activity of the heterogeneous nanocatalyst palladium nanoparticles decorated on functionalized graphitic carbon nitride (g–CN–SiNH2@Pd) for degradation of organic dye molecules. The g–CN–SiNH2@Pd nanocatalyst was synthesized in a facile four-step green synthetic route and successively characterized by several analytical techniques to confirm its composition, structure, morphology and stability. The g–CN–SiNH2@Pd nanocatalyst showed an excellent catalytic aptitude for the degradation of the synthetic organic dyes namely, methylene blue (99.63%), Chrysoidine Y (99.97%), Congo red (99.54%) and Evans blue (99.50%) using NaBH4 as the reducing agent. Further, the g–CN–SiNH2@Pd nanocatalyst exhibited recyclability up to five recycles substantiating its heterogeneous nature. Additionally, to broaden the scope of the g–CN–SiNH2@Pd nanocatalyst, peroxidase-type activity in the oxidation of o-phenylenediamine with H2O2 was assessed. The Km and Vmax values of 6.31 mM and 7.98 × 10−8 Ms−1 obtained, displayed the capability of the g–CN–SiNH2@Pd nanocatalyst to mediate oxidation and thereby the ability for H2O2 sensing. A green and stable g–CN–SiNH2@Pd nanocatalyst for degradation of organic dyes (MB, CY, CR and EB) and peroxidase-like activity in sensing H2O2 in aqueous medium at room temperature. [Display omitted] •The g–CN–SiNH2@Pd nanocatalyst was synthesized under green and clean strategies and characterized by various analytical techniques.•The g–CN–SiNH2@Pd nanocatalyst exhibited excellent catalytic activity in degradation of the organic dyes: MB, CY, CR and EB.•The g–CN–SiNH2@Pd nanocatalyst also demonstrated peroxidase-like activity and colorimetric sensing of H2O2.•The g–CN–SiNH2@Pd nanocatalyst was easily separated from the reaction medium by simple filtration or centrifugation method.•The recovered g–CN–SiNH2@Pd nanocatalyst showed very good recyclability of up to five recycles.