A highly efficient and stable PtNi bimetallic nanoparticles modified on Mo₂C decorated N-doped carbon flowers catalysts for the remediation of environmental pollutants

The unregulated discharge of nitroaromatics (NAs) and organic dye contaminants into aquatic ecosystems is a growing global concern, highlighting the urgent need for the development of effective wastewater treatment technology. In this study, we prepared Mo₂C decorated on N- doped carbon flowers supported with PtNi bimetallic (Pt_xNi_y@Mo₂C/NCF) nanoparticles using the self-polymerization of dopamine and followed by the chemical reduction methods. These catalysts, with varying Pt:Ni ratios, were designed for the highly efficient catalytic reduction of NAs and rhodamine b (RhB) under the mild reaction conditions. The HR-TEM images confirmed the formation of spherical PtNi bimetallic NPs with an average diameter of 1.68 ± 0.6 nm. The prepared Pt_xNi_y@Mo₂C/NCF catalysts exhibited significantly higher catalytic efficiency for 4-nitrophenol (4-NP) reduction compared to their respective monometallic counterparts using NaBH₄. Particularly, the Pt_0.75Ni_0.25@Mo₂C/NCF catalyst showed superior catalytic activity with the apparent rate constant (k_app: 0.6703 min⁻¹) and TOF (17.0 × 10⁻⁷ mol mg⁻¹ min⁻¹) and high recyclability over eight consecutive recycles. Furthermore, the Pt_0.75Ni_0.25@Mo₂C/NCF catalyst also exhibited high catalytic activity for other NAs and RhB dye reduction with excellent yields. This enhanced catalytic activity of Pt_0.75Ni_0.25@Mo₂C/NCF catalyst could be ascribed to the synergistic effect of the bimetallic systems, leading to more efficient reactions. Additional experiments were conducted on a fixed bed reactor to demonstrate that the Pt_0.75Ni_0.25@Mo₂C/NCF catalyst effectively reduce both 4-NP and RhB dye over 15 successive runs. This work may pave the way for using Pt_xNi_y@Mo₂C/NCF catalysts in various wastewater treatment applications.