Synthesis of amorphous PdP nanoparticles supported on carbon nanospheres for 4-nitrophenol reduction in environmental applications

Abstract Amorphous PdP nanoparticles supported on carbon nanospheres (CNSs) have been successfully synthesized via a chemical reduction of sodium hypophosphite, employed as an engineered high-performance catalyst. The morphology, composition and crystalline structure of the catalyst are characterized systematically. The as-prepared PdP/CNSs shows remarkable catalytic activity for the reduction of 4-nitrophenol (4-NP) in the presence of NaBH 4 , where its turnover frequency (TOF) is as high as 3.2 and 5.5 times those of crystalline Pd nanoparticles supported on CNSs (Pd/CNSs) and commercial Pd/C catalysts, respectively. The superior catalytic activity can be attributed to electronic effect between Pd and P and special 3D structure of CNSs. To achieve the feasibility for environmental applications, the effects of various inorganic salts and organic compounds are tested, and most have a negligible impact. Also, the PdP/CNSs catalyst exhibits a stable conversion efficiency of over 95% for up to seven cycles in simulated wastewater. Even for a liter-scale treatment of simulated wastewater containing 4-NP, the PdP/CNSs catalyst still keeps remarkably conversion efficiency. The water becomes colorless within one minute.