Tea polyphenol-assisted green synthesis of Ag-nanodiamond hybrid and its catalytic activity towards 4-nitrophenol reduction

ABSTRACT Herein, we describe an environmentally friendly strategy to synthesize Ag nanoparticles on Nanodiamond (ND) by utilizing natural adhering and reduction properties of tea polyphenols (TPs). Firstly, the surface of ND was modified by TPs through their natural adhering ability. Then, the modified TPs functioned as reducing agents for reducing Ag precursor in situ. The synthesis process, structure and its physicochemical properties of the nanohybrid were tracked and characterized by UV-Vis, FTIR, TGA, HRTEM, XRD and XPS. It has been shown that Ag nanoparticles with uniform size and distribution were anchored successfully on the surface of ND. The ND supported Ag nanoparticles displayed highly water dispersibility due to the hydrophilicity of TPs, as is very important in heterogeneous catalysis. The catalytic performance of this nanohybrid was evaluated comprehensively by catalyzing 4-nitrophenol reduction by sodium borohydride, which is often used as a model reaction, showing excellent catalytic activity and recycling stability. GRAPHICAL ABSTRAC