Catalytic reduction of 4-nitrophenol by silver nanoparticles stabilized on environmentally benign macroscopic biopolymer hydrogel

The direct use of macroscopic biopolymer alginate hydrogels (AHs) as a green and effective carrier to stabilize silver nanoparticles (Ag NPs) is presented. The Ag@AHs were characterized by UV–vis absorption spectroscopy, Fourier transform infrared spectroscopy (FTIR), scanning electronic microscopy (SEM) and X-ray energy dispersive spectroscopy (EDS). The Ag@AHs showed excellent catalytic performance for the reduction of 4-nitrophenol by NaBH4 in aqueous solution, which can be easily separated after catalytic reaction and readily reused for three successive reaction cycles, attributing to the high stability of the Ag NPs supported by AHs. Our findings shed light on the design and fabrication of new heterogeneous catalyst with high performance based on the environmentally benign biopolymer hydrogel.