The preparation of Ag/ZIF-8@ZIF-67 core-shell composites as excellent catalyst for degradation of the nitroaromatic compounds

The high effective Ag/[email protected] core-shell composite was fabricated by a convenient strategy and applied in the reduction of 4-nitrophenol. The obtained samples were fully characterized by transmission electron microcopy (TEM), element mapping, X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM) and the like. Catalytic experiments showed that the Ag/[email protected] exhibit superior catalytic activity in the reduction of 4-nitrophenol and another two nitroaromatic compounds. The apparent rate constant (Kapp) and the conversion frequency (TOF) of Ag/[email protected]0.4 for 4-nitrophenol were 12.22 × 10−3 s−1 and 5.611 min−1, respectively, and preserved high catalytic performance after four cycles. The catalytic activity of Ag/[email protected] was significantly increased compared to Ag/ZIF-8, which was mainly attributed to the high specific surface area of [email protected], the synergy of ZIF-8 core and ZIF-67 shell and the restriction of pores to Ag NPs.