Temperature-dependent catalytic reduction of 4-nitrophenol based on silver nanoclusters protected by a thermo-responsive copolymer ligand

Well-defined silver nanoclusters (NCs) were prepared by using a temperature-responsive copolymer ligand (CPL) containing 5-(2-methacryloylethyloxymethyl)-8-quinolinol (MQ) and N-isopropylacrylamide (NIPAM) units. The catalytic behaviors of the novel CPL-stabilized silver NCs were investigated through intensive kinetic evaluation using the reduction of 4-nitrophenol (4-NP) as a model reaction. The sizes of the silver NCs could be controlled in the range from 1.76 nm to 3.0 nm by the ratio of CPL and silver ion precursors. The highest catalytic activity was observed for the Ag NCs-a1. The as-prepared copolymer ligand capped Ag NCs also showed the temperature-responsive characteristics with a lower critical solution temperature (LCST) about 32 degrees C. The significant thermo-sensitive catalytic properties were studied in the catalytic reduction of 4-nitrophenol by the as-prepared silver nanocluster.