Synthesis and Composition-Dependent Visible Photocatalysis of Ag/AgBr Necklace-Like Heterostructures

A two-step synthesis was developed to fabricate Ag/AgBr necklace-like nano-heterostructures at room temperature. Multiple crystalline Ag nanowires were used as templates following an oxidation route in situ from CuBr₂ to create Ag/AgBr heterostructures. Polyvinylpyrrolidone can govern the formation of one-dimensional Ag/AgBr necklace-like nano-heterostructures. The composition of the heterostructures was adjusted by changing the amount of CuBr₂ . Experimental conditions were optimized. In particular, the concentration and injection rate of copper bromide solution play an important role in controlling the oxidation of the Ag nanowires for the purpose of adjusting the morphology of the Ag/AgBr heterostructures. As a result, the heterostructures with 40 mol % AgBr displayed a regular necklace-like morphology. Under visible-light irradiation, Ag/AgBr necklace-like heterostructures with AgBr molar ratios of 10 to 50 % exhibited enhanced plasmonic photocatalytic performance for the degradation of organic pollutants (methyl orange, methylene blue, and rhodamine B).