Flowerlike Bi2S3 microspheres: facile synthesis and application in the catalytic reduction of 4-nitroaniline

Abstract

Flowerlike Bi₂S₃ microspheres have been successfully synthesized via a facile wet chemical route in air at 110 °C for 10 min, employing bismuth nitrate and thiourea in a molar ratio of 1 : 2 as the starting reactants, ethylene glycol as the reaction medium and polyvinylpyrrolidone (PVP) as the structure-directing reagent. Electron microscopy observations showed that the as-obtained product looked like an Asteraceae plant called Echinops Sphaerocephalus Linn in nature. The N₂ sorption–desorption experiments showed that the Brunauer–Emmett–Teller (BET) area of the flowerlike microspheres was 32.4 m² g⁻¹. Some factors influencing the formation of flowerlike Bi₂S₃ microspheres were investigated, including the reaction temperature, and the sort and amount of the surfactant. The experiments showed that the Bi₂S₃ micro/nanostructures prepared in the present work could be used as new-type catalysts for the reduction of some aromatic nitro compounds, such as 4-nitroaniline, 2-nitrophenol and 4-nitrophenol. It was found that the as-obtained flowerlike Bi₂S₃ microspheres contributed to the best catalytic activity.