One-pot fabrication of core-shell fly ash@polypyrrole/Au composite microspheres and their performance for the reduction of nitrophenol

• Au nanoparticles were embedded in polypyrrole (PPy) chains on the surface of fly ash (FA) by a green, one-pot strategy.
• The Au-PPy/FA composite 15performed high efficiency in catalytic reduction of nitrophenol to corresponding aminophenol with NaBH4 as reducing agent.
• A possible reaction mechanism is proposed to explain the enhanced catalytic efficiency of Au-PPy/FA.

We reported a novel and simple strategy to construct core-shell composite microspheres with fly ash (FA) and Au nanoparticles embedded in polypyrrole (PPy) chains. In an acid medium, activation of FA microspheres, synthesization of Au nanoparticles, and polymerization of PPy were synergistically achieved in one-step green process. The physicochemical characteristics of the Au-PPy/FA composite microspheres were studied by SEM, TEM, FTIR, XRD, TGA and VSM. In the presence of NaBH4 as a reducing agent, the Au-PPy/FA composite microspheres exhibited highly catalytic efficiency in reduction of nitrophenol to aminophenol. The reaction rate constants were calculated through the pseudo-first-order kinetic equation by using the excess amount of NaBH4. For the two isomers of nitrophenol, the reduction rates were particularly investigated and followed the order: 4-nitrophenol > 2-nitrophenol. The electronic interaction between Au nanoparticles and PPy chains plays an important role for the highly catalytic efficiency of the Au-PPy/FA. A possible reaction mechanism for the reduction process was also emphasized.

A novel and highly efficient Au-PPy/FA composite microspheres has been constructed for reduction of nitrophenol with NaBH4 as reducing agent.Figure optionsDownload as PowerPoint slide