Synthesis, characterization and catalytic activity of Au nanoparticles supported on PANI/α-Fe2O3 composite carriers

A novel nanocomposite composed of gold nanoparticles, polyaniline (PANI) and hematite (α-Fe2O3) with core–shell structure has been successfully synthesized through a three-step process. Firstly, α-Fe2O3 cores were prepared by the forced hydrolysis of FeCl3. And then, aniline was polymerized in the suspension of α-Fe2O3. Finally, a surface reduction–oxidation was carried out between composite carriers and chloroauric acid to obtain the three-component nanocomposites. The morphology, crystalline structure and optical properties of the nanocomposites were measured by using transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectrometer and Ultraviolet–visible (UV–vis) spectrophotometer. The results showed that the surface of α-Fe2O3 cores was coated by PANI to form core–shell structure, and Au nanoparticles were deposited on the outer surface of PANI. The average sizes of immobilized Au were 5.6 and 8.1 nm respectively. In the degradation of Rhodamine B in the presence of NaBH4, the as-prepared nanocomposites exhibit an excellent catalytic activity, and the conversion rate of Rhodamine B reached 100% in 7.5 min.