Au/carbon as Fenton-like catalysts for the oxidative degradation of bisphenol A

The development of a new method for the degradation of bisphenol A (BPA) in aqueous solution is highly desired. Oxidative degradation using hydroxyl radicals (OH) is an efficient approach for the remedy of toxic organic compounds. This paper describes the design and utilization of a new Fenton system consisting of the Au/styrene based activated carbon catalyst and hydrogen peroxide (H2O2) for the degradation of BPA under non-photo-induced conditions. Transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) results showed that the negatively charged Au nanoparticles were evenly distributed in a range 3.9–6.4 nm dominated with (1 1 0) facet. The generation of OH over Au catalysts through the decomposition of H2O2 was evidenced using 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) trapped electron paramagnetic resonance (EPR). The experimental results suggested that the conversion of BPA was affected by several factors such as the loading amount of Au, pH value, reaction temperature and the initial concentration of H2O2. In an optimum experiment, BPA could be degraded from 110 to 10 ppm within 12 h. The active sites was envisaged to be negatively charged Au atoms at the interface between Au particles and carbon support, the carbon surface is enriched with dangling carbon atoms as evidenced by the O2-temperature programmed desorption (TPD) technique. A mechanism including the redox between Auδ− ↔ Au° during the decomposition of H2O2 has been proposed.

An active carbon supporting Au (Au/SRAC) catalyst has proved to an effective Fenton catalyst for the degradation of BPA.Figure optionsDownload as PowerPoint slideHighlights
► A highly effective Fenton-like system consisting of Au/active carbon and hydrogen peroxide.
► Rapid degradation of organic compounds without extra energy.
► The plausible mechanism for the creation of active sites envisaged using techniques such as EPR, O2-TPD and XPS.