A novel visible-light-response plasmonic photocatalyst CNT/Ag/AgBr and its photocatalytic properties

A facile, one-step synthesis of carbon nanotube (CNT)-loaded Ag/AgBr is reported. The as-prepared samples were characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), UV/Vis absorption spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, photoluminescence (PL) spectroscopy and electrochemical impedance spectroscopy (EIS). The CNT/Ag/AgBr composite exhibited much higher photocatalytic activity than pure Ag/AgBr in degrading methyl orange (MO) dye solution. The loading amount of CNT had a significant influence on the photoactivity of the CNT/Ag/AgBr composite. When the CNT loading amount was 1.4 at%, the hybrid material showed the highest photocatalytic ability. The result showed that a small amount of CNT was beneficial for photo-generated electron transfer, which could enhance the photoactivity of CNT/Ag/AgBr. The degradation dye solution was tested by liquid chromatography/mass spectrometry (LC/MS) and total organic carbon (TOC) analysis. Based on the results, the structure of the synthesized CNT/Ag/AgBr hybrid material was verified and the possible degradation path of the MO dye was proposed. A possible visible-light photocatalytic degradation mechanism was also discussed.