Research on the influence of alkyl ammonium bromides on the properties of Ag/AgBr/GO composites

Abstract

Silver/silver halides/graphene oxide (Ag/AgX/GO) plasma resonance photocatalysts have received extensive attention due to their excellent photocatalytic activities in the visible-light region. From a synthetic point of view, it is highly attractive to investigate the influence of synthesis conditions on the properties of Ag/AgX/GO, such as halide source, metal precursor and pH value. We present a water/oil method of fabricating Ag/AgBr/GO nanostructures by using alkyl ammonium bromides with different carbon chain length as halide sources. The structural details and textural properties of these resultant Ag/AgBr/GO nanocomposites are characterized by X-ray diffraction, transmission electron microscopy, and X-ray photoelectron spectroscopy studies. The results show that the decompositions of AgBr to Ag accelerate when using the short carbon chain of alkyl ammonium bromide. Photocatalytic experiments show that the photocatalytic activities of Ag/AgBr/GO-CTAB and Ag/AgBr/GO-DTAB are higher than those of Ag/AgBr/GO-TBAB and Ag/AgBr/GO-TMAB. Raman scattering studies indicate that these resultant Ag/AgBr/GO nanocomposites can not only enhance the Raman signals of GO, but also be used as surface-enhanced Raman scattering (SERS) substrates to enhance the Raman signals of dye molecules. Their enhancement degrees are different when using different carbon chain of alkyl ammonium bromide. Owing to the high photocatalytic performance, chemical stability and SERS effect, Ag/AgBr/GO-CTAB and Ag/AgBr/GO-DTAB nanocomposites can be used as the recyclable SERS substrates.