Polypyrrole/silver/graphene ternary nanocomposite synthesis and study on photocatalytic property in degrading Congo red dye under visible light

In this report, a simple chemical synthesis of polypyrrole/silver/graphene (Ppy/Ag/Gr) ternary nanocomposites with varying concentrations of graphene are described. The XRD spectra of the samples polypyrrole/silver (Ppy/ Ag) and Ppy/Ag/Gr show all the peaks of the face-centered cubic structure of silver. A broad peak between 10 degrees and 20 degrees and a peak at 26.7 degrees corresponds to Ppy and graphene respectively. Using FTIR, and UV-Vis. spectroscopies the interaction between polypyrrole, silver, and graphene were studied. In our work, we explored the photocatalytic property of the synthesised samples by using them to degrade the aqueous solution of a cancercausing dye, Congo red. The percentage degradation of Congo red dye using the sample Ppy/Ag/Gr (0.5 wt.%) is obtained as 96% and the reaction rate calculated is 0.162/min., greater than that of Ppy/Ag and Ppy/Gr binary composites. Thus, the addition of the optimum concentration of graphene into Ppy/Ag enhanced its photocatalytic property. The BET analysis shows an increased surface area for the sample Ppy/Ag/Gr (0.5 wt.%) and the reason for the enhancement of photocatalysis with this sample is confirmed since it is a surface-dependent property. The biodegradability of the dye solution was investigated by Chemical Oxygen Demand (COD) analysis and the COD value was reduced from 432 mg/L to 216 mg/L after 20 min of irradiation of light.

Automated summary

In this study, a simple chemical synthesis method was used to prepare polypyrrole/silver/graphene (Ppy/Ag/Gr) ternary nanocomposites with varying concentrations of graphene. The interaction between polypyrrole, silver, and graphene was studied using XRD, FTIR, and UV-Vis spectroscopies. The results showed that the addition of the optimum concentration of graphene into Ppy/Ag enhanced its photocatalytic property. Furthermore, it was confirmed that the enhancement of photocatalysis in the Ppy/Ag/Gr sample was due to the increased surface area.