Combined Electrosorption and Chemisorption of As(V) in Water by Using Fe-rGO@AC Electrode

A novel method of arsenic removal from water, combined electrosorption and chemisorption (CEC), has been presented in this work in order to deeply eliminate arsenic in water. This method was proposed using a mixture of activated carbon (AC) and reduced graphene–iron composite (Fe-rGO) as the electrode (Fe-rGO@AC). The results showed that the AC had a better electrosorption performance, while Fe-rGO was more suitable for chemisorption of As(V). The Fe-rGO@AC electrode combined the electrosorption with chemisorption. It was confirmed that the combination accelerated the adsorption rate of Fe-rGO. The AC on the electrode accelerated the mobility of arsenic ions and concentrated them in the electrical double layer (EDL) by means of electrostatic force underpotential. Meanwhlie, the concentrated As(V) ions reacted with Fe-rGO, contributing to a higher arsenic chemisorption on Fe-rGO. Therefore, the combination of electrosorption with chemisorption was an effective process for arsenic removal.