Graphene oxide/polydimethylsiloxane composite sponge for removing Pb() from water

• Published in: RSC advances 2020-06, Vol.1 (38), p.22492-22499
• Main Authors: Liu, Liao, Chen, Jiannan, Zhang, Wuhuan, Fan, Meikun, Gong, Zhengjun, Zhang, Jianqiang
• Format: Article
• Language: English
• Subjects: Chemistry; Graphene; Isotherms; Kinetics; Polydimethylsiloxane; Polyvinyl alcohol; Silicone resins; Sorption; Water purification
• ISSN: 2046-2069; 2046-2069
• DOI: 10.1039/d0ra03057k

An efficient adsorbent to remove Pb( ii ) from water was prepared by treating polydimethylsiloxane (PDMS) sponge with polyvinyl alcohol and then coating the sponge with graphene oxide (GO). The GO-PDMS sponge was highly hydrophilic, easily handled during and after use, and easily recycled. The kinetics and isotherms of Pb( ii ) sorption onto the GO-PDMS sponge were investigated by performing batch sorption tests. The kinetics of Pb( ii ) sorption onto the GO-PDMS sponge indicated that sorption equilibrium occurred rapidly (within 60 min) and that the sorption data could be described using a pseudo-second-order model. Maximum Pb( ii ) sorption onto the GO-PDMS sponge occurred at pH > 5. Increasing GO loading on the PDMS sponge increased the amount of Pb( ii ) that could be sorbed. The isotherm for Pb( ii ) sorption onto the GO-PDMS sponge was non-linear and was well described by the Langmuir isotherm model, indicating that Pb( ii ) sorption onto the GO-PDMS sponge was homogeneous and occurred through sorption of a monolayer of Pb( ii ). The GO-PDMS sponge, used as a filter, removed Pb( ii ) efficiently from water. The Pb( ii ) removal efficiencies were more than 50% and the maximum was 85%. A novel sorbent material for Pb( ii ) sorption was created by coating graphene oxide (GO) on a pretreated PDMS sponge.