Simultaneous polymerization and crosslinking for the synthesis of molecular-level graphene oxide–polyacryl amide–CeOx composites

• Polyacryl amide–graphene oxide–CeOx composite was synthesized at molecular-level.
• The as-proposed reaction mechanism was systematically analyzed.
• There are interaction between Ce(IV) (or (III)) ions and polyacryl amide chains.
• GO–PAM–CeOx composite shows superior photocatalytic activity.

Synthesis of molecular-level multiple-component composites are particularly challenging due to the lack of direct bonding among different components. In this study, molecular-level graphene oxide (GO)–polyacryl amide (PAM)–CeOx composites were successfully synthesized, using the simultaneous polymerization and crosslinking strategy. Attenuated total reflection Fourier transform infrared (ATR-FTIR) and nuclear magnetic resonance (NMR) techniques confirmed that polyacryl amide (PAM) chains were successfully grafted onto the surface of GO. X-ray photoelectron spectroscopic (XPS) and X-ray diffraction (XRD) analyses further revealed the characteristic signals of cerium elements and CeO2 phase respectively. Scanning electron microscopy (SEM) showed that the surface morphology of the GO–PAM–CeOx composites was substantially thicker and rougher than those of the original GO. Further exploration of the reaction mechanism clearly demonstrate the existence of strong chelating interaction among PAM chains and Ce(IV) ions. In particular, the polymerization of acryl amide monomers and the crosslinking reaction between PAM and Ce(IV) or Ce(III) ions were realized simultaneously, leading to the final formation of molecular-level GO–PAM–CeOx composites. Moreover, the as-synthesized GO–PAM–CeOx composites were capable of effectively decomposing Rhodamine B under simulated sunlight, making it a potential candidate as a new photo catalyst. To sum up, this report demonstrates the potential utility of simultaneous polymerization and crosslinking method for the synthesis of other multiple-component composites at molecular-level.

The proposed simultaneous polymerization and crosslinking method was reported for the first time to offer a new strategy for the effective synthesis of the multiple components composite at molecular-level. The entire reaction process is realized in four steps: chain initiation, simultaneous polymerization and crosslinkage, chain termination and final hydrolysis.Figure optionsDownload as PowerPoint slide