Sodium dodecyl sulfate-decorated MOF-derived porous Fe2O3 nanoparticles: High performance, recyclable photocatalysts for fuel denitrification

Magnetically recyclable porous sodium dodecyl sulfate (SDS)/Fe2O3 hybrids, which combine the porous structure of Fe2O3 and hydrophobicity of SDS, have been successfully synthesized for the first time. Porous Fe2O3 has been first pyrolyzed from MIL-100(Fe) using a simple two-step calcination route. Then, the obtained porous Fe2O3 nanoparticles have been self-assembled with SDS molecules and yielded hydrophobic SDS/Fe2O3 hybrids. The porous SDS/Fe2O3 hybrids have been demonstrated to be highly efficient for the denitrification of pyridine under visible light irradiation. The pyridine removal ratio has reached values as high as 100% after irradiation for 240 min. Combining the results of a series of experimental measurements, it was concluded that the superior photocatalytic performance of SDS/Fe2O3 hybrids could be attributed to (i) the fast electron transport owing to the unique porous structure of Fe2O3, (ii) the superior visible light absorption of Fe2O3 nanoparticles, and (iii) the "bridge molecule" role of SDS efficiently improving the separation and transfer across the interfacial domain of SDS/Fe2O3 of photogenerated electron-hole pairs. More significantly, after the catalytic reaction, the SDS/Fe2O3 hybrids could be easily recovered using magnets and reused during subsequent cycles, which indicated their stability and recyclability.