Ferric-ellagate complex: A promising multifunctional photocatalyst

The semiconductors have exhibited great potential in the field of photocatalytic energy production, environmental remediation and bactericidal. Nevertheless, those inorganic semiconductors are still restricted in commercial application due to the drawbacks of easy agglomeration and low solar energy conversion efficiency. Herein, ellagic acid (EA) based metal-organic complexes (MOCs) were synthesized through a facile stirring process at room temperature with Fe3+, Bi3+ and Ce3+ as the metal center. The EA-Fe photocatalyst exhibited superior photocatalytic activity toward Cr(VI) reduction, where Cr(VI) were completely removed within 20 min. Meanwhile, EA-Fe also displayed good photocatalytic degradation of organic contaminants and photocatalytic bactericidal performance. The photodegradation rates of TC and RhB by EA-Fe were 15 and 5 times that by bare EA, respectively. Moreover, EA-Fe was capable of effectively eliminating both E. coli and S. aureus bacteria. It was found that EA-Fe was capable of generating superoxide radicals, which could participate in the reduction of heavy metals, degradation of organic contaminants and inactivation of bacteria. A photocatalysis-self-Fenton system could be established by EA-Fe solely. This work would provide a new insight for designing multifunctional MOCs with high photocatalytic efficiency.