Covalent lindqvist polyoxometalate-cubic polyhedral oligomeric silsesquioxane hybrid material: enhancing photocatalytic antibacterial activity and hydrogen production as a heterogeneous catalyst

A novel approach for creating a hybrid material consisting of molecular polyoxometalate-polyhedral oligomeric silsesquioxane (POM-POSS) was developed, with a primary emphasis on overcoming the challenges related to the solar-driven production of hydrogen (H 2 ) and the elimination of harmful bacteria in polluted wastewater. Herein, the Lindqvist-type polyoxometalate cluster, tetrabutylammonium hexamolybdate [LPOM(Mo)] and the aminopropyl heptaisobutyl silsesquioxane (POSS-NH 2 ) were combined through covalent linkage to form the POM organoimido POSS hybrid material by a dehydration reaction. Various analytical techniques, such as FT-IR spectroscopy, BET, NMR spectroscopy, and ESI-MS, were used to investigate the development of a covalent POM-POSS hybrid material. HR-TEM images of the POM-POSS hybrid material demonstrated that the flat sheets were rectangular in shape with a size distribution ranging from 2.5 ± 0.2 μm in length to 0.2 ± 0.02 μm in width. The POM-POSS hybrid material showed a more efficient photocatalytic system compared to POM prompted by a visible region absorption shift, photoluminescence quenching effect, and increased photocurrent generation (2.1 μA cm −2 ). Antibacterial tests demonstrated the highest photoinactivation against Escherichia coli ( E. coli ) cells after 45 min of sunlight exposure. The POM-POSS hybrid material exhibited excellent H 2 generation (2461 μmol g −1 h −1 ) than LPOM(Mo) (2051 μmol g −1 h −1 ) owing to the improved photocatalytic system via the covalently linked organoimide ligand from POSS-NH 2 . Furthermore, the reusability of the POM-POSS hybrid material was assessed by measuring its photocatalytic H 2 production rate over ten consecutive cycles, and the stability of the catalytic activity was demonstrated. These findings demonstrate a rational method for constructing POM-POSS material with controlled chemical composition and architecture for H 2 production under abundant sunlight. Covalent POM-POSS hybrid material was found to be excellent in photocatalytic antibacterial activity against E. coli owing to the generation of hydroxyl radicals and showed improved hydrogen generation due to the synergistic effect of POM and POSS.