Photocatalytic generation of singlet oxygen for air purification

A system for inactivation of pathogens via singlet oxygen, the system comprising:

• a photosensitizing component for generating gaseous singlet oxygen, comprising:
• a substrate;
• and
• hexanuclear clusters operably immobilized on the substrate;
• wherein each of the hexanuclear clusters comprises a photosensitive octahedral core complex characterized by formula FX1a:
• M6X8 (FX1a);
• wherein each M is W;
• and
• wherein each X is independently a halide anion;
• a conveyed gas in gas-communication with the photosensitizing component;
• wherein the hexanuclear clusters are exposed to the gas and the gas comprises at least O2 gas;
• a light source configured to emit a light onto the hexanuclear clusters, the light being capable of photoactivating the hexanuclear clusters;
• wherein each of the hexanuclear clusters is a photosensitizer configured to generate the gaseous singlet oxygen when irradiated by the light in the presence of the O2 gas;
• and
• wherein the hexanuclear clusters are immobilized on the surface of the substrate via non-covalent association between the hexanuclear clusters and silane linker groups, the silane linker groups being covalently attached to the surface of the substrate.

A method for generating gaseous singlet oxygen in a gas, the method comprising:

• exposing hexanuclear clusters to the gas comprising at least 02 gas;
• and
• irradiating the hexanuclear clusters with a light;
• wherein:
• each of the hexanuclear cluster is a photosensitizer configured to generate the gaseous singlet oxygen when irradiated by the light in the presence of the O2 gas;
• the hexanuclear clusters are operably immobilized on at least a portion of a substrate;
• each of the hexanuclear clusters comprises a photosensitive octahedral core complex characterized by formula FX1a:
• M6X8 (FX1a);
• wherein each M is W;
• wherein each X is independently a halide anion ligand;
• and
• wherein the hexanuclear clusters are immobilized on the surface of the substrate via non-covalent association between the hexanuclear clusters and silane linker groups, the silane linker groups being covalently attached to the surface of the substrate.