A combination of bismuth oxyhalides is provided, which is a photooxidant, antibacterial and antiviral. The combination of bismuth oxyhalides is added to a filter medium (e.g., a multistage filter) to decompose VOCs and/or eliminate bacteria and/or viruses. Suitable designs of multistage filters are also provided.

A light shield structure is disposed between an ultraviolet lamp and a filter screen of an air purifier, and comprises a first light shield element and a second light shield element. The first light shield element is disposed on an inner wall of the second light shield element. The second light shield element is provided with air inlets, and the first light shield element is staggered with the second light shield element, so that the air inlets are completely blocked by the first light shield element in a radial direction. An air inlet channel is formed between the first light shield element and the second light shield element. Under the precondition that the air inlet channel is formed by the first light shield element and the second light shield element, ultraviolet light can be completely shielded, so that the service life of the filter screen is prolonged.

A gas irradiation system has an irradiation chamber having a plurality of irradiation compartments disposed circumferentially about a central axis. One of the compartments is an inlet compartment. The inlet compartment has an aperture at the bottom through which gas flows from the compartment. A UV LED is disposed within or adjacent to the aperture, where the UVC LED is configured to irradiate the gas and neutralize pathogens. Circumferentially adjacent to one side of the inlet irradiation compartment is an outlet irradiation compartment. Circumferentially adjacent in the opposite circumferential direction on the other side of the inlet radiation compartment is the first of a plurality of intermediate irradiation compartments. These intermediate compartments extend circumferentially about the central axis between the inlet compartment and the outlet compartment. The gas flows sequentially through each of the irradiation compartments, being irradiated in each compartment.

An excimer bulb assembly including an excimer bulb and a pass filter such that the excimer bulb assembly does not emit substantial UV radiation in wavelengths longer than 231 nm, 232 nm, 233 nm, 234 nm or 235 nm. The wavelengths are measured at an incident angle of zero (0) degrees to the filter plane. The pass filter is preferably constructed of a plurality of layers of hafnium oxide, and most preferably constructed of less than seventy five (75)layers of hafnium oxide. The excimer bulb, pass filter, and two electrical connectors may be adapted to form a cartridge which may be adapted to swivel along its main axis. The cartridge may further include a smart chip. The smart chip may retain and store information regarding the assembly and preferably retains hours of use of the excimer bulb.

An ultraviolet air germicidal lamp system includes a base frame including an air inlet and an air outlet, an ultraviolet germicidal module on the base frame, and a lamp module in the base frame. The ultraviolet germicidal module includes a fan, an inlet duct, an ultraviolet lamp module including a cavity and ultraviolet lamps in the cavity, and an outlet duct. The fan is connected to the air inlet. The intake of the cavity of the ultraviolet lamp module is connected to the fan by the inlet duct. The vent of the cavity of the ultraviolet lamp module is connected to the air outlet by the outlet duct. The body diameter of the cavity is larger than the diameters of the inlet duct and the outlet duct.

A system for the treatment of microorganisms includes: a textile web having optical fibers in warp and/or weft woven with binding threads in warp and/or weft, each of the optical fibers having invasive alterations along the fiber and allowing the emission of light propagating in the fiber at these alterations; a light source arranged opposite one or both free ends of the optical fibers. The textile web includes metallic warp and/or weft threads woven with the binding threads, the metallic threads being based on a metal having a negative effect on the growth of microorganisms. The light source generates a light beam having at least one wavelength in the visible or ultraviolet spectrum.

A light fixture is provided to be disposed within a room and operable to provide visible light for the room and air disinfection via application of UV light to air flowing through an air treatment chamber. In one embodiment, one or more baffles may be disposed within the air chamber to substantially prevent UV light from leaking past the one or more baffles into the room. In one embodiment, a UV light regulator may be provided to selectively control an amount of UV light directed into the room.

A photocatalytic device includes: a metal layer; and a photocatalytic layer provided on the metal layer and containing a photocatalytic material. In the photocatalytic layer, a slit or an opening is formed to expose a portion of the metal layer.

This publication discloses a filter unit connectable to a mobile communication device including a fan for generating an air flow inside the filter unit, electrodes covered with a photo catalytic material like TiO.sub.2 in the air flow, UV-LEDs illuminating the electrodes, and outlet for the air flow directed in direction of user of filter unit.

An optical system includes a plurality of laser light sources and an optical component. A first set of one or more laser light sources is configured to emit optical disinfection light at the optical component. A second set of one or more laser light sources is configured to emit optical communication light at the optical component. The optical component is configured to distribute the optical disinfection light in a first light distribution pattern, and to distribute the optical communication light in a second light distribution pattern. The optical component includes a first set of one or more metamaterial structures configured to distribute, in the first light distribution pattern, the optical disinfection light that is incident on the optical component, and a second set of one or more metamaterial structures configured to distribute, in the second light distribution pattern, the optical communication light that is incident on the optical component.