Air purifiers

A self-regenerating air purifier, comprising:

• a housing defining an enclosure and having an air entrance and an air exit;
• at least one particulate filter;
• an active oxygen generator (AOG) configured to generate at least one oxidant;
• a catalyst layer comprising an oxidant remover material;
• a fan unit configured to generate airflow from the air entrance to the air exit;
• and
• a pre-filter positioned to cover at least a portion of the air entrance and/or the air exit to filter air passing through the air entrance and/or the air exit;
• wherein the particulate filter, the catalyst layer, the AOG and the fan unit are positioned within the enclosure such that during operation, a flow of air passes from the air entrance to the air exit through the particulate filter and the catalyst layer along a direction of the flow of air;
• wherein the oxidant remover material is an ozone remover material;
• wherein the ozone remover material comprises a catalyst composition comprising:
• a porous material having a plurality of nanopores and comprising one or more of silicon dioxide, aluminium oxide, and zeolite;
• and
• one or more layers of nano sheet of manganese oxides comprising manganese in an amount of about 0.1-50% by weight of the catalyst composition;
• wherein the zeolite are aluminosilicate minerals;
• wherein the at least one particulate filter is a high-efficiency particulate air (HEPA) filter;
• wherein the AOG is an ozone generator configured to generate ozone;
• wherein the catalyst layer further comprises a nano-confined catalytic oxidation (NCCO) filter material configured to adsorb and decompose at least one gaseous pollutant;
• and
• wherein the ozone generator is configured to generate a concentration of ozone sufficient to disinfect at least 90% of bacteria/viruses;
• and
• wherein the porous material is provided in a form of granules.