The　air　purification　in　intensive　care　units　(ICU)　involving　the　removal　of　smog　and　volatile　organic　compounds　(VOCs),　disinfection,　and　sterilization　are　closely　linked　to　important　health　issues.　The　environmental　photocatalysis　technology　that　could　decompose　gaseous　pollutants　into　small　molecular　inorganic　substances　provides　the　potential　solution.　In　a　chamber　of　30-m(3)　simulated　ICU,　photocatalytic　purifier　with　ZnSn(OH)(6)　nanoparticles　photocatalyst　is　set　up　to　treat　10　VOCs　with　concentration　below　2　ppm.　Compared　with　regular　purifiers　of　plasma　and　activated　carbon,　the　present　photocatalytic　purifier　can　completely　eliminate　10　varieties　of　low-concentration　irritating　VOCs　without　CO　production.　The　continuous　tests　show　that　loading　of　600　g　ZnSn(OH)(6)　has　capacity　to　treat　large　volumes　of　VOCs　and　remains　high　removal　efficiencies　up　to　600-h　operation.　The　results　suggest　that　the　photocatalytic　purifier　could　be　potentially　applied　for　the　treatment　of　contaminated　indoor　air　particularly　ICU.　The　mechanism　of　ZnSn(OH)(6)　photocatalysis　is　proposed　to　interpret　the　high　performance　and　mineralization　of　the　degradation　process.