The present invention relates to methods and devices for providing microbialcontrol and/or disinfection/remediation of an environment. The methods generallycomprise: generating a Purified Hydrogen Peroxide Gas (PHPG) that is substantiallyfree of, e.g., hydration, ozone, plasma species, and/or organic species； anddirecting the gas comprising primarily PHPG into the environment such that thePHPG acts to provide microbial control and/or disinfection/remediation inthe environment, preferably both on surfaces and in the air. The vaporous hydrogenperoxide is generated from oxygen and water of the ambient air. Further, a diffuserapparatus for producing PHPG is disclosed, the latter comprising a source ofultraviolet light； a metal or metal oxide photo catalyst (e.g. TiO2), catalystsubstrate structure； and an air distribution mechanism, wherein the morphologyof the catalyst on its substrate is a thin, sail-like air-permeable structure,situated perpendicular to air flow through the diffuser apparatus； and whereinsaid morphology is supposed to alter the reaction equilibrium of the catalystsuch that it produces hydrogen peroxide from both the oxidation of water and fromthe reduction of dioxygen.
