The concept of this invention is to take a material that works for a specific application and modify it so that it can also be used for a new application simultaneously with the other existing capability. An example of this process would be to take a metal-loaded porous material that has demonstrated capacity for iodine gas capture (e.g., silver zeolite, silver aerogel, silver xerogel) and add functional groups to it so it can also be used to capture mercury gas at the same time. Functional groups that have been demonstrated to capture Hg gas include sulfur-containing species. These could be added using thiolation processes or by embedding elemental sulfur into the materials. Other materials could be used as well for these dual (or multi)-purpose applications.