Abstract: The present disclosure relates to a device that includes a first metal oxide layer having a first thickness, a second metal oxide layer having a second thickness, and a base layer having a third thickness, where the first metal oxide layer is positioned between the base layer and the second metal oxide layer, at least one of the base layer and/or the first metal oxide layer includes a carbon-containing material, and at least one of a carbon concentration gradient and/or an oxygen concentration gradient is present across at least one of a portion of the first thickness and/or a portion of the third thickness. In some embodiments of the present disclosure, the first metal oxide layer may be permeable to an oxygen-containing compound. In some embodiments of the present disclosure, the oxygen-containing compound may include at least one of O3, N2O, and/or H2O2.