Forming a porous multilayer material includes forming a multilayer material on a substrate. Forming the multilayer material includes alternately forming a sacrificial layer and a semi-sacrificial layer, where the sacrificial layer includes a first metal and the semi-sacrificial layer includes the first metal and a second metal or metallic alloy. Forming the porous multilayer material further includes removing at least a portion of the first metal from each of the sacrificial and semi-sacrificial layers to yield the porous multilayer material. The porous multilayer material includes a multiplicity of metal-containing layers, each layer having a thickness in a range between about 5 nm and about 100 nm and bonded to an adjacent layer. Each layer includes chromium, niobium, tantalum, vanadium, molybdenum, tungsten, or a combination thereof. A void is defined between each pair of layers, and a density of porous the multilayer material is