Porous materials and methods for forming them are disclosed. One method for immobilizing micro-particles and/or nano-particles onto internal pore surfaces and/or external pore surfaces of porous materials includes suspending the micro-particles and/or nano-particles in a liquid adapted to swell, soften, and/or deform either the porous materials and/or the particles, thereby forming a liquid-particle suspension. The method further includes adding the suspension to the porous materials; and removing the liquid, thereby forming the porous materials having the micro-particles and/or nano-particles immobilized on the internal pore surfaces and/or the external pore surfaces.