Porogen-Integrated Rapid Oxidation Enables Structured Mesoporous Metal Oxide Films

Structured metal oxide films have promise in optoelectronics, sensing, energy storage, and catalysis but their uptake is predominately limited due to their long and high-temperature syntheses. Here, a self-assembling polymer is used which can act as a chelating fuel source in a solution combustion reaction to generate highly structured mesoporous aluminum oxide films at <250 °C in a matter of minutes through a process termed porogen-integrated rapid oxidation (PiRO). The resulting films with thicknesses up to 500 nm show an open-cell, face-centered cubic structure of spheroidal pores. Further, an additional ligand can be included to control the self-assembly step to yield both through-film ordering or tunable disordering for increased pore volume as confirmed by both grazing incidence small angle X-ray scattering and ellipsometry. Finally, roll-to-roll manufacturing with PiRO is demonstrated on flexible polymeric substrates. The method offers a tunable, scalable, low-temperature, and lower-cost method to generate large-area structured mesoporous metal oxide films.