Ultrafast Crystallization of Ordered Mesoporous Metal Oxides and Carbon from Block Copolymer Self‐Assembly and Joule Heating

Abstract

AbstractConventional heat treatments to generate well‐ordered and crystalline mesoporous oxide and carbon structures are limited by long durations and annealing temperatures that can cause mesostructural collapse. This paper describes a facile strategy coupling block copolymer‐directed self‐assembly with high‐power Joule heating to form highly crystalline and well‐ordered mesoporous oxide and carbon nanostructures within second timeframes. The combined approach is compatible with various functional self‐assembled hybrid systems with a range of crystallization temperatures, generating mesoporous composites of γ‐Al2O3‐carbon, γ‐Al2O3/MgO‐carbon, and anatase‐TiO2‐carbon with p6mm symmetry, non‐close‐packed mesoporous carbon, as well as hierarchical mesoporous α‐Fe2O3‐carbon structures. Removing the polymer/carbon gives well‐defined, highly crystalline mesoporous all‐γ‐Al2O3 and all‐anatase‐TiO2 structures. Impregnation of chloroplatinic acid followed by Joule heating yields platinum nanoparticles decorated on the channel walls of mesoporous γ‐Al2O3‐carbon structures. The resultant Joule‐heating‐induced well‐ordered crystalline mesoporous oxide and oxide‐carbon structures have high thermal and structural stabilities and exhibit better performances in CO2 adsorption capacity and lithium‐ion batteries than conventional heat‐treated counterparts. This approach represents an energy‐efficient and time‐saving route toward ordered porous materials with high surface area and pore accessibility for a wide range of environmental applications such as carbon sequestration, renewable energy storage, and environmental filtration.