Thermo/photo-responsive porous organic frameworks for sustainable gas separation and bio-applications

Porous organic frameworks including metal-organic frameworks (MOFs), covalent organic frameworks (COFs), and hydrogen-bonded organic frameworks (HOFs), have emerged as structurally diverse and functionally tunable platforms in advanced materials science. Among these, stimuli-responsive porous organic frameworks that undergo reversible structural or physicochemical transformations under external stimuli such as temperature and light have attracted increasing attention. This review provides a critical overview of recent advances in the design, mechanisms, and functions of thermal- and photo-responsive porous organic frameworks. We categorize response strategies according to framework type and responsive element, and highlight how these features contribute to dynamic performance across multiple length scales. Applications such as spatiotemporally controlled drug release, selective gas separation, and switchable enzyme-mimetic catalysis are discussed as model systems to illustrate the functional impact of stimuli responsiveness. Despite recent progress, challenges remain in achieving high responsiveness without compromising stability, in tuning selectivity toward specific stimuli, and in integrating these systems into real-world applications. Looking ahead, a deeper understanding of structure-response correlations, coupled with advances in in situ characterization and computational modeling, will be key to unlocking the full potential of stimuli-responsive porous organic frameworks in next-generation adaptive systems.