Architecting Mesoporous Heterojunctions via Programmable Interfacial Engineering.

Mesoporous heterojunction materials (MHJs), integrating interconnected mesopore networks with electronically polarized heterointerfaces, have delivered unparalleled advantages across diverse frontier fields. Open mesopores expose otherwise buried junctions, shorten diffusion pathways, and create confined nanospaces, while heterointerfaces generate built-in electric fields and interfacial barriers that steer carrier migration and reaction trajectories. Despite substantial advances in mesoporous materials and heterostructures, the mesopore-enabled amplification of heterojunction functions has not been systematically articulated. This Review reframes MHJs through the concept of effective heterojunctions, emphasizing active interface accessibility and local electronic perturbation validity as central design criteria. The mechanistic roles of mesoporosity in interfacial barrier modulation, charge utilization, and microenvironment regulation are delineated, and their manifestations across representative MHJ configurations, synthetic strategies, and applications are systematically examined. Key challenges and opportunities are also outlined in artificial intelligence (AI)-guided predictive design, effective junction quantification, operando characterization, and scalable synthesis. This Review aims to establish a clearer guiding principle to promote MHJs progression from experience-based material integration toward precise interface programming.