Yolk-shell nanostructures have recently attracted tremendous research interests in various areas because of their unique structural merits.Currently,there is an urgent need for developing porous shells with multifunctional features to enhance their performance in various applications.Herein,advanced yolk-shell nanospheres have been facilely prepared by encapsulating silver nanoparticles with porous Janus polymer shells that consist of a hypercrosslinked polystyrene (xPS) outer layer and a tethered poly(acrylic acid) (PAA) brush lining.The xPS outer layer possesses well-developed porosity as mass diffusion pathways.More importantly,the tethered PAA brushes with customized carboxyl groups exhibit great affinity toward specific species (e.g.,cationic dyes),leading to their enrichment from the bulk solution into the interior cavity.The unusual combination of highly porous outer layers with customizable inbuilt polymer linings in the porous Janus shells endows them with great promise for synergistically catalytic degradation of cationic dyes.