Graphite-like carbon nitride (CN) has attracted much attention because of its distinct optical and photoelectrical properties, strong stability, and wide applications for environmental restoration and renewable energy. Herein, the CN nanolayer about 7.5-17.5 nm in thickness was in situ built uniformly on the external of carbonized PDA (cPDA) spheres to form the cPDA@CN core/shell nanomaterials on account of the bioinspired adhesion. They possess the mesopore about 4.8 nm in diameter and a high specific surface area (66.6 m(2) g(-1)). The optimal cPDA@CN sample exhibits efficient catalytic activities for the rhodamine B degradation (2.19 h(-1)) and H-2 release rate (630 mu mol g(-1) h(-1)), which are similar to 15.4 and similar to 10 times of pristine CN, respectively. This research affords a dextrous and scalable way to fabricate the nanostructured photocatalyst with superior performance, which may hold great promise in practical applications.