▎ 摘　　要

In this work, nitrogen-doped graphene quantum dots (N-GQDs) were proved to be an efficient photocatalyst for photochemical synthesis of Ag nanoparticle loaded porous graphitic C3N4 (p-g-C3N4) for the first time. The Ag nanoparticles were well-formed in high yield and closely anchored at the surface of p-g-C3N4 with uniform size distribution. Importantly, the as-prepared Ag/p-g-C3N4 nanocomposites exhibited excellent catalytic activity towards electrocatalytic reduction of hydrogen peroxide (H2O2). The cyclic voltammetry and amperometry results show that the sensor of the asprepared Ag/p-g-C3N4 composite exhibits excellent analytical response to H2O2 with fast response, wide linear range and low detection limit.