CN/rGO@BPQDs high-low junctions with stretching spatial charge separation ability for photocatalytic degradation and H2O2 production

Reduced graphene oxide modified black phosphorus quantum dots (rGO@BPQDs) were obtained through surface modification of BPQDs with rGO via an ultrasound-assisted liquid phase method. The rGO@BPQDs could effectively enhance the chemical and structural stability of BPQDs. Zero-dimension rGO@BPQDs were firmly anchored on mesoporous g-C3N4 (CN) via a self-trapping pore confinement effect and pi-pi interactions to form CN/rGO@BPQDs, which remarkably improved the photoelectric properties of CN. The responsive wavelength of CN/rGO@BPQDs could be extended to 800 nm. The kinetic constant of Rhodamine B and tetracycline degradation reached 0.183 and 0.0194 min(-1), respectively. The H2O2 production rate of CN/rGO@BPQDs was 2.6 times that of porous CN. The improved photocatalytic performance and remarkable increase in free radicals are attributed to the formation of n-n type high-low junctions as well as the internal electric field based on different Fermi levels between CN and BPQDs. These collectively promote spatial separation of photogenerated carriers.