Photocatalyst Co3O4/red phosphorus for efficient degradation of malachite green under visible light irradiation

Co 3 O 4 /red phosphorus (Co 3 O 4 /RP) photocatalysts were synthesized via facile hydrothermal and mechanically grinding approach. The catalysts were characterized via XRD , TEM , XPS , N 2 sorption , photoelectro chemical measurements and UV–vis DRS . The results showed that the Co 3 O 4 nanocrystals were assembled on the surface of the RP. The loading of Co 3 O 4 on RP was beneficial to enhance the light absorption compared with pure RP. Under visible light , 94.5% of malachite green (MG) can be photodegraded within 20 min over 10% Co 3 O 4 /RP composite, while only 17.3% and 59.9% of MG can be photodegraded over pure Co 3 O 4 and RP. The reaction rate constant k obtained over 10% Co 3 O 4 /RP heterojunction (0.1464 min −1 ) is approximately 3.2 times that of pure RP (0.0457 min −1 ), and 15.3 times that of bare Co 3 O 4 (0.0096 min −1 ). The cycle experiments showed that the catalyst had high photocatalytic stability. Co 3 O 4 nanocrystals inhibit the photoelectron-hole pair recombination of red phosphorus semiconductor, and exhibit improved visible light absorption . Consequently, the catalytic performance of Co 3 O 4 /RP has been enhanced under visible light .