Enhanced visible light induced photocatalytic degradation of oxytetracycline hydrochloride by n-ZnO/p-NiO composite

[Display omitted] •Porous n-ZnO/p-NiO photocatalysts were successfully synthesized by a facile hydrothermal and calcination method.•The heterojunction structures of the photocatalysts could enhance the efficiency of photogenerated electron-hole separation.•The photocatalysts could efficiently remove OTC-HCl from aqueous solutions under visible light.•O2− was the main active species in the photocatalytic degradation process. A series of porous n-ZnO/p-NiO with different Ni/Zn mass ratios photocatalysts were synthesized by a facile hydrothermal and calcination method. XRD, SEM, TEM, BET, XPS, FTIR, UV–vis analytical methods were used to characterize the composites. The results showed that, the composite material with a Ni/Zn mass ratio of 0.3 had a better photocatalytic effect, decomposing 79% of OTC-HCl in only 2 h. The increased photocatalytic activity might be attributed to the heterojunctions between n-ZnO and p-NiO. Notably, the photocatalysts had excellent stability. The scavenging experiments showed that O2− was the main active species in the photocatalytic degradation process.