Construction of Z-scheme (TiO2/Er3+:YAlO3)/NiFe2O4 photocatalyst composite for intensifying hydrodynamic cavitation degradation of oxytetracycline in aqueous solution

•A novel magnetic Z-scheme (TiO2/Er3+:YAlO3)/NiFe2O4 photocatalyst was designed.•Photocatalysis can enhance HC degradation ratio of organic pollutants to 84.45 %.•Construction of Z-scheme photocatalyst promotes separation of e- and h+ pairs.•(TiO2/Er3+:YAlO3)/NiFe2O4 photocatalyst is easily recycled due to the magnetism.•Er3+:YAlO3 can obviously enhance the activity of Z-scheme TiO2/NiFe2O4 photocatalyst.