Metallic 1T-phase MoS₂ is a newly emerging and attractive catalyst since it has more available active sites and high carrier mobility in comparison with its widely used counterpart of semiconducting 2H-MoS₂. Herein, 1T/2H-MoS₂(N) (N: MoO₃ nanowires were used to prepare 1T/2H-MoS₂) was synthesized by using molybdenum trioxide (MoO₃) nanowires as the starting material and applied in the photodegradation of antibiotic residue in water. Enhanced photocatalytic performance was observed on the obtained 1T/2H-MoS₂(N), which was 2.8 and 1.3 times higher than those on 1T/2H-MoS₂(P) (P: commercial MoO₃ powder was used to prepare 1T/2H-MoS₂) and 2H-MoS₂, respectively. The active component responsible for the photodegradation was detected and a reaction mechanism is proposed.