Novel plasma assisted preparation of ZnCuFeCr layered double hydroxides with improved photocatalytic performance of methyl orange degradation

[Display omitted] •ZnCuFeCr-LDHs was prepared assisted with DBD plasma.•ZnCuFeCr-LDHs had excellent visible light photocatalytic degradation performance.•Plasma assisted preparation generated more oxygen vacancies.•Plasma assisted preparation reduced photo-generated electron-hole recombination. Plasma assisted preparation of ZnCuFeCr layered double hydroxides used as photocatalyst showed excellent photocatalytic performance on methyl orange degradation under visible light. The catalysts were characterized by XRD, SEM, XPS, BET, UV–Vis DRS, EPR and PL. Compared with the traditional co-precipitation method, the plasma-assisted preparation of layered double hydroxides had obvious advantages of visible light photocatalysis. Plasma assisted preparation resulted in a tighter arrangement of the laminate atoms and more stable crystal structure, increased the specific surface area, generated more oxygen vacancies and reduced photoelectron-hole recombination during photocatalysis. The reaction mechanism of the preparation process and photocatalytic reaction process was inferred. Meanwhile, the effects of preparation time on the degradation were investigated, and the optimal preparation conditions were obtained. The degradation rate of 1000 mL (20 mg/L) methyl orange could reach up to 96.8% within 42 min in visible light photocatalysis under the preparation conditions that discharge voltage of 30.9 kV, photocatalyst addition amount of 1 g/L.