An excellent Z-scheme Ag2MoO4/Bi4Ti3O12 heterojunction photocatalyst: Construction strategy and application in environmental purification

Herein we have designed an excellent type of Z-scheme Ag₂MoO₄/Bi₄Ti₃O₁₂ (AMO/BTO) heterojunction photocatalysts by immobilizing AMO particles onto rod-like BTO hierarchical architectures. The formation of Z-scheme AMO/BTO heterostructures was verified by various characterization techniques including XRD, UV–vis DR spectroscopy, SEM, TEM, XPS and FTIR spectroscopy. PL spectroscopy, photocurrent response and EIS analyses suggest that the creation of AMO/BTO heterojunctions is conducive to the efficient separation of photoexcited electron-hole pairs. The photocatalytic performances of the AMO/BTO composites were investigated by simulated-sunlight driving photodegradation of methylene blue (MB), tetrabromobisphenol A (TBBPA), tetracycline hydrochloride (TC), phenol and methyl orange (MO)/rhodamine B (RhB)/MB mixture solutions. It is demonstrated that the AMO/BTO heterojunction photocatalysts are endowed with excellent photodegradation performances much higher than that of bare AMO and BTO. For example, the photodegradation rate of MB by using 30 wt%AMO/BTO — confirmed to be the optimal composite sample — is about 17.0 and 14.7 times as high as that by using bare BTO and AMO, respectively. A Z-scheme electron transfer mechanism was proposed to elucidate the enhanced photodegradation performances of the AMO/BTO heterojunction photocatalysts.