A direct dual Z-scheme 3DOM SnS2-ZnS/ZrO2 composite with excellent photocatalytic degradation and hydrogen production performance.

A novel direct dual Z-scheme 3DOM (three-dimensional ordered macropores) SnS2-ZnS/ZrO2 composite was prepared by the template method combined with the in situ sulfur replacement technology. The composition, structure, morphology, and surface physicochemical properties of the composites were well characterized. The results indicate that it possesses a uniform and periodical macroporous structure, a large surface area (121.1 m2 g-1), broad visible light absorption, and high separation ability of photoinduced electron/hole pairs. 3DOM SnS2-ZnS/ZrO2 composite removed 96.8% of methyl orange within 210 min of simulated sunlight irradiation. Moreover, photocatalytic hydrogen production achieved the rate of 928.1 μmol g-1, which was 66.3 times as high as that of the commercial P25 after 8 h simulated sunlight irradiation. The enhanced photocatalytic performance mainly attributed to the direct dual Z-scheme system, which improves the charge separation efficiency and optimizes the charge transfer pathway. The charge transfer mechanism over the 3DOM SnS2-ZnS/ZrO2 is discussed in detail based on the results of radical trapping experiments. Our work paves a new way to design 3DOM materials with direct dual Z-scheme structure.