Preparation of Pumice Stone Morphology AgAlO₂@ZnO S-Type Heterojunction Photocatalyst with the Synergistic Effect of Photocatalytic Degradation and Hydrogen Production

AgAlO₂ is a p-type semiconductor with strong absorption capacity to visible light and ZnO is an n-type semiconductor with strong absorption capacity to ultraviolet light, but they both possess strong recombination ability of electrons and holes. In this work, a kind of S-type heterojunction was constructed to realize the effective separation of photogenerated electrons and holes in a pumice stone morphology AgAlO₂@ZnO composite. The prepared material had macroporous and ordered mesoporous dual porous structures; the pumice stone structure provided the macroporous structures, and the mesoporous structure was derived from the wrapped ZnO precursor in AgAlO₂, which greatly improved the exposure rate of the active sites. The material showed excellent photocatalytic properties and showed photocatalytic degradation and photocatalytic hydrogen production performances under simulated solar light. More particularly, it showed photocatalytic hydrogen production performances in RhB or MO solution without the MeOH sacrificial agent. This study provided a new way for the construction of a new S-type heterojunction and a new idea for the further study of S-type heterojunction photocatalysts.