In-situ controlled growth of (102) and (311) crystal plane of polymorphous ZnIn2S4 assisted by inorganic anions for enhanced photocatalytic properties

The structural units and crystal orientation of ZnIn2S4 were affected by the electronegativity and polarity of the exogenous inorganic anions. The addition of Cl− can transform cubic ZnIn2S4 into hexagonal phase with the preferential growth of (102) crystal plane, while the modification of SO42− can better expose the (311) crystal plane of cubic ZnIn2S4. The photocatalytic experiment showed that ZnIn2S4-pHHCl with (102) crystal plane had the superior photocatalytic activity, the removal rate of tetracycline hydrochloride and Cr(VI) reached 91.78% and 99.48%, respectively. The relationship between the structure and properties of the materials can be explained that the more negative the conduction band position is with the exposure of the (102) or (311) crystal plane in the photocatalytic reaction system, the stronger the reducibility of the electrons. The modification of exogenous inorganic anions provides a new regulatory strategy for studying the phase transition and the growth of active crystal plane.