Development of CdTe quantum dot supported ZnIn<inf>2</inf>S<inf>4</inf> hierarchical microflowers for improved photocatalytic activity

Solar hydrogen production has been successfully demonstrated with CdTe quantum dot (QD) supported porous hierarchical ZnIn2S4. A reduction in effective bandgap from 2.7 eV (for ZnIn2S4) to 2.56 eV (for ZnIn2S4/CdTe QD composite) was observed. An efficient charge transfer between ZnIn2S4 and CdTe in the ZnIn2S4/CdTe QD composite is confirmed from Photoluminescence (PL) studies. Effective reduction in bandgap of composite heterostructure enhances the absorption in visible spectrum and generates more charge carriers, as corroborated from PEC measurements (~ 5.7 μA/cm2). In the present work 3% CdTe QDs decorated with ZnIn2S4 (ZCd3) exhibits higher photocatalytic activity during degradation of Rhodamine B (RhB) dye by 94% in 35 min. An excellent photocatalytic performance of ZCd3 sample was also noted during H2 production yielding a production rate of 1070 μmol g−1 in 3 h. It is believed that the integration of CdTe quantum dot with ZnIn2S4 enhances the photocatalytic efficiency of ZnIn2S4 by improving charge carrier separation and transfer.