Electron-withdrawing effect of carboxyl-functionalized CNT on the triiodide reduction of ZnIn2S4 in dye-sensitized solar cells

This study presents a straightforward yet effective one-step hydrothermal method for the homogeneous deposition of ZnIn 2 S 4 (ZIS) onto carbon nanotubes (CNT), resulting in the formation of a unique plum-blossom ZIS@CNT heterostructure composite. The heterostructure formed between ZIS and CNT not only constructs an efficient electron transfer channel, but also provides an appropriate driving force for the transfer of electrons to active sites through the electron-withdrawing effect of carboxyl groups. When the ZIS@CNT composite was utilized as the counter electrode (CE) in a dye-sensitized solar cell (DSSC), the resulting DSSC exhibited an extremely high photoelectric conversion efficiency (PCE) of 9.35 %, which is 27.73 % higher than that of based on the traditional Pt CE (7.32 %). This study provides a new idea for the application of carbon nanomaterials and ZIS in DSSCs, and reveals the reasons for the excellent PCE of ZIS@CNT from the perspective of interface charge distribution.