Glucose aided synthesis of molybdenum sulfide/carbon nanotubes composites as counter electrode for high performance dye-sensitized solar cells

Graphical abstract: - Highlights: • The glucose aided (G-A) preparation of MoS₂/CNTs composites were employed as CE in Pt-free DSSC. • The (G-A) MoS₂/CNTs* CE showed the low R_ct of 1.77 Ω cm². • The efficiency of the DSSC reached 7.92% based on the (G-A) MoS₂/CNTs* CE. - Abstract: In our present study, the composites of molybdenum disulfide/carbon nanotubes (MoS₂/CNTs) were synthesized with glucose aided (G-A) by using an in situ hydrothermal route, and proposed as counter electrode (CE) catalyst in the dye-sensitized solar cells (DSSCs) for enhancing electrocatalytic activity toward the reduction of triiodide. The MoS₂/CNTs composites with tentacle-like structure were confirmed by using the scanning and transmission electron microscopy. The superior structural characteristics including large active surface area and particularly the unique tentacle-like nanostructure along with 3D large interconnected interstitial volume guaranteed fast mass transport for the electrolyte, and enabled the (G-A) MoS₂/CNTs CE to speed up the reduction of triiodide to iodide. The extensive electrochemical studies by the cyclic voltammetry, electrochemical impedence spectroscopy and Tafel measurements indicated that the (G-A) MoS₂/CNTs CE possessed superior electrocatalytic activity, great electrochemical stability and impressive low charge transfer resistance on the electrolyte|electrode interface (1.77 Ω cm²) in the triiodide/iodide system compared to the pristine MoS₂, MoS₂/C and sputtered Pt CEs. The DSSC assembled with the novel (G-A) MoS₂/CNTs CE exhibited high power conversion efficiency of 7.92% under the illumination of 100 mW cm⁻², comparable to that of the DSSC with the Pt electrode (7.11%)