Synergistic Effect of Hybrid WS2 Quantum Dots/Co-Fe Nanocubes, WS2 Nanorods/Co-Fe Nanocubes: Towards Pt-Free Counter Electrode for Dye Sensitized Solar Cells

Abstract

WS2 (Transition-metal dichalcogenide) are known for their novel electro catalytic properties and have analogous structure with graphene. It is noted that catalytic performance of WS2 can be further increased by doping either heteroatom or transition metal. Facile one-pot hydrothermal method was used for synthesis of WS2 quantum dots and WS2 nanorods, Nanocubes are prepared by simple chemical ageing method. The obtained WS2 quantum dots, WS2 nanorods show good transmittance in visible region (400 – 800 nm). The photoluminescence peak was obtained around 420 nm for WS2 quantum dots, CoFe shows high intense peak at around 424 nm confirms the product quality. Raman active modes of CoFe around 501 cm-1 (T1g) and 620 cm-1 (A1g) reveals cubic structure formation. The structural features of the as prepared (0D/3D), (1D/3D) are characterized systematically by the X-ray diffraction, Field emission scanning electron microscopy, EDAX, High-resolution transmission electron microscopy, FTIR and Raman spectroscopy. Here we identified the synergistic effect of the prepared hybrid WS2 quantum dots/Co-Fe nanocubes (0D/3D), WS2 nanorods/ Co-Fe nanocubes (1D/3D) by appropriate doping composition shows more exposed edge sites, large specific surface area and outstanding catalytic activities, when compared with bare WS2 and CoFe and it is a real substitute for Pt-counter electrode in Dye sensitized solar cells.