Flower-Like MoS2/CNTs Composite as Efficient Counter Electrode for Quantum Dot Sensitized Solar Cells

A flower-like MoS2/CNTs composite as efficient counter electrode for quantum dot-sensitized solar cells (QDSSCs) was prepared by a facile one-step hydrothermal method. X-ray diffraction tests confirm the successful synthesis of MoS2/CNTs composite. SEM results show highly conductive CNTs significantly reduce the size of MoS2 and build bridges between MoS2 by incorporating into flower-like MoS2. Electrochemical impedance spectroscopy (EIS) and tafel polarization curve of the optimum MoS2/CNTs counter electrode (CE) show an impressive low charge transfer resistance (R-ct = 1.39 Omega), implying high electrocatalytic activity for S-n(2-) reduction at the CE/electrolyte interface. The QDSSC based it achieve a high power conversion efficiency of 5.05% under one standard sun illumination at 100 mW .cm(-2), which is higher than that of bare MoS2 CE (1.47%). The superior performance of MoS2/CNTs CE is ascribed to excellent electrical conductivity of one-dimensional CNTs, adequate exposure surface of MoS2 and the synergistic catalytic effect of MoS2 and CNTs. (c) 2019 The Electrochemical Society.