Chemical bath deposition of NiCo2S4 nanostructures supported on a conductive substrate for efficient quantum-dot-sensitized solar cells and methanol oxidation
Hierarchical nanostructures have recently attracted massive attention due to their remarkable performances in energy conversion, storage systems, catalysis, and electronic devices. Considering the advantage of hierarchical nanostructures, we have formulated a facile and cost-effective chemical bath deposition method to synthesize novel NiCo2S4 on a conductive substrate for quantum dot sensitized solar cells & methanol electro-oxidation. Owing to the unique nanoarchitecture, the NiCo2S4 electrodes were used to grow high quality thin films containing nanoflowers, nanoplatelets, or nanosheets. The nanoplate-structured NiCo2S4 CE in QDSSCs under one-sun illumination (AM 1.5, 100 mW cm−2) yielded a high short circuit current density (Jsc) of 11.91 mA cm−2, open circuit voltage (Voc) of 0.602 V, fill factor (FF) of 0.50, and power conversion efficiency (η) of 3.53%. These values are much higher than those of the Pt CE (Jsc = 6.98 mA cm−2, Voc = 0.579, FF = 0.36, and η = 1.10%). The electrocatalytic performance was investigated by cyclic voltammetry and chronoamperometry for NiCo2S4 electrodes via methanol electro-oxidation. Electrochemical studies reveal that the as-prepared NiCo2S4–NCS6h electrode displayed a significant enhancement in the electrocatalytic activity and stability for methanol oxidation in the presence of 2 M KOH with 0.5 M methanol. The results indicate that the hierarchical structure of NiCo2S4 offers a promising electrode material for QDSSCs and methanol electro-oxidation.