Significantly improved photo- and electro-chemical performance of CuS center dot PbS nanocomposites for dye degradation and paintable counter electrodes

Abstract

CuS nanoparticles (CuS NPs) are used in a variety of optical, photo-chemical, and photo-electrochemical applications. An unsophisticated but efficient strategy is reported here to enhance the performance of CuS by transforming it into CuS center dot PbS nanocomposites (NCs). A modified successive ionic layer adsorption and reaction method was employed to combine CuS NPs with PbS quantum-dots in a qualitatively-controlled way. Resultant CuS center dot PbS NCs were first qualitatively investigated using scanning electron microscopy coupled with an energy-dispersive spectroscope and an X-ray diffractometer. Owing to the improved optical behavior revealed by UV-vis spectroscopy, CuS center dot PbS NCs were employed first for photo-catalysis and then for electro-catalysis, where optimal CuS center dot PbS NCs (specifically, CuS center dot 2PbS) ensued an similar to 80 % degradation of the toxic Congo red dye. Moreover, the efficacy of the controlled deposition of PbS on CuS NPs was electrochemically investigated and a significant improvement in the imperative parameters, such as the charge transfer resistance at the electrode/electrolyte interface and electron lifetime, was obtained. CuS center dot 2PbS NCs also exhibited air-processable and heat-treatable characteristics which demarcated its suitability for paintable counter electrodes (as) in quantum-dot-sensitized solar cells (QDSCs).