Controllable synthesis and photoelectric properties of interconnected and self-assembled nanocomposite of porous hollow Cu7S4/CuS and nitrogen-doped graphene oxide

摘要

In this work, the novel, interconnected and self-assembled nanocomposite of porous hollow Cu7S4/CuS and nitrogen-doped reduced graphene oxide (Cu7S4/CuS@nGO) has been designed and synthesized successfully via a simple solvothermal process. An efficiently synthetic approach to selectively manufacture different morphologies of Cu7S4/CuS has been investigated by only controlling the hydrothermal temperature. The images of scanning electron microscopy (SEM) and transmission electron microscopy (TEM) indicate the temperature-dependent evolution of structures and morphologies of the samples. Considering the efficient morphology of Cu7S4/CuS(synthesized at 210 degrees C) with the porous hollow spherical structure, we speculate it should have good photoelectric properties, such as wide UV-vis absorption spectra, and its performance should be enhanced with further treatment like being encapsulated with nitrogen-doped reduced graphene oxide. In order to investigate the photoelectric properties of the Cu7S4/CuS and Cu7S4/CuS@nGO nanocomposites, they have been used as the counter electrodes (CE) in the dye-sensitized solar cells (DSSC). It is demonstrated that the Cu7S4/CuS@nGO nanocomposite not only shows the best photoelectric performance, whose power conversion efficiency is 9.14% (much higher than those of the devices with Pt, Cu7S4/CuS and nGO as CEs), but possesses remarkable electrochemical stability as well. (C) 2019 Elsevier Ltd. All rights reserved.