Carbon nanofiber based CuO nanorod counter electrode for enhanced solar cell performance and adsorptive photocatalytic activity

Dye-sensitized solar cells (DSSCs) are known as new generation solar cell of photovoltaic technologies (PV), and have become hotspot topic in the PV research. DSSCs include four main components such as photoanode, counter electrode, dye, and electrolyte. The counter electrode is a vital component of DSSCs which has a significant effect on the solar cell performance and cost of the devices. In this research, CuO nanorod/carbon nanofiber (CuO/CNF) thin films are produced with the diameter of nanorods and vary from 10 to 50 nm as counter electrodes (CEs) for DSSCs. The applications of as-synthesized materials were also investigated in the field of photocatalysis. It was shown that CuO/CNF CE–based solar cells exhibited 6.5% solar cell efficiency (η) under solar irradiation. We demonstrate that CuO nanorods can be good alternatives for expensive platinum as it is composed of inexpensive and abundant materials and prepared by a simple fabrication process. CNF, exhibiting high carrier electron mobility, was employed to improve the catalytic and electrical properties of resulting CuO/CNF CEs. The power conversion efficiency of the DSSC was enhanced by almost 29% in the case of CuO/CNF CEs. In addition, the synthesized CuO/CNF nano-heterostructures exhibited superior photocatalytic activity toward the degradation of textile dye (Orange II) and antibiotic (tetracycline) compared to raw CuO. The enhanced efficiency can be ascribed to the reduction of E_g~band-gap energy and to the synergetic effect of adsorption and photocatalysis.