Preparation of CoNi@CN composites based on metal-organic framework materials as high efficiency counter electrode materials for dye-sensitized solar cells

Abstract

In this paper, Co-based metal organic framework mixtures (MOFs) stuff are used as self-sustain templates to prepare CoNi alloys and N-codop porous carbon composites (CoNi@CN) by one-step calcination and ion exchange methods and apply to the study of the counter electrode (CE) of dye-sensitized solar cells (DSSCs). CoNi@CN retains a large specific surface area, high porosity and abundant unsaturated sites of MOFs, and the conductivity and catalytic activity of porous carbon are improved by the introduction of CoNi alloy and N. At the same time, the nitrogen-doped porous carbon protects the CoNi alloy from corrosion of the electrolyte and ensures the stability of the material. CoNi@CN is used in DSSCs for catalytic reduction of I3- exhibits the photoelectric conversion efficiency of 8.85%, that is overtop the exhibited by Pt CE under the equal conditions. Therefore, CoNi@CN composites are prepared based on MOFs are expected to instead of Pt as DSSCs CE materials because of their excellent optoelectronic properties and inexpensive.