Porous N-doped-carbon coated CoSe2 anchored on carbon cloth as 3D photocathode for dye-sensitized solar cell with efficiency and stability outperforming Pt

Photocathode with superior catalytic activity, long-term stability, and fast mass/electron transfer is highly desirable but challenging for dye-sensitized solar cell (DSC). Herein, the ZIF-67 grown on carbon cloth is successfully transformed into CoSe 2 embedded in N-doped carbon nanocage (CoSe 2 /N-C) via a growth-carbonization-selenization process. The carbon cloth supported CoSe 2 /N-C, as photocathode of DSC, demonstrates a good long-term stability and high photovoltaic efficiency (8.40%), outperforming Pt. The good efficiency can be attributed to the high catalytic activity of CoSe 2 , fast mass transfer of porous 3D structure, and good electron transport derived from the intimate contact between CoSe 2 and highly conductive carbon cloth. The high stability would be ascribed to N-doped carbon coating that perfectly prevents CoSe 2 from decomposition. This work will pave the way to develop highly efficient and stable Pt-free photocathode for DSC.