Construction of Highly Catalytic Porous TiOPC Nanocomposite Counter Electrodes for Dye-Sensitized Solar Cells

Developing low-cost, durable, and highly catalytic counter electrode (CE) materials based on earth-abundant elements is essential for dye-sensitized solar cells (DSSCs). In this study, we report a highly active nanostructured compositional material, TiOPC, which contains titanium, oxygen, phosphorus, and carbon, for efficient CE in I 3 – /I – electrolyte. The TiOPC nanocomposites are prepared from carbon thermal transformation of TiP 2 O 7 in an atmosphere of nitrogen at high temperature, and their catalytic performance is regulated by changing the carbon content in the nanocomposites. The TiOPC with appropriate 24.6 wt % carbon and porous structure exhibits an enhanced electrocatalytic activity in the reduction of I 3 –, providing a short-circuit current density of 16.64 mA cm –2, an open-circuit potential of 0.78 V, and an energy conversion efficiency of 8.65%. The photovoltaic performance of TiOPC CE-based DSSC is even superior to that of a Pt CE-based cell (13.80 mA cm –2, 0.79 V, and 6.66%). The enhanced catalytic activity of TiOPC is attributed to the presence of predominant Ti–O–P–C structure along with the continuous conductive carbon network and the porous structure.