High Electrocatalytic and Wettable Nitrogen‐Doped Microwave‐Exfoliated Graphene Nanosheets as Counter Electrode for Dye‐Sensitized Solar Cells

In this paper, high electrocatalytic and wettable nitrogen‐doped microwave‐exfoliated graphene (N‐MEG) nanosheets are used as Pt‐free counter electrode (CE) for dye‐sensitized solar cells (DSSCs). A low cost solution‐based process is developed by using cyanamide (NH₂CN) at room temperature and normal pressure. The pyrrolic and pyridinic N atoms are doped into the carbon conjugated lattice to enhance electrocatalytic activity. N‐MEG film having N‐doping active sites and large porosity provides a wettable surface to facilitate electrolyte diffusion so that improves fill factor. Moreover, the control of the air exposure time after completing N‐MEG film is found to be crucial to obtain a reliable N‐MEG CE. A high DSSC efficiency up to 7.18% can be achieved based on N‐MEG CE, which is nearly comparable to conventional Pt CE.