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 (NH2 CN) 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.
Department of Mechanical Engineering, The University of Hong Kong, Pokfulam Rd., Hong Kong.
Peng
P
Zhai
Tzu-Chien
TC
Wei
Ya-Huei
YH
Chang
Yu-Ting
YT
Huang
Wei-Ting
WT
Yeh
Haijun
H
Su
Shien-Ping
SP
Feng
dye-sensitized solar cells; electrocatalytic activity; graphene; nitrogen doped; wettable