▎ 摘　　要

The quick reduction and regeneration of the electrolyte (triiodide/iodide redox couple, I3-/I-) is one of the main issues in dye-sensitized solar cells (DSSCs). The well-known platinum counter electrodes (CEs) that facilitate electrolyte reduction and regeneration are very expensive; hence, low-cost and efficient CEs are in demand to substitute the platinum CEs. Herein, we report the hydrothermal synthesis of single (boron or nitrogen) and dual (boron/nitrogen mixture) heteroatom-doped reduced graphene oxide (rGO) and their comparison as CEs in DSSCs. The photovoltaic, electrochemical and conductivity properties were investigated. Dual heteroatom-doped rGO demonstrated a relatively large surface area and enhanced electrical conductivity (161.51 m2 g-1 and 22.07 S cm- 1, respectively) when compared to graphene oxide (GO), rGO and single heteroatom-doped rGO. The amount of boron- and nitrogen-doping, including their configuration, played a crucial role in the catalytic activity. The presence of pyridinic-N and pyrrolic-N in single and dual heteroatom-doped rGO promoted a triiodide reduction reaction, which shifted the redox potential, relative to GO and rGO. The BN-rGO-3 CE yielded a relatively higher PCE of 2.97%, further enhanced to 4.13% when the BN-rGO-3 CE was used in conjunction with polyaniline as a binder. Therefore, this showed that dual heteroatom-doped rGO CEs enhanced the PCE of the DSSCs due to the synergetic effect, doping configuration and higher doping levels. Thus, the present work provides a facile and productive strategy for configuring the dual heteroatom-doped graphene CE materials with high electrocatalytic activity for energy conversion devices.