Replacing
precious Pt-based counter electrodes (CEs) with a low-cost
and high-performance Pt-free catalyst of CEs is still in urgent need
to decrease the fabrication cost of dye-sensitized solar cells (DSSCs).
Herein, the elements V and A (A = C, O) of the final state of the
target materials are prefabricated in an organic complex precursor
by bonding, and then, the precursor was directly processed to prepare
V
x
A1–x
(x = 0–1, A = C, O) multiphase CE catalysts
by pyrolysis along the temperature gradient under N2 flow,
which further served as catalytic materials of CEs for the encapsulation
of DSSCs. The precursors were obtained utilizing polyoxovanadate (NH4)2V6O16 as a metal source
and glucose as a carbon source via a facile hydrothermal method. Power
conversion efficiencies of 5.38, 6.29, 6.60, 6.82, and 6.23% were
obtained from the five different V
x
A1–x
(x = 0–1,
A = C, O) multiphase CE catalysts as CEs to reduce iodide/triiodide
in DSSCs, which were prepared at pyrolysis temperatures of 600, 700,
800, 900, and 1000 °C, respectively. The enhanced performance
of V
x
A1–x
materials can be attributed to the more catalytic active site
number and the high conductivity, which is due to the higher specific
surface area provided by the pyrolysis and carbonization of glucose
and the activation and modification of materials at high temperature
and N-doping. The impressive finding in this work indicates that the
V
x
A1–x
composite can be considered as a promising candidate for low-cost
and high-efficient CEs in the fabrication of DSSCs.