Novel platinum C3N4 nanotubes as a photoanode to enhance dye-sensitized solar cell efficiency

Herein, synthesized platinum C3N4 nanotubes (Pt/C3N4 NTs), AgNO3 and TiO2 were used to prepare decorated TiO2 nanocomposite (Pt/C3N4 NTs/Ag/TiO2) with the hydrothermal method as a newly modified photoanode for dye-sensitized solar cell (DSSCs). The presence of Pt/C3N4 NTs and silver nanoparticles on TiO2 lead to an increase in specific surface area and creates the surface plasmonic effect which eventually makes a dramatic increase in photon to the current efficiency of the standard N719 DSSC. The photovoltaic performance of DSSC is studied by using impedance spectroscopy (EIS) and intensity modulated photocurrent spectroscopy (IMPS). Based on the results, the fabricated DSSC has comprehensive benefits such as efficient charge separation, low internal resistance and quick transmission of electrons which significantly contributes to reducing the recombination processes. As a result, after optimization of experimental and instrumental conditions, the shortcircuit photocurrent density (JSC) and the power conversion efficiency (ŋ) of DSSC made based on the Pt/C3N4 NTs/Ag/TiO2 photoanode are 18.17 mA cm-2 and 6.98%, respectively, which resulted in 161% increase in the efficiency compared to conventional pure TiO2 DSSC.