Ruthenium(ii) multi carboxylic acid complexes: chemistry and application in dye sensitized solar cells

Abstract

Novel ruthenium multi carboxylic complexes (RMCCs) have been synthesized by using ruthenium nitrosyl nitrate, 1,2,4,5-benzenetetracarboxylic acid (H₄btec) and 4,7-diphenyl-1,10-phenanthroline (BPhen) as photosensitizers for titanium dioxide semiconductor solar cells. The complexes were characterized by ¹H-NMR, FT-IR, UV–Vis, ICP and CHN analyses. The reaction details and features were then described. SEM analysis revealed that the penetration of dyes into the pores of the nanocrystalline TiO₂ surface was improved by increasing the number of btec units. The solar energy to electricity conversion efficiency of complexes shows that the number of attached carboxylates on a dye has an influence on the photoelectrochemical properties of the dye-sensitized electrode. An incident photon-to-current conversion efficiency (IPCE) of 13% at 510 nm was obtained for ruthenium complexes with three btec units.