A new polymeric photosensitizer for dye-sensitized solar cell with porous TiO2 from forest carbon resources

Abstract A series of new lignin derivatives (lignophenols) containing phenol, p -cresol, catechol, resorcinol and pyrogallol synthesized from Hinoki ( Chamaecyparis obtusa ) and Douglas fir ( Pseudotsuga menziessi ) as softwood and beech ( Fagas crenata ) as hardwood was investigated as sensitizers for a dye-sensitized solar cell (DSSCs) of porous TiO 2 under the irradiation of 150 W Xe lamp. For example, LPs–DSSCs of hinoki-ligno- p -cresol, directly derived from hinoki native lignin showed V oc =0.34 V, I sc =0.65 mA cm −2 , ff=0.49 and η =0.11% under AM 1.5 (100 W m −2 ). The strong interactions between lignophenols and TiO 2 surface were estimated by UV-Vis and FT-IR spectra. The importance of interactions between phenolic hydroxyl groups and TiO 2 surface was discussed by FT-IR, solid UV-Vis spectra and 1 H NMR. The effects of chemical modifications were discussed using acethylated lignophenols (LPsOAc) or re-cycled lignophenols, treated by 0.5 M NaOH at 413 K (LPs–SF413) or 443 K (LPs–SF443). These results implied interactions between LPs and TiO 2 were consisted of anchors and stacking on TiO 2 .