Sustainable lignin-driven homogenization of microarchitecture in improving TiO2 dye-sensitized photoanode

TiO 2 , as the mainstream of dye-sensitized photoanode, can provide two quantities of state density higher than ZnO. However, van der Waals forces between TiO 2 microcrystals make them more inclined to agglomerate, posing a major obstacle of poor dispersion and homogeneity. Since the charge kinetics of TiO 2 depends on reasonable microstructure arrangement, this study proposes an innovative strategy of sustainable lignin-driven homogenization of microarchitecture in TiO 2 . Herein, the uniform dispersion of TiO 2 microcrystals is successfully induced by alkali lignin (AL) with the reduced grain size of 42–18 nm, and the increased specific surface area of 879.55 m 2 /g. Moreover, AL does not change the anatase structure of TiO 2 . Notably, this micro-homogenized structure of more layered arrangement and active adsorption sites shortens the carrier/electron transport path, achieving high dye loading of 246 nM/cm 2 and photo-conversion efficiency (PCE) of 8.83 %, which exceeds the reported TiO 2 -based dye-sensitized solar cells. Moreover, AL substantially increases the J SC from 18.15 mA/cm 2 to 25.63 mA/cm 2 . Specially, molecular interaction between AL and TiO 2 further supports high PCE of >90 % after 240 h, with good stability. Consequently, this innovative strategy of lignin-driven micro-homogenization in TiO 2 serves as an inspiration for the development of biomass-enhanced TiO 2 -based photoelectric devices.