Use of ionic liquid TEA-PS.BF4 as media synthesis of ZnO based on coprecipitation method

ZnO was synthesized by coprecipitation method and the 3-triethylammonium-propanesulfonic acid tetrafluoroborate (TEA-PS∙BF4) ionic liquid (IL) (0–10 wt%) was used during the synthesis. The Rietveld refinements of materials obtained showed that the TEA-PS∙BF4 influences the microstructure, i.e., microstrain increase and crystallite size decrease when compared to the ZnO without TEA-PS∙BF4. Moreover, the addition of IL in the synthesis made the crystals more isotropic. The scanning microscopy studies have shown that the films of ZnO are porous and have agglomerated particles of different sizes (between 16 and 180 nm). The data obtained - for the ZnO films as photoelectrodes in photoelectrochemical cells - from the j-V curves showed that the cells achieved photocurrent efficiencies of up to 1.03%, fill factor of 0.63 and a current density of 3.03 mA cm−2. The relationship between the percentage of IL and morphological/microstructure characteristics of ZnO films were also considered as a possible origin of the increase of up to 78% in photoconversion efficiency for the photoelectrode with 1 wt% of TEA-PS.BF4 compared to the cell without the addition of TEA-PS∙BF4. •ZnO thick films were prepared by coprecipitation method.•Ionic liquid TEA-PS.BF4 as media synthesis of ZnO powder.•Microstrain increase and crystallite size decrease when compared to the ZnO without TEA-PS∙BF4.•Improvement photoconversion efficiency for the ZnO photoelectrode with TEA-PS.BF4.