Importance of buffering nanolayer position in Layer-by-Layer assembly on titania based hybrid photoactivity

AbstractNanoarchitecture of layer-by-layer (LbL) films is a convenient and simple way to control the photoelectrochemical properties of the semiconductor films. Hereby, we used the combination of polystyrenesulfonate (PSS) and polyethyleneimine (PEI) deposited on the TiO2 film for controlling the photochemical response of the hybrid system. Photogenerated protons on the TiO2 surface are responsible for the acidity change near the irradiated surface. We investigated that the photogenerated protons being absorbed by PEI spatially separated from the TiO2 surface with the nanoscale-thick PSS layer (with thickness ca. 5 nm) lead to the sufficient decrease in photoactivity of the hybrid system TiO2/PSS/PEI ca. 4 times in comparison with pristine TiO2. PEI nanolayer being deposited directly on the TiO2 surface can decrease the photoactivity of the system ca. 2–2.5 times. We show that the photoactivity of the sol–gel titania can be regulated by self-assembly of polyelectrolyte nanolayersand nanoarchitecture of these layers. The work highlights the importance of well-defined colloidal units for inkjet printing of gradient surface.HighlightsDeposition of TiO2 photoactive layer by inkjet printing.Investigation of photoactivity of the hybrid system based on titanium dioxide and polyelectrolyte layers (polystyrenesulfonate PSS, polyethyleneimine PEI).Variation in “proton sponge” activity of PEI depending on the distance from TiO2 surface.PEI nanolayer being deposited directly on the TiO2 surface can decrease the photoactivity of the system ca. 2–2.5 times, nanoarchitecture PSS/PEI – 4–4.5 times in comparison with pristine TiO2.