“…Low-temperature hydrothermal synthesis of ZnO nanorods from a seed layer was carried out using an aqueous solution of zinc nitrate (purity ≥ 98%, Vekton, Saint Petersburg Russia) and hexamethylenetetramine (purity ≥ 98%, Vekton, Saint Petersburg, Russia) with an equimolar concentration of 25 mM, to which ammonia water (purity ≥ 98%, Vekton, Saint Petersburg, Russia) and polyethyleneimine (branched, Mw ~ 800, Sigma-Aldrich, St. Louis, MO, USA) were added to ensure ZnO nucleation in the bulk of the solution. The features of the synthesis of the ZnO nanorods have been described in more detail in [49]. After synthesis, the ZnO nanorods were annealed at a temperature of +500 °C for 5 min.…”