Priority CommunicationN-TiO2/Cu-TiO2 double-layer films: Impact of stacking order on photocatalytic properties

•N-TiO2/Cu-TiO2 and Cu-TiO2/N-TiO2 layers were stacked in a thin film configuration.•Visible and simulated solar radiation were applied in the oxidation of 2-propanol.•Cu-TiO2 on the outer layer resulted in strong oxidation rate and moderate PL.•Cu-driven electrons are responsible for generation of reactive radicals on the surface.

In this work, we report for the first time a unique configuration of N-doped and Cu-doped TiO2 bilayer. The activity of TiO2 was improved by combining Cu- and N-doping in a layered thin-film structure. The impact of the stacking order was studied, pointing out how the best arrangement is by far the one with Cu-TiO2 as the top layer. The results reveal a unique and simple way to enhance the photocatalytic response of TiO2 in the visible domain.

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