Abstract
Polydopamine (PDA) films, when combined with model nanometric semiconductor substrates like titanium dioxide (TiO2) and zinc oxide (ZnO), enhance photocatalytic performance, generating a unique ex-situ functional heterojunction. We investigate PDA air/water films transferred onto large surfaces, revealing Janus-like films with strong chemical attachment. Spectroscopic methods confirm a functional hybrid heterojunction, while electrochemical studies show significant improvements with transfer resistance enhancement of ∼2250 %. This opens doors to various practical applications for hybrid heterojunctions.