AACVD-engineered TiO2/ZnO/CuFeO2/SnO2/Pt architectures for enhanced solar hydrogen production

This work reports the synthesis and characterization of multilayer oxide heterostructures based on TiO 2 , ZnO, CuFeO 2 , SnO 2 , and Pt nanoparticles prepared by aerosol-assisted chemical vapor deposition. The optimized TiO 2 /ZnO/CuFeO 2 /SnO 2 /Pt configuration was systematically analyzed by XRD, SEM, XPS, HR-TEM, Raman, and UV–Vis–NIR spectroscopy, confirming well-defined heterojunctions and a hierarchical architecture. An ultrathin TiO 2 layer promotes the growth of ZnO microrods, acting as a three-dimensional scaffold for active layers. Under UV irradiation, the system achieved 12.1 μmol H 2 in 24 h (0.50 μmol h −1 ; ∼1.58 × 10 −2 μmol h −1 cm −2 ) with an apparent quantum efficiency of ∼0.016%. Enhanced performance is attributed to synergistic interactions at the CuFeO 2 /SnO 2 /Pt interface, where CuFeO 2 acts as light absorber, SnO 2 facilitates electron transport, and Pt serves as an electron sink and catalytic site. Results highlight interfacial charge transfer as the key factor governing thin-film photocatalytic performance. • Hierarchical TiO 2 /ZnO/CuFeO 2 /SnO 2 /Pt heterostructure fabricated by AACVD. • ZnO microrods act as a 3D scaffold enabling multi-interface heterojunctions. • CuFeO 2 /SnO 2 interfaces enhance charge separation and directional transport. • Pt nanoparticles act as electron sinks promoting efficient hydrogen evolution. • Synergistic architecture achieves 12.1 μmol H 2 with improved charge dynamics.