Laras Fadillah, Damian Kowalski, Sho Kitano, Chunyu Zhu, Yoshitaka Aoki, Hiroki Habazaki
This study demonstrates the highly enhanced photocatalytic activity of Fe2O3 nanotubes by making a heterojunction with Fe2WO6 and doping of W6+ ions into the α-Fe2O3 phase for water splitting and decomposition of an organic pollutant. Both nanotubular and compact Fe2O3/Fe2WO6 films are formed by anodizing the magnetron-sputtered Fe-9 at% W alloy in fluoride-containing ethylene glycol electrolyte and subsequent annealing at 450 °C. Their photocatalytic activities are compared with W-free nanoporous Fe2O3 film formed on high-purity Fe. The nanotubular Fe2O3/Fe2WO6 film exhibits a markedly enhanced photoelectrochemical oxygen evolution reaction and photocatalytic degradation of methylene blue compared with the nanoporous W-free Fe2O3 film. Because of the larger surface area, the nanotubular Fe2O3/Fe2WO6 film reveals further increased activity than the compact Fe2O3/Fe2WO6 film. The STEM study discloses the dispersion of Fe2WO6 nanoparticles in the α-Fe2O3 phase after annealing at 450 °C, and XRD analysis shows the possible doping of W species into α-Fe2O3. The formation of the W-doped α-Fe2O3/Fe2WO6 heterojunction likely promotes the separation of photogenerated electron-hole pairs, enhancing photocatalytic activity. Hence, the nanotubular Fe2O3/Fe2WO6 film is a possible candidate for visible-light-driven photocatalysts. © 2023 The Authors
Graduate School of Chemical Sciences and Engineering, Hokkaido University, Hokkaido, Sapporo, 060-8628, Japan; Division of Applied Chemistry, Faculty of Engineering, Hokkaido University, Hokkaido, Sapporo, 060-8628, Japan; Engineering Physics, Institute Technology Sumatera, Jl. Terusan Ryacudu, Way Huwi, Kec. Jati Agung, Lampung, Kabupaten Lampung Selatan, 35365, Indonesia; Biological and Chemical Research Centre, University of Warsaw, Zwirki i Wigury 101, Warsaw, 02-089, Poland; Faculty of Chemistry, University of Warsaw, Pasteura 1, Warsaw, 02-093, Poland