Enhanced photoelectrocatalytic performance of α-Fe(2)O(3) thin films by surface plasmon resonance of Au nanoparticles coupled with surface passivation by atom layer deposition of Al(2)O(3)

The short lifetime of photogenerated charge carriers of hematite (α-Fe(2)O(3)) thin films strongly hindered the PEC performances. Herein, α-Fe(2)O(3) thin films with surface nanowire were synthesized by electrodeposition and post annealing method for photoelectrocatalytic (PEC) water splitting. The thickness of the α-Fe(2)O(3) films can be precisely controlled by adjusting the duration of the electrodeposition. The Au nanoparticles (NPs) and Al(2)O(3) shell by atom layer deposition were further introduced to modify the photoelectrodes. Different constructions were made with different deposition orders of Au and Al(2)O(3) on Fe(2)O(3) films. The Fe(2)O(3)-Au-Al(2)O(3) construction shows the best PEC performance with 1.78 times enhancement by localized surface plasmon resonance (LSPR) of NPs in conjunction with surface passivation of Al(2)O(3) shells. Numerical simulation was carried out to investigate the promotion mechanisms. The high PEC performance for Fe(2)O(3)-Au-Al(2)O(3) construction electrode could be attributed to the Al(2)O(3) intensified LSPR, effective surface passivation by Al(2)O(3) coating, and the efficient charge transfer due to the Fe(2)O(3)-Au Schottky junctions.