Enhanced photocatalytic water splitting of a SILAR deposited α-Fe(2)O(3) film on TiO(2) nanoparticles

We have investigated the effect of deposition of a α-Fe(2)O(3) thin layer on a substrate of TiO(2) nanoparticles for photoelectrochemical (PEC) water splitting. The TiO(2) layer was coated on an FTO substrate using the paste of TiO(2) nanoparticles. The α-Fe(2)O(3) layer was deposited on the TiO(2) thin film, using the method of Successive Ionic Layer Adsorption and Reaction (SILAR) with different cycles. Various characterizations including XRD, EDX and FE-SEM confirm the formation of α-Fe(2)O(3) and TiO(2) nanoparticles on the electrode. The UV-visible absorption spectrum confirms a remarkable enhancement of the absorption of the α-Fe(2)O(3)/TiO(2)/FTO composite relative to the bare TiO(2)/FTO. In addition, the photocurrents of the composite samples are remarkably higher than the bare TiO(2)/FTO. This is mainly due to the low band gap of α-Fe(2)O(3), which extends the absorption spectrum of the α-Fe(2)O(3)/TiO(2) composite toward the visible region. In addition, the impedance spectroscopy analysis shows that the recombination rate of the charge carriers in the α-Fe(2)O(3)/TiO(2) is lower than that for the bare TiO(2). The best PEC performance of the α-Fe(2)O(3)/TiO(2) sample was achieved by the sample of 70 cycles of α-Fe(2)O(3) deposition with about 7.5 times higher photocurrent relative to the bare TiO(2).