Abstract
In recent years, photoelectrochemical (PEC) based devices have become attractive due to produc- tion of hydrogen by splitting water using photocatalyst alpha (alpha)-hematite (Fe2O3) as an electrode material due to its bandgap, low cost, chemical stability and extreme abundance in nature. The alpha-Fe2O3 is also related to low carrier diffusion due to higher resistivity, slow surface kinetics, low electron mobility and higher electro-hole combination. The carrier mobility and carrier diffusion properties of alpha-Fe2O3 have been enhanced by doping as well as composite formation. Keeping in view the enhanced properties of alpha-Fe2O3, attempt is being made to dope and form composite using trivalent "aluminum" ions. The Al-alpha-Fe2O3 nanophotocatalytic materials were synthesized by varying the ratio of Al to alpha-Fe2O3 using sol-gel technique. The nanomaterials "alpha-Fe2O3 and Al-alpha- Fe2O3" were physically characterized through X-ray diffraction, scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy and UV-visible techniques, respectively. The diffusion coefficient of nanomaterials at the electrode/electrolyte interface was analyzed using electro- chemical analysis. Interestingly, the presence of aluminum causes the alpha-Fe2O3 to change the structural, optical and morphological properties of nanomaterials. The bandgaps of alpha-Fe2O3 vary from 2.2 eV to 2.45 eV due to presence of aluminum in the structure. The photocurrent studied on Al-alpha-Fe2O3 based electrode clearly shows the enhanced hydrogen production under photoelectrochemical cell.