Improvement of photoelectrochemical water splitting with natural dye of pitaya peel

The clean and recyclable production of hydrogen gas by water splitting over a semiconductor photocatalyts using solar energy is a promising process. Photoelectrochemical (PEC) water splitting is one of most favourable hydrogen production technologies. The development of TiO₂ semiconductor has been widely studied for its efficiency reasons. However, the large band gap of TiO₂ can only absorb UV light thus reducing its performance in PEC. Besides, recombination of electron-hole pairs also influenced efficiency of photoelectrochemical reaction. Thus, a lot of efforts have been made to increase the performance of PEC and considerably attention is given to dye sensitizers especially natural dye due to their environmental friendliness and low cost. Hence, this research studied the natural dye of pitaya peel which contains betalains due to its availability in local area and low in conservation cost. Thus, the physical and chemical characterization of TiO₂ thin film with dye has been investigated through SEM, XRD and UV-Vis analysis. The optical absorption for the dye is 546 nm show good absorption in visible light with band gap 2.3eV. For photoelectrochemical properties, photoelectrode TiO₂/dye/PEDOT:PSS has the highest photocurrent which are 0.62 μAcm^- and increased further to 1.4 μAcm^-2 with the addition of pitaya dye in aqueous electrolyte.