Semiconductor-septum photoelectrochemical cell for solar hydrogen production

The present paper describes the fabrication and solar hydrogen production studies employing a new semiconductor-septum (SC-SEP) photoelectrode ns-TiO2–In2O3 admixed/Ti based photoelectrochemical solar cell. The current-voltage characteristics of the above SC-SEP cell revealed that an enhancement in short-circuit current (ISC) up to three times (5∼18.6 mA cm−2). The rate of hydrogen production was found to change with variation in the concentration of the electrolyte in the dark compartment; e.g. for 1 M H2SO4 it is 6.0 lh−1 m−2 and for 6 M it is 14.6 lh−1 m−2. The optimum hydrogen production rate was found to be 14.6 lh−1 m−2 for 6 M H2SO4 and with a further increase in H2SO4 concentration, the hydrogen production rate was found to be invariant. another part of our study instead of using new SC-SEP solar cell design, we used a new material form such as ns-TiO2–VO2. The VO2 admixed ns-TiO2 exhibited a high photo-current and photo-voltage of 19.2 mA cm−2, 680 mV, respectively. The ns-TiO2–VO2 electrode exhibited a higher hydrogen gas evolution rate of 16 l/h1/m2. ces and arguments are put forward to show that, whereas for the bare ns-TiO2 electrode, the improvement in the performance of this photo-electrode compared with its original form was due to the higher quantum yield. In the case of ns-TiO2–In2O3 and ns-TiO2–VO2 photo-electrodes, the improvement is due to the improved spectral response resulting from decrease of energy band gap.