Comparative photoelectrochemical study of PEC solar cell fabricated with n-TiO2 photoelectrodes at different temperatures and under different oxygen flow rates

Abstract

Photoelectrochemical splitting of water induced by solar energy for hydrogen production has been studied in the present investigation. PEC solar cell was fabricated with n-TiO2 photoelectrodes synthesized at different oxidation temperatures e.g. 700°C, 750°C, 800°C and 850°C under oxygen flow rate 200 ml/min, 350 ml/min and 500 ml/min. The optimum oxygen flow rate for all the temperatures was found to be 350 ml/min. This is therefore kept invariant for synthesis of electrodes at different temperatures. The photoelectrochemical characterization of the PEC cell was done in the three-electrode configuration, i.e Ti/n-TiO2/1M-NaOH/Pt. It has been observed that the optimum values of the PEC solar cell parameters are exhibited by the solar cell employing the photoelectrodes prepared at ∼750°C. The XRD and SEM explorations revealed that the TiO2 prepared at ∼750°C is in the nanometric range (∼100-150 nm). The TiO2 films formed at this temperature has been found to exhibit optimum PEC solar cell parameters. The PEC parameters, like photocurrent density, photoconversion efficiency and hydrogen production rate, with this photoelectrode correspond to 0.93 mA/cm2, 0.472% and 4.00 l/hm 2 respectively.