This paper develops and analyzes a new photo electrochemical reactor that uses zinc sulfide as a photo catalyst to produce hydrogen, chlorine and sodium hydroxide. The effects of different parameters on the rate of hydrogen, chlorine and sodium hydroxide production are experimentally studied. The parameters include the applied voltage, varied from 4 V to 5 V, amount of catalyst, varied from 1 g/425 mL to 5 g/425 mL and light intensity, varied from 20 W/m(2) to 55 W/m(2). A factorial design of experiments is applied and an analysis of variance (ANOVA) is used to examine the experimental results. Energy and exergy efficiencies are also calculated. An optimization is performed to find the optimal catalyst concentration. At the optimized catalyst concentration, salt water is used to check its effect on the rate of hydrogen production. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.