This study aims to determine the maximum concentration of hydrogen gas produced through the electrolysis process of dry cell generators. This research using experimental generator apparatus with Sensor-MQ-8 Arduino and optimizing using Response Surface Method with Design Expert 6. To produce hydrogen gas is done through the method of water electrolysis by decomposing the molecule H2O into hydrogen gas and oxygen gas with the help of direct electric current. Hydrogen gas productivity by electrolysis method applied to DC generators using 4/4 plate electrodes (Cu/Al) as cathodes and NaNO3 solutions as electrolytes. The current and voltage used in this electrolysis process is 0.6 ampere and 2 volts for 1 hour. The optimum condition of hydrogen gas concentration obtained is at NaNO3 1 M concentration and 60 minutes with hydrogen concentration produced as much as 143.393 ppm. The verification result value for hydrogen gas concentration is 144 ppm.

The needs energy for fossil fuels continues to increase in people's lives and industry. Fossil energy that cannot be renewed and has an impact on environmental damage needs to be sought alternatives from renewable energy, one of which is hydrogen because it is more environmentally friendly and does not cause air pollution. Hydrogen production through water electrolysis is a processof equicurity of water molecules into hydrogen and oxygen gases using electric current. In this study aims to determine the optimum condition of hydrogen gas produced, which is influenced by electrolyte concentration, time and number of electrode plates with the method used that is electrolysis. Hydrogen gas concentrations are used by MQ-8 gas sensors and dry cell generators as gas production reactors. In this study, Cu/Al electrode plate was used because it has good electrical conductivity as electrode and NaNO3 is used as electrolyte. The current and voltage used in this electrolysis process remained at 0.6 ampere and 2 volts for 1 hour. The results of the measurement of optimum conditions using the RSM program obtained the optimum concentration of hydrogen gas at the number of plates 3/3 (Cu/Al) namely at the concentration of NaNO3 1 M and time 60 minutes with a hydrogen gas concentration of 75.8907 ppm and the result verification of 76 ppm, while on the number of plates 4/4 (Cu/Al) obtained hydrogen gas concentration of 129,841 ppm and verification of 130 ppm at NaNO3 concentration 1 M and time 60 minutes. Based on the data shows the prediction of optimum solution suggested by RSM program is good enough.