In water electrolysis, what is the effect of increasing: 1.voltage and 2.current?

Answer 1

The resaction will speed up, in both instances.

Answer 2

Typically the current is the important factor in electrochemistry for production of aluminum, sodium metal, or chlorine.

But you need to be over a minimum voltage, which is determined by what you are performing the electrolysis on.

Not sure how reliable the first poster's source is but I know that you need to use a 9 volt battery minimum to use in a chem lab where you have water electrolysis into hydrogen and oxygen.

If you work with batteries at the range of below 2 volts nothing will happen in the electrolytic solution.

Answer 3

If you increase the voltage between your two electrodes the current will increase and the rate of electrolytic decomposition of the water will go up. Alternatively, if you add a small amount of an electrolyte(a substance that provides ions to carry charge between the electrodes, like acid or a salt) and keep the voltage constant, the current will increase.

Answer 4

Increasing the voltage past about 1.8 V is not really possible since this is more than the overvoltage of about 0.6 V plus the decomposition potential for the water, about 1.2 V. Increasing the current, or electron passage rate, will increase the rate at which hydrogen and oxygen are produced.