i need help in designing electric circuit for chemical reaction
the required components are

DC voltage ( i must control it so that i can see the reaction response to different voltages ) in range from zero to 2.5 volt (the main power in my work is AC 110-220 V)

current density in range from Zero to 0.2 Amp/cm2 (also i must control it so that i can see the response of the reactin to different current densities )

thanks too much for any help