Seeking help with electrolysis experiments
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Dear sea friends, I am conducting an electrolysis experiment. The anode is a titanium-coated electrode, while the cathode is a titanium metal plate. The electrolyte consists of 0.2 mol/L sodium sulfate and 200 mg/L phenol. The voltage applied is 3.6 V, resulting in a current of 0.16 A. However, within two minutes, the current began to decrease, and in less than half an hour it dropped to 0.04 A; at this point, almost no electrolytic reaction took place anymore. I would like to ask fellow sailors why the current keeps decreasing when the voltage remains constant, and also why it is so low (whether it’s 0.04A or 0.16A?) My guess: The current keeps decreasing because the resistance keeps increasing, but the composition of the solution shouldn’t change that quickly, right? The current is also too low; could it be due to the high internal resistance of the power supply? The model of power supply I’m using is JC3005A-3 LABORATORY DC POWER SUPPLY. Also, if the power supply is used for too long, will its internal resistance increase?
It must be that the formation of colloids in the solution leads to a decrease in ionic conductivity!
If the internal resistance increases, will the power supply get damaged? Does the power supply generate heat?
The starting current is relatively high but then drops; I guess it’s because of the gold!
It is not the electrolysis of precious metals; rather, a electrochemical method is used to oxidize phenol, with hydrogen being produced at the cathode and phenol being oxidized at the anode.
It contains sodium sulfate, as well as trace amounts of phenol; it shouldn’t form a colloid, right?
Oh, the power supply isn’t heating up. I used a multimeter to measure the resistance of the two power supplies; one had a resistance of 900 ohms, and the other had 1800 ohms. Are these values normal? Thank you
The positive electrode is connected to the DSA-coated electrode, and the negative electrode is connected to the titanium plate; that should be correct
In simple terms, it means that the current drops sharply; this is definitely due to a problem with the conductivity of the solution, that is, there are fewer ions available to move freely within the solution