Is the adsorption of dissolved iodine onto activated carbon physical adsorption or chemical adsorption? For an experiment, I am looking to see the effect of temperatures from 0–100 °C on the efficacy of activated carbon as an adsorbent. My adsorbate is iodine and I am confused as to whether the adsorption taking place below 100 °C is physical or chemical adsorption.

I have also read that physical adsorption decreases with an increase in temperature while chemical adsorption increases and then decreases with an increase in temperature. Additionally, I was wondering whether chemical adsorption takes place at all temperatures.
The mechanism(s) of iodine adsorption into carbons are complex and strongly dependent on each carbon. That is, iodine can be physisorbed in the carbon micro/mesopores, but in carbons with a rich surface chamistry, it can also be chemically adsorbed through charge transfer interactions.
There are many papers about this, but this one shows clear evidence of both mechanisms. (Written by the carbon "connoisseur" Harry Marsh).
They clearly mention:


  Thus, both classical physical adsorption theory and more specific chemical interactions have been proposed to model the adsorption of iodine by carbonaceous materials.


Strong evidence is provided in the paper itself.