The procedure for the preparation o

The procedure for the preparation of the PANI:PSS homogeneous polymer solution was modified from a similar one reported previously,[27a]and the details are described as follows. First, 15 mL of deionized water, 0.621 mL of concentrated HCl, 56 μL of AN, and a magnetic stir bar (30 mm × 3 mm) were added into a DURAN® glass laboratory bottle (100 mL), and the obtained solution was stirred at 1,000 rpm at room temperature for 30 min in order to acidize AN. Thereafter, 0.5 g of PSS was dissolved in 15 mL of deionized water to obtain a colorless solution named as solution A, and 0.157 g of APS, which plays the role of initiator in polymerization, was dissolved in 10 mL of deionized water to obtain solution B. The solution A was then added into the aforementioned solution in the DURAN® glass bottle, and the mixture was stirred at 1,000 rpm at room temperature for 6 h. Thereafter, the solution B was added into the mixture under continuous stirring with a slow injecting rate of 1 mL/min. After finishing the addition of APS, the obtained colorless solution was further allowed to stir at 1,000 rpm for 20 min. The color of the solution gradually changed from colorless to green during the 20 min of stirring. The solution was then kept for overnight at room temperature to ensure the complete polymerization before further use or processing; a homogeneous polymer solution of well disperse PANI:PSS with a dark green color was thus obtained (Figure S1(a)). This PANI:PSS solution can be stored at room temperature for days without forming any precipitate. No precipitation was observed even after the centrifugation of the PANI:PSS solution at 12,300 rpm for 5 min, as shown in Figures S1(b) and S1(c).To obtain the bulk PANI solid that does not contain a majority of PSS and other reagents in order to fairly compare it with the poreconfined PANI in UiO-66-NH2, 120 mL of acetone was added into 15 mL of the aforementioned polymer solution; significant amount of green solid generated in the mixture, as shown in Figure S1(d). The obtained mixture was subjected to centrifugation at 12,300 rpm for 5 min to remove the supernatant. Thereafter, the solid was washed with 30 mL of 0.2 M HCl aqueous solutions for three times by centrifugation in order to remove the excess PSS and other reagents from the solid. The solid was then washed with 30 mL of acetone for three times, with the immersing periods of 2 h, overnight, and 2 h in between, respectively; all these washing steps were kept the same as those for washing PANI/UiO-66-NH2. After the removal of the supernatant, the resulting solid was dried at 60 °C under vacuum for 2 h, and the PANI solid with a dark green color was obtained.