Lab 3

April 25th, 2014

Today our group conducted the coating of the Iron Hydroxide film onto the substrates.

Figure 1. Sodium Hydroxide (left) and Iron(III)
chloride hexahydrate (Right)

The first part of the lab consisted of preparing the solutions for the substrates to be dipped in and coated with. The solutions were comprised of  Sodium Hydroxide (left side of Figure 1) and Iron(III) chloride hexahydrate (Right side of Figure 1). The first made was a 0.1 molar solution of Sodium Hydroxide. The second was a 0.5 molar solution of Iron(III) chloride hexahydrate. The solutions were both mixed using the magnetic stirrer seen in Figure 2.




Figure 2. Magnetic Stirrer

Figure 3. SILAR Machine

After the synthesis of the solutions was complete, the substrates were put through successive ionic layer absorption and reaction (SILAR) using the machine seen in Figure 3. Unfortunately, while attempting to remove the substrates from the petri dish left in for storage, the titanium dioxide coating had dried and stuck to the dish for substrate 2. This resulted in the substrate being damaged on the conductive side rendering it useless. This left us with only 3 good substrates left for testing. The solutions were placed in the circular order of 6 solutions starting with the Iron(III) chloride hexahydrate, then a rinse solution of DI water, the Sodium Hydroxide to follow, another rinse, and then repeat. The substrates were held by a robotic arm inside the machine that dipped them into the solution and rotated rapidly. After the substrates were put into place, they were left to run through the SILAR for 30 cycles. After that, we removed the first substrate, and left the two others in for another 60 cycles for a total of 90.