Removal Efficiency for TiO2 nanotubes
The Cu2+ adsorbed by the TiO2 nanotubes was calculated by measuring the remaining concentration of Cu2+ remaining in the various solution, using the ICP, and subtracting it from the original concentration of Cu2+ added. The % removal of Cu2+ by the TiO2 nanotube was then calculated. The sample containing an initial concentration of 10.0 mg/L had the highest removal efficiency of 99.57%, followed by the sample with 1.0 mg/L, 90.90%, the sample with 100.0 mg/L, 9.92%, and lastly, the control.
For deeper analysis, the efficiency of Cu2+ removal per g of TiO2 nanotube was also calculated. Sample 3, with a Cu2+ concentration of 10.0 mg/L, also demonstrated the highest removal efficiency of 9.96 mg/g. With a difference of only 0.04 mg/g, sample 4, which had a Cu2+ concentration of 100.0 mg/L, was able to remove 9.92 g of Cu2+ per g of TiO2. Lastly, sample 2 removed only 0.91 mg per g of TiO2. The control, having no Cu2+ present in the solution had no Cu2+ removal.