Average diameter and standard deviation of particles obtained for TiO₂ NPs/BMI·BF₄ IL, 1% Fe³⁺-doped TiO₂ NPs/BMI·BF₄ IL and 1% Cu²⁺-doped TiO₂ NPs/BMI·BF₄ IL analyzed by TEM.

Material	Average particle diameter (nm)
TiO2 NPs/BMI·BF4 IL	21.8 ± 2.9
1% Fe3+-doped TiO2 NPs/BMI·BF4 IL	18.9 ± 2.8
1% Cu2+-doped TiO2 NPs/BMI·BF4 IL	20.2 ± 3.2