The substrates were degassed and stored under argon prior
to use. The ionic liquid 1-n-butyl-3-methylimidazolium tetrafluoroborate
(BMI.BF4) used for the synthesis of TiO2 NPs was
prepared from a reported procedure [29]. All the other chemicals
were purchased from commercial sources. Mass spectra were
obtained using a GC–MS Schimadzu QP-5050 (EI, 70 eV) and gas
chromatography analyses were performed with an Agilent Technologies
6820 gas chromatograph with a flame ionisation detector
and 30 m capillary column with a (5%-phenyl)-methylpolysiloxane
stationary phase. Transmission electron microscopy (TEM) analysis
was measured in a JEOL JEM 1200 ExII 120 kV operating at
80 kV. SEM measurements were recorded in a JEOL JSM 5800 at
20 kV equipped with an EDS detector. X-ray powder diffraction
(XRD) experiments were conducted on a D/max-3B diffractometer
with Cu K radiation.