Pure and modified
mesoporous TiO2 nanoparticles with
different loadings of NiO (3–20.0 wt %) were prepared through
the surfactant-assisted sol–gel approach with the use of cetyltrimethylammonium
bromide as a template. The optical and structural properties of different
samples were examined using N2 adsorption–desorption
analysis, energy-dispersive spectroscopy, scanning electron microscopy,
transmission electron microscopy, X-ray diffraction, X-ray photoelectron
spectroscopy, UV–vis spectroscopy, Fourier transform infrared
spectroscopy, and photoluminescence (PL) spectroscopy. X-ray diffraction
results confirmed the insertion of Ni2+ into the lattice
of TiO2, and the crystallite size reduced remarkably after
the addition of NiO. The diffuse reflectance spectroscopy spectra
displayed obvious red shift in the absorption edges, and new absorption
bands appeared in the visible region when NiO was added, which indicates
the formation of surface defects and oxygen vacancies. The optical
band gap of TiO2 reduced sharply when the contents of NiO
were increased. The increase in the surface defects as well as oxygen
vacancies were examined using PL spectroscopy. The photocatalytic
performance of the as-synthesized samples was investigated over photodegradation
of brilliant green (BG) and phenol and hydrogen generation under visible
light. 10% NiO/TiO2 exhibited the highest photocatalytic
efficiency. The photocatalytic activity was improved due to the creation
of a p–n junction at the interface of NiO/TiO2,
which efficiently promotes the separation of photogenerated electron/hole
pairs and consequently enhances its photodegradation activity. According
to the photocatalytic activity results, NiO contents were considered
one of the most important factors affecting the photodegradation of
BG and phenol and H2 evolution. Also, we discussed the
mechanism of photodegradation, mineralization (total organic carbon),
and photocatalytic reaction kinetics of BG and phenol.
Polyaniline (PANI) has received significant attention in basic and applied studies because it has electrical and electrochemical properties comparable to conventional semiconductors and metals. PANI's electrical and electrochemical properties can be controlled through its preparation methods. Accordingly, in the present work, two different samples of PANI were prepared by the polymerization of aniline monomer via in situ polymerization method using two different oxidizers of dichromate (PANI (1)) and persulphate (PANI (2)). The products were blended with BaTiO3 (BTO) to form BTO@PANI composites. The composites were characterized by scanning electron microscopy (SEM), Fourier transforms infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). SEM illustrated the covering of PANI layers on the BTO nanoparticles. The electrical and electrochemical properties of the prepared composites were studied. The BTO@PANI(2) composite sample showed a conductivity of 1.2 × 10–3 S/cm higher than that found for each BTO@PANI(1) 9.1 × 10–4 S/cm and its constituents. The supercapacity showed higher capacity values of 70 F/g, and 76 F/g for BTO@PANI(1), and BTO@PANI(2), respectively, which are higher than its constituents.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.