Surface Morphology-Dependent Functionality of Titanium Dioxide–Nickel Oxide Nanocomposite Semiconductors

Abstract

In this study, TiO2–NiO heterostructures were synthesized by combining hydrothermal and chemical bath deposition methods. The post-annealing temperature was varied to control the surface features of the TiO2–NiO heterostructures. TiO2–NiO heterostructures annealed at 350 °C comprised NiO-nanosheet-decorated TiO2 nanostructures (NST), whereas those annealed at 500 °C comprised NiO-nanoparticle-decorated TiO2 nanostructures (NPT). The NPT exhibited higher photodegradation activity than the NST in terms of methylene blue (MB) degradation under irradiation. Structural analyses demonstrated that the NPT had a higher surface adsorption capability for MB dyes and superior light-harvesting ability; thus, they exhibited greater photodegradation ability toward MB dyes. In addition, the NST showed high gas-sensing responses compared with the NPT when exposed to acetone vapor. This result was attributable to the higher number of oxygen-deficient regions on the surfaces of the NST, which increased the amount of surface-chemisorbed oxygen species. This resulted in a relatively large resistance variation for the NST when exposed to acetone vapor.

Fabrication of TiO2/NiO p-n Nanocomposite for Enhancement Dye Photodegradation under Solar Radiation

“…The space charge layer induces an internal electrical field by polarization. The built-in electron field leads to changes in the energy band bending of the TiO 2 NTs and NiO NPs at the interface [ 93 ].…”

Coverage Layer Phase Composition-Dependent Photoactivity of One-Dimensional TiO2–Bi2O3 Composites

“…The formation of a homojunction consisted of the Bi2O3 polymorphs demonstrates a higher light harvesting ability than that of the single constituent counterpart [24]. Moreover, the sheet-like surface crystal feature in a one-dimensional composite has also been shown in several heterogeneous systems that is beneficial for light-harvesting enhancement [9,25]. Figure 7a displays photoresponse curves of the TiO2, TiO2/s-Bi2O3, and TiO2/a-Bi2O3 rods at the 1 V under chopped light irradiation.…”

Physical Characterization and Cellular Toxicity Studies of Commercial NiO Nanoparticles

“…Nickel oxide (NiO) nanoparticles are used in a wide array of industrial applications including in batteries, semiconductors [ 1 , 2 ], textiles [ 3 ], solar cells, and other electronic components [ 4 , 5 ]. Human exposure arises from the production of these materials both from the manufacturing processes as well as their use.…”