High Pressure Plasma Treatment for Controlling the Surface Activity and Optical Properties of TiO₂ Nanoparticles

Abstract

The effect of high pressure radio frequency (RF) plasma treatment on TiO2 surface and photocatalytic property has been investigated. X-ray photoelectron spectroscopy (XPS) measurements have shown the two different oxidation states of oxygen in the untreated TiO2 powder. Its relative proportion changes with the different dose of plasma treatments. The proportion of Ti3+ surface states also changes after plasma treatment and strongly depends on combination of plasma power and treatment time. The photocatalytic activity of plasma-untreated and -treated samples was measured by observing the relative degradation of methylene blue. The result showed about 50% increase in photoactivity at the sample treated with 10 W RF power plasma. Low power plasma treatment is a more efficient process for achieving a photoactive surface. The effect of total dose (power and treatment time) and power has been also studied to modify the surface activity of TiO2 nanoparticles.

Synthesis, Characterization, and Synergic Photocatalytic Activity of Amorphous TiO2/Chitosan Carbon Microspheres

“…59 The binding energies of O III (at 532.2 and 530.6 eV) and O IV (at 532.9 and 531.8 eV) corresponded to adsorbed hydroxide and molecular water on the rutile TiO 2 (110) surface, respectively. 50,51 The intensities of these peaks were in good agreement with the Ti 2p XPS spectra of the samples.…”

“…In addition, peaks at 463 eV (Ti 2p 1/2) and 456.7 eV (Ti 2p 3/2), assigned to Ti 3+ , clearly indicated the presence of oxygen vacancies generated by the removal of O 2− from the lattice. [50][51][52] The spectrum for CS/TiS/C-1 (Figure 8b) featured peaks at 464.1 and 459.2 eV, corresponding to Ti 2p 1/2 and Ti 2p 3/2 of Ti 4+ , respectively. An additional peak at 458.3 eV suggested the incorporation of C in the local Ti−O bond structure.…”

Optimized Method for Preparation of TiO<SUB>2</SUB> Nanoparticles Dispersion for Biological Study

“…Since the frequency of ultrasonic vibration in our study is set at 20 kHz, the energy effect on dispersion (2 ml) was examined in a series intensity of 0 W, 33 (Fig. 1).…”

Magnetic and structural properties of ion nitrided stainless steel

“…[1][2][3] Plasma nitriding of austenitic stainless steel, in particular, attracted strong interest owing to the formation of the expanded austenite ͑S, ␥ N , or m phase͒, a nitrogen-supersaturated compound with fcc-like crystalline structure. 4 A wealth of research was devoted to explain the nature of expanded austenite, so far without a satisfactory understanding of its formation and structure.…”