First-Principles Study on the Adsorption Characteristics of Corrosive Species on Passive Film TiO2 in a NaCl Solution Containing H2S and CO2

Abstract

The adsorption characteristics of corrosive anions (Cl−, HS−, S2−, HCO3− and CO32−) on TiO2 of TC4 titanium alloy in a NaCl solution containing H2S and CO2 were studied by density functional theory (DFT). The stable adsorption configuration of each corrosive species on the TiO2 (110) surface was obtained by geometric optimization, and the electronic structure and interface binding energy were calculated and analyzed. The results showed that the optimal adsorption positions of Cl−, HS−, S2−, HCO3−and CO32− on TiO2 (110) were all bridge positions. There was a strong charge interaction between the negatively charged Cl, S and O atoms in Cl−, HS−, S2−, HCO3− and CO32− and the positively charged Ti atoms of TiO2. The interface bonding was mainly caused by charge movement from around Ti atoms to around Cl, O, S atoms. The energy levels were mainly caused by the electron orbital hybridization of Cl-3p5, S-3p4, O-2p4 and Ti-3d2. All adsorption configurations were chemical adsorption. The order of influence of the five ions on the stability of TiO2 was S2− > CO32− > Cl− > HS− > HCO3−. Finally, a novel corrosion mechanism was proposed to illustrate the dynamic evolution processes of pits.

The Microstructure and Properties of Ni-Si-La2O3 Coatings Deposited on 304 Stainless Steel by Microwave Cladding

“…The “wear rate and coefficient of friction” of the developed “cladded surface” with “69.72% Ni, 19.28% Si, and 11% La 2 O 3 particles” were observed to be 0.00367 mm 3 /m and 0.312, respectively, which is appropriate to be utilized anywhere. Nevertheless, the foremost purpose for “good wear resistance” is the “use of La 2 O 3 with Ni and Si powder” in the development of the “cladding surface” [ 60 , 61 , 62 ]. The development of “hard phases such as Ni 3 C, NiC, and La 2 O 3 phases” ( Figure 12 ) on the “surface of SS-304” with “microwave cladding of the mixture of 69.72% Ni, 19.28% Si, and 11% La 2 O 3 particles” was responsible for increased “wear resistance”.…”

Stimuli-Activable Metal-Bearing Nanomaterials and Precise On-Demand Antibacterial Strategies

“…Using light as an external trigger to control biological actions is highly attractive because it provides high spatiotemporal resolution without physical contact. , Among various mechanisms, photodynamic therapy that uses ROS to induce cellular oxidative stress leading to cell death has become a promising antibacterial strategy. − Metal-bearing nanomaterials with photocatalytic activity are usually made of semiconductor materials, like zinc oxide (ZnO), titanium dioxide (TiO 2 ), copper oxide (CuO), etc . They have been widely used in antibacterial studies where light is essential for them to catalyze O 2 or H 2 O to generate ROS ( e.g.…”

“…83−86 Metal-bearing nanomaterials with photocatalytic activity are usually made of semiconductor materials, like zinc oxide (ZnO), titanium dioxide (TiO 2 ), copper oxide (CuO), etc. 87 They have been widely used in antibacterial studies where light is essential for them to catalyze O 2 or H 2 O to generate ROS (e.g., O 2 −• , • OH, 1 O 2 ) and so as to kill bacterial. 88−95 In addition to these ROS generation properties that have been extensively exploited earlier, 8 nanomaterials' peroxidase-mimicking activity (as known as nanozymes) for ROS generation under hydrogen peroxide (H 2 O 2 ) have also been exploited in antibacterial fields.…”

Fe3O4@ABA-aniline-CuI nanocomposite as a highly efficient and reusable nanocatalyst for the synthesis of benzothiazole-sulfide aryls and heteroaryls

“…7 One of the most important goals of modern chemistry is to combine the benefits of both heterogeneous and homogeneous catalysts. 15–19 Nanocatalysts have the advantages of both the mentioned systems and their activity, selectivity, high stability and ability to be recovered from the reaction medium. 20–22 Nanoparticles are a group of materials that are artificially produced by combining atoms, molecules or groups of them.…”