Gradient Design of Vacancies and Their Positive Correlation with Electrochemical Anticorrosion Protection

Abstract

The contribution of defects to electrochemistry is a controversial but practically applicable subject. Meanwhile, it is challenging to obtain precisely a certain nonchemometric single phase in mixed-valence compounds. The precise design of nonchemometric single-phase WO3–x (x = 0, 0.1, 0.28, and 1) mixed-valence metal oxides (MVMOs) was achieved by the gradient intrinsic reduction method, and the correlation between oxygen vacancies and electrochemical anticorrosion protection was explored systematically. Then, the decisive role of periodic oxygen vacancies in electrochemical anticorrosion was confirmed. And the origin was the synergistic reaction of oxygen vacancy-upgraded photocathodic protection, vacancy-induced passivation, and mixed-valence reductive protection, which were brought about by the high oxygen vacancy concentration. Integrating the above three aspects, the WO2.72 MVMO showed the best electrochemical anticorrosion performance by increasing the resistance value to 7.67 times that of the epoxy resin coating. The establishment of a positive correlation between oxygen vacancy and corrosion protection in WO3–x (x = 0, 0.1, 0.28, and 1) materials can not only guide the design of MVMOs but also make an important contribution to the rapid precorrosion performance of the materials.

Synthesis and Mechanism of Co2+/Sr2+ Codoped Magnetic Lanthanum Cuprate with Excellent Corrosion Resistance

“…One was an oxygen vacancy site proved by the EPR test, and the other was an interstitial channel based on the unique perovskite-like structure of La 1.96 Sr 0.04 Cu 0.98 Co 0.02 O 4 . The positions of the O β peaks of the doped samples showed a tendency to move toward a lower temperature compared to La 2 CuO 4 , indicating that oxygen vacancies could effectively enhance the mobility of oxygen species . In summary, La 1.96 Sr 0.04 Cu 0.98 Co 0.02 O 4 crystals had a strong spatial inclusion and reduction ability to hinder the electrochemical cathodic corrosion reaction by accommodating and reducing adsorbed oxygen through oxygen vacancies and lattice interstices (Figure b). E g = E normalV normalB − E normalC normalB O 2 ↔ O 2 ( a d s ) O 2 ( a d s ) + e − ↔ O 2 ( a d s ) − O 2 ( a d s ) − + e − ↔ 2 O normala normald normals − O normala normald normals − + e − ...…”

“…The positions of the O β peaks of the doped samples showed a tendency to move toward a lower temperature compared to La 2 CuO 4 , indicating that oxygen vacancies could effectively enhance the mobility of oxygen species. 41 In summary, La 1.96 Sr 0.04 Cu 0.98 Co 0.02 O 4 crystals had a strong spatial inclusion and reduction ability to hinder the electrochemical cathodic corrosion reaction by accommodating and reducing adsorbed oxygen through oxygen vacancies and lattice interstices (Figure 8b).…”

Enhanced Weathering and Corrosion Resistance of Eu-Doped ZnO Solid Solution Material by Fluorescence Modification

“…Bode plots (Figure e–h) of the above coatings were also compared, including the impedance modulus and phase angle. The low frequency (0.1 Hz) impedance modulus is usually considered as the semiquantitative indicator of corrosion resistance. , The impedance value of the EP coating at low frequency after 72 h immersion was 2799.4 ohm·cm –2 , and the impedance value of the ZEOSS-2 composite shielding layer at low frequency was 16,602 ohm·cm –2 , which was increased by 493.1%. Typically, the maximum phase angle can be used as a qualitative reference for the integrity of the coating .…”

Vanadium-Doped Induction of Bare Active Crystalline Planes of Tungsten Oxide and Its Excellent Anticorrosion Properties

“…The significantly enhanced anticorrosion performance of nonchemometric tungsten oxide (WO 3−x , 0 > x ≤ 1) due to its special defect structure was explored by Zhou et al 6 to provide a new idea for the design of smart electrochemical corrosion inhibitor materials. The main crystallographic planes of monoclinic WO 3 are usually (002), (020), and (200), but the (110) crystallographic plane is rarely reported.…”