Plasma treated Bi₂WO₆ ultrathin nanosheets with oxygen vacancies for improved photocatalytic CO₂ reduction

Abstract

Ar-plasma treatment quickly and effectively increased the amount of oxygen vacancies on the surface of Bi2WO6. In photocatalytic CO2 reduction, the CO generation rate of Bi2WO6 with abundant surface oxygen vacancies increased by 2.4 times.

Facile Route of P‐doped Defect‐rich Manganese‐cobalt Oxide Spinel with Enhanced Oxygen Evolution Reaction Performance

“…This result suggests that plasma etching can create rich oxygen vacancies on the surface of MCO. Oxygen vacancy also can be etched by plasma on other metal oxides [7c,14c,15a,17] . In Figure 4c, the orange inset shows typical dark sites, and the red inset shows large dark local areas, suggesting the formation of a disordered structure on the MCO−P, such as dopants and defects; [7c] this structure is caused by losing metals, doping phosphorus, and etching oxygen vacancies during the reaction between MnCo 2 O 4 and NaH 2 PO 2 under plasma.…”

“…Oxygen vacancy also can be etched by plasma on other metal oxides [7c,14c,15a,17] . In Figure 4c, the orange inset shows typical dark sites, and the red inset shows large dark local areas, suggesting the formation of a disordered structure on the MCO−P, such as dopants and defects; [7c] this structure is caused by losing metals, doping phosphorus, and etching oxygen vacancies during the reaction between MnCo 2 O 4 and NaH 2 PO 2 under plasma. These disordered phases can provide extra active sites for electrochemical reaction and improve electrical conductivity [18] …”

“…Plasma is normally formed at a high voltage to ionize gas that contains amounts of high‐energy electrons and activated particles. Recently, plasma has been used to introduce oxygen vacancies and dope heteroatoms into catalysts [7c,13–14] . In those works, the defect or dopant structure of catalysts on the surface were determined by the gaseous composition of plasma.…”

Vacancy Engineering of Ultrathin 2D Materials for Photocatalytic CO2Reduction

“…Thanks to the presence of surface defects, the CO 2 photoreduction performance is obviously improved (Table 1). In this section, according to these research papers’ results, some typical strategies, including solvent‐thermal methods, [21,40] liquid exfoliation, high temperature calcination, [39,41] plasma treatment, [30,42] and ultraviolet irradiation, [32] are discussed in detail, and their associated mechanism for vacancy formation will be proposed.…”

“…Taking defective C 3 N 4 nanosheet as an example, [31] Ar plasma treatment endowed C 3 N 4 with abundant surface defects, which was verified by the EPR spectra. In another work, a dielectric barrier discharge plasma etching technique was employed to create oxygen vacancies on the ultrathin Bi 2 WO 6 nanosheets [30] . In this case, the 15 min's plasma etching can give rise to an dramatically increased oxygen vacancy concentration as compared to pristine Bi 2 WO 6 nanosheets.…”