Intrinsic Photocatalysis of Morphology and Oxygen Vacancy‐Tunable Ultrathin WO₃ Nanosheets

Abstract

The oxygen-deficient WO 3 nanosheets (WO 3 NS) with pore structure were synthesized by a facile solvothermal approach and their microstructure and oxygen vacancy (V o ) were regulated via heat treating atmosphere. The mean thickness of WO 3 NS is about 1.2 nm, which is equivalent to the thickness of single atom or molecule layer. The quantitative analyses on the ultrathin WO 3 NS of catalytic dynamic and V o concentrations have been done. The appropriate V o concentration can play a critical role in the transfer/separation of surface photogener-ated carriers. Using phenol as the target compound and hydrogen peroxide as the accelerant, under visible-light irradiation, the apparent rate constant of WO 3 -Ar NS is about 2.0 times and 1.8 times than that of WO 3 nanoparticles and WO 3 -air NS, respectively. These unique photocatalytic properties were attributed to the contribution of atomic layers, suitable crystal phase and porous surface and appropriate V o content, which increases the specific surface areas and regulates the electrical properties.[a] Prof.

Functionalization-Mediated Preparation via Acid Precipitation and Photocatalytic Activity of In Situ Ag2WO4@WO3.H2O Nanoplates

“…However, an obstacle for the wide use of WO 3 in photocatalytic applications is the high recombination rate of photogenerated electron-hole pairs, resulting in low photocatalytic activity of pristine WO 3 . 5 Many efforts have been made to reduce the recombination rate of photogenerated electron-hole pairs in WO 3 -based nanomaterials, including compositing with electronstorage or electron-capturing materials, such as graphene, 6 graphitic-like carbon nitride, 7 and noble metal nanoparticles (such as Pt) 8 or even engineering the phase junction in WO 3 nanomaterials. 9 Among the various approaches to reduce the recombination rate of photogenerated electron-hole pairs in WO 3 -based nanomaterials, the functionalization of WO 3 with Ag or Ag-based compounds is one of the most popular approaches.…”

Active W Sites Promoted by Defect Engineering Enhanced C2H6S3 Sensing Performance of WO3 Nanosheets

“…Figure shows typical bending vibration and stretching vibrations of O–W–O of D-WO 3 . The peaks near 709.2 and 806.1 cm –1 are ascribed to the stretching modes of W–O vibrations, while the peaks at 265.6 and 326.2 cm –1 corresponded to the W–O–W bending vibration peak. , As the hydrogenation time increases, all characteristic peak positions gradually red-shift, and these changes indicate that the increase in hydrogenation time aggravates the lack of oxygen atoms in the sample, thereby affecting the molecular vibration of WO 3 NSs. Figure S3a shows the UV–vis absorbance of D-WO 3 .…”

“…Raman spectroscopy was employed to obtain more information on the molecular vibration mode of WO 3 to further explore the structure information of WO 3 with oxygen defects. Figure 3 38,39 As the hydrogenation time increases, all characteristic peak positions gradually red-shift, and these changes indicate that the increase in hydrogenation time aggravates the lack of oxygen atoms in the sample, thereby affecting the molecular vibration of WO 3 NSs. Figure S3a shows the UV−vis absorbance of D-WO 3 .…”

Doping regulates pyro-photo-electric catalysis to achieve efficient water splitting in Ba1−xSrxTiO3 through solar energy and thermal resources

“…1,2 Since Fujishima and Honda used n-type semiconductor TiO 2 to achieve the decomposition of aqueous hydrogen in 1972, 3 photoelectrochemical (PEC) water splitting based on semiconductors has been considered to be an important way to develop renewable hydrogen. In recent years, some n-type semiconductors such as WO 3 , 4 Fe 2 O 3 , 5 ZnO, 6,7 and BaTiO 3 8 have been used for photoelectrochemical water splitting. However, a limited light response range, low carrier separation and utilization efficiency are still the bottleneck of large-scale applications.…”