2D–2D WO₃–Bi₂WO₆ photocatalyst with an S-scheme heterojunction for highly efficient Cr(vi) reduction

Abstract

A two-dimensional (2D)-2D WO3-Bi2WO6 photocatalyst is developed by using a hydrothermal method. Ultrathin Bi2WO6 nanosheets are grown on the surface of WO3 nanoplates by crystal-oriented epitaxy. The 2D-2D WO3-Bi2WO6...

WO3 Nanosheet/ZnIn2S4 S-Scheme Heterojunctions for Enhanced CO2 Photoreduction

“…Figure a shows the XPS survey spectrum of WO 3 /ZnIn 2 S 4 (WZ-2), showing that the binary composite is constructed by the C, O, W, Zn, In, and S elements. The XPS spectrum of C 1s is shown in Figure S6, where the peak position occurs at 284.8 eV, and it is consistent with a previous research . This may be due to the indeterminate carbon content within the test environment.…”

“…The XPS spectrum of C 1s is shown in Figure S6, where the peak position occurs at 284.8 eV, and it is consistent with a previous research. 22 This may be due to the indeterminate carbon content within the test environment. The XPS spectrum of Zn 2p in Figure 3b exhibits two peaks at around 1021.8 and 1044.8 eV, which are attributed to Zn 2p 2/3 and Zn 2p 1/2 .…”

“…18−21 For example, Zhao et al obtained a 2D−2D WO 3 −Bi 2 WO 6 Sscheme heterojunction by epitaxial growth of ultrathin Bi 2 WO 6 nanosheets (NSs) on the surface of WO 3 NSs by crystal orientation, which showed great photoreduction activity of Cr(VI). 22 Sun et al developed a CdS/WO 3 S-Scheme heterojunction. The composite not only improves the stability of CdS with WO 3 but also enhances the ability to selectively reduce CO 2 to CO and CH 4 .…”

“…For the selection of OP materials, it is important to have a good oxidation ability and act as the carrier to provide a good structural basis for the loading of the RP. WO 3 with the E g of about 2.8 eV, great light absorption ability, good chemical stability, and thermal stability is considered as a great photocatalyst and has been greatly researched in the field of environmental protection. , WO 3 is a typical excellent OP material, and its positive enough valence band (VB) position ( E VB ≈ +2.24 V) can cause the h + photogenerated inside the VB of WO 3 to have the tremendous ability to convert hydroxyl (OH – ) groups into hydroxyl radicals (•OH). − For example, Zhao et al obtained a 2D–2D WO 3 –Bi 2 WO 6 S-scheme heterojunction by epitaxial growth of ultrathin Bi 2 WO 6 nanosheets (NSs) on the surface of WO 3 NSs by crystal orientation, which showed great photoreduction activity of Cr­(VI) . Sun et al developed a CdS/WO 3 S-Scheme heterojunction.…”

Comprehensive Insights into the Family of Atomically Thin 2D‐Materials for Diverse Photocatalytic Applications

“…[416,417] Other 2D/2D heterojunctions but not atomically thin such as Z-scheme BiOCl/g-C 3 N 4 nanosheets showed ≈94% reduction after 2h irradiation and the Bi 2 MoO 6 /Ti 3 C 2 nanocomposites showed ≈100% reduction after 60 min irradiation. [418,419] These observations in turn suggest that the ultrathin dimension of 2D materials can excel in photocatalytic process as compared to other bulk and lowdimensional structure of the similar materials. Accordingly, few more examples of ultrathin 2D photocatalytic systems employed for heavy metal reduction are given in Table 6.…”