Au‐Mediated Composite In₂S₃–Au–BiVO₄ with Enhanced Photocatalytic Activity for Organic Pollutant Degradation

Abstract

A ternary composite photocatalyst In2S3–Au–BiVO4 was fabricated by stepwise photo‐reduction and deposition−precipitation methods. It was found that the Au nanoparticles (NPs) were selectively anchored on the {010} facets of decahedral BiVO4 crystals due to the oriented accumulation of electrons during the photo‐reduction stage. Based on the strong interaction between S−Au, In2S3 was loaded on the surface of Au NPs on BiVO4 {010} facets. Photocatalytic degradations of organic contaminants Rhodamine B and phenol indicated that In2S3–Au–BiVO4 showed evidently improved visible light photocatalytic activity than BiVO4, Au–BiVO4, and In2S3–BiVO4. On the basis of the photoelectrochemical and photoluminescence (PL) analyses, it can be inferred that the facet hetero‐juction and Au‐mediated composite structures of In2S3–Au–BiVO4 can improve the separation efficiency of photo‐generated carriers as well as make the carriers keep higher redox ability. The radical trapping experiments indicated that for In2S3–Au–BiVO4, •OH, h+, and •O2− are the main reactive species which take part in the organic contaminant degradation.

Facet-Engineered Surface and Interface Design of Monoclinic Scheelite Bismuth Vanadate for Enhanced Photocatalytic Performance

“…SEM image of (g) Au-BiVO 4 , (h) In 2 S 3 –Au-BiVO 4 and (i) HR-TEM image of In 2 S 3 –Au-BiVO 4 . Reproduced with permission from ref . Copyright 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.…”

“…In contrast, BiVO4-Au@CdS with the randomly deposited Au (Figure 14d) and Au@CdS NPs (Figure 14e) on both {010} and {110} facet prepared by the chemical reduction method exhibited a relatively poor photocatalytic performance for 4-nonylphenol degradation compared with the selectively prepared BiVO4-Au@CdS, demonstrating the important role of facet-induced carrier separation in achieving excellent photocatalytic activity (Figure 14f). Likewise, as reported by Wu et al, 159 Au 3+ ions were deposited on the electron-rich BiVO 4 {010} facets through a photoreduction process (Figure 14g), followed by the deposition of In 2 S 3 on Au NPs to form In 2 S 3 −Au-BiVO 4 (Figure 14h,i). In this ternary system, Au NPs severed as the recombination center of photogenerated electrons from the CB of {010}-BiVO 4 and the holes from the VB of In 2 S 3 , which not only greatly facilitated the charge separation of individuals but also remained the strongly reductive electrons in the CB of In 2 S 3 and strongly oxidized holes in the VB of {110} facet mBiVO 4 , leading to the optimal photocatalytic performance for RhB and phenol degradation.…”

Facet-Heterojunction-Based Z-Scheme BiVO4{010} Microplates Decorated with AgBr-Ag Nanoparticles for the Photocatalytic Inactivation of Bacteria and the Decomposition of Organic Contaminants

“…These results reveal that Z-scheme can effectively enhance the photocatalytic property of AgBr-Ag-BiVO 4 {010}. Compared to our previous works, 40,41 the photocatalytic activity of AgBr-Ag-BiVO 4 {010} for degrading RhB is about 2 and 3 times as high as that of CdS-Au-BiVO 4 and In 2 S 3 -Au-BiVO 4 , respectively. Therefore, it can be concluded that it is a cheap and highefficiency strategy of using the cheaper Ag instead of Au as the junction to construct Z-scheme photocatalytic materials.…”

“…80−83 According to previous reports in the literature, the conduction band (CB) and valence band (VB) energy levels of AgBr are −0.57 eV (vs SHE) and 2.18 eV (vs SHE) 84,85 and those of BiVO 4 are estimated to be 0.34 eV (vs SHE) and 2.74 eV (vs SHE), respectively. 86,87 If AgBr-Ag-BiVO 4 {010} is a traditional composite semiconductor, the migrate pathway of electrons should be from the AgBr CB to the BiVO On the basis of the above experimental results and analyses, we proposed the photocatalytic mechanisms of bacterium inactivation and organic pollutant degradation over AgBr-Ag-BiVO 4 {010}. As illustrated in Figure 11, after absorbing visible light, both BiVO 4 and AgBr can produce holes on their VB and electrons on their CB.…”

“…Recently, combining Z-scheme with facet-heterojunction has been successfully used in enhancing the carrier separation efficiency of BiVO 4 -based semiconductor materials. − We fabricated visible-light-driven materials CdS-Au-BiVO 4 and In 2 S 3 -Au-BiVO 4 by photodeposition technique. , These Z-scheme composite photocatalysts exhibited high separation efficiency of carriers and photocatalytic activity for organic contaminant degradation. Unfortunately, there still exist several shortcomings such as high cost and weak interaction between Au NPs and semiconductors.…”