Achieving efficient photocatalytic uranium extraction within a record short period of 3 min by Up-conversion erbium doped ZnO nanosheets

Gong, Xiang; Tang, Li; Wang, Ruixiang; Guo, Zhenghong; Huang, Pengling; Zhou, Li; Zou, Jie; Lei, Jia; Liu, Huanhuan; Li, Nan; Tang, Xingrui; Zhu, Wenkun; He, Rong

doi:10.1016/j.cej.2022.138044

“…6c and d exhibited U 4f 5/2 (392.7–393 eV, 391.9–392.4 eV) and U 4f 7/2 (382.4–382.6 eV, 381.2–381.6 eV) doublet peaks after photoreaction, indicating the coexistence of U( iv ) and U( vi ) in the LDHs. 51 Before photocatalysis, the adsorption on the NiAl and ZnNiAl surfaces was mainly in the form of hexavalent U( vi ), shown in Fig. S7 and 8 †.…”

Section: Resultsmentioning

confidence: 99%

Adsorption-photoreduction behaviors and mechanisms of layered double hydroxide loaded on uranium(vi) removal

Ling

¹

,

Kuang

²

,

Zhong

³

2023

Dalton Trans.

5

0

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“…Throughout the process, electrons (e – ), superoxide radicals (•O 2 – ), holes (h + ), and hydroxyl radicals (•OH – ) were selectively removed using silver nitrate, p -benzoquinone, methanol, and mannitol, respectively. , As shown in Figure S9a, the addition of both silver nitrate and p -benzoquinone significantly reduced the removal of uranium by 3% Ag-CdSe nanosheets; this result indicates that both e – and •O 2 – can promote the photocatalytic reduction of U(VI). Among them, after U(VI) is electron-reduced to U(IV), part of it is oxidized by •O 2 – to the removable (UO 2 )O 2 ·2H 2 O form − (Figure S9b). The addition of methanol acts as a hole scavenger and enhances the removal of uranium from the nanosheets.…”

Section: Resultsmentioning

confidence: 99%

Ag-Doped CdSe Nanosheets as Photocatalysts for Uranium Reduction

Li

¹

,

Dong

²

,

Sun

³

et al. 2022

ACS Appl. Nano Mater.

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Doping is a simple method to modulate the electronic configuration of semiconductor photocatalysts. This study regulated the energy band structure of CdSe nanosheets by Ag doping, which reduced the energy bandwidth of CdSe nanosheets by increasing the carrier density, thereby improving the efficiency of the photocatalytic reduction of uranium by CdSe nanosheets. A 96% removal of U(VI) was achieved by 3% Ag-CdSe nanosheets, which was 1.9 and 1.2 times higher than that of pristine CdSe nanosheets (50%), and 1% Ag-CdSe nanosheets (81%), respectively. Additionally, at pH = 4.0 and a solid−liquid ratio of 0.25, the reduction of uranium by 3% Ag-CdSe nanosheets (765 mg/g) was 2.2 times higher than that of pristine CdSe nanosheets (345.6 mg/g). This study provides a new idea for other efficient photocatalysts designed for uranium reduction.

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“…(3) The amino groups of MnO x /NH 2 -UiO-66 acted as the U(VI) confinement sites, trapping free U(VI) and reducing its reduction potential. (4) The photogenerated electrons in the CB of MnO x /NH 2 -UiO-66 further reduce the adsorbed U(VI) and form a stable UO 2 O 2 ·2H 2 O in the presence of O 2 . , We list the reduction reaction equation of U(VI) as follows normalU normalO 2 2 + + normale − → normalU normalO 2 + normalU normalO 2 + + normale − → normalU normalO 2 false↓ O 2 + e − → • O 2 − • normalO 2 − + normalU normalO 2 + + 2 normalH 2 normalO → normalU normalO 2 normalO 2 · 2 normalH 2 normalO false↓ …”

Section: Resultsmentioning

confidence: 99%

“…(3) The amino groups of MnO x /NH 2 -UiO-66 acted as the U(VI) confinement sites, trapping free U(VI) and reducing its reduction potential. (4) The photogenerated electrons in the CB of MnO x /NH 2 -UiO-66 further reduce the adsorbed U(VI) and form a stable UO 2 O 2 ·2H 2 O in the presence of O 2 . , We list the reduction reaction equation of U(VI) as follows …”

Section: Resultsmentioning

confidence: 99%

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Efficient Strategy for U(VI) Photoreduction: Simultaneous Construction of U(VI) Confinement Sites and Water Oxidation Sites

Cao

¹

,

Yu

²

,

Zhang

³

et al. 2022

ACS Appl. Mater. Interfaces

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Reduction of hexavalent uranium [U(VI)] by the photocatalytic method opens up a novel way to promote the selectivity, kinetics, and capacity during uranium removal, where organic molecules act as the sacrificial agents. However, the addition of sacrificial agents can cause a secondary environmental pollution and increase the cost. Here, a UiO-66-based photocatalyst (denoted as MnO x /NH 2 -UiO-66) simultaneously with efficient U(VI) confinement sites and water oxidation sites was successfully developed, achieving excellent U(VI) removal without sacrificial agents. In MnO x /NH 2 -UiO-66, the amino groups served as efficient U(VI) confinement sites and further decreased the U(VI) reduction potential. Besides, MnO x nanoparticles separated the photogenerated electron−hole pairs and provided water oxidation sites. The U(VI) confinement sites and water oxidation sites jointly promoted the U(VI) photoreduction performance of MnO x /NH 2 -UiO-66, resulting in the removal ratio of MnO x /NH 2 -UiO-66 for U(VI) achieving 97.8% in 2 h without hole sacrifice agents. This work not only provides an effective UiO-66-based photocatalyst but also offers a strategy for effective U(VI) photoreduction.

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Achieving efficient photocatalytic uranium extraction within a record short period of 3 min by Up-conversion erbium doped ZnO nanosheets

Cited by 33 publications

References 51 publications

Adsorption-photoreduction behaviors and mechanisms of layered double hydroxide loaded on uranium(vi) removal

Adsorption-photoreduction behaviors and mechanisms of layered double hydroxide loaded on uranium(vi) removal

Ag-Doped CdSe Nanosheets as Photocatalysts for Uranium Reduction

Efficient Strategy for U(VI) Photoreduction: Simultaneous Construction of U(VI) Confinement Sites and Water Oxidation Sites

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