Ultrafast recovery of aqueous uranium: Photocatalytic U(VI) reduction over CdS/g-C3N4

Li, Ping; Wang, Jingjing; Wang, Yun; Liang, Dong; Wang, Wei; Geng, Rongyue; Ding, Zhe; Luo, Dongxia; Pan, Duoqiang; Liang, Jianjun; Fan, Qiaohui

doi:10.1016/j.cej.2021.131552

Cited by 79 publications

(25 citation statements)

References 48 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, XPS analysis also indicated that uranium partially existed in its hexa-valence in the products after the photocatalytic reactions. This phenomenon was similar to all studies involving the photocatalytic U(VI) reduction [ 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 ]. It was considered that the products were UO 2+x (x < 0.25) [ 40 , 41 , 42 ], or the reduced products was re-oxidized again on the surface [ 34 ].…”

Section: Resultssupporting

confidence: 87%

“…The HRTEM image of raw ferrihydrite showed that the space of the lattice fringe was about 0.25 nm ( Figure 3 C), corresponding to the (110) plane of ferrihydrite [ 43 ]. Upon light illumination, additional fringes with a spacing of 0.31 nm were observed ( Figure 3 D), which is in accord with the characteristic of the (111) facet of UO 2+x [ 33 , 40 ]. The formation of the uranium-containing deposits on ferrihydrite surface could be further verified by the elemental mapping ( Figure 3 E), where uranium uniformly deposited on ferrihydrite surface.…”

Section: Resultssupporting

confidence: 74%

“…Therefore, it was evidenced that light-irradiated ferrihydrite promoted the U(VI) removal under anaerobic conditions, which should be closely related to the semiconductor properties of ferrihydrite. Recent studies proved that U(VI) was rapidly reduced by light-irradiated semiconductors, especially under anaerobic conditions [ 28 , 29 , 30 , 31 , 32 , 33 , 34 ]. The enhanced photocatalytic U(VI) reduction at higher pH was attributed to the weaker competition of H + for the photogenerated reactive reductive species [ 34 ].…”

Section: Resultsmentioning

confidence: 99%

“…The roles of •O 2 − and •OH in reducing U(VI) were determined with radical capture experiments, as exhibited in Figure 2 C. Obviously, the photocatalytic reduction of U(VI) was remarkably inhibited by p-benzoquinone (PBQ), while tertiary butanol (TBA) slightly affected the reduction of U(VI). Therefore, •O 2 − radicals were proved to be the dominant reductive species for U(VI) reduction on ferrihydrite [ 33 , 40 ].…”

Section: Resultsmentioning

confidence: 99%

“…Hence, ferrihydrite is expected to show photocatalytic properties and induce redox reactions. For U(VI), it has been suggested that the presence of semiconductors would lead to rapid reduction of U(VI) under anaerobic conditions, forming reduced deposits on solid surface [ 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 ]. Therefore, it is considered that light-irradiated ferrihydrite would bring change to the chemical state of uranium and subsequently impact its environmental behaviors, deserving further exploration.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Light Promotes the Immobilization of U(VI) by Ferrihydrite

Wang

Ding

et al. 2022

Molecules

Self Cite

View full text Add to dashboard Cite

The environmental behaviors of uranium closely depend on its interaction with natural minerals. Ferrihydrite widely distributed in nature is considered as one main natural media that is able to change the geochemical behaviors of various elements. However, the semiconductor properties of ferrihydrite and its impacts on the environmental fate of elements are sometimes ignored. The present study systematically clarified the photocatalysis of U(VI) on ferrihydrite under anaerobic and aerobic conditions, respectively. Ferrihydrite showed excellent photoelectric response. Under anaerobic conditions, U(VI) was converted to U(IV) by light-irradiated ferrihydrite, in the form of UO2+x (x < 0.25), where •O2− was the dominant reactive reductive species. At pH 5.0, ~50% of U(VI) was removed after light irradiation for 2 h, while 100% U(VI) was eliminated at pH 6.0. The presence of methanol accelerated the reduction of U(VI). Under aerobic conditions, the light illumination on ferrihydrite also led to an obvious but slower removal of U(VI). The removal of U(VI) increased from ~25% to 70% as the pH increased from 5.0 to 6.0. The generation of H2O2 under aerobic conditions led to the formation of UO4•xH2O precipitates on ferrihydrite. Therefore, it is proved that light irradiation on ferrihydrite significantly changed the species of U(VI) and promoted the removal of uranium both under anaerobic and aerobic conditions.

show abstract

Section: Resultssupporting

confidence: 87%

Section: Resultssupporting

confidence: 74%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Light Promotes the Immobilization of U(VI) by Ferrihydrite

Wang

Ding

et al. 2022

Molecules

Self Cite

View full text Add to dashboard Cite

show abstract

Cyano‐Functionalized Graphitic Carbon Nitride with Adsorption and Photoreduction Isosite Achieving Efficient Uranium Extraction from Seawater

Hu,

Chen,

Gao

et al. 2024

Adv Funct Materials

View full text Add to dashboard Cite

Photocatalytic uranium extraction from seawater is an ideal strategy to obtain uranium resources. Herein, the cyano‐functionalized graphitic carbon nitride (g‐C3N4‐CN) with an isosite structure of adsorption and photoreduction for U(VI) is successfully prepared to achieve efficient photocatalytic uranium extraction from seawater. As the key of the isosite structure, the cyano group not only dramatically promotes the separation of photogenerated charges of g‐C3N4‐CN and enriched electrons around it, but also greatly improves the adsorption capacity and selectivity for U(VI) over g‐C3N4‐CN by complexing with U(VI). Therefore, g‐C3N4‐CN exhibits efficient and stable photocatalytic U(VI) reduction performance, with a saturated uranium extraction capacity of 2644.3 mg g−1, significantly higher than most reported g‐C3N4‐based photocatalysts. Moreover, it also performs well in solar light‐driven uranium extraction from actual seawater. Briefly, this work illustrates the importance of constructing the isosite structure of adsorption and photoreduction for U(VI) in improving the photocatalytic uranium extraction performance.

show abstract

New Strategy for the Persistent Photocatalytic Reduction of U(VI): Utilization and Storage of Solar Energy in K⁺ and Cyano Co‐Decorated Poly(Heptazine Imide)

Wang

et al. 2022

Advanced Science

Self Cite

View full text Add to dashboard Cite

The photocatalytic conversion of soluble U(VI) into insoluble U(IV) is a robust strategy to harvest aqueous uranium, but remains challenging owing to the intermittent availability of solar influx and reoxidation of U(IV) without illumination. Herein, a dual platform based on K + and cyano group co-decorated poly(heptazine imide) (K-CN-PHI) is reported that can drive persistent U(VI) extraction upon/beyond light. K-CN-PHI achieves the photocatalytic reduction of U(VI) with a reaction rate of 0.89 min −1 , being 47 times greater than that over pristine carbon nitride (PCN). This system can further be triggered by light to form long-living radicals, driving the reduction of U(VI) in the dark for over 3 d. The flexible structural K + as counterions stabilize the electrons trapped by cyanamide groups, enabling the long lifetime of the generated radicals. The results collectively prove K-CN-PHI to be a novel and efficient photocatalyst enabling persistent U(VI) extraction around the clock, and broadening the practical applications of the photocatalytic extraction of U(VI).

show abstract

Ultrafast recovery of aqueous uranium: Photocatalytic U(VI) reduction over CdS/g-C3N4

Cited by 79 publications

References 48 publications

Light Promotes the Immobilization of U(VI) by Ferrihydrite

Light Promotes the Immobilization of U(VI) by Ferrihydrite

Cyano‐Functionalized Graphitic Carbon Nitride with Adsorption and Photoreduction Isosite Achieving Efficient Uranium Extraction from Seawater

New Strategy for the Persistent Photocatalytic Reduction of U(VI): Utilization and Storage of Solar Energy in K⁺ and Cyano Co‐Decorated Poly(Heptazine Imide)

Contact Info

Product

Resources

About

Ultrafast recovery of aqueous uranium: Photocatalytic U(VI) reduction over CdS/g-C3N4

Cited by 79 publications

References 48 publications

Light Promotes the Immobilization of U(VI) by Ferrihydrite

Light Promotes the Immobilization of U(VI) by Ferrihydrite

Cyano‐Functionalized Graphitic Carbon Nitride with Adsorption and Photoreduction Isosite Achieving Efficient Uranium Extraction from Seawater

New Strategy for the Persistent Photocatalytic Reduction of U(VI): Utilization and Storage of Solar Energy in K+ and Cyano Co‐Decorated Poly(Heptazine Imide)

Contact Info

Product

Resources

About

New Strategy for the Persistent Photocatalytic Reduction of U(VI): Utilization and Storage of Solar Energy in K⁺ and Cyano Co‐Decorated Poly(Heptazine Imide)