Amidoxime Groups Research Articles

Theoretical Implications of Bifunctional Ligands to Improve Uranium Extraction Performance

AbstractExtraction of uranium from seawater is considered to be an effective way to solve the shortage of uranium resources, and the development of efficient adsorption functional groups is the key to uranium extraction. In this work, the complexation of uranyl cations with a series of diamidoxime and bifunctional (amidoximate‐carboxylate, amidoximate‐phosphate) ligands has been probed by quantum chemical calculations. For most of the uranyl complexes, the amidoxime groups adopt η2 mode to uranyl cations. Based on bonding analyses, we found that the uranyl complexes with methyl‐substituted ligands (H2L′) possess stronger covalent interactions than those with phenyl‐substituted ligands (H2L). Consequently, the uranyl complexes with H2L’ are more stable in the extraction process according to thermodynamic analysis. The amidoximate‐phosphate bifunctional ligand (H2L3′) has stronger extraction capacity to uranyl cations than other ligands, which is related to the relatively lower decomposition energy, and it shows selectivity in seawater for uranyl cations over vanadium ions, which may be a potential ligand for uranium extraction. Therefore, the introduction of synergistic functional groups, i. e. the bifunctional ligands, enhance the extraction properties of uranyl cations. This work improves understanding of synergistic ligands, and may contribute to design and development of efficient ligands for recovery of uranium from seawater.

Boosting uranium extraction from Seawater by micro-redox reactors anchored in a seaweed-like adsorbent

Efficient extraction of uranium from seawater is expected to provide virtually infinite fuel sources to power nuclear reactors and thus enable sustainable development of nuclear energy. The extraction efficiency for uranium greatly depends on the availability of active adsorption sites on the adsorbents. Maximization of the utilization rate of the binding sites in the adsorbent is vital for improving adsorption capacity. Herein, micro-redox reactors functioned by Cu(I)/Cu(II) conversion are constructed internally in an adsorbent bearing both amidoxime and carboxyl groups to induce active regeneration of the inactivated binding sites to enhance uranium capture. This adsorbent has high adsorption capacity (962.40 mg-U/g-Ads), superior anti-fouling ability as well as excellent uranium uptake (14.62 mg-U/g-Ads) in natural seawater after 56 days, placing it at the top of high-performance sorbent materials for uranium harvest from seawater.

The amidoxime-functionalized magnetic dendritic fibrous nano-silica with a core–shell structure for the efficient capture of U(VI)

The U(VI) extraction from nuclear wastewater through adsorption techniques is vital for reclaiming uranium resources and mitigating environmental pollution. Herein, amidoxime-functionalized dendritic fibrous nano-silica with magnetic reponsiveness and core–shell structure (Fe3O4@DFNS-AO) was synthesized. The rapid absorption of U(VI) by Fe3O4@DFNS-AO achieved equilibrium within 40 min. Fe3O4@DFNS-AO showed great adsorption efficiency, as well as good reusability and selectivity, with a capacity of 175.4 mg/g at optimal pH 6.0. Furthermore, the mechanism was disclosed based upon the study of adsorption behavior and XPS analysis. The study of kinetic and isotherm indicated chemisorption dominated the adsorption and U(VI) could be adsorbed onto Fe3O4@DFNS-AO by monolayer. The amidoxime groups in Fe3O4@DFNS-AO acted as electron donors and formed coordination bonds with uranyl ions, leading to the efficient capture of U(VI). Overall, Fe3O4@DFNS-AO shows great promise in extracting uranium from wastewater.

Synthesis and structural characterization of acrylonitrile/vinyl imidazole copolymers and their amidoximated derivatives

Recently, environmental applications of copolymers such as CO2 capture and separation have become of significant interest. The development of copolymers with basic functional groups, such as amidoxime (AO) groups, represents a successful approach for enhancing absorption and separation of acidic molecules, such as CO2. In this research, acrylonitrile/N-vinyl imidazole (AN/VIM) copolymers were first synthesized through a free radical copolymerization method using 2,2′-azobisisobutyronitrile (AIBN) as the initiator and dimethylformamide as the solvent. The synthesized copolymers were then functionalized using hydroxylamine hydrochloride (NH2OH · HCl), the result being amidoximated (AO) copolymers. The synthesized copolymers were characterized by nuclear magnetic resonance (NMR) spectroscopy, thermogravimetric analysis and Fourier transform infrared spectroscopy. The analytical results simply confirmed that the copolymers and their amidoximated derivatives had successfully been synthesized. A microstructural study of amidoximated polymers using NMR spectroscopy clearly showed the tautomerization of AO groups.

Hit-to-lead optimization of 4,5-dihydrofuran-3-sulfonyl scaffold against Leishmania amazonensis. Effect of an aliphatic moiety

In line with our objective of designing new antileishmanial compounds for oral use, we report the synthesis and biological evaluation in vitro of original 4,5-dihydrofuran derivatives bearing an amidoxime group. Previous optimization focused on position 3 of the dihydrofuran ring involving aromatic fragments, resulting in the identification of the compound (HIT) 4-(5-benzyl-3-((4-fluorophenyl)sulfonyl)-5-methyl-4,5-dihydrofuran-2-yl)-N′-hydroxybenzimidamide (IC50 = 5.4 ± 1.0 μM, L. amazonensis promastigote, IC50 = 7.9 ± 1.1 μM, L. amazonensis intracellular amastigote). In the present work, position 3 was substituted with an aliphatic moiety. This modification was guided by a ligand-based approach, given the unknown biological target or mechanism of action for this compound. The 4,5-dihydrofuran derivatives were synthesized using microwave-assisted manganese (III) acetate-based oxidative cyclization of linear β-keto-carboxylic and β-keto-sulfone substrates, overcoming synthetic challenges to obtain aliphatic derivatives of 4,5-dihydrofuran-3-carboxamides. Finally, an unexpected and interesting biological activity with the 4,5-dihydrofuran-3-carboxylate (IC50 < 5 μM) against the amastigote form is discussed.

High-Performance Polyamidoxime Porous Membrane Prepared by the In Situ Modification/Nonsolvent-Induced Phase Separation Strategy for Uranium Extraction from Seawater.

The abundance of uranium (U(VI)) reserves in seawater makes it crucial to develop economically efficient methods for uranium extraction from seawater. In this work, an enhanced polyamidoxime porous membrane (PAOM) was fabricated by pre-in situ amidoxime modification combined with nonsolvent-induced phase separation (NIPS). The strategy of in situ modification of the polyacrylonitrile (PAN) solution served to enhance the homogeneity of the reaction and avoid the destruction of the membrane matrix and pore structure. Compared with the control sample (AOPM), PAOM possessed better mechanical strength and hydrophilicity. The introduction of polyvinylpyrrolidone (PVP) formed a porous structure in PAOM, improving spatial accessibility and facilitating the diffusion transport and capture of UO22+ inside the membrane. The more uniform and abundant distribution of amidoxime groups in PAOM gave it ultrahigh adsorption capacity and selectivity. The equilibrium adsorption capacity and Kd value of PAOM were 1.72 and 5.51 times higher than those of AOPM. Meanwhile, PAOM also demonstrated good recyclability, with only a 6.15% decrease in adsorption capacity after seven cycles. Additionally, PAOM exhibited excellent dynamic adsorption performance, and after 14 days of continuous filtration and adsorption, PAOM could extract 2.03 mg·g-1 U(VI) from natural seawater.

Redox-active sp2-c connected metal covalent organic frameworks for selective detection and reductive separation of uranium

It is economically desirable to develop a material that can simultaneously detect and recover uranium. Herein, a CC-bridged two-dimensional metal-covalent organic framework (Cu-BTAN-AO MCOF) was constructed by condensation of metal single crystals with a rigid structure (Cu3(PyCA)3) and cyano monomers (BTAN) via Knoevenagel reaction for simultaneous detection and adsorption of uranium. The amidoxime group within the pore and the presence of unsaturated Cu(I) in the framework facilitate the adsorption of uranyl ions onto the amidoxime group, leading to fluorescence quenching via the photoinduced electron transfer (PET) mechanism, achieving a detection limit of as low as 167 nM uranyl ions. Furthermore, Cu-BTAN-AO demonstrates exceptional efficiency in capturing uranium from wastewater characterized by rapid kinetics and superior selectivity. It is noteworthy that Cu-BTAN-AO is the first example of simultaneous detection, adsorption and chemical reduction of uranium using metal centers and functional groups in MCOF, indicating that Cu-BTAN-AO has great potential for the detection and recovery of uranium-containing wastewater. This design strategy may also be applicable to advancing sensing and energy materials for other important metal ions.

Overcoming Chemical Dissociation Processes: Electrochemical Modulation of High‐Affinity Binding Sites for Rapid Uranium Extraction from Seawater

AbstractCurrently reported adsorption (hydroxyl or amidoxime) groups must dissociate hydrogen ions to form ─O− units for the coordination with uranyl ions. However, this process suffers a high energy barrier for bond dissociation, leading to the sluggish uptake speed and low adsorption capacity for uranium extraction from natural seawater. Herein, this study proposes a strategy for electrochemical modulation of adsorption sites, which overcomes the chemical dissociation processes of hydrogen ions. Poly‐2,5‐dihydroxy‐1,4‐benzoquinone containing redox carbonyl groups is intercalated into the channels of a covalent organic framework (COF) through in situ cross‐linking of 2,5‐dihydroxy‐1,4‐benzoquinone. Under electrochemical modulation, the C═O groups are transformed into adjacent phenol–oxygen anions to cooperate with the coordination atoms (O and N) on the COF channel for rapid binding of uranyl ions, which gave an absorption rate of 4.2 mg g−1 d−1 (≈3.3 ppb of uranium in natural seawater). Notably, the COF‐based electrodes delivered an average capacity of ≈20.8 mg‐U per g for uranyl ion adsorption during 5 days of extraction, ≈3000 times larger than that of classical tannin‐based adsorbents. The proposed method for preparing electrochemically modulated binding sites is expected to provide guidance for designing high‐efficiency adsorbents in the future.

Two-step post-synthetic modification of bipydine-based sp2c-COF for stepwise gold recovery

Recovery of gold element from electronic waste is a promising approach for mitigating the rising gold demand in semiconductor industry. However, the complex and harsh environment in gold recovery restricted the selectivity and stability of absorbents. Herein, taking advantage of the robust sp2-conjugated covalent organic frameworks (COFs), we proposed a two-step post-synthetic modification (PSM) strategy to prepare the isp2c-COFox-NH2 for efficient Au extraction with high selectivity and recyclability. The stepwise electrostatic and chelation interaction of the modified quaternary ammonium and amidoxime groups resulted in an efficient adsorption capacity of 1389 mg/g. Experimental and theoretical studies show that the quaternary ammonium groups ionize the sp2c-COFs and significantly enhance the selectivity of gold adsorption (Ni2+, Co2+ and Cu2+ for negligible influence), and the amidoxime groups further increase the adsorption capacity of the COFs via chemical reduction. Furthermore, the isp2c-COFox-NH2 retained 95.1 % of its adsorption efficiency even after 10 adsorption–desorption cycles. It is worth mentioning that isp2c-COFox-NH2 displays good adsorption performance for trace amounts of gold in complex water samples and practical electronic waste, demonstrating excellent potential for practical applications. This study not only provides novel inspirations for improving the efficiency of gold resource recovery but also paves the way for the widespread application of sp2c-COF materials.

Controllable synthesis of amidoximated self-propelled tubular micromotors for enhanced uranium recovery: non-invasive mixing and on-the-move capturing

Micro-/nanomotors that combine attributes of autonomous movement and adsorption performance are attractive for efficient pollutant treatment. However, micro/nanomotors design still suffers from challenges including complex manufacturing processes, specific instrument demands and low yields. Herein, we proposed amidoxime-functionalized polydopamine tubular micromotors (DNBMs-AO) and demonstrated their application for rapid selective adsorption of uranium from contaminated seawater. The whole fabrication procedure is simplified and straightforward by curcumin templating and in-situ reduction/graft method. The manganese dioxide (MnO2) catalyst and amidoxime groups are subsequently anchored on the outer and inner side of nanotube surface. Besides, the distribution and amount of modified MnO2 and amidoxime groups can be manipulated via directly changing the reduction time. DNBMs-AO are driven and propelled by microbubbles produced by MnO2-triggered catalytic decomposition of hydrogen peroxide, which can reach high velocity at 302.6 μm s−1. The static adsorption results indicate that the adsorption of U(VI) onto DNBMs-AO can be better described by Langmuir model with the maximum adsorption capacity of 313.9 mg/g. Moreover, the motion of DNBMs-AO can efficiently improve the U(VI) diffusion under low H2O2 concentration, and enhance the adsorption kinetics to approximately 2.5 times. DNBMs-AO also exhibits high selectivity towards U(VI) and excellent performance stability, endowing its potential application in environmental engineering field.

Incorporating hydrogen bonding networks in microporous polymer membranes for high-flux hydrocarbon separation

Polymer membranes have been most commonly utilized in gas separations, while they often suffer from the trade-off between membrane permeability and selectivity, which arises from the inherent coupling between polymer chain rigidity and interchain spacing. Here, we propose a hydrogen bonding network strategy, where hydrogen bonding acceptors are incorporated into amidoxime-functionalized polymer of intrinsic microporosity (AO-PIM) membranes to in situ construct hydrogen bonding networks with amidoxime groups, and to modulate the interchain spacing/micropore structure in AO-PIM. Especially, 2,2′-bipyridine endows AO-PIM membranes with appropriate match between polymer chain rigidity and interchain spacing, leading to dramatically enhanced C3H6 permeability of 262 Barrer, 2.9 times higher than AO-PIM membranes, with a C3H6/C3H8 selectivity of 24 under mixed-gas tests, surpassing all the reported polymer membranes and most mixed matrix membranes. We envision this scalable, generic hydrogen bonding network strategy opens an alternative avenue for polymer membranes to break the trade-off effect.

Amidoxime‐based Star Polymer Adsorbent with Ultra‐High Uranyl Affinity for Extremely Fast Uranium Extraction from Natural Seawater

AbstractPolymer adsorbents functionalized with amidoxime groups are widely considered to have the most industrial potential for uranium extraction from seawater. However, the entanglement upon the collapse of polymer chain in seawater greatly reduces the utilization ratio of amidoxime ligands. Herein, a novel star‐shaped molecular brush adsorbent (β‐CD‐g‐PAO) is obtained by densely grafting polyamidoxime (PAO) chains from β‐cyclodextrin (β‐CD). Experimental and theoretical results reveal that, in contrast to conventional linear polymer adsorbents, the star polymer adsorbent with a high grafting density of PAO side chains enables strong steric repulsion between the polymer chains, leading to increased persistence length and disentanglement of side chains. As a result, the star polymer adsorbent shows higher accessibility of the adsorption ligands with lower adsorption energy, achieving an adsorption capacity of up to 944.75 mg g−1 in uranium‐spiked seawater, surpassing that of conventional linear PAO by 3.2 times. Remarkably, this star polymer adsorbent demonstrates an extraordinarily adsorption capacity of 10.9 mg−1 g−1 in only 1 day in natural seawater, coupled with excellent affinity for uranyl ions (K = 0.31 pM). The unique topological structure design provides a new approach to solving the problem of low utilization ratio of functional ligands in polymer adsorbents.

Immobilization of novel bifunctional polymer with amide and amidoxime groups in biochar-chitosan composite gels for enhancing uranium(VI) uptake

This work synthesized poly ethanolamine amidoxime modified winter melon and chitosan-derived biochar (PEA-CTS@WBC) using chemical crosslinking method for uranium(VI) removal. The factors influencing uranium(VI) adsorption by PEA-CTS@WBC, including pH, adsorbent dosage, time, temperature, and initial U(VI) concentration were explored. The material’s performance was characterized, and the underlying mechanism of U(VI) removal was analyzed using various techniques. The characterization results indicated that the PEA-CTS@WBC took on a membrane shape with numerous pores and wrinkles distributed on the surface, providing more active sites that can effectively promote the complexation and adsorption of U(VI). The results demonstrated that PEA-CTS@WBC effectively removed U(VI), achieving a maximum adsorption capacity of 485.89 mg/g at the pH of 5.0. The process suggested a dominant role for chemical adsorption. The Freundlich isotherm model demonstrated a high degree of alignment with the observed adsorption behavior, indicating a predominantly multilayer adsorption process. Thermodynamic studies indicated that adsorption was a spontaneous endothermic process. The XPS analysis demonstrated that the adsorption process was primarily due to the formation of stable complexes with NH3+-C(O), N–C, C–N, C=C, O–H and C=O. This research showed that the introduction of amide and amidoxime groups significantly improved the adsorption effect of biochar-chitosan gels on U(VI). PEA-CTS@WBC had a high selective adsorption characteristics and good reusability for U(VI) in aqueous solutions. PEA-CTS@WBC was an economical, efficient and stable composite material. These findings provided a theoretical basis for the treatment of wastewater contaminated with U(VI).

Efficient removal of U(VI) by graphene-based electrode modified with amidoxime: Performance and mechanism

The burgeoning interest in nuclear energy as a sustainable power source brings to the fore significant environmental and human health concerns associated with wastewater from uranium mining. This study presented the successful synthesis of amidoxime modified graphene-based electrode materials (PAO-N-rGO/CF) designed for treating uranium containing wastewater. The influencing factors of PAO-N-rGO/CF during the electrokinetic restoration process were systematically investigated, exploring the mechanisms of adsorption and electrochemical reduction from the perspectives of establishing adsorption theoretical models, evaluating electrochemical performance, and characterizing reduction products. According to the results, the optimal removal efficiency for U(VI) by PAO-N-rGO/CF reached 99.93 % under conditions of an applied voltage of 5 V, an electrification duration of 20 min, and a pH of 7. Compared to Ca2+, K+, and Mg2+, PAO-N-rGO/CF exhibited strong selectivity for UO22+. Whether dissolved oxygen was present or not, PAO-N-rGO/CF maintained its excellent electrochemical performance. After undergoing 10 cycles of reuse, the removal efficiency for U(VI) only decreased by 8.75 %. The establishment of the adsorption model demonstrated the presence of a chemical bond between uranium and amidoxime groups. The electrochemical performance tests evidenced that PAO-N-rGO/CF exhibited superior electron transfer capability. The reduction of (UO2)3(OH+)5 to UO2 in wastewater at a pH = 7 was verified by analysis of the reduction products. The successful development and mechanistic study of the novel and efficient electrode material provide theoretical support for the control of radioactive nuclide pollution and possess practical value for engineering applications in treating uranium containing wastewater.

Lignin-based covalent organic polymers for highly efficient uranium extraction under highly acidic conditions

Uranium is the main actinide highly related with recycling fission fuel. In this study, we controllably construct a lignin-based covalent organic polymers (AO-EHL), for uranium extraction with high adsorption capacity (94.70 mg/g). The balanced adsorption efficiency for uranium is remarkably high under highly acidic conditions, and even maintains 99.99 % in pH = 1.0. Moreover, the high adaptability, excellent reusability, and extremely low operating costs further indicated the high feasibility of AO-EHL for uranium extraction in industrial scale. The excellent adsorption performance of AO-EHL for uranium is reasonably attributed to synthetic effects of amidoxime groups and the covalent structure of lignin, which can highly prevent the protonation of amidoxime groups, and thus showing strong complexation with uranium at high acidities. This study suggests a promising method to construct advanced functional materials by using cheap and green natural materials and realizing the efficient uranium extraction under highly acidic conditions.

Bifunctional hyper-cross-linked polymer with phosphorylated-amidoximated groups for efficient uranium extraction from water

Designing and developing a uranium adsorbent with high adsorption capacity and good selectivity is highly significant. We synthesized a novel hyper-cross-linked polymer adsorbent with bifunctional groups, (PHCP-4-AO), such as phosphate and amidoxime groups, via simple Scholl reaction and subsequent functionalization for the first time highly efficient extraction of U(VI) from aqueous solution. Due to its unique molecular structure design, it can enhance the selectivity and adsorption capacity of uranium by using two different functional groups. The maximum uranium adsorption capacity of PHCP-4-AO was 424.33 mg/g, which was higher than the single-functional group phosphorylated (PHCP-4) (315.43 mg/g) and amidoximated (HCP-4-AO) (260.38 mg/g) adsorbents. The combination of phosphate and amidoxime groups improves the adsorption effect. PHCP-4-AO has good selectivity and affinity for uranyl ions. In simulated wastewater, the Kd of PHCP-4-AO for uranium was 7266.3 mL/g, which was more than 15 times that of other ions. After three adsorption–desorption cycles, the adsorption capacity of PHCP-4-AO can still be maintained above 300.00 mg/g. Through XPS analysis, it is speculated that the sorption of uranium by PHCP-4-AO is owing to the lone pair electrons found on the oxygen atom of the phosphate groups, as well as the oxime oxygen and amino nitrogen atoms of the amidoxime groups entering the uranium’s empty orbit to form the coordination bonds. These findings demonstrated that this new hyper-cross-linked polymer could be considered as a valuable material in the extraction and recovery of uranium from uranium-containing aqueous solutions.

Amidoxime functionalized magnetic MXene/chitosan composites for efficient uranium extraction

Uranium extraction from unconventional uranium resources is among the major constraints to the development of the nuclear industry at present. In this dissertation, we here propose to effectively graft amidoxime groups on magnetic MXene and chitosan (CS) composites to extract uranium from low-enriched uranium solutions (MCF-AO). The data of adsorption experiments displayed that MCF-AO possessed fast adsorption kinetics (within 120 min), outstanding selectivity and salient adsorption capacity (1305.7 mg/g at pH=4, T=298.15 K) for uranium and could be easily separated with a magnet. Adsorption studies revealed a behavior consistent with the pseudo-second-order kinetic model and the Langmuir adsorption isotherm model, which is suitable for the spontaneous heat-absorption chemical monolayer adsorption process. Its sorption remains at more than 55 % of the original after 5 adsorption-desorption tests, and has great tolerance to interfering ions. Mechanistic research pointed out that the selective adsorption of uranium by MCF-AO was significantly enhanced by the presence of hydroxyl, amino and amidoxime groups. Meanwhile, MCF-AO exhibited superb resistance to two common bacteria (E. coli and B. subtilis) and achieved more than 95 % uranium extraction capacity in simulated seawater, even more 4.12 mg/g of uranium extraction in Salt Lake water. Consequently, MCF-AO has a broad application prospect in the recovery and treatment of complex uranium systems.

Fabrication of amidoxime grafted polyacrylonitrile for iodine vapor capture from off-gas

The exploration of effective gaseous iodine adsorbents is an interesting and challenging task in the field of radwaste disposal. In this study, amidoxime groups (AO) were successfully grafted onto polyacrylonitrile to obtain amidoxime grafted polyacrylonitrile (PAN-AO) for capturing gaseous iodine. The results of the combined characterization analysis have confirmed that the introduction of AO greatly improved its thermostability, porosity and available functional groups of PAN. The impacts of reaction time, iodine concentration and reaction heat on the uptake capacity for gaseous iodine were systematically studied. The PAN-AO exhibited higher iodine capture capacity (1534.4 mg/g) than PAN (72.1 mg/g) at 80 °C and 600 min, which was ascribed to the chemical reaction between electron-rich AO groups and electron-deficient iodine molecules. The studies of kinetic fitting and activation energy (Ea = 44.11 kJ/mol) further confirmed that chemical adsorption was the major fashion during the whole uptake process of PAN-AO for iodine. Besides, PAN-AO still had an iodine uptake capacity of 704.4 mg/g after five recycling, manifesting the remarkable cycle performance of PAN-AO. In brief, this study offered a new reference for radioactive iodine uptake and the synthesized PAN-AO was able to serve as an efficient iodine capture material.

Novel Olefin-Linked Covalent Organic Framework with Multifunctional Group Modification for the Fluorescence/Smartphone Detection of Uranyl Ion.

Monitoring and purification of uranium contamination are of great importance for the rational utilization of uranium resources and maintaining the environment. In this work, an olefin-linked covalent organic framework (GC-TFPB) and its amidoxime-modified product (GC-TFPB-AO) are synthesized with 3-cyano-4,6-dimethyl-2-hydroxypyridine (GC) and 1,3,5-tris(4-formylphenyl) benzene (TFPB) by Knoevenagel condensation. GC-TFPB-AO results in specificity for rapid fluorescent/smartphone uranyl ion (UO22+) detection based on the synergistic effect of multifunctional groups (amidoxime, pyridine, and hydroxyl groups). GC-TFPB-AO features a rapid and highly sensitive detection and adsorption of UO22+ with a detection limit of 21.25 nM. In addition, it has a good recovery (100-111%) for fluorescence detection in real samples, demonstrating an excellent potential of predesigned olefin-linked fluorescent COFs in nuclear contaminated wastewater detection and removal.

Phytic acid-functionalized polyamidoxime/alginate hydrogel for targeted uranium extraction from acidic wastewater

Efficient removal of uranium from radioactive wastewater is crucial for both environmental protection and sustainable development of nuclear energy. However, selectively extracting uranium from acidic wastewater remains a significant challenge. Here we present a phytic acid-functionalized polyamidoxime/alginate hydrogel (PAG) via a facile one-step hydrothermal reaction. The PAG, leveraging the robust binding affinity of phytic acid and the selective coordination of amidoxime for U(VI), exhibited high efficiency and selectivity in adsorbing U(VI) from acidic uranium-containing wastewater. At pH 2.50, U(VI) adsorption equilibrium was achieved within 60 min, showcasing a maximum theoretical adsorption capacity of 218.34 mg/g. Additionally, the PAG demonstrated excellent reusability, maintaining a uranium removal rate exceeding 90 % over five adsorption-desorption cycles. Remarkably, the as-synthesized PAG removed 94.1 % of U(VI) from actual acidic uranium-contaminated groundwater with excellent anti-interference performance, reducing U(VI) concentration from 272.0 μg/L to 16.1 μg/L and making it meet the WHO drinking water standards (30 μg/L). The adsorption mechanism was elucidated through XPS and DFT calculation, revealing that the uranyl ion primarily coordinated with phosphate and amidoxime groups on phytic acid and polyamidoxime, respectively. These findings underscore the promising potential of PAG hydrogel for addressing acidic uranium-containing wastewater from uranium mining and metallurgy.