The development of high-performance photocatalysts is crucial for the efficient photodegradation of antibiotics. A key challenge in photocatalysis is charge recombination, which occurs both within the bulk and at the surface of semiconductor catalysts. In this study, charge recombination was suppressed by enhancing carrier dynamics through ferroelectric polarization in Bi4Ti3O12 (BTO)-based materials, leading to a significant improvement in tetracycline (TC) degradation performance. Our results demonstrate that La doping strengthens ferroelectric polarization, improving charge carrier dynamics and emphasizing the critical role of polarization in photocatalysis. Differences in polarization led to varying effects on charge carrier dynamics, which directly influenced the photocatalytic degradation of TC. La-doped BTO (La-BTO) exhibited the highest photocurrent density, the lowest charge transfer resistance, and a reduced photoluminescence (PL) lifetime when compared with both pristine and depolarized BTO. Photocatalytic tests revealed that La-BTO achieved nearly complete TC degradation within 30 min under light irradiation, with center dot O-2(-) and center dot OH radicals identified as the primary oxidative species. Specifically, La-BTO achieved a 94.6% degradation rate, which is significantly higher than that of undoped BTO (70.7%) and depolarized BTO (40.7%). These findings demonstrate that polarization-driven carrier dynamics are crucial for optimizing photocatalytic antibiotic degradation, offering new insights into the rational design of high-performance photocatalysts for water purification.

The uranyl ion (UO22+), characterized by its heavy metal toxicity and radioactivity, poses significant threats to environmental safety and public health. In this study, a ratiometric fluorescent probe named Targeted-Naphthalimide-Sensor (TNS) with self-calibrating capability was designed for UO22+ detection. Based on the 1,8-naphthalimide fluorophore and specific heterocyclic ligands, TNS exhibits unique intramolecular proton transfer characteristics in the excited state (ESIPT), demonstrating excellent sensitivity and anti-interference ability. Under high water ratio conditions, TNS coordinates with UO22+, resulting in ratiometric fluorescence changes. It shows a good linear relationship in the presence of low-concentration UO22+, and the detection limit is calculated to be as low as 4.6 × 10-8 M. Experiments and theoretical calculations suggest that the sensing mechanism of the probe might be attributed to the alteration of the electronic transfer state caused by UO22+ coordination. Cell imaging experiments demonstrate that the morpholine-functionalized TNS exhibits excellent lysosomal targeting capabilities, enabling precise localization and quantitative imaging of UO22+ within lysosomes. Further in vivo zebrafish imaging studies reveal that TNS accumulates in the digestive system of zebrafish, facilitating the detection and imaging of UO22+ within the digestive tract. The quantitative test strip fabricated from TNS enables the visual and portable detection of UO22+ in practical samples. Further practical testing demonstrates that TNS exhibits excellent utility across diverse environmental water samples.

Photochemical reduction of hexavalent uranium (U(VI)) to insoluble tetravalent uranium (U(IV)) presents a sustainable catalytic conversion approach for the alleviation of growing nuclear environmental pollution. However, achieving superior U(VI) reduction activity is hindered by the challenges of low carrier separation efficiency, limited active sites, and unclear catalytic mechanisms. Here, we report a K/PD/CN featuring multiple catalytic sites for photocatalytic U(VI) reduction. The Lewis base sites, provided by the terminal C ≡ N groups, facilitate the reduction of hexavalent U(VI). The electron-deficient K atom acts as the Lewis acid site to oxidize CH3OH to CH2O. The coexistence of acid and base sites results in a strong synergistic effect during the photocatalytic aerobic reduction of U(VI). P doping sites cause charge redistribution and boost Lewis acid-base active sites. Spectroscopy and density functional theory calculations show that efficient charge separation is achieved through electron delocalization within the K/PD/CN The combination of abundant active sites and effective carrier separation leads to an impressive 99.2 % U(VI) remove efficiency in 30 min for K/PD/CN, which is approximately 5.6 times faster than CN. This study presents a novel approach for advancing the high-efficiency reduction of uranyl with well-designed multisite Lewis acid-base catalysts.

Piezo-photocatalysis technology holds immense potential for nuclear wastewater treatment due to its high efficiency and environmental friendliness. However, its application is constrained by issues such as limited active sites, poor charge separation, and rapid recombination. Defect engineering can effectively optimize active sites and charge dynamics, with metal vacancies significantly enhancing carrier separation efficiency. This study synthesized a layered MnIn2S4-VMn+In (MIS-VMn+In) catalyst containing dual manganese/indium cation vacancies. Under air conditions without sacrificial agents, its piezo-catalysis-visible light synergy achieved 99.7% hexavalent uranium (U(VI)) removal within 60 min, representing a 26.5-fold increase in rate compared to pristine MnIn2S4 (MIS). After 10 cycles of simulated wastewater, seawater, and uranium tailings water, the removal rates remained at 92.1%, 83.5%, and 79.7%, respectively, indicating that the material exhibits excellent cycle stability and resistance to interference. Electron pparamagnetic resonance (EPR) / Piezoresponse force microscopy (PFM) confirmed that the solvothermal method introduced abundant double vacancies, inducing lattice distortion to enhance piezo-catalysis. Ultraviolet spectrum (UV) / Photocatalysis / Density functional theory (DFT) calculations reveal that double cation vacancies significantly enhance uranium adsorption and reaction by modulating the energy band structure, increasing specific surface area/active site density, improving charge separation and migration efficiency, and optimizing Mn-d band center and S-p band center. This study provides a novel approach for designing highly efficient piezo-catalysis photocatalysts based on cation vacancies, applicable to fields such as nuclear wastewater treatment.

The declining availability of natural uranium has positioned thorium-based nuclear energy as a highly promising alternative. Accordingly, recovering Th(IV) from radioactive wastewater is crucial for resource recycling and the ecological restoration of polluted waters. In this study, PAN electrospun fibers were modified via two different PDA functionalization strategies and subsequently loaded in situ with HKUST‐1 to fabricate MOF‐based composite nanofiber membranes. Adsorption performance tests revealed that the HK/PDA‐E/PAN membrane, prepared through post‐interfacial modification, outperformed the other in Th(IV) uptake. At pH = 3 and C0 = 80 mg L-1, the saturated adsorption capacity was 314.50 mg g-1. The composite membrane is recyclable, resistant to ionic interference, and exhibits spontaneous endothermic adsorption. Dynamic filtration experiments further revealed that a high adsorption capacity of 232.37 mg g-1 could still be achieved even at a low initial Th(IV) concentration of 20 mg L-1. Combined SEM, XPS, FTIR, and DFT calculations reveal that surface-modified PDA not only provides abundant adsorption sites but also stabilizes the composite interface and suppresses MOF agglomeration. The synergistic interplay between PDA and HKUST1 enables the specific and highly efficient capture of Th(IV). This MOFbased composite nanofiber membrane thus holds great promise for the treatment of thoriumcontaminated radioactive wastewater and the recovery of thorium resources.

In order to obtain 177Lu with both diagnostic and therapeutic functions from the preparation process of carrierfree 177Lu, the separation of 176Yb/177Lu is required. However, the existing electrochemical methods require high voltage, are not conducive to controlling the pH value of the system, and need to be carried out under anaerobic conditions. Herein, this study innovatively proposes to synergize the combination of photocatalysis and electrochemistry, the bridging role of the medium, and the electron transfer effect of oxygen to address the issues existing in the pure electrochemical removal of Yb3+. Therefore, using a nitrogen-doped CdS/carbon felt (N-CdSCF) photoanode, a mercury cathode, and tartaric acid as a medium. Under optimal conditions (initial pH 7.00, 80.0 mg N-CdS-CF, 80 ppm Yb3+), a 40-min treatment at only 6.0 V achieved a 96.7% removal of Yb3+-significantly higher than the 42.2% obtained with pure electrochemistry at 8.0 V. Moreover, the pH value of the system is increased and effectively controlled. Meanwhile, the study finds that O2 in this system not only plays a role in electron transfer to improve the removal of Yb3+ but also reduces the voltage for water oxidation, thus reducing the generation of H+ in the solution. The interaction between tartaric acid, Yb3+ and mercury helps Yb3+ to be reduced to form an amalgam. This study has opened up a brand-new technical approach for the efficient and green preparation of carrier-free 177Lu.

Bi-based oxides are emerging as highly promising piezocatalysts owing to their diverse crystal chemistries, strong intrinsic polarization, and environmentally benign characteristics. This review presents a comprehensive overview of the fundamentals of piezocatalysis, including piezoelectric polarization, its coupling with catalytic reactions, and the mechanistic pathways governing charge generation, separation, and reactive oxygen species (ROS) formation under dynamic mechanical fields. Key performance-determining parameters, piezoelectric coefficients, band structures, carrier density, mobility, and lifetimes, and surface adsorption properties, are systematically analyzed, together with a clear distinction between piezocatalysis, sonocatalysis, and tribocatalysis. The structural features, polarization behavior, and catalytic properties of major Bi-based materials, including perovskite-type oxides, BiVO4, Aurivillius layered phases, Sillén-structured and Bi-rich oxyhalides, and Sillén-Aurivillius hybrids, are critically summarized. Strategies for enhancing activity, including nanostructuring, doping, defect modulation, heterojunction construction, surface modification, domain engineering, and multi-field coupling, are discussed in detail. Recent advances in environmental remediation, energy conversion (H2 and H2O2 production, CO2 reduction), and biomedical applications such as antibacterial activity and ROS-driven cancer therapy are highlighted. This review provides a coherent framework to guide the rational design, mechanistic understanding, and practical deployment of next-generation Bi-based piezocatalysts.

The uranyl ion (UO22+), characterized by its heavy metal toxicity and radioactivity, poses significant threats to environmental safety and public health. In this study, a ratiometric fluorescent probe named TargetedNaphthalimide-Sensor (TNS) with self-calibrating capability was designed for UO22+ detection. Based on the 1,8-naphthalimide fluorophore and specific heterocyclic ligands, TNS exhibits unique intramolecular proton transfer characteristics in the excited state (ESIPT), demonstrating excellent sensitivity and anti-interference ability. Under high water ratio conditions, TNS coordinates with UO22+, resulting in ratiometric fluorescence changes. It shows a good linear relationship in the presence of low-concentration UO22+, and the detection limit is calculated to be as low as 4.6 & times; 10_8 M. Experiments and theoretical calculations suggest that the sensing mechanism of the probe might be attributed to the alteration of the electronic transfer state caused by UO22+ coordination. Cell imaging experiments demonstrate that the morpholine-functionalized TNS exhibits excellent lysosomal targeting capabilities, enabling precise localization and quantitative imaging of UO22+ within lysosomes. Further in vivo zebrafish imaging studies reveal that TNS accumulates in the digestive system of zebrafish, facilitating the detection and imaging of UO22+ within the digestive tract. The quantitative test strip fabricated from TNS enables the visual and portable detection of UO22+ in practical samples. Further practical testing demonstrates that TNS exhibits excellent utility across diverse environmental water samples.

While covalent organic frameworks (COFs) are promising candidates for the extraction of radioactive contaminants from aqueous solutions, the molecular-level mechanisms by which functional group modifications determine their adsorption performance remain elusive. To address this, molecular dynamics (MD) simulations were conducted to systematically investigate, at the atomic/molecular level, the adsorption behavior of uranyl ion (UO22+) in COFs modified with three charged functional groups: sulfonic (-SO3-), carboxyl (-COO-), and phosphonic (-PO3H-). The results reveal that the adsorption of UO22+ in the functionalized COFs was governed by three distinct mechanisms: hydrogen bonding, a synergistic combination of hydrogen bonding and coordination, and coordination. Notably, in the -COO--modified COFs, hydrogen bonding effectively promotes the migration of UO22+ into the pore channels, while coordination interactions enhance adsorption stability. This synergy significantly improves the utilization efficiency of adsorption sites, leading to optimal adsorption performance. These findings provided a fundamental guideline for the rational design of functional COFs.

Promoting dual-channel piezo-photocatalytic removal of uranium( vi ) via a Bi 2 WO 6 @COF Z-scheme heterojunction: synergistic interfacial bonds and triple electric fields.

In this study, a Cu/Fe-dual single-atom catalyst (Cu/Fe-N-C) was prepared in combination with carbon nitride (gC(3)N(4) ) and subjected to phosphating treatment. The resulting Cu/Fe-N-C-P/g-C3N4 composite electrode was used for efficient separation of uranium from aqueous solutions. Under identical conditions (pH 6, initial U concentration: 10 mg/L), the Cu/Fe-N-C-P/g-C3N4 composite electrode achieved a uranium removal rate of 99% within just 20 min, significantly outperforming the individual electrochemical treatment by Cu/Fe-N-C-P 75% in 20 min) and the individual photocatalytic treatment by g-C3N4 (38.6% in 20 min). Mechanism analysis indicates that under PEC conditions, the migration of UO22+ toward the Fe/Cu-Nx sites on the electrode was enhanced. Uranyl ions reaching the surface were primarily reduced to U(V) by the copper-iron bimetallic single-atom catalyst and subsequently underwent oxidized to form Na2O(UO3 & sdot;H2O)x precipitate. Meanwhile, some uranium ions were directly reduced by photogenerated electrons to U(IV), which together with the above precipitate were deposited at the bottom of the reactor, achieving efficient separation and solidification of uranium from the aqueous phase. When treating actual uranium-containing wastewater, after 12 h of microalgae biological adsorption pretreatment, followed by photoelectric treatment, the uranium removal rate within 5 min could reach almost complete removal (>99.9%), which was much higher than the direct photoelectric treatment removal effect of 56.6%. This integrated process of photoelectrocatalytic and biological pre-treatment significantly enhanced the efficiency of selective separation of uranium from complex aqueous systems by strengthening the migration, enrichment, and phase separation processes of the target substance.

Featuring both piezoelectric and photocatalytic properties, 2D Bi4Ti3O12 (BIT) offers high potential for uranium(VI) (U(VI)) remediation by efficiently suppressing photogenerated electron-hole recombination. However, its practical efficiency is severely limited by the low piezoelectric coefficient, insufficient active sites, and large bandgap. Herein, a series of alkaline-earth metals (ca, Sr, Ba, etc.) were, for the first time, introduced as A-site dopants in BIT to systematically investigate their piezo-photoelectric performance. Through combined theoretical and experimental verification, Ba-doping proved to be optimal for enhancing the piezo-photocatalysis of BIT. Accordingly, Ba-doped Bi4Ti3O12 (BBIT-x) catalysts with varying doping concentrations (x = 0.3, 0.5, 1.0, 2.0, 3.0) were synthesized for piezo-photocatalytic U(VI) removal. U(VI) capture experiments show that BBIT-0.5 possesses a superior U(VI) removal of 93.2% within 120 min under piezo-photocatalysis, far exceeding the 55.8% achieved by pristine BIT. Its kinetic rate constant is 3.5 times that of BIT, and 84.6 and 5.6 times those of the individual piezo-catalytic and photocatalytic modes, respectively. Mechanistic studies reveal that the superior U(VI) removal performance originates from the Ba-doping-induced synergistic effect, which promotes the generation of abundant electron-hole pairs via a narrowed bandgap, accelerates charge carrier separation through an enhanced built-in electric field, strengthens U(VI) capture by enriched oxygen vacancy sites, and enables the release of active sites upon the formation of uranyl deposits (i.e., UO2, (UO2)O2·4H2O) with electrons as the catalytic shuttle. Overall, this work deepens our understanding of the rational design of piezo-photocatalysts and offers mechanistic insight into nuclide pollution remediation.

As uranium reserves deplete, thorium emerges as a key alternative, making its recovery from mining wastewater a pivotal step for resource sustainability and environmental remediation. In this study, HKUST-1@PAN composite nanofiber membranes were prepared using the electrostatic spinning technique to uniformly load HKUST1 onto polypropylene (PAN) polymer membranes for the enrichment of radioactive Th(IV). The HKUST-1@PAN nanofiber membrane with 40 wt% MOF loading exhibited superior Th(IV) adsorption performance, achieving a highest capacity of 303.95 mg g- 1 at the initial concentration (C0) of 200 mg L- 1 and pH = 3. This nanofiber membrane demonstrates high ionic strength tolerance and rapid adsorption kinetics, achieving equilibrium within just 20 min. Thermodynamic analyses confirm that the adsorption process is both endothermic and spontaneous. Dynamic membrane filtration experiments showed the membrane achieved 98 % removal of lowconcentration Th(IV) (20 mg L-1). Furthermore, the adsorption mechanism was thoroughly analyzed through SEM, XPS, FT-IR, and DFT calculations, revealing that the pore confinement effect of HKUST-1 affords specific adsorption sites for Th(IV). The incorporation of PAN with HKUST-1 maintains the hierarchical porous architecture of the MOFs while overcoming the inherent solid-liquid separation issue of powdered adsorbents. This work highlights the promising application of MOFs-incorporated nanocomposite membranes as efficient platforms for radioactive thorium extraction from aqueous waste streams.

Efficient charge separation and the construction of water oxidation active sites are crucial to achieving desirable photocatalytic uranium(VI) (U(VI)) removal. Herein, a Zn0.5Cd0.5S/WO3 heterojunction photocatalyst with its contact interface tightly bridged by interfacial W-S bonds was designed and fabricated. This catalyst features both efficient charge transport pathways and abundant water oxidation active sites, exhibiting excellent U(VI) removal efficiency without sacrificial agents. The interfacial W-S bonds established atomic-level channels for charge migration, which not only significantly promoted charge separation efficiency but also effectively reduced the energy barrier of the water oxidation reaction. Meanwhile, the WO3 component provided sufficient water oxidation active sites. Owing to these synergistic effects, the U(VI) removal rate of Zn0.5Cd0.5S/WO3 reached 97.7 % under simulated sunlight irradiation for 30 min, and its photocatalytic activity was 8.6-fold and 67.5-fold that of pristine Zn0.5Cd0.5S and WO3, respectively. This study contributes a novel insight and strategy for the design of efficient photocatalysts for U(VI) removal.

Fast industrial development not only requires a sustainable energy supply but also generates environmental pollutants. Carbon materials, particularly sustainable carbon materials (SCMs), have attracted multidisciplinary interest because of their special physicochemical properties, such as porous structures, high surface areas, sufficient active sites, abundant functional groups, high stability, and post-modification. Herein, the techniques for the synthesis and characterization of SCMs are summarized, along with recent achievements in the removal of environmental pollutants (e.g., heavy metal ions, radionuclides, and organic pollutants), and in energy-related applications (e.g., CO2 reduction reaction, hydrogen evolution reaction, oxygen evolution reaction, and battery systems). The reaction mechanisms are discussed from macroscopic results, advanced spectroscopic characterization, and theoretical calculations. The potential toxicity to the environment and living organisms is described, and artificial intelligence techniques in the carbon material studies are also explored. Finally, the challenges and perspectives regarding the applications of SCMs in energy and environmental areas are presented from the authors' viewpoint.

Photo-assisted catalytic uranium reduction is recognized as an innovative approach for the treatment of uranium-laden wastewater, yet it currently encounters challenges, including difficulties in carrier separation, a scarcity of active sites, and uncertainties regarding the catalytic mechanism. Herein, a novel Co3O4/P-PHI S-scheme heterojunction with well-defined Lewis acid and base sites was developed for efficient photocatalytic uranium reduction and methanol oxidation. The Lewis base sites of the terminal CN groups on P-PHI facilitate the reduction of positively charged uranyl, and electron-deficient Lewis acid sites of Co-OH on Co3O4 are liable to donate protons for the facile CHOH3 adsorption and oxidation to *CH2O and CH2O. These coexistent acid and base sites result in a strong synergistic effect in photocatalytic aerobic uranium reduction. Moreover, S-scheme charge transfer mechanism based on the energy band alignment is proved by radical formation, UPS analysis and density functional theory (DFT) calculations. Spectroscopy and photoelectrochemical analyses indicate that the transfer and separation of photogenerated carriers are effectively enhanced within the S-scheme heterojunction. Benefiting from efficient carrier separation and abundant active sites, the photocatalytic reduction of U(VI) attains an efficiency rate of 99.6 % in 30 min under atmospheric air conditions on 4 % Co3O4/P-PHI, which is similar to 7.6 x faster than that of pristine P-PHI. This research underscores the potential of employing a strategy centered on Lewis acid and base sites for the photo-assisted catalytic reduction of uranium.

Spent fuel reprocessing entails controlling the valence state of Np and its routing in the plutonium-uranium reduction extraction (PUREX) process. Hydroxylamine (HA) and its derivatives are effective salt-free reductants that can reduce Np(VI) to Np(V) without its further reduction. Experimentally, hydroxylamine, N-methylhydroxylamine (MHA) and N,N-dimethylhydroxylamine (DMHA) reduce Np(VI) at different reaction rates. To investigate the impact of methyl substitution on the Np(VI) reduction mechanism, we theoretically studied the Np(VI) reduction reaction by HA, MHA and DMHA. It was observed that the reduction of Np(VI) involves hydrogen atom transfer from these reductants. The two steps for Np(VI) reduction by HA occurre via hydrogen transfer. Alternatively, Np(VI) reduction by both MHA and DMHA initially proceede via hydrogen atom transfer, followed by an outer-sphere electron transfer mechanism. The rate-determining step for MHA and DMHA is the first Np(VI) reduction step, and the energy barrier for DMHA is lower than that for MHA, which are 6.2 and 7.7 kcal mol-1, respectively. So the reaction rate for the reduction of Np(VI) by DMHA is faster than that by MHA due to the influence of the methyl group, which is consistent with the experimental results. Finally, we analyzed the bonding evolution using the quantum theory of atoms in molecules (QTAIM), interaction region indicator (IRI), Mayer bond order (MBO), localized molecular orbitals (LMO) and spin density. This study presents kinetic insights into the effect of methyl substitution on the reduction of Np(VI) by hydroxylamine, providing an in-depth understanding of Np(VI) reduction by hydroxylamine derivatives in spent fuel reprocessing.

In this study, nitrogen-doped nanotube-encapsulated iron nanoparticle catalysts (Fe/Fe3C@NCNTs) were prepared using a one-step pyrolysis strategy for the efficiently activating of peroxymonosulfate (PMS) to degrade tetracycline hydrochloride (TC). The embedded structure greatly minimized the leaching of metals and enhanced the catalyst stability. The prepared Fe/Fe3C@NCNT-800 (0.05 g/L) exhibited excellent PMS (0.5 g/L) catalytic activity for the rapid degradation of TC (30 mg/L) with degradation rate of 90.5 % within 5 min under the pH of 7 and 25 degrees C. Its performance was nearly unaffected by environmental factors (temperature, pH, inorganic anions and organic matter). Moreover, the Fe/Fe3C@NCNT-800/PMS system maintained a TC removal rate of 85.5 % after four cycles of degradation experiments, with a negligible amount of metal leaching. X-ray photoelectron spectroscopy, electron paramagnetic resonance spectroscopy and electrochemical measurements showed that iron nanoparticles and graphitic nitrogen promoted Fe2+/Fe3+ cycling and reactive oxygen species generation as catalytic centers. Among them, 1O2 and electron transfer were shown to be the main degradation pathways for degrading TC.