The application of microbubbles (MBs) in ozone contactors improves pollutant removal efficiency. However, conventional MB generation methods significantly increase maintenance and operational costs. This study discusses the application of ceramic membranes for ozone microbubble aeration. Effluent from a sedimentation tank was used as the influent to a pilot-scale system, and the system's degradation capacity for dissolved organic matter (DOM) was compared under different aeration systems and operating conditions. Analysis of the effluent using parallel factor analysis (PARAFAC) and LC-OCD revealed that the ceramic membrane aeration system enhances DOM degradation efficiency. This study confirmed that, unlike titanium diffusers, ceramic membranes are not directly arranged at the bottom of the ozone contactor. The results indicate that appropriately increasing the height of the ceramic membrane arrangement improves the ozone mass transfer rate. The flow-guiding effect of the ceramic membranes can be utilised to improve ozone concentration uniformity. The reaction of hydroxyl groups on the ceramic membrane surface with liquid-phase ozone also generates additional •OH radicals. Through degradation experiments with atrazine (ATZ), we found that ceramic membrane aeration offers promising potential to improve organic pollutant removal in water and reduce system energy consumption. Furthermore, the additional pressure required for ceramic membrane use does not increase energy consumption. The ceramic membrane aeration method is easier to implement and more environmentally friendly than other microbubble generation methods.

Ammonia-fueled protonic ceramic fuel cells (PCFCs) are emerging as promising alternatives to H2-fueled PCFCs, offering advantages such as higher energy density and enhanced safety. However, their widespread application is impeded by challenges, including insufficient catalytic activity towards ammonia and limited stability of the anode structure. Herein, we report a rational design for Ni97Co3-BaCe0.7Zr0.1Y0.1Yb0.1O3-delta (BCZYYb) cermet anodes, aimed at enhancing both catalytic activity and durability for ammonia utilization. The cell featuring the Ni97Co3-BCZYYb anode leverage the synergistic interaction between Ni and Co to enhance ammonia adsorption and nitrogen desorption, resulting in a remarkable 67.8 % increase in power density when operating with NH3 at 600 degrees C. Notably, upon switching the fuel from H2 to NH3, this achieves an unprecedented power retention of 87.2 % at 700 degrees C, representing one of the highest values recorded for ammonia-fueled PCFCs, while most ammonia-fueled cells exhibit power retention in the range of only 60-80 %. Furthermore, the cell with Ni97Co3- BCZYYb cermet anode demonstrates exceptional durability, stable operation over 30 h at 650 degrees C under NH3 with no degradation observed. This longevity is attributed to the excellent sintering resistance of the NiCo alloy, highlighting the potential of the Ni97Co3-BCZYYb cermet anode for long-term applications. This work provides an effective strategy for designing highly active and durable anodes for ammonia-fueled PCFCs.

Double perovskite PrBaFe2O5+s (PBF) is a promising cathode material for solid oxide fuel cell (SOFCs) due to the favorable catalytic activity and superior electrochemical stability. Herein, to further tailor the oxygen-ion transport kinetics and electrochemical performance, unlike the typical approach through using higher valence, non-transition metal In3+ ion doping is initially investigated to partially replace Fe3+/Fe4+ site, forming the compositions of PrBaFe2_xInxO5+s (PBFInx, x = 0, 0.05, 0.1, and 0.15). Xray diffraction (XRD) analysis indicates that PBFInx exhibit satisfactory chemical and thermal compatibility with the gadolinia-doped ceria (GDC) electrolyte. Expectedly, the polarization resistance (Rp) of PBFIn0.1 cathode is decreased by approximately 40 % and an anode-supported single cell with PBFIn0.1 cathode yields a 36 % higher peak power density (PPD) at 800 degrees C compared to that of PBF. Moreover, the single cell using PBFIn0.1 as the cathode can be operated stably at 0.4 A cm_ 2 for more than 50 h without obvious performance degradation. In addition, the X-ray photoelectron spectroscopy (XPS) results confirm that the low-valence state In3+ introduced into PBF have a positive impact on the oxygen vacancy concentration and boost the oxygen reduction reaction (ORR) activity, thus significantly enhancing the electrochemical performance of the PBF cathode. The results show that the non-transition metal In3+ ion doping is an effective method to improve the performance of the PBF cathode for SOFCs.

The removal of natural organic matter (NOM) through biofiltration can be significantly influenced by the diversity of acclimated microbes on the substrate surface. In this study, three types of granular activated carbon (GAC), each with different surface functional group distributions, were selected as substrates for biofiltration to explore their effects on microbial and NOM removal in surface water. The results showed that GAC with a higher percentage of carboxyl group achieved better NOM removal efficiency during approximately one year of continuous operation (83.6 +/- 1.4 %). Using Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR-MS), it was found that coal-based GAC(C-GAC) was more effective at removing biorefractory compounds of NOM, including 42 %, 47 %, and 59 % more lignin, tannins, and condensed aromatic hydrocarbons, respectively. Microbial sequencing analyses revealed that physical and chemical properties of C-GAC favored the acclimation of species involved in the biodegradation of humic substances, such as the family Rhodocyclaceae and the genus Desulfosporosinus. More importantly, microbial interactions and metabolism (related to biodegradation) were found to be strongly influenced by the surface carboxyl group and pore size distribution of GAC, with the influence of surface carboxyl group being particularly critical. This study provides valuable insights into how the physicochemical properties of GAC synergistically govern microbial community dynamics and DOM removal efficiency, laying a foundation for enhancing the performance of biofilters in future water purification and reuse applications.

Protonic ceramic cells (PCCs) have been identified as promising energy conversion devices, offering flexible fuel options and reduced operating consumption at intermediate temperatures. However, the application of traditional cobalt-based perovskite air electrodes in PCCs is hindered by their insufficient durability and high coefficient of thermal expansion. In this study, a straightforward metal-oxygen bond engineering is conducted, introducing a single-phase perovskite, Ba0.95La0.05(Fe0.8Zn0.2)0.9Ni0.1O3-delta (BLFZN0.1), as a substitution for cobalt-based perovskite. BLFZN0.1 demonstrates superior electrochemical properties, with an area-specific resistance of 0.015 Omega cm2 at 700 degrees C, and demonstrates reliable durability over 100 h. The introduction of Ni element increases the concentration of oxygen defects and enhances the oxygen catalytic activity. As a result, a protonic ceramic fuel cell using BLFZN0.1 air electrode achieves the highest peak power density (1353 mW cm(-)2 at 700 degrees C) yet recorded for cells with BLFZ-based air electrodes. Furthermore, the single cell with BLFZN0.1 exhibits remarkable current density (1.66 A cm-2 at 700 degrees C) in the electrolysis mode, highlighting its potential for application in electrolysis devices. This study presents an effective and straightforward strategy for modifying PCC air electrodes with high electrochemical performance and comparable durability, thereby facilitating their commercial application.

Triggering transient radical generation based on redox reactions has become a new focus for advanced oxidation processes. However, the microscopic process of free radical generation and the effect of disinfection by-products (DBPs) generation in the subsequent chlorine disinfection remained to be elucidated during S(IV)/PAA process. This study assessed the formation of dichloroacetonitrile (DCAN), dichloroacetamide (DCAcAm), and trichloronitromethane (TCNM). Results revealed that oxygen atoms cooperating with single electron, meanwhile the sulfite radical (SO3 center dot-) reacts with the oxygen released during the self-decomposition of PAA, generating hydroxide radical (center dot OH) and sulfate radical (SO4 center dot-). The free energy changes of the intermediates converted to HO-CH2O-CH=NH, HO-CH2O-CN and C(Cl-2)=C-NO2 via SO4 center dot- and center dot OH-mediated alpha-hydrogen extraction and beta-hydrogen extraction under low concentration oxidation conditions were calculated by Gaussian simulation. The DCAN, DCAcAm, and TCNM formation were enhanced in low concentration oxidation. Therefore, the formation of DCAN, DCAcAm, and TCNM could be reduced by regulating the concentration of reactants and pH to control SO4 center dot- and center dot OH concentration and the degree of intermediates mineralization. Only 4.3-fold increase in toxicity at high mineralization of CAP demonstrated that the N-DBPs formation potential of applying S(IV)/PAA process to degrade CAP, however, the N-DBPs should still be evaluated prior to downstream application.

Reversible solid oxide cells (RSOCs) represent a promising technology for efficient energy conversion and storage. However, the performance is often limited by the sluggish oxygen kinetics and poor structural stability of the air electrode. The cobalt-free Bi0.5Sr0.5FeO3-delta (BSF) air electrode exhibits a comparatively desirable performance and is expected to be further optimized. Herein, we propose a B-site co-doping strategy by incorporating high valence Nb5+ and Ta5+ into BSF to synergistically optimize the oxygen transport capacity and surface reactivity. The optimized Bi0.5Sr0.5Fe0.8Nb0.1Ta0.1O3-delta (BSFN0.1T0.1) demonstrates exceptional oxygen ion diffusivity (Dchem = 4.378 x 10-4 cm2 s-1) and exchange kinetics (Kchem = 1.330 x 10-3 cm s-1), leading to a 69% reduction in polarization resistance (from 0.195 to 0.06 Omega cm2) at 750 degrees C. Notably, the BSFN0.1T0.1 air electrode maintains stable performance under 3-10% CO2 atmosphere, demonstrating superior CO2 tolerance. In fuel cell mode, the single cell delivers a peak power density of 616 mW cm-2 (98% enhancement over BSF) at 750 degrees C. In electrolysis cell mode, a current density of 1370 mA cm-2 is obtained at 750 degrees C and 1.5 V in 70% CO2/30% CO atmosphere (116% enhancement over BSF). The synergistic effect of Nb5+ and Ta5+ co-doping arises from their similar ionic radii, stable high valence states, and electronegativity differences, which stabilize the perovskite lattice and facilitate oxygen migration, thereby optimizing oxygen reduction/evolution reaction (ORR/OER) activity and electrochemical performance. This work provides a rational design strategy for advanced RSOC air electrodes.

The effect of N, N-bis(carboxymethyl)glutamic acid (GLDA) on the removal of organic pollutants by Fe(II)mediated periodate (PI) advanced oxidation process at neutral pH was investigated, in which N-(1,3-dimethylbutyl)-N '-phenyl-p-phenylenediamine quinone (6PPD-Q) was used as the model pollutant. The results showed that the Fe(II)-GLDA complex formed by mixing GLDA with Fe(II) in a 1:1 ratio reacted with PI can degrade 6PPD-Q effectively. The presence of GLDA alters the redox potential of Fe(II)/Fe(III), which allows for a better utilization of Fe(II) under the synergistic effect of ultraviolet (UV) irradiation. Based on quenching experiments, sulfoxide probe transformation and electron spin resonance (ESR) signals, the reactive species that play a major role in this process are FeIV--O and IO3 center dot. The degradation products of 6PPD-Q were detected by Ultra Performance Liquid Chromatography-Tandem Mass Spectrometry (UPLC-MS/MS) and two possible degradation pathways were proposed based on density functional theory (DFT) calculations. The toxicity of 6PPD-Q was found to be effectively reduced after degradation by Ecological Structure Activity Relationships (ECOSAR) software analysis and zebrafish experiments. This study provides some fundamental insights for the removal of organic pollutants by GLDA-enhanced Fe(II)/PI system under neutral conditions.

Proton ceramic fuel cells (PCFCs) face significant challenges in developing electrolytes that simultaneously exhibit high proton conductivity and good sinterability at reduced temperatures. While SrSn0.8Sc0.2O3-delta (SSS) has emerged as a promising alternative to traditional BaZrO3- and BaCeO3-based systems due to its superior thermochemical stability, its conductivity remains insufficient for practical low-temperature (<500 degrees C) applications. In this study, where single doping fails, we develop a rational co-doping strategy through the incorporation of both Ba and Yb to simultaneously enhance bulk conductivity and reduce grain boundary resistance in SSS electrolytes. The optimized composition, Sr0.95Ba0.05Sn0.8Sc0.15Yb0.05O3-delta, shows a 26.3 % increase in conductivity and a 71.7 % reduction in grain boundary resistance at 400 degrees C, due to synergistic phase modification and defect optimization. Single-cell tests demonstrate practical benefits, as the co-doped electrolyte delivering a 38.7 % increase in power density at 500 degrees C compared to its undoped counterpart. These findings contribute valuable insights into the development of improved proton-conducting electrolytes through controlled co-doping, and suggest a promising avenue for optimizing SSS-based materials in low-temperature PCFCs.

Sulfite (S(IV))-based advanced oxidation processes (AOPs) have recently gained attention as viable alternatives to peroxosulfate-based AOPs due to their low toxicity and cost-effectiveness. Hydrogen peroxide (H2O2) is widely recognized as an effective and environmentally friendly oxidant in drinking water treatment. This study introduces a novel H2O2/S(IV) AOP based on the observation of over-stoichiometric consumption of S(IV) by H2O2. This system generates a variety of reactive species (RSs), including sulfate radicals (SO4•-), hydroxyl radicals (•OH), superoxide anion radicals (O2•-), and singlet oxygen (1O2), to achieve rapid degradation of micro-contaminants in drinking water. With dosages of H2O2 and S(IV) set at 0.1 mM and 1.0 mM, respectively, the H2O2/S(IV) system generated concentrations of SO4•-, •OH, O2•- and 1O2 at approximately 10-12, 10-12, 10-13, and 10-13 M. This occurred even in complex water matrices containing bicarbonate (HCO3-), chloride (Cl-), and humic acid (HA) across a pH range of 3.0-11.0. A kinetic model was developed to simulate RS generation and predict the pseudo-first-order degradation rate constants (k) for 15 micro-contaminants in the H2O2/S(IV) system. Theoretical calculations indicated that micro-contaminants with high EHOMO and low ΔE (i.e., ELUMO - EHOMO) are more susceptible to degradation. Compared to UV/H2O2, UV/S(IV), Fe2+/H2O2, and Fe3+/S(IV) systems, the H2O2/S(IV) system demonstrated faster degradation rates, with k values 1-2 orders of magnitude higher, towards micro-contaminants. Additionally, the H2O2/S(IV) system was more effective in controlling disinfection by-product formation during subsequent chlorination, highlighting the application potential of the H2O2/S(IV) system in drinking water treatment.

As the tire-derived quinone, IPPD-Q emerges as one of the most acutely toxic emerging contaminants in urban waters, its fate during final disinfection remains unclear. This study demonstrates that IPPD-Q reacts rapidly with both chlorine and chloramine, exhibiting second-order rate constants of 110.4 ± 10.9 M-1 s-1 and 46.2 ± 3.8 M-1 s-1 at pH 7.0, respectively. HOCl dominates over OCl⁻ in chlorination, whereas NH2Cl is the sole reactive species in chloramination during pH 6.0 ∼ 8.0. Eighteen chlorinated and twelve chloraminated transformation products (TPs) were structurally elucidated, revealing that HOCl drives sequential Cl substitutions at C2, C9 and C12 or OH substitution at C9 and C12 sites followed by benzoquinone cleavage. Whereas, NH2Cl yields both Cl-substituted TPs via Cl substitution at C2 and C12 sites and unique NH2-substituted TPs via nitrogen incorporation at C9 site. Density functional theory (DFT) calculations show that electrophilic attack is governed by the lowest activation free energy at C2 (ΔG‡ = 11.95 kcal/mol for HOCl and 10.82 kcal/mol for NH2Cl), aligning with the observed preferential formation of highly toxic chlorinated TPs. Zebrafish embryo assays combined with ECOSAR predictions reveal that some TPs are more toxic than IPPD-Q itself, with chlorination TPs exhibiting the highest lethality. Dynamic electron-distribution analysis unravels synchronous σC-H/πCC bond rupture and σC-Cl/C-N/C-O bond formation directed by frontier-orbital interactions. This work provides the first molecular-orbital-based roadmap for predicting and mitigating the risks associated with tire-derived quinones during drinking water disinfection.

The emergence of recalcitrant organic pollutants poses a significant threat to aquatic environments. PI-based AOPs have been widely used in water treatment and show great potential in degrading these pollutants. This study pioneers the application of low-dose ozone-activated periodate (O₃/IO₄⁻), a novel advanced oxidation process (AOP), for rapid degradation of β-blocker contaminants exemplified by pindolol (PIN). The O₃/PI system exhibits broad pH applicability. Under optimal conditions of 0.175 mg/L O₃, 0.1 mM IO₄⁻, and pH 7.0, the system achieved 99.2 % PIN degradation within 20 s (kobs = 0.254 s⁻¹) when treating an initial PIN concentration of 1 µM, indicating a strong synergistic effect between low-dose O₃ and PI activation. Radical quenching experiments coupled with electron paramagnetic resonance (EPR) spectroscopy revealed a multi-radical mechanism involving iodine species (IO₃•) and reactive oxygen species (ROS) (•OH, •O₂⁻, ¹O₂), with density functional theory (DFT) calculations confirming ozone-periodate adduct formation (OOOIO₄⁻) as the initiation step for radical chain propagation. The degradation of PIN by the O₃/PI system was minimally affected by coexisting substances in the aqueous matrix, with only high concentrations of HCO₃⁻ and humic acid (HA) showing some influence, while Cl⁻ had negligible effects. This highlights the stability of the O₃/PI system and its potential for practical water treatment applications. The identification of transformation products (TPs) and theoretical calculations elucidated the key ROS (IO₃• and •OH) in the PIN degradation process and their attack pathways (HAA, RAF, and SET). Potential degradation pathways for PIN are proposed. Zebrafish toxicity experiments showed that the O₃/PI system effectively detoxifies PIN, though the toxicity of intermediates warrants attention. In conclusion, the developed O₃/PI system offers an efficient and environmentally friendly strategy for PI activation and the treatment of emerging organic pollutants such as PIN.

Porous ceramics are widely used in industries such as thermal insulation, aerospace, and biomedicine. The direct foaming technique is an eco-friendly method used to produce porous materials with high porosity and narrow pore size distribution. However, a high solid powder content is often required because of pore collapse and low strength. In this study, high-strength porous ceramics were prepared using stable wet foams with ultra-low solid content. The effects of heptanoic acid and sepiolite fiber (SEPF) on the rheological properties, microstructure, and mechanical strength of alumina ceramics were examined. The addition of SEPF enhanced foam stability by forming a nanofiber membrane. Alumina ceramics with 15 vol% solid content, 82.91 % porosity, 0.33 g/cm3 density, and 14.17 MPa compressive strength are successfully produced. The presence of forsterite and pyrope, along with uniform fine pores and strong pore walls, improves mechanical strength. This study provides a new technical direction for the development of the ceramic industry.

Sulfite (S(IV))-based advanced oxidation processes (AOPs) have emerged as a cost-effective and low-toxicity alternative to persulfate-based AOPs. Ozone (O3) has been applied in the purification and treatment of drinking water as a strong oxidant. In this study, an advanced oxidation processes (O3/S(IV) process) was built by using S(IV)-activated O3 to achieve a 87.4% of gatifloxacin (GAT) degradation within 5 min. The molar ratio of S(IV) to O3 ([S(IV)]/[O3]) determines whether S(IV) promotes or inhibits ozonation. A low [S(IV)]/[O3] promotes the generation of reactive species, while high [S(IV)]/[O3] completely inhibit GAT removal. The optimum [S(IV)]/[O3] is influenced by pH, e.g., 0.4 at pH=7.0. Quenching experiments and electron paramagnetic resonance (EPR) spectra confirmed that SO4•- and •OH are the main reactive species responsible for GAT degradation. Density functional theory (DFT) revealed the reaction mechanism of reactive species with GAT. The single electron transfer reaction (SET) route can only occur via SO4•-, while •OH can degrade GAT through solely the hydrogen atom abstraction (HAA) route. Additionally, radical adduct formation (RAF) route is thermodynamically favorable for both SO4•- and •OH. SO4•- attacks GAT with a lower energy barrier to overcome than •OH, which is kinetically more favorable. The presence of natural water matrix such as HCO3- and humic acids (HA) reduces the performance of O3/S(IV) for GAT removal, while the effect of Cl- on the removal rate can be negligible. Three GAT degradation pathways were proposed based on DFT with HPLC-MS/MS monitoring. Zebrafish toxicity assays demonstrate that detoxification effects accompanied the degradation process of GAT. Besides, using O3/S(IV) process as a pretreatment process can effectively control the formation of disinfection by-products (DBPs) during post-chlorination. The results provide new avenues for designing S(IV)-based AOPs and removing GAT efficiently.

Reversible solid oxide cells (RSOCs) offer a revolutionary pathway for sustainable energy conversion and storage; however, their commercial viability is severely limited by the suboptimal catalytic capabilities and long-term stability of air electrodes. Herein, this work presents a novel approach to concurrently enhance the catalytic activity, durability, and CO2 tolerance of the Bi0.5Sr0.5FeO3-s (BSF) air electrode by substituting oxygen sites with chloride (Cl-) anion. Notably, the optimized Bi0.5Sr0.5FeO2.95-sCl0.05 (BSFCl5) electrode exhibits a remarkable 49 % reduction in polarization resistance (Rp) at 800 degrees C, while maintaining exceptional CO2 tolerance-Rp remains unchanged even under 10 % CO2. In full-cell configurations, BSFCl5 achieves a peak power density of 1.22 W cm-2 (vs. 0.8 W cm-2 for BSF) and an electrolysis current density of 2.33 A cm-2 at 1.5 V in a 70 % CO2/30 % CO atmosphere, representing a 52.5 % and 72.6 % improvement, respectively. The BSFCl5 half-cell and full-cell exhibit excellent operational stability over 350 h and 150 h, respectively. Combined density functional theory (DFT) simulations and comprehensive experimental characterizations elucidate that Cl doping strengthens the metal-oxygen (M-O) covalency, synergistically boosting the oxygen reduction/evolution reaction (ORR/OER) kinetics and stability. This work presents a highly anticipated design approach for the future design of air electrodes for RSOCs with excellent catalytic performance and stability.

In situ constructing active metal/oxide interfaces has extensive applications for CO2 electrolysis in solid oxide electrolysis cells (SOECs) but faces critical challenges due to sluggish diffusion process of B-site cations inside the perovskite bulk. Herein, the diffusion kinetics of Fe and Ni cations in Sr0.9Ti0.45Fe0.5Ni0.09O3-δ (S0.9TFN0.09) are greatly facilitated via structural flexibility. The synergistic modification of Sr-site defects and excess Ni incorporation enables flexible coordination and enhanced intrinsic oxygen properties, driving a bulk-surface reconstruction under reducing condition. As a consequence, the heterostructured FeNi alloy (FNA) and metallic Fe nanoparticles are readily in situ exsolved onto Ruddlesden-Popper layered perovskite (RP-STF) surface. The phase transition process significantly increases the number of exsolved particles. Compared with pristine matrix, the reconstructed FNA/Fe@RP-STF interfaces deliver markedly enhanced electrocatalytic activity for CO2 adsorption and dissociation, thus reach a 51% improvement in CO2 electrolysis performance at 1.5 V and 800 °C. Moreover, the operating stability and anticoke properties are enhanced due to strongly interactive heterointerfaces. This work provides a sufficiently simple strategy to rapidly achieve microstructural evolution for CO2 electrolysis and other energy conversion.

In a recent issue of Nature Nanotechnology, Li and coworkers presented a tandem catalyst design, constructing an atomically intimate assembly with dual interfaces for ethanol production. This approach leverages the synergy of distinct interfaces tailored to specific reactions, ensuring seamless coordination for cascade processes and achieving high activity and selectivity.

Protonic ceramic electrolysis cells (PCECs) have attracted significant interest because of their efficiency and environmental sustainability in energy conversion. However, their commercial application is hindered by the absence of effective and robust electrodes capable of operating in harsh environments, such as those characterized by high vapor or CO2 concentrations. In this study, we developed a stable steam electrode composed of PrBaMn2O5+δ (PBM) and the durable proton conductor BaZr0.85Y0.15O3−δ (BZY), which was enhanced with the deposition of PrOx nano-catalysts. The composite electrode exhibited a low polarization resistance (~0.34 Ω·cm² at 600 °C), comparable to that of conventional cobalt-based electrodes. Additionally, extensive testing over hundreds of hours under severe conditions revealed exceptional durability, with no significant degradation observed. Notably, the electrode composited with cube-shaped BZY microcrystals and PBM showed a higher proton conductivity of 2.15×10−5 S·cm−¹ at 500 °C, representing an entire order of magnitude greater than that of the electrode composited with irregular nanosized BZY. In addition, the single cell achieved a superior electrolysis current of 2.0 A·cm−2 at 700 °C and 1.3 V. These findings demonstrate the superiority of constructing an innovative interface between the mixed ionic‒electronic conductor (MIEC) and the proton conductor. Our work presents a promising strategy for designing durable steam electrodes for PCECs through a rational compositing approach.

Perfluorooctanoic acid (PFOA) exhibits strong bioaccumulation potential and toxicity, posing a serious threat to human health. Conventional water treatment processes are almost ineffective in treating perfluorinated compounds. Thus, this study aimed to utilize vacuum ultraviolet (VUV) light to activate dithionite (S2O42-) under anaerobic conditions for PFOA degradation. This system achieved a degradation rate of 91.40 % and a defluorination rate of 52.41 % within a reaction time of 1 h. Hydrated electron (e-aq) was found to be the main active species for PFOA degradation. Defluorination was most effective under strong alkaline conditions, and its degradation efficiency was higher than that of the VUV/sulfite (SO32-) system under neutral and acidic conditions. We investigated the effects of co-existing anions, humic acids, and actual water environment on PFOA degradation to further understand the application potential of this system. UPLC-MS/MS analysis and density-functional theory calculations revealed 14 degradation products formed by five major degradation mechanisms, namely, H/F exchange, SO3 center dot-/F exchange, decarboxylation-hydroxylation-elimination-hydrolysis, defluorination to form C--C bonds, and hydroxylation. The results of ecological structure modeling software and zebrafish toxicity experiments indicated that all the degradation products were significantly less toxic than PFOA. The study confirmed that the VUV/S2O42-/N2 system can efficiently degrade PFOA without creating new ecological hazards, offering a novel approach for the sustainable treatment of PFOA-contaminated water.

Symmetrical solid oxide fuel cell (S-SOFC) has gained extensive attention for its simplifying fabrication process and reducing cost. Fe-based double perovskite PrBaFe2O5+delta (PBF) is a potential electrode material for S-SOFC due to the excellent mixed electronic and oxygen ionic conductivity. However, the electrochemical performance of PBF is limited by lacking enough oxygen vacancies and the sluggish oxygen-ion transport kinetics. Herein, a BaCoO3-delta(BCO) impregnated PBF (PBF-BCO) electrode is investigated with enhanced catalytic activity. The BCO decoration can significantly decrease the polarization resistance (Rp) by approximately 36.5% and 26.0% compared to PBF at 800 degrees C in air and hydrogen atmosphere, respectively. The peak power density (PPD) of an electrolyte-supported S-SOFC with PBF-BCO electrode is nearly 36% higher than that of PBF electrode. The prominent electrochemical performance of the PBF-BCO electrode is attributed to the significantly accelerated oxygen adsorption/dissociation processes, which promote the oxygen reduction reactions (ORR) and enhanced charge transfer processes in H2 atmosphere for superior hydrogen oxidation reaction (HOR). The results demonstrate that the BCO impregnated PBF is one of the promising electrode materials for S-SOFC.