To achieve efficient conversion of coal resources into oil and gas, the involvement of cost-effective and highly active catalysts is essential. FeOOH is a significant iron-based compound widely utilized in adsorption, catalysis, and various other fields, particularly as a catalyst in coal direct liquefaction and coal-oil co-hydrogenation processes. However, due to the considerable impact of factors such as crystal configuration and metal ion doping on its performance, the catalytic efficacy remains unsatisfactory. In this study, Mo-doped FeOOH catalysts were synthesized through a one step air oxidation process in an NH4+-MoO42--Fe2+ solution. The crystal structure of FeOOH transitions from needle-like alpha-FeOOH to shuttle-like (3-FeOOH and ultimately to small spherical ferrihydrite with increasing Mo/Fe ratios. During this transition in crystal configuration, iron vacancies are generated, leading to lattice contraction and reduction in grain size. The catalytic effects of Mo-Fe0.1 and Mo-Fe0.2 are comparable when applied in coal-oil co-hydrogenation reactions. In comparison with the alpha-FeOOH prepared under identical conditions, both oil yield and coal conversion increased by approximately 6.36% and 3.90%, respectively; additionally, the content of alkane and aromatic composition in the liquefied oil were improved by about 3% and 10%, respectively. Furthermore, the reaction peak pressure decreased by around 1.1 MPa.

Induction heating offers a promising route to intensify CO2 desorption. Conventionally, ferromagnetic powders are dispersed in the solvent as susceptor materials. In this study, 430 stainless steel mesh coated with a thin layer of copper and directly immersed in the solvent was used to replace such powders. Induction tests show that the coated mesh reaches the target temperature even at low frequency and low excitation current. Desorption experiments were subsequently conducted for various CO2-rich ChCl-MEA formulations. Under electromagnetic induction, the MCu3 system delivered the best performance: a desorption efficiency of 93.54%, a desorption rate of 0.3302 × 10-3 g CO2·g-1 absorbent·s-1, and an energy requirement of only 2.33 GJ·t-1 CO2. Compared with the uncatalyzed system under conventional conduction heating, this exceptionally high desorption rate benefits from the stainless-steel mesh's highly efficient magnetothermal effect, the proton-transfer active sites that the surface copper layer offers for chemical catalysis, and-thanks to copper's high thermal conductivity-the noticeably more uniform heat transfer achieved under induction heating. This magnetothermal-catalytic strategy opens a scalable, low-energy pathway for absorbent regeneration in industrial CO2 capture processes.

ZIF-8-derived carbon materials possess great advantages in the field of electrochemical adsorption due to their abundant porous structures, excellent specific surface areas, and good electrical conductivity. The efficient separation and capture of bromide ions (Br) from brine systems represent a critical pathway to achieving high-efficiency utilization of brine resources and environmental protection. In this study, a nitrogen (N)-doped ZIF-8-derived carbon material (NC-800) was synthesized via high-temperature calcination at 800 degrees C, and its performance in separating and capturing Br- from brine was systematically investigated. Electrochemical test results showed that the NC-800 membrane electrode achieved a maximum intercalation capacity of 115.65 mg center dot g-1 for Br- at an oxidation voltage of 1.0 V. Moreover, the captured Br- could be successfully converted into elemental bromine (Br2) through carbon tetrachloride (CCl4) extraction, realizing the resource recovery of Br. Cyclic stability tests indicated that after 10 adsorption-desorption cycles, the maximum intercalation capacity of the electrode remained at 57 mg center dot g-1, demonstrating excellent cyclic reusability. Systematic characterizations were conducted to analyze the microstructure of NC-800 and the adsorption mechanism of Br. Combined with electrochemical performance analysis, the effects of different operating conditions on Br- adsorption performance were examined. Density functional theory (DFT) was employed to verify the adsorption mechanism of Br- on NC-800, and the results confirmed that nitrogen doping significantly enhances the Br- adsorption capacity of porous carbon materials. This study deepens the understanding of the "physical-chemical synergistic adsorption mechanism" during Br- separation by the NC-800 material, offering new insights for the development of sustainable bromine resource recovery technologies.

Investigating phase equilibria in sulfate-based brines rich in K and Li is essential for the efficient extraction of these critical elements, among others. Accordingly, this study examines the phase equilibria of the complex senary system (Li+, Na+, K+, Mg2+//Cl-, SO42--H2O) at low temperatures (258.15 K). Moreover, the solubilities of the senary system and its subsystem Li+, Na+, K+//Cl-, SO42--H2O are measured accurately via the isothermal dissolution equilibrium approach, and the corresponding phase diagrams are constructed. Notably, the phase relationships of this system are considerably simplified at 258.15 K (with NaCl center dot 2H2O cosaturation) relative to at ambient and elevated temperatures. Additionally, the phase diagram of senary system exhibits eight two-salt cosaturation zones and six co-saturation points, with only two double salts being observed: Car (KCl center dot MgCl2 center dot 6H2O) and Lic (LiCl center dot MgCl2 center dot 7H2O). Most significantly, all the sulfate double salt crystallization regions disappear at 258.15 K in the respective phase diagrams, contrary to the case in the diagrams corresponding to ambient temperature. To elucidate the underlying physicochemical mechanism of this phase diagram simplification, cross-temperature molecular dynamics simulations are performed, revealing a fundamental transformation in the microscopic solution structure at low temperatures. Specifically, Na+ ions exhibit markedly enhanced cooperative binding capabilities with SO42-and H2O molecules than those of other cations (particularly Mg2+ and Li+). Such a low-temperature-enhanced, Na-dominated competitive hydration approach selectively drives the preferential nucleation and crystallization of Na2SO4 center dot 10H2O. This process consumes SO42-in the system, altering the activity coefficients and saturation states of the remaining ions in the solution, inhibiting the precipitation of sulfate double salts. Overall, this study clarifies the intrinsic correlation mechanism underlying the process of 'microscopic hydrated structure dynamic evolution -> macroscopic phase equilibrium reconstruction.' Furthermore, the study elucidates the selective regulation of low-temperature conditions as a key thermodynamic control variable on dominant crystallization pathways. Finally, the findings provide theoretical foundations and process design guidance for developing novel salt lake Li extraction technologies rooted in low-temperature phase transformation regulation.

Background: Existing molybdenum-based catalysts exhibit unsatisfactory performance in coal tar hydroupgrading due to limited active sites and weak cracking capability. Methods: Supported NiMoSx@TiO2 catalysts with a tunable Ni/Mo atomic ratio were prepared via a two-step method and applied in coal tar hydrogenation. Findings: Importantly, Ni shows dual regulation over MoS2 formation. With Ni/Mo approximate to 0.1, Ni promotes the conversion of Mo7SxO(21_x) intermediates to highly dispersed, truncated MoS2 slabs (1-2 layers, 3-8 nm), enhancing nucleation while suppressing stacking and achieving a 64.99 % gasoline and diesel yield. When Ni/Mo >= 0.3, excess Ni consumes sulfide to form NiSx and occupies TiO2 anchoring sites, hindering MoS2 growth and driving slab fusion into thicker aggregates (4-8 layers, 20-40 nm) that bury edges. This study reveals Ni's dualregulation mechanism on MoS2 nucleation and layer-number evolution, which governs edge-site exposure and dictates coal-tar hydro-upgrading performance.

Sheep manure (SM) composting is time-consuming and polluting, creating significant agricultural waste challenges. This study utilized rapid hydrothermal humification to convert SM to humic acid (HA). Optimal yield (23.88%) was achieved at 250 °C for 2 h with an SM:KOH mass ratio of 20:3. FeOOH catalyst addition significantly enriched the functional groups. The resulting organic fertilizer boosted pea germination to 93% and doubled stem/leaf dry weight versus the control. With the addition of HA, the state of heavy metals in soil has been improved. Hydroponic experiments and soil property analysis confirmed the superior performance. Life cycle assessment demonstrated that this HA fertilizer causes substantially less environmental damage than conventional inorganic fertilizer, offering a sustainable waste-to-resource solution for modern agricultural systems.

ABSTRACT In deep reservoir environments, the effectiveness of polymer gel systems for enhanced oil recovery (EOR) is often compromised by extreme conditions of high temperature, high salinity, and elevated pressure. As the most extensively used polymer gel, polyacrylamide‐based gel particles have shown great promise but suffer from limited thermal and chemical stability under harsh conditions. The multiscale degradation mechanisms governing their breakdown remain poorly understood. In this study, we systematically investigate the degradation behavior of polyacrylamide nanospheres, a model system with controlled particle size under representative reservoir conditions (150°C, 5 MPa, up to 100 g/L salinity). Through a combination of thermal analysis, structural and surface characterization, gas‐phase product profiling, in situ high‐pressure IR spectroscopy, and density functional theory (DFT) calculations, we map out the key degradation pathways and their molecular origins. Results show that salinity promotes hydrolysis of amide groups, particularly at MBA crosslinking sites, while high‐pressure oxygen accelerates deamination and chain scission. In situ IR confirms the evolution of functional groups into carboxylic acids, and DFT results reveal that carboxyl‐rich environments significantly reduce the activation energy for bond cleavage, initiating autocatalytic degradation. Importantly, oxidative degradation under air proves more damaging than ionic effects alone. This comprehensive, multiscale approach not only clarifies the intertwined roles of heat, salt, and oxygen in destabilizing polymer gels but also provides a mechanistic foundation for developing salt‐tolerant, oxidation‐resistant gel formulations for high‐temperature reservoir applications.

Water-induced pore-mouth wetting severely undermines the dynamic performance of amine-functionalized MOFs for post-combustion CO2 capture under low-partial-pressure, high-humidity flue gases. Formation of water films and competitive H2O/CO2 adsorption at pore entrances imposes strong mass-transfer limitations, which manifests as premature breakthrough and a marked loss of humid-state working capacity. Here, this study designs a spatially partitioned MIL-101(Cr)-based adsorbent (denoted 101-10 A-F) that decouples intrapore chemisorption from pore-mouth wetting via hydrophobic interfacial gating. MIL-101(Cr), synthesized through an HF-free acetic-acid route, serves as a large-pore scaffold to confine a mixed PEI/DETA phase inside the cages by capillary infiltration, forming a high-affinity reaction domain. A fluorinated FOTS layer is subsequently deposited on the external surfaces and pore mouths to generate a low-surface-energy gate, which suppresses water ingress while preserving CO2 accessibility. The gated sample 101-10 A-F displays pronounced hydrophobicity, with a water contact angle of approximate to 134 degrees. In fixed-bed breakthrough experiments at 75% relative humidity, its humid-state breakthrough capacity q0.05 increases from 0.55 to 4.62 mmol g-1 relative to the ungated analogue, corresponding to an 8.25-fold enhancement. 101-10 A-F also exhibits robust cycling performance, retaining 92.4% of q0.05 (4.27 mmol g-1) and 95.0% of qtotal(4.79 mmol g-1) after 15 adsorption-desorption cycles. Molecular-level interaction analysis indicates that the fluorinated interface is thermodynamically disfavored for water yet remains permeable to CO2, thereby mitigating wetting-induced transport degradation and preserving access to intrapore amine sites. This interfacial gating concept, as exemplified by 101-10 A-F, provides a generalizable route to amplify humid-state performance while maintaining cycling stability for CO2 capture from high-humidity flue gases.

The sewage from the No. 2 Combined Station of Tahe Oilfield has the characteristics of high salinity, high chloride ion concentration, high water temperature, and a small amount of H2S and CO2 gas, which is highly corrosive. Using dynamic corrosion weight loss, electrochemical, SEM, EDS and other test methods, the effect of high concentration of Cl− on the corrosion of 20# steel in wastewater containing H2S and CO2 was studied. The research shows that: in the sewage containing H2S and CO2, high concentration of Cl− has obvious promoting effect on the corrosion of 20# steel. Within the research range, no critical concentration that causes the rapid change of the corrosion rate of 20# steel has been found; The competitive adsorption and strong permeability of S2− obviously affect the structure of the corrosion product, and will cause a large area of the corrosion product film to fall off; with the increase of Cl− concentration, the falling off and formation of the 20# steel corrosion product film alternately occur, and the corrosion at the same time, the corrosion current showed a general trend of increasing, and the corrosion potential did not change significantly.

In oilfield brine, the bromide ion (Br-) concentration ranges from 100 to 300 mg/L, accompanied by high concentrations of coexisting anions, especially chloride (Cl-) at 100-300 g/L. The selective separation of Br- remains extremely challenging due to the similar structural and charge properties of halide ions. This study developed an electrodeposited self-assembled bromide ion-trap polyaniline (Br-trap PANI) film, leveraging the synergistic enhancement between the highly selective Br- capture capability of the Br-trap structure and the electrical conductivity of PANI. Under optimized conditions (voltage: 0.7-1.0 V, pH: 1-14), the composite film demonstrated a maximum Br- adsorption capacity of 68.05 mg/g with excellent cyclic stability, retaining over 50 mg/g upon repeated use. At an anion concentration ratio of 1:1, the selectivity coefficients for Cl-, SO4 2-, and NO3 - were 1.17, 1.44, and 1.59, respectively. It was found that these coefficients increased with the increase of the concentration difference between Br- and competing anions. Furthermore, the film exhibits rapid adsorption kinetics, acid resistance, and electrochemical stability. The composite material also features low production costs, benefiting from the low cost and wide availability of aniline monomer, combined with the scalable nature of the electrodeposition synthesis method. This technology provides an effective approach for the sustainable extraction of Br- from complex brines. It is clear that the effective utilization of oilfield brine represents a valuable resource, with significant implications for the goals of critical mineral security and resource recycling.

Deep eutectic solvents (DESs) are promising non-aqueous absorbents for CO2 capture, but highly reactive superbase-based systems often suffer from component volatilization, excessive viscosity increase after absorption, and limited regeneration stability. In this work, a quaternary ammonium microenvironment regulation strategy was developed to construct ternary superbase DESs with balanced CO2 uptake, volatility resistance, and regeneration performance. By systematically screening the salt structure, hydrogen-bond donor (HBD), and composition, TBAC:DBN:DEG (1:4:6) was identified as the optimal system. Relative to the corresponding salt-free binary system, the incorporation of TBAC markedly reduced thermal loss, improved thermal stability, and moderated the viscosity rise of the CO2-rich liquid. Under the optimized conditions, the ternary DES achieved a CO2 uptake of 0.163 g CO2 /g absorbent at 303.15 K, could be nearly completely regenerated at 353.15 K, and retained 90.4% of its effective working capacity after 10 cycles. The CO2-rich absorbent also showed a much lower corrosion rate than 30 wt% MEA and a total regeneration energy of only 1.92 GJ/t CO2. 13C NMR, DFT calculations, and molecular dynamics simulations consistently showed that TBAC did not alter the fundamental carbonate-forming pathway governed by cooperative DBN-assisted hydroxyl activation and CO2 insertion, but instead reconstructed the local ionic environment and multispecies association pattern in the liquid phase. This microenvironment regulation suppressed component volatilization and alleviated excessive structural densification in the CO2-rich liquid, thereby improving the overall capture-regeneration performance. These results provide an effective route for the design of low-volatility and low-energy non-aqueous DES absorbents.

The direct conversion of carbon dioxide and diols into polycarbonate is a promising approach in the field of carbon utilization. However, simultaneous enhancement of the activity and stability of catalytic systems remains challenging. In this study, a series of lanthanide-substituted CeO2 solid solutions were synthesized and evaluated in the copolymerization of CO2 with 1,6-hexanediol (1,6-HDO). X-ray photoelectron spectroscopy and O2 temperature-programmed desorption indicate that the surface oxygen vacancy density initially increases and then decreases with the increase in Gd or Pr content; 1%Gd-CeO2 and 1%Pr-CeO2 exhibit the highest diol conversion and oligomer selectivity. CO2 temperature-programmed desorption, in-situ infrared spectroscopy, and Density Functional Theory calculations demonstrate that 1%Pr-CeO2 possesses a higher surface vacancy concentration, stronger CO2 chemisorption, and superior resistance to catalyst poisoning compared with pristine CeO2. Collectively, these characteristics endow the catalyst with enhanced competitive activity and stability compared to pristine CeO2. A plausible deactivation pathway and atomistic reaction mechanism are proposed based on combined spectroscopic and theoretical evidence.

The direct synthesis of dimethyl carbonate (DMC) from CO2 has become a central research focus in CO2 conversion. Fe-doped CeO2 catalysts were synthesized using a hydrothermal method and applied to the direct synthesis of DMC from CO2 and CH3OH. Iron doping regulates the concentration of oxygen vacancies and the ratio of acid and base sites on the CeO2 surface, promoting the formation of frustrated Lewis pairs (FLPs). In situ infrared spectroscopy shows that Fe doping enhances CO2 adsorption at oxygen vacancies on the CeO2 surface, resulting in the formation of bidentate carbonate species. These species subsequently react with methanol to generate monomethyl carbonate intermediates, which facilitate DMC synthesis. The catalyst with the optimal Fe/Ce ratio (Fe1.2%-CeO2) achieved a DMC yield of 10.97 mmol·g·cat−1. This study provides insight into the preparation of high-performance nano-CeO2 catalysts for DMC synthesis from carbon dioxide and methanol.

The solid-liquid equilibria of the binary system Na2SeO3-H2O and the ternary systems NaCl-Na2SeO3-H2O and Na2SO4-Na2SeO3-H2O at 268.15 and 288.15 K were investigated by isothermal dissolution equilibrium method. The results indicate that for the ternary system NaCl-Na2SeO3-H2O at 268.15 K, the equilibrium phase diagram contains two invariant points, three univariable curves, and five crystallization regions comprising NaCl & centerdot;2H2O, NaCl & centerdot;2H2O + NaCl, NaCl, NaCl + Na2SeO3 & centerdot;5H2O and Na2SeO3 & centerdot;5H2O. By 288.15 K, the phase diagram undergoes a transition from five to three crystallization regions, with the NaCl & centerdot;2H2O crystallization region disappearing. The equilibrium phase diagram at 268.15 K for the ternary system Na2SO4-Na2SeO3-H2O comprises two invariant points, three univariant curves, and five crystallization regions. The invariant points are characterized by the equilibrium solid phase ice + Na2SO4 & centerdot;10H2O and Na2SO4 & centerdot;10H2O + Na2SeO3 & centerdot;5H2O. When heated to 288.15 K, the ice regions in the equilibrium phase diagram of the ternary system disappeared, but five crystal regions were still displayed. As temperature increases, the crystalline forms of salts in the equilibrium phase diagram change.

MoS2 demonstrates strong catalytic potential for the co-hydrogenation of coal and petroleum residue (CHCPR) because of its excellent hydrogenation activity; however, its high cost limits practical application. To address this, a technical route was developed herein for catalysing the CHCPR using single-layer-dominant active MoS2 generated in situ from ammonium molybdate directly loaded onto coal (MoDLRC). The mechanism and influencing factors governing in situ MoS2 formation from MoDLRC were investigated. Furthermore, the catalytic performance of MoDLRC in the CHCPR was evaluated and compared with that of Fe-based catalysts. The results revealed that in tetralin solvent, higher temperatures (>400 degrees C) and higher initial hydrogen pressure favoured the reaction of ammonium molybdate with H-2 and S, promoted the rapid reduction of Mo6+ to Mo4+ and accelerated in situ MoS2 formation while reducing intermediate accumulation. Under the CHCPR conditions involving a temperature of 400 degrees C, an initial hydrogen pressure of 7 MPa, a reaction time of 1 h and a sulphur/molybdenum molar ratio of 2, impregnation of an ammonium molybdate solution onto coal powder generated active MoS2 in situ with a single-layer-dominant structure and particle size of 4-11 nm. Because this structure exposed additional active sites, it exhibited strong catalytic performance. The oil yield reached 81.35%, representing increases of 19.57% and 30.27% relative to FeOOH and Fe2O3, respectively, whereas the residue rate decreased to 2.84%. CH4 and CO2 generation was also suppressed, thereby improving hydrogen utilisation efficiency. Overall, the MoDLRC route for the CHCPR is simple, efficient and cost-effective and provides theoretical support and practical guidance for CHCPR optimisation.

This study developed a MIL-88 A(Fe)-modified electrode by integrating iron-based metal-organic framework MIL-88 A(Fe) with high selenium affinity into an electrochemical adsorption system. Under a controllable potential in a three-electrode configuration, rapid and efficient capture of Se(IV) from simulated and real salt lake brines was achieved, providing a novel strategy for selective selenium removal from complex water matrices. The adsorption performance of MIL-88 A(Fe) synthesized with different solvent ratios (DMF:H2O = 1:1, 1:0, 0:1) toward Se(IV) was systematically evaluated. Combined adsorption isotherm and kinetic analyses clarified its adsorption characteristics. Material characterization and electrochemical tests revealed that the adsorption process was synergistically governed by electrostatic attraction, hydrogen bonding, and redox mechanisms. The FeO clusters in MIL-88 A(Fe) exhibited intrinsic electrochemical activity through the formation of Fe-O-Se configurations, and the applied potential enabled reversible and precise modulation of the Fe3+/Fe2+ redox states, significantly enhancing selenium capture. Experimental results demonstrated a theoretical maximum adsorption capacity of 74.67 mg Se/g. After 20 consecutive adsorption-desorption cycles, the electrode retained high adsorption efficiency, with a 61.77% performance improvement compared to potential-free adsorption. In real brine, the electrode achieved 62.36% Se(IV) removal efficiency, demonstrating good stability and practical potential. Theoretical simulations indicated that SeO32- ions match the pore size of MIL-88 A(Fe) and can be adsorbed via coordination with Fe-bonded O atoms, with a coordination binding energy of approximately -2.58 eV, characteristic of chemisorption. Mulliken charge analysis further revealed a significant charge-transfer of similar to 1.035 e from SeO32- to the Fe-coordinated O, confirming strong electronic interaction and coordination bonding between Se(IV) and the active sites of MIL-88 A(Fe).

Blood glucose monitoring is critical for diabetes management, but traditional enzymatic sensors suffer from poor stability and complex fabrication. Non-enzymatic electrochemical sensors, which utilise metal oxides for direct glucose oxidation, offer a cost-effective and stable alternative. This study employs a dimethylamine (DMA)-assisted hydrothermal strategy to engineer oxygen vacancies (Ov) in mesoporous CuO catalysts. By adjusting DMA dosage, Ov concentration was regulated, yielding CuO-250 (250 mu L DMA) with a mesoporous structure and optimal Ov density. Synchrotron radiation confirmed intermediate-valence Cudelta+ (1 < delta < 2) species associated with Ov. The CuO-250 sample exhibits excellent performance under alkaline conditions, with a sensitivity of 738.1 mu A/(mMcm2) in the range of 1.97 mu M to 1.39 mM and 104.3 mu A/(mMcm2) in the range of 1.39-7 mM. The detection limit is as low as 1.97 mu M (S/N = 3). Notably, this outstanding performance was achieved under optimised alkaline conditions (0.1 M NaOH). However, translating these results to a neutral physiological environment still requires addressing the critical challenge of pH-dependent sensor performance. The applicability of this method was demonstrated by the determination of glucose in real samples, showing favourable recovery rates. Mechanistic studies revealed dual roles of Ov: Moderate Ov enhances charge transfer and exposes dual-Cu active sites, lowering the energy barrier for glucose oxidation; excessive Ov impairs glucose adsorption and catalytic efficiency. This work provides a high-performance electrode material for glucose sensors and offers insights into oxygen vacancy mechanisms in glucose sensing, advancing rational design of defect-engineered electrocatalysts.

With the accelerated industrialization process and the increased combustion of fossil fuels, the concentration of CO2 continues to rise, making carbon emission reduction an urgent global issue. Electrochemically mediated amine regeneration (EMAR), as an emerging carbon capture technology, circumvents the high energy consumption and thermal degradation problems associated with conventional amine-based absorption technology. In this work, based on density functional theory (DFT), polyamines (AEEA, DMAPA, PDA, DAP, DETA) were used as absorbents. And systematically investigate the effects of temperature, electrolyte, and copper ions on their CO2 absorption performance, Also the systems were characterized by using electrochemical methods. Results demonstrate that both the AEEA and DETA systems exhibit a one-step reduction and distributed oxidation, with low charge transfer resistance, per mole of copper ion releasing 2.033 mol and 2.124 mol of CO2, respectively. During desorption at a current density of 100 A/m(2), the energy consumption values were 30.53 kJe/mol and 35.36 kJe/mol, respectively. Corrosion studies reveal that the formation of copper-amine complex protective films during the EMAR process enhances corrosion resistance. Additionally, the toxicity evaluation of the absorbents demonstrated that the AEEA and DETA systems possessed significantly lower toxicity than the remaining systems. The absorption mechanism was studied using FT-IR, C-13 NMR, and DFT, revealing that the AEEA and DETA systems ultimately form carbamate (AEEACOO(P)H--((S))+ and DETACOO(P)H--((S))+) and carbonate-like products, with van der Waals interactions and weak hydrogen bonding prevailing among the ionic products. This research aims to develop efficient and environmentally friendly absorbents, providing a theoretical foundation and technical support for the practical implementation of EMAR systems.

In oilfield brines, bromide ions (Br-) are typically low (10-100 mgL-1), while coexisting anions (e.g., Cl-, SO42-, NO3-) are present at high concentrations-especially Cl-, which often reaches 100-300 gL-1. As both are halide ions, they share similar ionic radii and charge properties, resulting in minimal affinity differences for separation materials (e.g., adsorbents, extractants). This makes it difficult to achieve the selectivity of preferentially adsorbing/extracting Br- while excluding Cl-. An electrodeposited polyaniline (PANI)/BiOBr composite membrane was engineered for selective bromide (Br-) recovery from oilfield brine. The bilayer design synergizes Br--trapping BiOBr (high selectivity) and PANI (enhanced conductivity/storage), with density functional theory (DFT) elucidating adsorption mechanisms. Optimized operation (0.5-1.0 V, pH 3-7) achieved a maximum Br- capacity of 294.6 mgg(-1), >90 % desorption efficiency over cycles, >280 mgg(-1) retained capacity after reuse, and high selectivity against Cl-/SO42-/NO3-(1.43, 2.25, and 2.59). The membrane demonstrated rapid kinetics, acid resistance, and stability during electrochemical ion exchange. Furthermore, aniline is inexpensive and readily available, and BiOBr can be synthesized in large quantities, resulting in a low preparation cost for the Br--trapping BiOBr/PANI composite material. This technology enables sustainable bromide extraction from complex brine waste streams, supporting critical mineral security and circular resource recovery goals through efficient valorization of industrial wastewater.