Sen Lin

The adsorption-based lithium extraction technology from ultralow-grade salt lake brine is severely restricted by the inherent activity–stability trade-off of traditional granular Li/Al-LDHs adsorbents (GLDHs). Herein, a nanoisland encapsulation strategy integrated with hydrophilic interface engineering is developed to fabricate Li/Al-LDHs composite granules with tailored hydrophilic interfaces (HILDHs), breaking the long-standing bottleneck of conventional aluminum-based lithium adsorbents used in the salt lake industry. Systematic experiments and multiscale simulations reveal that the strong water affinity of polyacrylonitrile cyano groups (−C≡N) creates a highly hydrated microenvironment for rapid Li+ transport, while the nanoisland-confined structure anchors Li/Al-LDHs nanosheets to preserve the layered framework under harsh deep desorption conditions, thus enabling excellent cycling stability. The optimized HILDHs deliver a 3.02-fold higher working adsorption capacity (7.25 mg g–1 vs 2.40 mg g–1 for GLDHs) in actual Qarhan old brine within 60 min, along with a 13.36-fold increase in adsorption rate constant, 40% lower rinsing water consumption, and excellent cycle stability. It is calculated the nanoisland encapsulation strategy can achieve a nearly 5-fold increase for the annual Li2CO3 production capacity from salt lake lithium industrial lines.

Long-root Eichhornia crassipes , an aquatic plant with extensive root systems, has demonstrated potential in remediating eutrophicated water bodies. However, improper disposal of large quantities of discarded plants post-remediation can easily cause secondary pollution. In this study, rapidly recoverable magnetic carbon quantum dots (MCQDs) were greenly synthesized via hydrothermal treatment of long-root Eichhornia crassipes and subsequent coupling with Fe ₃ O ₄ nanoparticles. Adsorption experiments demonstrated that MCQDs displayed a commendable adsorption capacity for various heavy metals in municipal wastewater under the synergistic effect of CODs and Fe ₃ O ₄ . Mechanistic analyses revealed that the adsorption involved chemical binding with oxygen-containing functional groups and amino groups on the surface of MCOQs. The saturated MCQDs were efficiently recovered within 5 min using an applied magnetic field, offering a practical solution for nanoparticle recovery. This study provides valuable insights into the green resource utilization of Long-root Eichhornia crassipes based on CQD technology. Graphical abstract

Conventional lithium extraction methods exhibit limited efficiency in strongly acidic solutions. This study developed a brand‐new and universal lithium recovery strategy from strongly acidic systems using Li ⁺ migration between directionally formed solid phase of lithium‐aluminum layered double hydroxides (Li/Al‐LDHs) and alternate aqueous solutions. Li ⁺ ions in strongly acidic solutions with massive coexisting cations (Na ⁺ , K ⁺ , Fe ²⁺ , Ca ²⁺ , Mg ²⁺ , Al ³⁺ , etc.) were inductively converted into the solid precipitate through a precise crystal phase regulation. A non‐equilibrium thermodynamic model was developed and revealed that the lithium deintercalation flux exhibited a linear dependence on the chemical potential gradient, systematically elucidating the critical parameters governing extraction efficiency. Subsequently, lithium extraction from Li ⁺ ‐enriched solid could be accomplished easily using neutral aqueous solutions with a complete delithiation, and the overall lithium recovery from acidic systems exceeded 96% with the residual solid recycling process and waste‐free disposal. Furthermore, the lithium extraction strategy was proven applicable in authentic multi‐component acidic solutions with efficient lithium recovery and low costs. This work is expected to significantly promote the development of universal extreme system lithium separation technology.

Conventional lithium extraction methods exhibit limited efficiency in strongly acidic solutions. This study developed a brand‐new and universal lithium recovery strategy from strongly acidic systems using Li ⁺ migration between directionally formed solid phase of lithium‐aluminum layered double hydroxides (Li/Al‐LDHs) and alternate aqueous solutions. Li ⁺ ions in strongly acidic solutions with massive coexisting cations (Na ⁺ , K ⁺ , Fe ²⁺ , Ca ²⁺ , Mg ²⁺ , Al ³⁺ , etc.) were inductively converted into the solid precipitate through a precise crystal phase regulation. A non‐equilibrium thermodynamic model was developed and revealed that the lithium deintercalation flux exhibited a linear dependence on the chemical potential gradient, systematically elucidating the critical parameters governing extraction efficiency. Subsequently, lithium extraction from Li ⁺ ‐enriched solid could be accomplished easily using neutral aqueous solutions with a complete delithiation, and the overall lithium recovery from acidic systems exceeded 96% with the residual solid recycling process and waste‐free disposal. Furthermore, the lithium extraction strategy was proven applicable in authentic multi‐component acidic solutions with efficient lithium recovery and low costs. This work is expected to significantly promote the development of universal extreme system lithium separation technology.

Sluggish internal mass transfer within granulated adsorbents constrains the efficiency of Li ⁺ extraction from low‐grade salt lakes. In this study, Li ⁺ diffusion behavior simulations using finite element analysis indicated that reducing the granule dimensionality enhanced Li ⁺ transfer in aluminum‐based lithium adsorbents, with ionic strength as the driving force. Hence, low‐dimensional aluminum‐based adsorbent granules (LD‐LDHs) with fast transport channels and highly accessible adsorption sites were directionally prepared via a wet‐spinning method. Adsorption kinetics suggested LD‐LDHs with reduced internal diffusion resistance achieved equilibrium in less than 30 min, which was significantly shorter than the 36 h required for larger granules prepared by conventional extrusion molding, while maintaining the performance of the encapsulated active components. During continuous lithium extraction from low‐grade Qarhan old brine, LD‐LDHs reached adsorption saturation in 60 min, with a 1.8‐fold increased working capacity, and the desorption solution was of higher quality, favorable for subsequent lithium carbonate production processes.

Steel slag is a promising secondary resource necessitating recycling and high-value utilization. This study innovatively converted steel slag into micronano FePO₄ and well-performing LiFePO₄/C through a selective two-step leaching process followed by fast coprecipitation in HMCRR under superior mass transfer, and a subsequent in situ carbothermal reduction afterward, thereby realizing a waste-to-resource conversion pathway. Besides, a metal leaching mechanism was proposed based on comprehensive slag composition analysis, affirming the process selectivity. Thermomechanical analysis for precipitation underscored the importance of controlling reaction pH to prevent the formation of impure sediments. Leveraging efficient leaching and superior mass transfer during precursor preparation, the further-made carbon-coated LiFePO₄/C derived from steel slag exhibited favorable morphology and enhanced discharge capacity, especially at high rates, owing to fast ion diffusion kinetics, minimized Li⁺ migration distance, and improved structure stability. Notably, the discharge capacity could reach 167.44, 153.56, and 119.62 mAh/g at 0.1, 1, and 10 C, respectively.

The hydrophobic surface properties of catalysts, generally overlooked in the field of sulfate radical-based advanced oxidation processes (SR-AOPs), have significant potential in anti-interference, self-cleaning, and anti-fouling in realistic wastewater treatment. The conflicting nature of hydrophobicity and catalytic activity presents considerable challenges in developing heterogeneous oxidation. To overcome such limitation, herein, different surfactants were employed to regulate the surface properties of CoCu-layered double hydroxides (LDH) for the activation of peroxymonosulfate (PMS). Our results demonstrated that by comparison with sodium dodecyl sulfate (SDS) and sodium laurate (SLA), sodium dodecyl sulfonate (SDSO) regulated LDH (SDSO-LDH) exhibited the most effective interpolation of organic anions into the interlayer space, simultaneously showing efficient ability for PMS activation and degradation of various emerging contaminants (ECs). The SDSO-LDH/PMS system also exhibited excellent stability and recyclability, with Co(IV)=O and SO4•- species working as the dominant oxidative intermediates. Density functional theory (DFT) calculations further confirmed the thermodynamic feasibility of these reactions. Moreover, the effective degradation of intrinsic organic substances in realistic wastewater and sustained hydrophobicity establishes SDSO-LDH a competitive candidate catalyst for SR-AOPs. The synergy between catalytic activity and hydrophobicity offers a novel perspective for the application of SR-AOPs in wastewater treatment.