ChemSusChem最新文献

Pharmaceutical residues, especially non-steroidal anti-inflammatory drugs (NSAIDs), are emerging contaminants that hinder sustainable water management and limit wastewater upcycling. In this work, we address the challenge of wastewater upcycling via the scale-up of a hybrid advanced oxidation process (AOP) that couples hydrodynamic cavitation (HC) and non-thermal electrical discharge (ED) plasma, and that will enable the in situ generation of ROS. In order to demonstrate process scalability, the hybrid HC/ED plasma system was initially validated at pilot scale (600 L h⁻¹) and subsequently up-scaled to a semi-industrial reactor (3200 L h⁻¹), specifically designed starting from the pilot unit. The effective exploitation of HC/ED plasma synergy led to the process achieving the quantitative degradation of model pollutants, specifically ibuprofen and diclofenac (10 mg/L), in competitive times (13 passes) and without detectable byproducts, thereby validating the process’ robustness and successful scale-up. Although current wastewater treatment plants (WWTPs) recover nutrients from sludge, biologically treated effluents still contain pharmaceutical residues. This work therefore, potentially solves this issue by providing a sustainable strategy for complete wastewater upcycling in WWTPs, delivering safe regenerated water for agricultural and irrigation reuse, while closing the water cycle.

Aqueous NH₄⁺ storage holds great promise but is hindered by its strongly hydrated shell, which elevates the desolvation barrier. Notably, α-MoO₃ stands out for its layered structure and multivalent redox activity, yet its wide bandgap significantly slows down interfacial reactivity. To tackle these challenges, we propose a strategy by integrating host material coupled with electrolyte design. Specifically, Mg²⁺ aliovalent substitution could optimize α-MoO₃ band structure, thereby enhancing its electronic conductivity. Meanwhile, the introduction of a proton-enriched electrolyte disrupts the NH₄⁺ solvation shell and reduces the desolvation barrier. Remarkably, the optimized electrode delivers a specific capacity of 239.2 mAh g⁻¹ at 2 A g⁻¹ with a capacity retention of 87.8% after 5000 cycles. Moreover, the assembled aqueous symmetric device delivers a high-energy density of 46.7 Wh kg⁻¹ at 800.6 W kg⁻¹. In situ/ex situ characterizations and DFT calculations reveal a synergistic NH₄⁺/H⁺ costorage mechanism in MMO-A, involving reversible Mo⁶⁺/Mo⁵⁺ transitions, MoO bond evolution and dynamic MoOH formation, as well as increased NH₄⁺ adsorption energy and interfacial charge transfer. This work offers insightful design principles and application prospects for advanced aqueous NH₄⁺ storage systems.

High-entropy composition design offers an effective approach to overcome the sluggish oxygen evolution reaction (OER) kinetics of lanthanum-based perovskite oxides. By incorporating a wider variety of metal cations into the B-site sublattice, the configurational entropy increases accordingly. Following this high-entropy compositional strategy, low-entropy LaCoO₃, medium-entropy La(FeCoNi)O₃, and high-entropy La(MnFeCoNiCu)O₃ were successfully synthesized via a facile sol–gel combustion method. The construction of the high-entropy perovskite oxide (HEPO) was found to substantially alter the morphology, crystal structure, and electronic environment, leading to reduced particle size, modulated B-site metal valence states, and enriched oxygen vacancies. These modifications collectively induce synergistic effects among multiple B-site metal active sites and promote the participation of lattice oxygen through the introduction of surface oxygen defects, thereby activating the oxygen-mediated (LOM) pathway of OER. Remarkably, the as-prepared HEPO exhibited superior OER performance in alkaline media, achieving a low overpotential of 303 mV at 10 mA cm⁻², a small Tafel slope of 43 mV dec⁻¹, and excellent stability over 100 h of continuous operation. This work provides valuable insights into the role of B-site configurational entropy in perovskite oxides and highlights the potential of high-entropy design strategies for developing advanced OER electrocatalysts.

A comprehensive comparison was conducted between formamidinium–methylammonium lead iodide (FAMAPbI₃) perovskite solar cells (PSCs) fabricated using an optimized one-step process in a glovebox and a two-step method under ambient air to identify the key factors governing performance and stability. Systematic optimization of processing parameters revealed that the one-step films exhibited smaller grains, higher defect densities, and greater moisture sensitivity, which promotes trap-assisted recombination and reduces stability. In contrast, the two-step films contained larger and better-connected crystalline domains, enhanced crystallinity, and lower trap densities, resulting in stronger light absorption and more efficient charge transport. Optical and electrical analyses, including steady-state photoluminescence (PL), time-resolved photoluminescence (TRPL), dark current, and space-charge-limited current (SCLC) measurements, confirmed longer carrier lifetimes, suppressed nonradiative recombination, and reduced deep-trap density in the two-step films. The champion two-step PSC achieved a power conversion efficiency of 21.34%, outperforming the one-step device (18.90%). Despite exhibiting higher hysteresis associated with stronger ion migration, the two-step method demonstrated good reproducibility and retained 83% of its initial efficiency, compared with the one-step device, after 500 h of continuous illumination. These results indicate the effectiveness of the ambient-air two-step route in producing good quality FAMAPbI₃ films and provide valuable insights into process–structure–property relationships for scalable, high-efficiency PSCs.

Small changes in molecular structure can modify the energy landscape by altering the electronic functions of the covalent organic frameworks (COFs) toward photocatalytic reactions. Herein, porphyrin-based visible-light photosensitizers embedded in crystalline and porous COFs are showcased, offering substantial utilization of natural sunlight during photocatalysis. A detailed investigation of photophysical, photoelectrochemical, and photocatalysis reaction kinetics, along with controlled experiments, suggests that π-conjugation in COFs plays an indispensable role in highly selective and efficient photocatalysis by in situ generating singlet oxygen (¹O₂) from triplet molecular oxygen via an energy or electron-transfer mechanism. The pharmaceutically important sulfoxide precursors with various functional group tolerances were synthesized via selective oxidation under mild and environmentally friendly synthesis conditions. The metal-free COF catalyst was recycled at least five times without deteriorating the photocatalytic activity. The density functional theory calculation further reveals that efficient access to the low-energy triplet state, via enhanced intersystem crossing efficiency, relies on the molecular design of sustainable COF catalysts that influence ¹O₂ generation kinetics, high selectivity, and conversion. Sunlight-driven photocatalysis under mild conditions without requiring toxic reagents or nonrecyclable additives is an emerging strategy to access value-added chemicals in a “greener” and sustainable fashion, considering the energy efficiency and environmental safety.

The development of air-stable non-noble metal catalysts with high efficiency for hydrogen production from ammonia borane (AB) is crucial for advancing the hydrogen economy. In this work, Prussian blue analogs-derived air-stable Cu_xNi_y@NC/SiO₂ catalysts have been synthesized by a facile precipitation and thermal decomposition method. The optimized Cu₁Ni₆@NC/SiO₂ exhibits the best hydrogen production performance at room temperature, being 5 times more active than Cu₁Ni₆@NC and superior to other Cu_xNi_y@NC/SiO₂ catalysts. Beyond the reactivity, Cu₁Ni₆@NC/SiO₂ exhibits outstanding durability and antioxidant properties, maintaining its catalytic activity unchanged even after 6 months of air exposure. Characterization tools indicated that the enhanced performance and durability of the Cu₁Ni₆@NC/SiO₂ catalyst originated from a combination of the synergistic effect of Ni–Cu alloying and the core–shell structure. Moreover, Cu₁Ni₆@NC/SiO₂ also exhibits high efficiency and excellent recyclability toward the hydrogenation of adiponitrile and 2-methylglutaronitrile at ambient conditions on coupling with AB dehydrogenation. This research not only provides a simple strategy for the construction of air-stable non-noble metal catalysts for AB hydrolysis, but also offers a promising way for the design of heterogeneous non-noble metal catalysts with excellent oxygen resistance for industrial applications.

Membrane electrode assembly (MEA) systems hold promise as a technology capable of achieving high stability and current density for electrochemical CO₂ reduction (ECR). The fabrication techniques, including the selection of MEA components, the defined technological route, and the activation process, determine both the normal operation of the system and the proper performance of catalysis. Besides, the mass transfer of ions and water within the membrane directly impacts the local microenvironment, ultimately leading to variations in product distribution. In this article, we elucidate the characteristics and functionalities of each component within the MEA electrolyzers. Additionally, the fabrication techniques and activation processes of MEA are emphasized for their practical production. Besides, the developments and challenges of MEA for ECR are concluded, along with proposed solutions. Finally, we concentrate on the ions transport and water management within MEA, which directly impacts the availability of MEA electrolyzers and the distribution of products for ECR.

Practical research on the electrochemical nitrogen reduction reaction (eNRR) requires quantitative ammonia trace analysis because production rates are on the order of µg h^-1 in aqueous electrolyte. This challenge is further aggravated by complex sample matrices. Ion chromatography is a powerful analytical technique for the quantitative determination of ammonium down to ppb-concentrations, but requires matrix elimination (ME) for these kinds of sample. We developed a suppressed cation chromatography method using automated matrix neutralization and ME to quantitatively determine ammonium in 0.2 M sulfuric acid electrolyte at µg L^-1 concentrations for use in NRR research. Although direct conductivity detection of cations is less sensitive than unsuppressed indirect conductivity detection, baseline noise requires suppression at these concentrations. Nonlinearity of the calibration curve became noticeable below ≈ 1 ng ammonium. A method limit of detection of 2 µg L^-1 (ppb_mol) for ammonium was achieved at 100 µL injection volume. Direct coupling of the electrochemical cell and IC enabled online quantification. This online measurement of ammonium in 0.2 M sulfuric acid electrolyte revealed ammonium contamination rapidly liberated from the hitherto judged negligible Nafion ionomer of the gas diffusion electrode at open circuit voltage, showing prior production rates to be likely false positives.

The growing energy shortages and environmental damage make it urgent to activate chemical reactions under mild conditions, reducing energy consumption and improving efficiency. Mechanocatalysis, with its advantages of simplicity, scalability, and sustainability, has demonstrated exceptional performance in many key heterogeneous catalytic reactions and surpassed traditional catalytic methods. It possesses significant potential for future applications and development. In this review, recent advances in the field of mechanocatalysis for energy and environmental applications are systematically summarized. Meanwhile, insights into the design of effective mechanical catalysts and the mechanocatalytic reactions, especially those with gaseous reactants, are highlighted and discussed in detail. Lastly, challenges and future perspectives in the mechanocatalysis are described to guide its broader application in the field of catalysis.

The growing transition from fossil fuels to renewable energy sources such as wind and solar requires efficient stationary energy storage systems to ensure grid stability. Among emerging technologies, redox flow batteries (RFBs) offer a promising solution due to their unique decoupling of energy and power capacities, allowing flexible system design. Recent advances in organic RFBs (ORFBs) have highlighted redox-active organic molecules as sustainable alternatives to conventional vanadium-based systems, addressing issues of cost and corrosivity. In particular, nitroxide radicals such as tetramethylpiperidinyloxyl (TEMPO) derivatives have demonstrated high reversibility and fast kinetics in aqueous systems, though the stability of their oxidized N-oxoammonium form remains a challenge for long-term storage. Isoindoline-based nitroxides offer potential for enhanced stability but have been limited by complex and low-yield synthetic routes. Herein, we present a convenient metal-catalyzed [2 + 2 + 2] intermolecular cycloaddition strategy for the synthesis of isoindoline-based nitroxides and their aza analogs, including two new candidates, TC-TMIO and PPO. Electrochemical characterization reveals that PPO, a cationic 2,3-dihydropyrrolo[3,4-c]pyridinium nitroxide, exhibits an oxidation potential 220 mV higher than the benchmark 4-TMA-TEMPO and achieves solubility exceeding 3 M in 1 M NaCl aqueous solution. Preliminary stability assessments of the PPO and RFB testing using a methyl viologen/PPO system demonstrate its potential as a high-performance, sustainable posolyte for aqueous ORFBs.