ChemSusChem最新文献

Electrochemical water splitting driven by renewable energy provides a sustainable route for generating high-purity hydrogen, yet its efficiency is hampered by the sluggish and economically unfavorable oxygen evolution reaction (OER) at the anode. Replacing OER with the urea oxidation reaction (UOR) has emerged as an attractive strategy to reduce energy input and simultaneously achieve wastewater remediation. Nevertheless, the six-electron transfer process of UOR still suffers from kinetic limitations, highlighting the urgent need for robust and cost-effective electrocatalysts. Recent progress has demonstrated that nanostructure-engineered catalysts enable precise regulation of surface electronic structures, optimization of intermediate adsorption energies, and enhancement of catalytic activity. In this review, we systematically summarize the recent advancements of nanostructural catalysts for UOR-assisted hydrogen evolution, highlighting how rational nanostructuring and compositional engineering contribute to improved intrinsic performance and energy efficiency. The underlying reaction mechanisms are critically discussed based on both experimental and theoretical perspectives. In addition, the practical application of the Zn-urea battery system is introduced, encompassing its electrochemical performance and potential for integrated energy storage and hydrogen production. Finally, we present the current challenges and propose future research directions aimed at bridging the gap between laboratory-scale studies and practical implementation.

Supercapacitors have garnered considerable attention as next-generation energy storage systems due to their high-power density, rapid charge–discharge kinetics, and long operational lifespan. In this study, we report the design and development of a nitrogen-doped activated borane (ActB), a porous borane cluster-based network, synthesized through the controlled cothermolysis of arachno-B₉H₁₃(NEt₃) and [Et₃NH][nido-B₁₁H₁₄] in toluene. The resulting polymeric materials integrate electron-rich nitrogen sites with the unique 3D boron cluster architecture, offering a synergistic platform for enhanced electrochemical performance. Electrochemical evaluation in a three-electrode system revealed a high specific capacitance of 607 F g⁻¹ at 0.5 A g⁻¹, with remarkable cycling stability, retaining 95% of the initial capacitance after 15,000 charge–discharge cycles. When configured into an asymmetric supercapacitor device using activated carbon as the negative electrode, the system achieved a specific capacitance of 354 F g⁻¹, along with an energy density of 25.6 Wh kg⁻¹ and a power density of 486.2 W kg⁻¹ at a current density of 0.5 A g⁻¹. The device also demonstrated long-term reliability, retaining 88% of its initial capacitance after 15,000 cycles. The outstanding performance is attributed to the integration of redox-active nitrogen functionalities and the inherent stability and tunability of the borane-based framework. This work establishes nitrogen-doped borane cluster polymers as a promising new class of electrode materials for high-performance supercapacitors and broader electrochemical energy storage applications.

Rechargeable zinc–air battery (ZAB) commercialization is hampered by low efficiency at the air cathodes, where sluggish kinetics and different reaction mechanisms for the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) at charging and discharging state, limit overall performance. Herein, we demonstrate a carbon nanotubes-supported ruthenium–manganese dioxide (Ru–MnO₂/CNTs) as a high-performance bifunctional ZABs catalyst fabricated via in situ growth and cation exchange approach. The catalyst features a hierarchical architecture where the CNTs scaffold serves as the structural backbone, while Ru–MnO₂ solid solution nanosheets with intrinsic bifunctional activity grow conformally on its surface. This CNTs-supported design synergistically enables a low ruthenium loading of 9.1 wt% while promising electrochemical performance. Critically, the catalyst achieves an ORR half-wave potential of 0.84 V, a OER overpotential of 210 mV at 10 mA cm⁻², and a narrow OER/ORR potential gap of merely 0.6 V. When integrated into ZABs, this catalyst exhibits excellent performance, with the peak power density of 156 mW cm⁻², a high specific capacity of 802 mA h g⁻¹, and stable cycling performance exceeding 200 h. Consequently, this work demonstrates a viable strategy for synthesizing cost-effective and highly active bifunctional oxygen electrocatalysts with optimized noble metal utilization.

With the surging global demand for renewable energy, stimuli-responsive hydrogels have emerged asa research hotspot in this field, owing to their unique stimuli-responsive properties, high water content, and remarkable design flexibility. First, this work systematically introduces the molecular and structural design strategies of stimuli-responsive hydrogels, encompassing diverse stimulus-responsive mechanisms. Subsequently, it comprehensively reviews the application progress of stimuli-responsive hydrogels in emerging energy technologies, including sustainable solar utilization, energy storage and conversion, and intelligent energy management. Additionally, the review analyzes current challenges and explores the future development directions of stimuli-responsive hydrogels in conjunction with sustainable development needs. This review not only comprehensively presents the application potential of stimuli-responsive hydrogels in the new energy field but also provides key references for the subsequent development of high-performance hydrogels and the advancement of renewable energy technologies.

CO₂ electroreduction (CO₂R) using Cu catalysts under acidic conditions currently receives substantial attention as it allows to limit detrimental (bi)carbonate salts formation and precipitation. However, it usually requires high concentrations of K-based electrolytes for suppressing hydrogen evolution (HER) and favoring C₂ products formation. Here we used crown-ethers in order to immobilize alkali cations at the surface of the catalyst and show that this strategy not only allows suppressing HER with much less concentrated electrolyte but also orientates the reaction towards CH₄ formation during acidic CO₂R. The utilization of 10 different crown-ethers allowed to study the effect of the structure of the ligand and the nature of the cation on CO₂R selectivity. The largest Faradic Efficiency for methane (FE_CH4 = 55%) was obtained under an applied current density of −150 mA.cm⁻², using the 4′-amino-benzo-15-crown-5-Na⁺ complex.

Aluminum–sulfur (Al–S) batteries are garnering significant interest as candidates for affordable energy storage systems due to their high theoretical capacity of 1672 mAh g^–1 and the cost-effectiveness of naturally abundant aluminum and sulfur. Nevertheless, challenges such as poor cyclic reversibility and limited practical capacity have resulted in only a few reversibly operating Al–S cells to date. In this study, we introduce an improved Al–S battery configuration by incorporating a novel VN@graphene catalyst into the sulfur cathode in Al–S battery applications. Comprehensive electrochemical tests and ex situ characterizations reveal that, during discharge, the catalyst effectively suppresses the polysulfide shuttle effect through strong adsorption, whereas during charging, it enhances sulfide redox kinetics. Consequently, the modified Al–S cell delivers an initial capacity of approximately 1354 mAh g^–1, maintaining around 507 mAh g^–1 after 200 cycles.

Green hydrogen adoption demands intensive research efforts focusing on improving the performance and durability of electrodes used in water electrolyzers, enabling cheaper hydrogen production on a commercial scale. For catalyzing the oxygen evolution (OER) and hydrogen evolution (HER) electrode reactions in a water electrolyzer, the state-of-the-art electrocatalysts used are expensive and scarce, thus preventing their successful commercialization. There is a dire-need to replace those expensive catalysts with cheaper, earth-abundant non-platinum group of transition metals. Heterointerface engineering could be employed as an effective strategy to synthesize such kind of electrocatalysts to tune the electronic and catalytic properties of these environmentally friendly transition metal electrocatalysts. In this report, we have studied the heterointerface formation between Ni₃S₂ and MnO₂ phases using two synthesis approaches: sequential as well as simultaneous growth methods. Our studies show that sequential growth exhibits a critical impact on the chemical and electrocatalytic behavior of the as-synthesized vertically aligned nanoflakes. When Ni₃S₂ was grown over the MnO₂ phase, it resulted in the most superior bifunctional electrocatalytic activity. Along with the electrical impedance measurement, X-ray photoelectron spectroscopy and Raman spectroscopy reveal that the interfacial charge transfer due to heterointerface formation via sequential growth is more effective than the simultaneous method of heterojunction preparation. The best catalyst exhibits a lowering of OER overpotentials of 300 mV and HER onset overpotentials of 230 mV, surpassing the standard catalysts. DFT study has been performed to correlate the experimental and theoretical reaction kinetics over Ni₃S₂@MnO₂@NF heterointerfaces, which suggests a lower overpotential of 1.391 V when Ni₃S₂ is grown over MnO₂ for OER as compared with the MnO₂ (1.719 V) grown over Ni₃S₂. Ni₃S₂@MnO₂@NF electrodes registered a low cell voltage of 1.68 V at 10 mA cm⁻² current density in an alkaline water electrolysis prototype, performing better than the standard catalyst in terms of cell voltage and operation stability at higher current densities of up to 50 mA cm⁻². This study shows how strategic design of interfaces in heterojunction can control the overall catalytic performance.

Late-stage functionalization (LSF) enables the direct, site-selective modification of complex molecules and has become a key strategy in sustainable drug discovery and chemical biology. While homogeneous photocatalysis has traditionally dominated this field, recent advances in materials engineering and catalyst design have triggered a new interest in heterogeneous photocatalysis. Although classical heterogeneous photocatalysts such as metal oxides and carbon nitrides are long established, their nanoscale re-engineering and integration into LSF have only recently enabled enhanced reactivity, selectivity, and recyclability. This review surveys the recent evolution of heterogeneous photocatalytic systems, from traditional semiconductors to covalent organic frameworks and metal–organic frameworks, for selective LSF. By connecting developments in materials chemistry with photoredox catalysis, this contribution highlights the growing potential of heterogeneous photocatalysts as scalable and sustainable platforms for complex molecule synthesis.

Elemental first row transition metal electrocatalysts typically exhibit a tradeoff between Faradaic efficiency (FE) for the nitrate reduction reaction (NO₃RR) and selectivity toward NH₄⁺. Here, we find that NiFe alloys have high NO₃RR FE and substantially higher NH₄⁺ selectivity than Ni or Fe. We introduce “relative nitrate adsorption,” a simple descriptor of the difference in NO₃* and H* binding strength that rationalizes experimental trends in reaction rate order. This descriptor is consistent with competitive adsorption demonstrated in a microkinetic model that shows Fe inclusion promotes NO₃* adsorption and increased NO₃RR FE, but cannot describe the higher NH₄⁺ selectivity observed for NiFe alloys. In fact, calculated activation energies of subsequent reduction steps illustrate that no one active site motif can explain both improved FE and NH₄⁺ selectivity. Instead, our experimental and computational findings indicate NO₂* deoxygenation is promoted by Ni-rich active sites, whereas NO* dissociation is promoted by both surface Fe atoms and an underlying Fe lattice. These findings suggest that NiFe alloys leverage local site diversity via a spillover mechanism, explaining why the performance enhancements are similar regardless of the specific Ni/Fe ratio.

Organic carbonates play a central role as functional platform molecules for the manufacture of materials and chemicals. The atom-economical formation of cyclic carbonates from epoxides and CO₂ under mild catalytic conditions is a prime example of the concept of green chemistry. However, the sustainability of such strategies is often limited by the unfavorable parameters of the epoxide formation from olefin oxidation. Herein, a new, highly sustainable, triple-catalytic approach to the formation of biogenic cyclic carbonates from all-natural building blocks is documented. Three biogenic resources (fatty acid derivatives, O₂, CO₂) are combined with 100% atom-economy in the presence of easily accessible catalysts (porphyrin, VO(acac)₂, pyridine). Key step is a photo-oxygenation with full incorporation of O₂ into hydrocarbons. Use of the resultant cyclic carbonates in the synthesis of environmentally benign non-isocyanate polyurethanes is demonstrated.