Energy Barrier Research Articles

Advanced electrochemical oxidation of EDTA-Ni via cobalt single-atom catalysts: Exploring indirect persulfate activation pathways

This study explores an innovative electrochemical strategy for the removal of the highly stable and toxic EDTA-Ni complex found in electroplating wastewater. Utilizing a cobalt-based single-atom catalyst (Co-NC) in an electro-enhanced system, we achieved significant activation of peroxydisulfate (PDS) for effective degradation of EDTA-Ni. Under optimal conditions of 40 mA current density and a pH range of 3–7, more than 97% of EDTA-Ni (1 mM) was successfully degraded within 90 min. Through detailed electrochemical experiments, we identified that atomic hydrogen (H*) played a crucial role in the indirect activation of PDS, facilitating the formation of reactive sulfate radicals (·SO4-). Computational analysis using density functional theory (DFT) confirmed that the H*-mediated reduction pathway had a notably low energy barrier (ΔGbs = 0.51 eV), making it the dominant activation mechanism. Gas chromatography-mass spectrometry (GC–MS) further revealed the primary degradation intermediates, providing insights into the breakdown process of EDTA-Ni. This research underscores the potential of Co-NC catalyst as a highly effective catalyst for treating persistent heavy metal complexes in advanced oxidation systems.

Heterogeneous Interface Design with Oxygen Vacancy-Rich Assistance High-Capacity Titanium-Based Oxide Anode Materials for Sodium-Ion Batteries.

Researchers are paying more attention to sodium-ion batteries (SIBs) because of their abundant supply of sodium resources and affordable price. TiO2 offers excellent safety and a long lifespan as an anode material for SIBs. However, the process kinetics is slow due to its limited Na+ storage efficiency, weak conductivity, and irreversible Na+ capture. In order to address these issues, this review uses a mix of the template approach and the double-hydrolysis method to manage the structure and diffusion of TiO2-based anode materials by synthesizing FeTiO3/TiO2 heterostructured double-shell microspheres (FTO). Through the built-in electric field effect caused by their heterostructures, FTO materials improve reaction kinetics, boost electronic conductivity, and lower the diffusion energy barrier of Na+. Their distinctive double-shell structure can increase electrolyte infiltration, shorten the diffusion distance between ions and electrons, and accommodate volume expansion during cycling. Furthermore, the irreversible capture of Na+ and the unfavorable interactions between the surface active site and electrolyte can be successfully inhibited by FTO heterostructures. FTO has an exceptionally high capacity (reaching 362.7 mA h g-1 after 60 cycles at 20 mA g-1) and excellent cycle stability (with a decay rate of 0.0061% after 1000 cycles at 2 A g-1). The strategy of constructing heterogeneous interfaces assists with high-performance SIB anode design.

Dual Redox-active Covalent Organic Framework-based Memristors forHighly-efficient Neuromorphic Computing.

Organic memristors based on covalent organic frameworks (COFs) exhibit significant potential for future neuromorphic computing applications. The preparation of high-quality COF nanosheets through appropriate structural design and building block selection is critical for the enhancement of memristor performance. In this study, a novel room-temperature single-phase method was used to synthesize Ta-Cu3 COF, which contains two redox-active units: trinuclear copper and triphenylamine. The resultant COF nanosheets were dispersed through acid-assisted exfoliation and subsequently spin-coated to fabricate a high-quality COF film on an indium tin oxide (ITO) substrate. The synergistic effect of the dual redox-active centers in the COF film, combined with its distinct crystallinity, significantly reduces the redox energy barrier, enabling the efficient modulation of 128 non-volatile conductive states in the Al/Ta-Cu3 COF/ITO memristor. Utilizing a convolutional neural network (CNN) based on these 128 conductance states, image recognition for ten representative campus landmarks was successfully executed, achieving a high recognition accuracy of 95.13% after 25 training epochs. Compared to devices based on binary conductance states, the memristor with 128 conductance states exhibits a 45.56% improvement in recognition accuracy and significantly enhances the efficiency of neuromorphic computing.

Artificially interconnected ion-diffusion nanochannels in ion-indiffusible phase-conversion cathodes for rechargeable aqueous zinc batteries

A substantial proportion of multivalent-ion battery cathodes undergo solid-solid phase conversion that embrace adequate energy densities, but considerable gaps remain between theoretical prediction and experimental realization of such features owing to thermodynamically large-energy-barrier or even infeasible ion migration between interstitial sites of close-packed anionic frameworks. We build artificially interconnected ion-diffusion nanochannels in ion-indiffusible cathodes, or bixbyite α-phase Mn2O3 more specifically, on the basis of grain boundary (GB) networks, realized via a glucose-assisted solution thermal shock strategy. Remarkable tensile and shear strains coexist along GB grids and Zn2+-diffusion energy barriers within them are merely ∼56% of that in ion-diffusible layered MnO2 polymorphs, causing two orders of magnitude increase in ion-diffusion coefficients, modulated diffusion-/capacitance-controlled kinetic processes and reduced charge-transfer resistance. Consequently, this phase-transition cathode is characterized by faster kinetics than reported analogues, delivering specific capacities of 365 mAh g−1 at 0.1 A g−1 and 108 mAh g−1 at 10 A g−1, along with impressive cycling stability with 91% capacity retention at 1A g−1 after 1000 cycles. Designing analogously hierarchical architectures provides a promising direction for further optimization of cathodes with close-packed anionic frameworks.

Tandem Electroreduction of Nitrate to Ammonia Using a Cobalt–Copper Mixed Single‐Atom/Cluster Catalyst with Synergistic Effects

AbstractElectrochemical conversion of waste nitrate (NO3−) to ammonia (NH3) for environmental applications, such as carbon‐neutral energy sources and hydrogen carriers, is a promising alternative to the energy‐intensive Haber–Bosch process. However, increasing the energy efficiency is limited by the high overpotential and selectivity. Herein, a Co─Cu mixed single‐atom/cluster catalyst (Co─Cu SCC) is demonstrated—with well‐dispersed Co and Cu active sites anchored on a carbon support—that delivers high NH3 Faradaic efficiency of 91.2% at low potential (–0.3 V vs. RHE) due to synergism between the heterogenous active sites. Electrochemical analyses reveal that Cu in Co─Cu SCC preferentially catalyzes the NO3−‐to‐NO2− pathway, whereupon Co catalyzes the NO2−‐to‐NH3 pathway. This tandem electroreduction bypasses the rate‐determining steps (RDSs) for Co and Cu to lower the reaction energy barrier and surpass scaling relationship limitations. The electrocatalytic performance is amplified by the subnanoscale catalyst to increase the partial current density of NH3 by 2.3 and 5.4 times compared to those of individual Co, Cu single‐atom/cluster catalysts (Co SCC, Cu SCC), respectively. This Co─Cu SCC is operated stably for 32 h in a long‐term bipolar membrane (BPM)‐based membrane electrode assembly (MEA) system for high‐concentration NH3 synthesis to produce over 1 m NH3 for conversion into high‐purity NH4Cl at 2.1 g day−1.

Leaf-like Multiphase Metal Phosphides as Bifunctional Oxygen Electrocatalysts toward Rechargeable Zinc-Air Batteries.

Developing a bifunctional oxygen electrocatalyst is crucial to improve the reversibility and cycle life of a rechargeable zinc-air battery (RZAB). Here, transition metal phosphides (TMPs) with a leaf-like hierarchical structure and multiphase composition can be synthesized by the "alloying-dealloying-phosphating" strategy. The as-prepared P-NiCo(1:1) electrode takes advantage of its internal dense nanoholes and synergistic effects induced by NiCoP-containing polyphase to reveal multifunctional catalysis, such as OER and ORR. In combination of these advantages, P-NiCo(1:1) exhibits an extremely low OER overpotential of 220 mV at 10 mA cm-2, a higher half-wave potential of 0.79 V for ORR, and a smaller potential difference (ΔE) of 0.66 V. The liquid RZAB with P-NiCo(1:1) as a cathodic bifunctional catalyst delivers a higher open-circuit voltage (OCV), a larger power density of 175 mW cm-2, and longer cycling life for more than 180 h. Even when applied in solid-state flexible RZABs, the lightweight module could start high-power devices. With theoretical confirmation, the major phase NiCoP of P-NiCo(1:1) is helpful to increase the density of states, regulate the d-band center, and decrease the energy barrier to 2.13 eV, which are significantly superior to those of Co2P and Ni2P. It is believable that the synthetic strategy and activity-promoting mechanism acquired from this research can offer a guide to designing a promising rechargeable zinc-air battery system.

A theoretical exploration of monomer activation mechanisms in bis-lithium N[sbnd]heterocyclic carbenes complexes for enhanced understanding of charge distribution in ring-opening polymerization of ε-caprolactone

A comprehensive examination was conducted on the ring-opening polymerization (ROP) mechanism of ε-caprolactone (ε-CL) employing bis-lithium N-heterocyclic carbene complexes (bisLiNHCs) in a theoretical framework. The modeled reactions were carried out utilizing density functional theory at B3LYP level. An activated-monomer mechanism was observed, characterized by occurrence of two distinct transition states. Initiating with activation of ε-CL via two lithium atoms from bisLiNHCs catalysts, the ensuing step involved nucleophilic addition of carbonyl group stemming from the lithium benzoxide (LiBnO) initiator. The ring opening ε-CL was accomplished via classical cleavage of acyl-oxygen bond. The determination of reaction barrier heights for ε-caprolactone with bisLiNHCs catalysts involved the examination of potential energy profiles. The computed energy profiles revealed exothermic characteristics for each ROP reaction, with the identification of a rate-determining step occurring at the second transition state, which entailed cleavage of acyl-oxygen bond from monomer. Furthermore, through comparisons catalytic capabilities of bisLiNHCs derivatives and energy barrier heights, it was observed that the length and flexibility of linker chain as well as steric effects from substituent groups, significantly influenced the geometric configuration. These specific variations induce alterations in both distance and angular orientation, which are pivotal aspects influencing the chelation dynamics between lithium and oxygen atoms.

A Customized Strategy Realizes Stable Cycle of Large‐Capacity and High‐Voltage Layered Cathode for Sodium‐Ion Batteries

High‐voltage P2‐Na0.67Ni0.33Mn0.67O2 layered oxide cathode exhibits significant potential for sodium‐ion batteries, owing to the elevated operating voltage and theoretical energy density beyond lithium iron phosphate, but the large‐volume phase transition is the devil. Currently, this type cathode still suffers from stability–capacity trade‐off dilemma. Herein, a concept of customized strategy via multiple rock‐forming elements trace doping is presented to address the mentioned issue. The customized Mg‐Al‐Ti trace doped cathode maintains a notable capacity of 140.3 mAh g − 1 with an energy density approaching 500 Wh kg − 1, and shows good cycle stability, retaining 89.0% of its capacity after 50 cycles at 0.1C. Additionally, the full cell, paired with a hard carbon anode, achieves an advanced energy density of 303.3 Wh kg−1. The multiple characterizations reveal the failure mechanism of contrast sample involving severe intragranular cracks coupled with layer to rock salt transformation, which reduces active substance and increases charge transfer resistance. The doped sample with increased sliding energy barrier well suppresses this phenomenon. Impressively, the customized strategy can be extended to Mg‐Fe‐Ti system. This research provides a novel concept for the design of high energy sodium‐ion cathode.

Dissolved ammonia catalyzes proto-dolomite precipitation at Earth surface temperature

Marine carbonate rocks are the major reservoir of carbon through CaCO3 and CaMg(CO3)2 precipitation extracting CO2/HCO3- from the atmosphere/oceans; hence dolomite is one of the major sinks in the global carbon cycle. Most ancient dolomite has been considered as mainly precipitated under Earth surface conditions. Previous studies have demonstrated that microbes can mediate dolomite formation. However, the “microbial dolomite” model is not sufficient to explain the dolomite that shows no or little evidence of a microbial origin. Although attempted for decades, the synthesis of inorganically-produced dolomite at normal temperatures (<50 °C) has been relatively unsuccessful. Hence, this "dolomite enigma" has been one principal research focus this century. Here we demonstrate that NH3 catalyzes proto-dolomite precipitation inorganically with higher Mg/Ca molar ratios and CO32- activity at normal temperatures of 30 °C and 40 °C. NH3 dissolution increases the alkalinity of the solution and transformes into NH4+ ions, which prefer to bond with H2O on Mg[(H2O)6]2+ rather than free H2O, thus releasing Mg2+ to facilitate proto-dolomite nucleation. Furthermore, the low dielectric constant and low dipole moment allow NH4+ absorbed on crystal surfaces to lower the energy barrier of Mg[(H2O)6]2+ dehydration, promoting proto-dolomite nucleis growth. The system for proto-dolomite precipitation in our experiments closely simulates the natural aqueous environment. This study brings new insights to understanding the mechanisms of dolomite precipitation in natural waters.

Oxygen vacancy modulation for enhanced hydrogen production via chemical looping water-gas shift

Chemical looping water gas shift (CL-WGS)is prospective to generate high-purity hydrogen with integrated CO2 capture. However, this technology is impeded by the lack of active oxygen carriers at mid-temperatures. Here, we synthesized several Ni-doped CoFe2O4-δ to modulate oxygen vacancies and investigate its effect on promoting hydrogen production reaction via chemical looping water gas shift at 650 °C. The findings delineate that doping Ni considerably lowers the energy barriers associated with the oxygen vacancies formation, thereby augmenting their concentration. The underlying mechanism elucidates that within the CL-WGS process, the transfer of lattice oxygen acts as the rate-limiting step. NixCo1-xFe2O4 lowers the formation energy of oxygen vacancies and facilitates the bulk lattice oxygen diffusion through the bulk. Hence, Ni0.5Co0.5Fe2O4 demonstrates the most reduction depth and reversibility via redox reactions, resulting in an elevated hydrogen yield (∼15.5 mmol g−1) at 650 °C, which surpasses the yield from undoped CoFe2O4 by 1.4 times. This performance remains consistently high with only a minimal decline over 100 cycles. The findings introduce a promising approach to promote the reactivity of oxygen carriers, particularly for mid-temperature applications.

Fluorine-Tuned Carbon-Based Nickel Single-Atom Catalysts for Scalable and Highly Efficient CO2 Electrocatalytic Reduction.

Electrocatalytic CO2 reduction is garnering significant interest due to its potential applications in mitigating CO2 and producing fuel. However, the scaling up of related catalysis is still hindered by several challenges, including the cost of the catalytic materials, low selectivity, small current densities to maintain desirable selectivity. In this study, Fluorine (F) atoms were introduced into an N-doped carbon-supported single nickel (Ni) atom catalyst via facile polymer-assisted pyrolysis. This method not only maintains the high atom utilization efficiency of Ni in a cost-effective and sustainable manner but also effectively manipulates the electronic structure of the active Ni-N4 site through F doping. The catalyst has also been further optimized by controlling the F states, including convalent and semi-ionic states, by adjusting the fluorine sources involved. Consequently, this catalyst with unique structure exhibited comparable electrocatalytic performance for CO2-to-CO conversion, achieving a Faradaic efficiency (FE) of over 99% across a wide potential range and an exceptional CO evolution rate of 9.5 × 104 h-1 at -1.16 V vs reversible hydrogen electrode (RHE). It also delivered a practical current of 400 mA cm-2 while maintaining more than 95% CO FE. Experimental analysis combined with density functional theory (DFT) calculations have also shown that F-doping modifies the electron configuration at the central Ni-N4 sites. This modification lowers the energy barrier for CO2 activation, thereby facilitating the production of the crucial *COOH intermediate.

A Customized Strategy Realizes Stable Cycle of Large‐Capacity and High‐Voltage Layered Cathode for Sodium‐Ion Batteries

High‐voltage P2‐Na0.67Ni0.33Mn0.67O2 layered oxide cathode exhibits significant potential for sodium‐ion batteries, owing to the elevated operating voltage and theoretical energy density beyond lithium iron phosphate, but the large‐volume phase transition is the devil. Currently, this type cathode still suffers from stability–capacity trade‐off dilemma. Herein, a concept of customized strategy via multiple rock‐forming elements trace doping is presented to address the mentioned issue. The customized Mg‐Al‐Ti trace doped cathode maintains a notable capacity of 140.3 mAh g − 1 with an energy density approaching 500 Wh kg − 1, and shows good cycle stability, retaining 89.0% of its capacity after 50 cycles at 0.1C. Additionally, the full cell, paired with a hard carbon anode, achieves an advanced energy density of 303.3 Wh kg−1. The multiple characterizations reveal the failure mechanism of contrast sample involving severe intragranular cracks coupled with layer to rock salt transformation, which reduces active substance and increases charge transfer resistance. The doped sample with increased sliding energy barrier well suppresses this phenomenon. Impressively, the customized strategy can be extended to Mg‐Fe‐Ti system. This research provides a novel concept for the design of high energy sodium‐ion cathode.

Sulfur-doped Bi2O2CO3 nanosheet for enhanced visible-light-driven photocatalytic CO2 reduction to CO with ultra-high selectivity.

The photocatalytic reduction of carbon dioxide (CO2) has emerged as a compelling strategy for the conversion of renewable energy. However, the expeditious recombination of photogenerated charge carriers and the inadequate light absorption capabilities are currently predominant challenges. Herein, we developed a facile hydrothermal approach to synthesize a sulfur doped Bi2O2CO3 nanosheet with a tunable energy band structure designed to enhance visible light absorption. Our findings indicate that the incorporation of sulfur into the catalytic sites induces an electron sink effect, significantly improving the separation efficiency of photogenerated charge carriers. Consequently, this sulfur-doped Bi2O2CO3 catalyst exhibits a remarkable carbon monoxide (CO) yield of 16.64 μmol gcat-1 h-1 with nearly 100 % selectivity under illumination ranging from 420 to 780 nm. Through in-situ characterization techniques and theoretical calculations, it was revealed that sulfur-coordinated bismuth sites greatly enhance CO2 adsorption and decrease the energy barrier for critical intermediates formation (*COOH), thus selectively driving the reaction towards CO production. This work not only advances our understanding of mechanisms underlying photocatalytic reduction of CO2 on sulfur-doped bismuth-based catalysts but also sets a precedent for developing sophisticated photocatalytic systems for enhanced photoreduction reactions.

C-C Bonding in Molecular Systems via Cross-Coupling-like Reactions Involving Noncovalently Bound Constituent Ions.

Carbon-based molecules are of universal importance for a huge variety of chemical and biological processes. The complication of the structure of such molecules proceeds via the bonding of carbon atoms. An efficient mechanism for such reactions proceeds via cross-coupling, related to the association of bond-terminating counter-ions. Here, an uncommon version of such a process is investigated, with at least some ions bound in the system noncovalently and/or switching the bonding mode in due course. The analyzed sample reactions involve a single C-C bond formation in environmentally relevant halocarbon species and involve alkali-halide ion-pair components. A consistent ab initio computational study predicts the related energy barriers to alter significantly in the presence of the ion pair. Different channels are checked, with the carbon-halogen bond cleavage preceding or following the actual C-C bonding and with the counter-ions located closely or farther apart. The relative heights of the corresponding energy barriers are found to be switched by the ion pair. The above results suggest a possibility of facilitating such reactions without expensive catalysts.

Combination of nanoparticles with single-metal sites synergistically boosts co-catalyzed formic acid dehydrogenation

The development of hydrogen technologies is at the heart of a green economy. As prerequisite for implementation of hydrogen storage, active and stable catalysts for (de)hydrogenation reactions are needed. So far, the use of precious metals associated with expensive costs dominates in this area. Herein, we present a new class of lower-cost Co-based catalysts (Co-SAs/NPs@NC) in which highly distributed single-metal sites are synergistically combined with small defined nanoparticles allowing efficient formic acid dehydrogenation. The optimal material with atomically dispersed CoN2C2 units and encapsulated 7-8 nm nanoparticles achieves an excellent gas yield of 1403.8 mL·g−1·h−1 using propylene carbonate as solvent, with no activity loss after 5 cycles, which is 15 times higher than that of the commercial Pd/C. In situ analytic experiments show that Co-SAs/NPs@NC enhances the adsorption and activation of the key intermediate monodentate HCOO*, thereby facilitating the following C-H bond breaking, compared to related single metal atom and nanoparticle catalysts. Theoretical calculations show that the integration of cobalt nanoparticles elevates the d-band center of the Co single atoms as the active center, which consequently enhances the coupling of the carbonyl O of the HCOO* intermediate to the Co centers, thereby lowering the energy barrier.

Operando X-ray and Mass Spectroscopy of Reduced Graphene Oxide ( rGO )-Mediated Cobalt Catalysts for Boosting the Hydrogen Evolution Reaction

Inserting underlying reduced graphene oxide (rGO) into Co aims to regulate the chemical integrity and catalytic ability of the Co upper layer for hydrogen evolution reaction (HER) as a green-hydrogen goal. Principally, an mass spectrometer indicates 3.8 times more considerable hydrogen generation in Co/rGO than in Co. The spectroscopical approaches, combining soft and hard X-ray probing, illustrate the chemical oxidation evolution of electronic Co-3 and Co-4 states differently regarding the underlying rGO contribution. A unique examination is regarded as the phase transition from the initial middle to high oxidation and to deoxidation, related to the intermediate Co0 existence and H2 generation. The chemical adsorption of Co–O(H), Co–Hads, and H2 molecules desorption have been assigned their spectral significances. The rGO mediation indicates two significant metal Co and Co–O(H) blocks in the two-dimensional - domain. Density-functional-theory (DFT) calculation provides the regeneration, sustained stability, and decreasing energy barrier of Co–Hads catalysts due to the rGO incorporation, thereby augmenting the HER enhancement through the alternative Volmer-Heyrovsky process. The experiment, including mass spectrometer, soft, and hard X-ray, provides evidence regarding the catalyst’s HER enhancement. This study offers insights into the chemical composition, electronic structure, and active role of Co bonded with or without the extinct OH and H bonds, advancing our comprehension of electrocatalytic reactions, thus taking our knowledge of composite materials to stepwise electrocatalytic reactions forward. This cutting-edge experiment under environment and DFT studies gives critical information regarding the catalytic mechanism and chemical stability of the Co and rGO materials. Published by the American Physical Society 2024

Highly Active Photoreduction of Atmospheric-Concentration CO2 into CH3COOH over Palladium Particles on Nb2O5 Nanosheets.

The endeavor to drive CO2 photoreduction towards the synthesis of C2 products is largely thwarted by the colossal energy hurdle inherent in C-C coupling. Herein, we load active metal particles on metal oxide nanosheets to build the dual metal pair sites for steering C-C coupling to form C2 products. Taking Pd particles anchored on the Nb2O5 nanosheets as an example, the high-angle annular dark-field image and X-ray photoelectron spectroscopy demonstrate the presence of Pd-Nb metal pair sites on the Pd-Nb2O5 nanosheets. Density functional theory calculations reveal these sites exhibit a low reaction energy barrier of only 1.02 eV for C-C coupling, implying that the introduction of Pd particles effectively tailors the reaction step to form C2 products. Therefore, the Pd-Nb2O5 nanosheets achieve a CH3COOH evolution rate of 13.5 μmol g-1 h-1 in photoreduction of atmospheric-concentration CO2, outshining all other single photocatalysts reported to date under analogous conditions.

Highly Active Photoreduction of Atmospheric‐Concentration CO2 into CH3COOH over Palladium Particles on Nb2O5 Nanosheets

The endeavor to drive CO2 photoreduction towards the synthesis of C2 products is largely thwarted by the colossal energy hurdle inherent in C−C coupling. Herein, we load active metal particles on metal oxide nanosheets to build the dual metal pair sites for steering C−C coupling to form C2 products. Taking Pd particles anchored on the Nb2O5 nanosheets as an example, the high‐angle annular dark‐field image and X‐ray photoelectron spectroscopy demonstrate the presence of Pd−Nb metal pair sites on the Pd‐Nb2O5 nanosheets. Density functional theory calculations reveal these sites exhibit a low reaction energy barrier of only 1.02 eV for C−C coupling, implying that the introduction of Pd particles effectively tailors the reaction step to form C2 products. Therefore, the Pd‐Nb2O5 nanosheets achieve a CH3COOH evolution rate of 13.5 μmol g−1 h−1 in photoreduction of atmospheric‐concentration CO2, outshining all other single photocatalysts reported to date under analogous conditions.

Molten Salt Modulation of Potassium-Nitrogen-Carbon for the Breaking Kinetics Bottleneck of Photocatalytic Overall Water Splitting and Environmental Impact Reduction.

Sluggish interfacial water dissociation and the O2 evolution reaction (OER) kinetics are the main obstacles that limit the photocatalytic overall water-splitting performance. A molten salt modulation of potassium-nitrogen-carbon is herein demonstrated as the formation of highly crystalline potassium-doped poly(triazine imide) (KPTI). The in situ X-ray diffraction patterns and theoretical calculation show that the KCl melt can significantly reduce the free energy for the polycondensation of triazine building blocks owing to the formation of a kinetically stable KPTI. Benefiting from the presence of potassium-carbon-nitrogen moiety, the catalyst not only weakens the excitonic confinement to improve the separation efficiency of photogenerated charge carriers but also enhances the stability of carbon sites by suppressing the undesired C═O formation. Moreover, KPTI accelerates water dissociation by forming interfacial K·H2O clusters with an ordered structure, which supplies sufficient protons for the H2 evolution reaction and lowers the energy barrier to enhance the kinetics of OER. Therefore, a stable photocatalytic overall water-splitting performance can be achieved over KPTI with a stoichiometric generation of products (H2 and O2). Life cycle assessment shows that a carbon-neutral scenario can be achieved on KPTI production in the near term with an increase in green power in the electricity grid.

Entropy-Modulated Short-Chain Cathode for Low-Temperature All-Solid-State Li-S Batteries.

All-solid-state Li-S batteries (ASSLSBs) due to high theoretical energy density and exceptional safety are highly desirable for electric aircraft. However, as the flight altitude rises, the low-temperature performance is hampered by inadequate practical capacity. Here, we discover that low-temperature sulfur utilization is constrained by the multi-step endothermic conversion reaction. By introducing multi-chalcogen to modulate the local entropy, a short-chain molecule cathode is designed to shorten the reduction pathways and enhance low-temperature discharge capacity. Furthermore, the mismatched lithiation lattice of the short-chain cathode reduces the decomposition energy barriers, thus enhancing low-temperature charge/discharge reversibility. The designed short-chain cathode exhibits high cathode utilization (99.4%) and cycling stability (400 cycles, 92.2% retention) at room temperature, as well as delivers excellent discharge capacity (579.6 mAh g-1, -40 °C) and cycling performance (100 cycles, 98.4% retention, 394.9 Wh kg-1electrode, -20 °C) at low temperature. This study presents new opportunities to stimulate the development of low-temperature ASSLSBs.