Photocatalytic N2 fixation provides a promising pathway to sustainable ammonia (NH3) production. However, limited surface active sites and rapid photogenerated carrier recombination severely restrict the photocatalytic efficiency. Herein, the aforementioned challenges are addressed by manipulating oxygen vacancy (Ov) and surface spin state in ferroelectric BaTiO3 (BTO) by doping Fe cations and applying an external magnetic field. Experimental and theoretical calculations reveal that Fe doping promotes the formation of oxygen vacancies and regulates the electronic and magnetic properties of BTO through the induction of asymmetric charge distribution and spin selectivity effect. The strengthened built-in electric field significantly facilitates bulk carrier separation efficiency. Fe-doped BTO, with a matched symmetric orbit, enhances the electron-transfer capability for triple N2, and lowers activation barriers for *N2 hydrogenation and *NH3 desorption. Consequently, Fe:BTO–5.0 delivers an exceptional NH3 yield of 184.84 µmol gcat−1 h−1 under an applied magnetic field, about 17.2 times higher than pristine BTO. The origin of the improved NH3 yield is due to the electromagnetic synergistic effect between the internal electric field and an external magnetic field, resulting in facilitated photoexcited carrier separation and promoted N2 activation and *NH3 desorption. Our result presents a viable N2 activation strategy via the synergy of transition metal electronic modulation, spin selectivity effect, and external magnetic field assistance.

Optimal electrode structure design is essential for performance improvement. In the present work, the NiSe/MnSe hetero-nanosheets were vertically grown on conductive Nb2CTx substrates to construct the rapid electron/ion/electrolyte triple-transport channels (Nb2CTx@NiMn-Se). The Nb2CTx@NiMn-Se heterostructure features the characteristics of high theoretical capacity, excellent redox reversibility and built-in electric field of bimetallic chalcogenides as well as the metallic conductivity and elastic mechanical strength of MXenes. Furthermore, the vertically growing NiSe/MnSe hetero-nanosheets into the multilayered Nb2CTx interlamination provide structural support to guarantee sufficient contact between electrode and electrolyte. Consequently, the fabricated Nb2CTx@NiMn-Se achieves a harmonious high-rate capability of 222 mAh g−1 at 500 mA g−1 and exceptional long-term durability over 500 cycles in potassium-ion battery. The full PlBs battery with Prussian blue as cathode and Nb2CTx@NiMn-Se as anode exhibits excellent stability beyond 200 cycles. This work opens up a strategy for precisely tailoring both of carrier and electrolyte transport channels.

Improving the surface atoms utilization efficiency of catalysts is extremely important for large-scale H2 production by electrochemical water splitting, but it remains a great challenge. Herein, we reported two kinds of MoO3-polyoxometalate hybrid nanobelt superstructures (MoO3-POM HNSs, POM= PW 12 O 40 and SiW 12 O 40 ) using a simple hydrothermal method. Such superstructure with highly uniform nanoparticles as building blocks can expose more surface atoms and emanate increased specific surface area. The incorporated POMs generated abundant oxygen vacancies, improved the electronic mobility, and modulated the surface electronic structure of MoO3, allowing to optimize the H* adsorption/desorption and dehydrogenation kinetics of catalyst. Notably, the as-prepared MoO3-PW12O40 HNSs electrodes not only displayed the low overpotentials of 108 mV at 10 mA/cm2 current density in 0.5 mol/L H2SO4 electrolyte but also displayed excellent long-term stability. The hydrogen evolution reaction (HER) performance of MoO3- POM superstructures is significantly better than that of corresponding bulk materials MoO3 @PW 12 O 40 and MoO3 @SiW12O40, and the overpotentials are about 8.3 and 4.9 times lower than that of single MoO3. This work opens an avenue for designing highly surface-exposed catalysts for electrocatalytic H2 production and other electrochemical applications. (c) 2024 Published by Elsevier B.V. on behalf of Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences.

The utilization of terahertz (THz) emission spectroscopy in femtosecond photoexcited spintronic heterostructures has emerged as a versatile tool for investigating ultrafast spin-transport in a noncontact and non-invasive manner. However, the investigation of ultrafast orbital-transport is still in the primitive stage. Here, we experimentally demonstrate the orbital-to-charge current conversion in Co/ Zr/Al2O3 heterostructures. Our experimental results indicate a photoinduced orbital current (JL) from Co propagating through Zr layer with a long-distance ballistic transport and a velocity of similar to 0:27 +/- 0:02nmfs(-1). On the one hand, we demonstrate a critical pump fluence required to overcome the collisions in orbital transport, enabling a swifter flow of JL. On the other hand, a critical temperature is observed, below which the orbital transport is impeded. Finally, we observe a nearly 2.95-fold enhancement in the THz emission due to an additional conversion of the spin-to-orbital current conversion from a 1 nm thick W-insertion layer between Co and Zr layers. Our results pave the way for designing promising opto-spin-orbitronic devices and THz emitters.

Developing effective and robust catalysts with high gas adsorption capacities and electron-hole separation rates for direct photochemical N-2 reduction reaction is extremely crucial but remains quite challenging. Here, a novel dual Z-scheme heterostructured polyoxometalate/activated carbon/TiO2 (Co4PW9-C-TiO2) ternary composite was constructed through a well-designed two-step hydrothermal method and first applied for efficient and stable N-2 fixation under mild conditions without any precious-metal cocatalysts and organic scavengers. The rational heterostructure brings a remarkable NH3 production rate of 399.9 mu molh(-1)g(cat)(-1)L-1, which significantly exceeds the corresponding binary composites, and about 9-fold and 6-fold improvement over that of discrete TiO2 and Co4PW9, respectively. Further comprehensive characterization and analysis revealed a reasonable dual Z-scheme charge transfer mechanism and demonstrated that such superior photocatalytic performance can be ascribed to the unique structure of the ternary composite, including the improved solar energy utilization efficiency, enhanced N-2 absorption ability, facilitated photoexcited charge carrier transport/separation rate and elevated redox ability. This work provides a reasonable construction strategy to further develop excellent catalysts for photocatalytic ammonia synthesis.

Dielectric capacitors have attracted considerable interest for energy storage applications owing to their ultra‐fast charge–discharge capabilities. However, the concurrent realization of high recoverable energy storage density ( W rec ) and energy efficiency ( η ) remains a persistent challenge. In this study, NaNbO 3 (NN) is introduced into the 0.85Ba 0.85 Ca 0.15 Zr 0.1 Ti 0.9 O 3 –0.15Bi(Zn 2/3 Ta 1/3 )O 3 (BCZT–0.15BZT) lattice, resulting in the emergence of a unique structural feature identified as ordered–disordered domains ( O – DO – Ds ). Detailed analysis reveals that the ordered domains exhibit ferroelectric hysteresis behavior, consistent with previous reports, while the disordered domains play a critical role in enhancing both breakdown strength and energy storage efficiency. These improvements are primarily attributed to energy dissipation mechanisms and the stabilization of a triple‐phase coexistence. Additionally, the formation of defect dipoles and the presence of weakly coupled orthorhombic–tetragonal–cubic ( O–T–C ) asymmetric phases contribute synergistically to achieving high polarization and low hysteresis. Consequently, the optimized composition, (1‐ x )BCZT–0.15BZT– x NN with x = 0.15 exhibits an exceptionally high W rec of 9.12 J cm −3 and an η of 95.3%. These findings offer a promising and innovative strategy for the design of next‐generation high‐performance energy storage capacitors.

Mo2CTx is relatively less studied among MXenes family, especially for rechargeable alkali metal ion batteries. Herein, a systematic investigation has been conducted to unlock its potential as electrode materials in potassium-ion battery (PIBs), including innovative fluorine-free synthesis strategy, construction of heterostructure, and exploration of suitable electrolyte systems. Firstly, Cetyltriethylammnonium bromide (CTAB)-assisted etching route was provided to fabricate high-quality multilayer Mo2CTx with expanded interlayer space (C-Mo2CTx). The as-obtained C-Mo2CTx demonstrates a large specific capacity of 200 mAh g(-1)over 300 cycles in potassium-ion battery, surpassing the HF etched counterparts (F-Mo2CTx) by about 300 %. Afterwards, Zeolitic Imidazolate Frameworks (ZIF-67) derived Co, N-codoped carbon nanotubes (Co@NCNTs) were homogenously grown on the surface of Mo2CTx, working as embedding spacer to open the stacked Mo2CTx conductive layers (Mo2CTx-Co@NCNTs). Mo2CTx-Co@NCNTs electrode represents stable reversible capacity of 280 mA h g(-1) over 300 cycles. The highly conductive matrix constructed by the strong bond between CNTs arrays and Mo2CTx conductive layer could provide numerous K-ion-diffusion pathways, and buffer volume strain and facilitate electron transfer. The present work proves the potential of Mo2CTx in PIBs and gives the systematic research methodologies on Mo2CTx-based materials in alkali metal ion storage.

The electrocatalytic nitrogen reduction reaction (NRR) is a highly promising process for synthesizing ammonia and holds great potential to replace the traditional Haber-Bosch process. Here, we report a novel flower-shaped ZnS/CoS composite electrocatalyst for the NRR. Remarkably, the ZnS/CoS-105 heterojunction catalyst achieved an NH3 yield rate of 20.42 mu g h(-1) mg(cat.)(-1) and a faradaic efficiency (FE) of 11.83% at -0.45 V VS. RHE in an aqueous 0.1 M Na2SO4 solution. In addition, ZnS/CoS-105 showed remarkable stability (up to 24 h) for the NRR process.

The exploration of high-nuclearity molecular molybdenum titanium-oxo clusters (MoTOCs) and their reactivity is a great challenge for polyoxometalate chemistry and materials science. Herein, we report a giant MoTOC [K-8(H2O)(8)][Ti-12(O-2)(6)(OH)(12)Mo42O124(O-2)(18)(H2O)(17)]31H(2)O (1) by self-assembly of degraded lacunary isopolymolybdate fragments and peroxide-stabilized titanium ions in aqueous solution. Compound 1 features 54 metal centers and a rare pure inorganic triangular prism structure with a size of 1.8 x 1.8 x 1.5 nm(3), which is the first and largest water-soluble MoTOC found to date. More importantly, it contains multiple peroxo groups on the surface, which makes it exhibit superior benzyl alcohol/benzaldehyde (photo)catalytic oxidation performance. This work opens an unusual avenue for the synthesis of giant MoTOCs.

The orbital Hall effect in light materials has attracted considerable attention for developing novel orbitronic devices. Here we investigate the orbital torque efficiency and demonstrate the switching of the perpendicularly magnetized materials through the orbital Hall material (OHM), i.e., Zirconium (Zr). The orbital torque efficiency of approximately 0.78 is achieved in the Zr OHM with the perpendicularly magnetized [Co/Pt]3 sample, which significantly surpasses that of the perpendicularly magnetized CoFeB/Gd/CoFeB sample (approximately 0.04). Such notable difference is attributed to the different spin-orbit correlation strength between the [Co/Pt]3 sample and the CoFeB/Gd/CoFeB sample, which has been confirmed through the theoretical calculations. Furthermore, the full magnetization switching of the [Co/Pt]3 sample with a switching current density of approximately 2.6x106 A/cm2 has been realized through Zr, which even outperforms that of the W spin Hall material. Our finding provides a guideline to understand orbital torque efficiency and paves the way to develop energy-efficient orbitronic devices.

Exploring robust electrode materials which could permit fast and reversible insertion/extraction of large K + is a crucial challenge for potassium -ion batteries (PIBs). Smart interfacial design could facilitate electron/ion transport as well as assure the integrity of electrode. Herein, Cetyltrimethylammonium bromide (CTAB) was found to play bifunctional roles in construction of Nb 2 CT x @MoSe 2 heterostructure. Firstly, functionalization of CTAB on the surface of Nb 2 CT x could influence the subsequent growth of MoSe 2 by electrostatic effect, stereochemical effect and the synergetic Lewis acid -base interaction, leading to the formation of Nb 2 CT x @MoSe 2 with tiled heterostructure. Secondly, the interlayer spacing of Nb 2 CT x was expanded from 0.77 to 1.21 nm owing to the pillar effect of CTAB. As excepted, the capacity retention was 80 % from 100 mA g - 1 (406 mA h g - 1 ) to 1000 mA g - 1 concerning rate capability and the specific capacity maintained at 240 mA h g - 1 (at 2000 mA g - 1 ) over 300 cycles. The calculated D K values from Galvanostatic intermittent titration technique (GITT) measurement of Journal of Colloid And Interface Science 674 (2024) 19-28 the titled C-T-Nb 2 CT x @MoSe 2 @C electrode is two orders of magnitude larger than the traditional TNb 2 CT x @MoSe 2 @C electrode, further confirming intimate interface between MoSe 2 and Nb 2 CT x could provide convenient potassium -ion transport channels and fast diffusion kinetics. Finally, ex -situ characterizations at different charging and discharging voltage stages, including ex -situ XRD/Raman/HRTEM/XPS have been carried out to reveal the potassium storage mechanism. This work provides a facile strategy for the regulation of interface engineering by the assist of CTAB which could extend to other MXenes-TMDs (Transition metal dichalcogenides) hybrid electrodes.

Photocatalytic N2 fixation can convert the abundant but inert N2 into NH3 under atmospheric conditions. However, the dissatisfactory yield rate of NH3 greatly hinders its development. The rational design of a highly efficient N2 fixation photocatalyst enables large-scale ammonia production but is challenging due to the thermodynamic obstacles of N2 activation. Herein, the W/Mo-heteropoly blue modified defective W18O49 heterojunction composite catalysts (r-HPW/W18O49 and r-HPMo/W18O49) are prepared for N2 photofixaiton without sacrificial agents and cocatalysts under ambient conditions for the first time. The heteropoly blue nanoparticles are loaded on the surface of W18O49 by electro-reduction and subsequent solvothermal methods. The as-fabricated r-HPW/W18O49 show unusual activity with NH3 formation rates of 184.54 mu mol g-1 h-1, about 2.6 times higher than that of initial W18O49. The excellent photocatalysis property is attributed to the synergistic effect between W18O49 and heteropoly blues. The defective W18O49 provides rich active sites for the effective adsorption of N2 molecules and acts as a robust support to inhibit the aggregation of heteropoly blues. The photo-generated electrons in W18O49 quickly transfer to the heteropoly blues, retarding charge pair recombination and enabling the constructed "Z-Scheme" hetero-structure to stronger redox capacity. This work offers a new perspective for preparing advanced heteropoly blues-based N2 photofixation nanomaterials. (c) 2022 Elsevier B.V. All rights reserved.

Extensive efforts to enhance the oxygen evolution reaction (OER) catalytic performance of transition metal oxides mainly concentrate on the extrinsic morphology tailoring, lattice doping, and electrode interface optimizing. Nevertheless, little room is left for performance improvement using these methods and an obvious gap still exists compared to the precious metal catalysts. In this work, a novel "mixed-valent cobalt modulation" strategy is presented to enhance the electrocatalytic OER of perovskite LaCoO3 (LCO) oxide. The valence transition of cobalt is realized by ethylenediamine post reduction procedure at room temperature, which further induces the variation of magnetic properties for LCO catalyst. The optimized LCO catalyst with Co2+ /Co3+ of 1.98 % exhibits the best OER activity, and the overpotential at 10 mA cm-2 current density is decreased by 170 mV compared pristine LCO. Impressively, the ferromagnetic LCO catalyst can perform magnetic OER enhancement. By application of an external magnetic field, the overpotential of LCO at 10 mA cm-2 can be further decreased by 20 mV compared to that of under zero magnetic field, which arises from the enhanced energy states of electrons and accelerated electron transfer process driven by magnetic field. Our findings may provide a promising strategy to break the bottleneck for further enhancement of OER performance.

High-performance triiodide reduction reaction (IRR) catalysts in dye-sensitized solar cells (DSSCs) and hydrogen evolution reaction (HER) catalysts in electrochemical water splitting are extremely compelling for renewable energy conversion and storage. The best IRR and HER catalysts generally rely on the use of noble metal platinum (Pt), which suffers obstacles in real-world implementation. The rational design of efficient bifunctional IRR and HER catalysts based on inexpensive and earth-abundant elements to replace scarce Pt could enable low-cost photoelectric conversion and hydrogen production but is challenging and rarely reported. Herein, we present a bifunctional NiFeCoW@NC hybrid with the unique architecture of WC loaded on the in situ formed carbon nanotubes embedded with Co-doped FeNi3 nanoparticles based on the anisotropic integration design principle, which operates efficiently for DSSCs and hydrogen evolution. The assembled DSSCs using the designed multimetal-based NiFeCoW@NC counter electrode delivered a high power conversion efficiency of 6.92% and long-term stability superior to bimetal-based NiFe@NC, CoW@NC, and Pt counterparts. It also exhibited eminent hydrogen evolution performance with a low overpotential of 127.8 mV to drive a 10 mA cm-2 current density, a Tafel slope of 60.4 mV dec-1, and satisfactory durable stability in 0.5 M H2SO4. This work provides a design principle for low-cost and highly active bifunctional catalysts to replace Pt for DSSCs and hydrogen evolution.

Over the years, transition metal-based hybrids have been advocated as one of the most promising classes of nonnoble catalysts and investigated exclusively for the electrocatalytic triiodide reduction reaction (IRR) or hydrogen evolution reaction (HER). However, there is lack of effective strategy to address their site accessibility, intrinsic activity and structural stability issues, and their successful utilization as bifunctional catalysts of IRR and HER is rarely explored. Herein, presented is a multimetal-based carbon nanotube hybrid (CoFeNiMo@NCNT), synthesized from a novel polyoxometalate (P0M)-intercalated layered double hydroxide (LDH) pyrolysis strategy, as an efficient catalyst for IRR and HER. During both electrochemical IRR and HER, the regulated NCNT provides a highway for electron migration and acts as a network for I-3(-)/H+ adsorption. Benefitting from the features of porous structure, multimetal component and fast electron transfer, the CoFeNiMo@NCNT catalyst delivers a high power conversion efficiency of 6.46 % when assembled as counter electrode in dye-sensitized solar cell, superior to N benchmark. Furthermore, it mediates efficient HER with a relatively small overpotential of 209.9 mV at 10 mA cm(-2). The strategy to achieve tunable catalytic properties via in situ pyrolysis well-defined inorganic materials paves a new way to design cost-effective and efficient bifunctional catalysts.

Highly dispersed POM nanoparticles as functional components have been deposited on CNTs to produce periodic functionalized CNTs. The obtained Co4PW9/CNTs CE exhibits the best photovoltaic performance with a PCE of 7.60%, higher than both pure CNTs and Pt CE.

A titanium-polyoxomolybdate K6(H3O)8[{PMo9O34TiO}2]·32H2O (1) was successfully synthesized and structurally characterized. It is an unprecedented instance that the titanium-containing polyoxomolybdate is water-soluble and was synthesized by using a conventional aqueous solution method. The Ti4+ ions exist in an unusual coordination mode. Besides, compound 1 as a wide band gap semiconductor showed evident photocatalytic activity for the oxidation of benzaldehyde into benzoic acid.