Tunable Chemical Composition Research Articles

Anion substitution strategy for constructing abundant oxygen vacancies in perovskites enables efficient nitrate electroreduction

Perovskite oxides have emerged as promising candidates for electrocatalytic nitrate reduction (ERN) catalysts due to their unique electronic structures and tunable chemical compositions. In this work, we employed a fluorine ion substitution strategy to modulate the oxygen site of LaCoO3 (LCO), resulting in the construction of F-substituted LaCoO3 (LCOF0.5) catalyst for efficient ERN. The incorporation of fluorine ions leads to a weakening of the hybridization between the O 1 s orbital and Co 3d orbital of the catalyst, thereby inducing an increase in oxygen vacancies. The abundant oxygen vacancies can facilitate the electron transfer and surface adsorption energy of the ERN reaction intermediates. This leads to a reduction in the energy barriers for both the reduction of *HNO3 to *NO2 and the reduction of *HNO2 to *NO, thereby enhancing the performance of ERN. As excepted, LCOF0.5 exhibits a rapid reaction rate of k = 5.48 × 10−3 min−1, which is 1.70 times faster than that of pristine LCO, and its catalytic activity approaches that of the state-of-the-art electrocatalysts for ERN. Applying this strategy to LaFeO3 and LaMnO3 also yields similar results, demonstrating its general applicability. The F-anion substitution strategy offers new opportunities for significantly enhancing ERN performance.

Ti3C2Tx MXene deposition: A simple surface engineering technique for dual enhancement of biological functions for nonbearing applications

Implant-associated complications, such as infection and poor osseointegration, present significant challenges in the field of biomedical implants. To address these issues, it is crucial to develop implant surfaces that possess both bacteriostatic and osteoconductive properties. In recent years, the field of surface modification for metallic substrates using two-dimensional materials has emerged as a highly promising strategy to enhance their biological properties. Among these materials, MXenes stand out as an excellent candidate for surface modifications due to their unique properties, such as biocompatibility, high specific surface area, and tunable chemical composition. In the present study, we introduce a simple deposition method of Ti3C2Tx MXene films on SS316L substrates to improve surface-cell interactions. The differentiation study demonstrated the alkaline phosphatase (ALP) enzyme activity on Ti3C2Tx-MXene-coated samples without osteogenic medium compared to uncoated samples in both, basic and osteogenic media. Moreover, the bacteriostatic character of the deposited MXene-coatings was confirmed against Gram-positive Staphylococcus aureus as well as Gram-negative Escherichia coli bacteria. The improved stimulation of both cell osteogenic differentiation and distinctive antimicrobial features triggered by Ti3C2Tx-MXene-coatings emphasizes their great potential as implant surface modifiers to improve integration and reduce the risk of infection in various biomedical applications.

Wide Range Near-Zero Thermal Quenching of Orange-Yellow Phosphor via Impeding Self-Oxidation of Eu2+ for Versatile Optoelectronic Applications.

Li2SrSiO4:Eu2+ is a promising substitute for traditional Y3Al5O12:Ce3+ (YAG:Ce3+) owing to its strong orange-yellow emission of 4f-5d transition originating from Eu2+ dopant, covering the more red-light region. However, its inevitable luminescence thermal quenching at high temperatures and the self-oxidation of Eu2+ strongly impede their applications. Their remediation remains highly challenging. Herein, an anti-self-oxidation(ASO) concept of Eu2+ in Li2SrSiO4 substrate by adding trivalent rare-earth ions (A3+: A = La, Gd, Y, Lu) for highly efficient and stable orange-yellow light emission have been proposed. A significantly increased orange-yellow emission (202% improvement) from Li2Sr0.95A0.05SiO4:Eu2+ with a wide range near-zero thermal quenching is obtained, superior to other Eu2+ activated phosphors. The presence of A3+ ions with various radii modifies the ASO degree of Eu2+ ions, achieving the tunable chemical state, composition, electronic configuration, crystal-field strength, and luminescent characteristics of the developed phosphors. For the proof of the concept, a W-LED device and a PDMS (Polydimethylsiloxane) luminescent film are fabricated, endowing excellent luminescence performance and thermal stability and the huge application prospects of Li2SrSiO4:Eu2+ in lighting and display fields.

In-situ synthesis of NiTi shape memory alloys with tunable chemical composition and thermomechanical response by dual-wire-feed electron beam directed energy deposition

In this study, we demonstrate the direct in-situ synthesis of NiTi alloys with tunable chemical composition (Ni/Ti atomic ratio) and corresponding thermomechanical response. This synthesis is achieved by regulating the feeding speed ratio of pure Ni and Ti wires during the additive manufacturing process based on dual-wire-feed electron beam directed energy deposition (EB-DED) technology. Under appropriate process conditions, the resulting NiTi alloys exhibit a controllable evolution around the near-equiatomic composition and display a typical columnar grain morphology characteristic of additively manufactured NiTi alloys. With an increase in Ni content (shifting from Ti-rich to Ni-rich), the second phase particles present in the samples change from Ti-rich phase (Ti2Ni) to Ni-rich phases (such as Ni4Ti3 and Ni3Ti2). The phase transformation temperatures gradually decrease with increasing Ni content, and the predominant matrix phase transitions from martensite to austenite. The as-built NiTi alloy exhibits a typical tensile curve with a good tensile elongation of 11 %, fabricated under suitable composition and microstructure conditions. This result surpasses values reported in current in-situ synthesized NiTi alloys through additive manufacturing methods. Moreover, it almost reaches the levels achieved by additively manufactured NiTi alloys using pre-alloyed raw materials. Furthermore, this study reports, for the first time in the field of in-situ synthesized NiTi alloys, a good tensile shape memory effect, achieving an impressive recovery rate of up to 70 % under a tensile strain of 6 %. This investigation provides a meaningful theoretical perspective and technical strategy for the integrated customization of NiTi alloy components in structure, composition, and function. This low-cost and high-efficiency approach is particularly attractive for the preparation of functional graded, large-scale and disposable NiTi components.

Liquid Metal Alloys Enable Efficient Formate Electrosynthesis

AbstractLiquid metals are an interesting class of materials with the unique combination of metallic nature and liquid fluidity, and have recently been explored in many emerging fields. Their potential applications in catalysis, unfortunately, remain largely untapped. Herein, Ga‐mediated liquid metal alloying as an effective strategy is demonstrated to prepare functional alloys for catalysis. The alloying is carried out by dissolving indium or tin pellets in liquid gallium at room temperature or assisted by gentle heating, giving rise to binary Ga1−xInx and Ga1−xSnx liquid metal alloys with tunable chemical compositions. When further subjected to ultrasonication in water, they are ruptured into nanosized particles with liquid metal cores and thin surface oxide shells. Electrochemical measurements reveal that the liquid metal alloying significantly promotes electrocatalytic CO2 reduction to formate. Taking Ga0.75In0.25 as an example, its formate Faradaic efficiency is enhanced by 10%–20% compared to those of Ga and In, and its formate partial current density is 4–6 times larger than those of Ga and In. This enhancement is rationalized via computational simulations showing that the surrounding of In active sites with Ga atoms deactivates the undesirable reaction pathways to CO or H2, and facilitates selective formate electrosynthesis.

Layered double hydroxides and metal-organic frameworks for electrocatalytic CO2 reduction: A comprehensive review

Electrocatalytic carbon dioxide (CO2) reduction has emerged as a promising approach for converting CO2 into value-added products and mitigating greenhouse gas emissions. Layered double hydroxides (LDHs) and metal-organic frameworks (MOFs) have attracted significant attention as potential electrocatalysts for CO2 reduction due to their unique structural properties and tunable chemical compositions. In this review, we provide a comprehensive overview of recent advances in the utilization of LDHs and MOFs as electrocatalysts for CO2 reduction. Scrutiny on various catalysts, along with their general design ways for CO2 reduction is presented. This review will provide insight into the up-to-date research progress in MOF-based materials for CO2 conversion. Furthermore, we highlight opportunities in this field and propose future research directions aimed at optimizing the performance of LDHs and MOFs for CO2 reduction applications.

Prussian Blue Analogues Derived Bimetallic CoNi@NC as Efficient Oxygen Reduction Reaction Catalyst for Mg‐Air Batteries

The magnesium‐air (Mg‐air) batteries are regarded as a highly promising system for electrochemical energy conversion and storage, owing to exceptional energy density, notable safety and eco‐friendliness. The development of high‐performance and durable non‐noble metal catalysts for the cathodic oxygen reduction reaction (ORR) is crucial for advancing the practical use of Mg‐air batteries. The synergistic interaction between different metals in bimetallic catalysts is an effective strategy for enhancing the activity and stability of the catalysts. Herein, various prussian blue analogues (PBA) were selected as precursors to synthesis the bimetallic CoNi@NC, monometallic Co@NC and Ni@NC catalysts due to tunable chemical compositions. Compared with Co@NC and Ni@NC, the bimetallic CoNi@NC pyrolyzed at 600°C (CoNi@NC‐600) exhibits outstanding ORR performances and stability in alkaline (0.1 M KOH) and neutral (3.5 wt% NaCl) electrolytes. Following 5000 CV cycles, the half‐wave potentials for CoNi@NC‐600 show only minor negative shifts of 8 and 7 mV, respectively. Meanwhile, the CoNi@NC‐600 possesses the similar ORR reaction mechanism and activity with Pt/C. The primary Mg‐air battery assembled with CoNi@NC‐600 displays better discharge performances than that of Co@NC and Ni@NC. This study lays the foundation for future investigations into the advancement of non‐precious bimetallic catalysts for ORR in Mg‐air batteries.

Recent Functionalized Strategies of Metal-Organic Frameworks for Anode Protection of Aqueous Zinc-Ion Battery.

The inherent benefits of aqueous Zn-ion batteries (ZIBs), such as environmental friendliness, affordability, and high theoretical capacity, render them promising candidates for energy storage systems. Nevertheless, the Zn anodes of ZIBs encounter severe challenges, including dendrite formation, hydrogen evolution reaction, corrosion, and surface passivation. These would result in the infeasibility of ZIBs in practical situations. To this end, artificial interfaces with functionalized materials are crafted to protect the Zn anode. They have the capability to modulate the zinc ion flux in proximity to the electrode surface and shield it from aqueous electrolytes by leveraging either size effects or charge effects. Considering metal-organic frameworks (MOFs) with tunable pore size, chemical composition, and stable framework structures, they have emerged as effective materials for building artificial interfaces, prolonging the lifespan, and improving the unitization of Zn anode. In this review, the contributions of MOFs for protecting Zn anode, which mainly involves facilitating homogeneous nucleation, manipulating selective deposition, regulating ion and charge flux, accelerating Zn desolvation, and shielding against free water and anions are comprehensively summarized. Importantly, the future research trajectories of MOFs for the protection of the Zn anode are underscored, which may propose new perspectives on the practical Zn anode and endow the MOFs with high-value applications.

Molecular templating of layered halide perovskite nanowires.

Layered metal-halide perovskites, or two-dimensional perovskites, can be synthesized in solution, and their optical and electronic properties can be tuned by changing their composition. We report a molecular templating method that restricted crystal growth along all crystallographic directions except for [110] and promoted one-dimensional growth. Our approach is widely applicable to synthesize a range of high-quality layered perovskite nanowires with large aspect ratios and tunable organic-inorganic chemical compositions. These nanowires form exceptionally well-defined and flexible cavities that exhibited a wide range of unusual optical properties beyond those of conventional perovskite nanowires. We observed anisotropic emission polarization, low-loss waveguiding (below 3 decibels per millimeter), and efficient low-threshold light amplification (below 20 microjoules per square centimeter).

Catalytic upgrading of Naomaohu coal pyrolysis volatiles over NiAl and NiLiAl oxides

Catalytic upgrading of volatiles is an essential technology to improve the product distribution of pyrolysis for the clean and efficient utilization of low-rank coals. In this work, novel acid-base bifunctional catalysts composed of Ni/Li/Al oxides were designed and prepared using LDH precursors with tunable chemical composition and structural properties. The catalysts were systematically characterized by X-ray diffraction (XRD), thermogravimetric analysis (TGA), physisorption, NH3-temperature programmed desorption (NH3-TPD), CO2-temperature programmed desorption (CO2-TPD), H2-temperature programmed reduction (H2-TPR), and scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS). A two-stage fixed bed reactor was employed to evaluate the performance of the catalysts. Characterization results suggest that the crystal size of NiO and the surface area of the catalyst decreased with increasing Li content and decreasing Ni content in the catalyst, while the pore volume and pore diameter were positively correlated with Li content. Moreover, the addition of Li reduced the amount of weak acid sites and raised the amount of total basic sites. Consequently, the bifunctional catalysts boosted the yield of light tar and the contents of aromatics and phenols in tar. Specifically, with the highest total acid sites (569 μmol/g) promoting the cracking of heavy pitch components, Ni2.5Li0.5Al1 decreased the content of pitch in tar to 23.8 wt%, representing a 42.7 % drop from the corresponding non-catalytic pyrolysis. Accordingly, it improved the light tar yield to 7.2 wt%, which was 18 % higher than non-catalytic pyrolysis. 450 °C is identified as a suitable temperature for the catalytic upgrading of volatiles from Naomaohu coal; higher catalysis temperatures at 500 °C and 550 °C led to lower tar yield and lower phenols content, along with higher gas yield and more carbon deposition.

Ultrathin High-Entropy Fe-Based Spinel Oxide Nanosheets with Metalloid Band Structures for Efficient Nitrate Reduction toward Ammonia.

Spinel oxides with tunable chemical compositions have emerged as versatile electrocatalysts, however their performance is greatly limited by small surface area and low electron conductivity. Here, ultrathin high-entropy Fe-based spinel oxides nanosheets are rationally designed (i.e., (Co0.2Ni0.2Zn0.2Mg0.2Cu0.2)Fe2O4; denotes A5Fe2O4) in thickness of ≈4.3nm with large surface area and highly exposed active sites via a modified sol-gel method. Theoretic and experimental results confirm that the bandgap of A5Fe2O4 nanosheets is significantly smaller than that of ordinary Fe-based spinel oxides, realizing the transformation of binary spinel oxide from semiconductors to metalloids. As a result, such A5Fe2O4 nanosheets manifest excellent performance for the nitrate reduction reaction (NO3 -RR) to ammonia (NH3), with a NH3 yield rate of ≈2.1mmol h-1 cm-2 at -0.5V versus Reversible hydrogen electrode, outperforming other spinel-based electrocatalysts. Systematic mechanism investigations reveal that the NO3 -RR is mainly occurred on Fe sites, and introducing high-entropy compositions in tetrahedral sites regulates the adsorption strength of N and O-related intermediates on Fe for boosting the NO3 -RR. The above findings offer a high-entropy platform to regulate the bandgap and enhance the electrocatalytic performance of spinel oxides.

Ring‐opening metathesis polymerization for synthesizing molecular bottlebrushes via the grafting‐through strategy

AbstractMolecular bottlebrush (MBB) has been considered as an important type of unimolecular nanomaterial for widespread applications ranging from energy to biomedicine, due to its typical one‐dimensional molecular conformation with tunable aspect ratio and chemical composition. In the recently decades, the ring‐opening metathesis polymerization (ROMP) combined with the grafting‐through strategy has emerged as a powerful tool for synthesizing MBBs with various architecture, including (multi)block MBBs, core‐shell MBBs, random MBBs and Janus MBBs et al. In this review, the recent advances on the synthesis of MBBs including the rational preparation of NB terminated macromonomers (MMs) and the grafting‐through ROMP are briefly summarized. Moreover, the emerging progress on the grafting‐through ROMP performed in the aqueous media is also highlighted.

Three-dimensional hierarchical nanosheets based spherical bismuth metal-organic frameworks: Controllable synthesis and high performance for supercapacitor

Metal-organic frameworks (MOFs) are considered as promising electrode materials in energy storage applications because of tunable chemical composition, large internal pore volume and high specific surface area. In this work, Bi-MOF materials with different molar ratios of Bi3+/benzene-1,3,5-tricarboxylic acid (H3BTC) are successfully prepared by solvothermal method. When the molar ratio of Bi3+/H3BTC is adjusted to 2:1, three-dimensional hierarchical Bi-MOF microspheres composed of many interconnected thin nanosheets are perfectly obtained. As-prepared Bi-MOF displays favorable specific surface area (69.5 m2 g−1) and pore size distribution (mean pore size of 6.43 nm), which provides abundant reactive electroactive centers, thereby exhibiting outstanding electrochemical performance. As-prepared Bi-MOF based electrode demonstrates a specific capacity of up to 896.1 C g−1 at 0.5 A g−1, and still possesses a capacity retention rate of 80.2 % from 0.5 A g−1 to 5.0 A g−1. At the same time, at 2.0 A g−1, it has a retention rate of 71.2 % even after 2000 cycles. The assembled BM-2//activated carbon device exhibits high energy density of 33.7 Wh kg−1 at power density of 1699.2 W kg−1. In addition, the device has capacity retention of 79.5 % after 1000 cycle at 5 A g−1. The results fully prove that as-prepared Bi-MOF based electrode possesses satisfactory electrochemical behavior, which provides a valuable reference for research and application of Bi-based materials in the field of supercapacitors.

A comprehensive transformer-based approach for high-accuracy gas adsorption predictions in metal-organic frameworks

Gas separation is crucial for industrial production and environmental protection, with metal-organic frameworks (MOFs) offering a promising solution due to their tunable structural properties and chemical compositions. Traditional simulation approaches, such as molecular dynamics, are complex and computationally demanding. Although feature engineering-based machine learning methods perform better, they are susceptible to overfitting because of limited labeled data. Furthermore, these methods are typically designed for single tasks, such as predicting gas adsorption capacity under specific conditions, which restricts the utilization of comprehensive datasets including all adsorption capacities. To address these challenges, we propose Uni-MOF, an innovative framework for large-scale, three-dimensional MOF representation learning, designed for multi-purpose gas prediction. Specifically, Uni-MOF serves as a versatile gas adsorption estimator for MOF materials, employing pure three-dimensional representations learned from over 631,000 collected MOF and COF structures. Our experimental results show that Uni-MOF can automatically extract structural representations and predict adsorption capacities under various operating conditions using a single model. For simulated data, Uni-MOF exhibits remarkably high predictive accuracy across all datasets. Additionally, the values predicted by Uni-MOF correspond with the outcomes of adsorption experiments. Furthermore, Uni-MOF demonstrates considerable potential for broad applicability in predicting a wide array of other properties.

Cation-π interactions enabled water-stable perovskite X-ray flat mini-panel imager

Sensitive and stable perovskite X-ray detectors are attractive in low-dosage medical examinations. The high sensitivity, tunable chemical compositions, electronic dimensions, and low-cost raw materials make perovskites promising next-generation semiconductors. However, their ionic nature brings serious concerns about their chemical and water stability, limiting their applications in well-established technologies like crystal polishing, micro-processing, photolithography, etc. Herein we report a one-dimensional tryptamine lead iodide perovskite, which is stable in water for several months as the strong cation-π interactions between organic cations. The one-dimensional and two-dimensional tryptamine lead iodide perovskite tablets are switchable through thermal-annealing or water-soaking treatments to relax microstrains. The water-stable and microstrain-free one-dimensional perovskite tablets yield a large sensitivity of 2.5 × 106 μC Gyair−1 cm−2 with the lowest detectable dose rate of 5 nGyair s−1. Microelectrode arrays are realized by surface photolithography to construct high-performance X-ray flat mini-panels with good X-ray imaging capability, and a record spatial resolution of 17.2 lp mm−1 is demonstrated.

Layered double hydroxide-based electrode materials derived from metal-organic frameworks: synthesis and applications in supercapacitors.

Metal-organic frameworks (MOFs) have emerged as promising electrode materials for supercapacitors (SCs) due to their highly porous structures, tunable chemical compositions, and diverse morphologies. However, their applications are hindered by low conductivity and poor cycling performance. A novel approach for resolving this issue involves the growth of layered double hydroxides (LDHs) using MOFs as efficient templates or precursors for electrode material preparation. This method effectively enhances the stability, electrical conductivity, and mass transport ability of MOFs. The MOF-derived LDH exhibits a well-defined porous micro-/nano-structure, facilitating the dispersion of active sites and preventing the aggregation of LDHs. Firstly, this paper introduces synthesis strategies for converting MOFs into LDHs. Subsequently, recent research progress in MOF-derived LDHs encompassing pristine LDH powders, LDH composites, and LDH-based arrays, along with their applications in SCs, is overviewed. Finally, the challenges associated with MOF-derived LDH electrode materials and potential solutions are discussed.

(Invited) Layered Double Hydroxides with Enhanced Interlayer Space for Electrochemical Energy Storage and Deionization

Layered double hydroxides (LDHs) have been extensively studied as promising functional nanomaterials owing to their excellent electrochemical activity and tunable chemical composition. In this work, we presented a series of investigations on enhanced interlayer space of LDHs for electrochemical energy and deionization.Firstly, using acetate anions (Ac-) as an intercalating element, NiCo-LDH nanosheets arraying on Ni Foam with different amounts of Ac- anions intercalation or volumes of hydrothermal solution were prepared by a simple hydrothermal method. The optimized amount of Ac- anions expanded the interlayer space of LDH nanosheets from 0.8 to 0.94 nm. An ultrahigh specific capacity of 1200 C g-1 at 1 A g-1 (690 C g-1 without Ac- anions), outstanding rate capability of 72.5% at 30 A g-1 and cycle stability of 79.90% after 4500 cycles, which were mainly attributed to the higher interlayer spacing of Ac- anions intercalation.Moreover, CoAl-LDH nanosheets intercalated by sodium dodecyl sulfate (SDS) with an enhanced interlayer spacing from 0.76 to 1.33 nm are synthesized and used as an anode of electrosorption. The enlarged interlayer spacing provides an enhanced ion diffusion channel and improves the utilization of the interlayer electroactive sites, while heat treatment transferring LDHs to layered metal oxides offers additional active oxidation reaction sites to facilitate the electro-sorption rate, contributing to the high salt adsorption capacity (31.78 mg g-1) and average salt adsorption rate (3.75 mg g-1 min-1) at 1.2 V in 500 mg L-1 NaCl solution. In addition, the excellent long-term cycling stability (92.9%) after 40 cycles proves the strong electronic interaction between SDS and the host layer, which is validated by density functional theory calculations later on.In addition, ionic surfactants like SDS and cetyl trimethyl ammonium bromide (CTAB) can be used to modify the morphology of LDH. The original LDH shows microspheres formed by nanorods, and LDH-CTAB is similar, yet more tangled, while LDH-SDS is like micro flowers consisting of interwoven nanosheets. LDH-SDS achieved better electrochemical performance (1003.6 C g-1 at 1 A g-1 and 73.84% after 3500 cycles) than LDHs-CTAB (430.54 C g-1, 57.3%), and both higher than the original LDH (278.5 C g-1, 54.3%), while the electrocatalytic performance like Tafel slope follows an opposite trend owing to the difficulty of bubbles detachment from the nanosheets or nanorods, clearly showing the importance of morphology regulation in the synthesis of nanomaterials.

Recent Progress on Perovskite-Based Electrocatalysts for Efficient CO2 Reduction.

An efficient carbon dioxide reduction reaction (CO2RR), which reduces CO2 to low-carbon fuels and high-value chemicals, is a promising approach for realizing the goal of carbon neutrality, for which effective but low-cost catalysts are critically important. Recently, many inorganic perovskite-based materials with tunable chemical compositions have been applied in the electrochemical CO2RR, which exhibited advanced catalytic performance. Therefore, a timely review of this progress, which has not been reported to date, is imperative. Herein, the physicochemical characteristics, fabrication methods and applications of inorganic perovskites and their derivatives in electrochemical CO2RR are systematically reviewed, with emphasis on the structural evolution and product selectivity of these electrocatalysts. What is more, the current challenges and future directions of perovskite-based materials regarding efficient CO2RR are proposed, to shed light on the further development of this prospective research area.

Dimensionality Engineering of Organic-Inorganic Halide Perovskites for Next-Generation X-Ray Detector.

The next-generation X-ray detectors require novel semiconductors with low material/fabrication cost, excellent X-ray response characteristics, and robust operational stability. The family of organic-inorganic hybrid perovskites (OIHPs) materials comprises a range of crystal configuration (i.e., films, wafers, and single crystals) with tunable chemical composition, structures, and electronic properties, which can perfectly meet the multiple-stringent requirements of high-energy radiation detection, making them emerging as the cutting-edge candidate for next-generation X-ray detectors. From the perspective of molecular dimensionality, the physicochemical and optoelectronic characteristics of OIHPs exhibit dimensionality-dependent behavior, and thus the structural dimensionality is recognized as the key factor that determines the device performance of OIHPs-based X-ray detectors. Nevertheless, the correlation between dimensionality of OIHPs and performance of their X-ray detectors is still short of theoretical guidance, which become a bottleneck that impedes the development of efficient X-ray detectors. In the review, the advanced studies on the dimensionality engineering of OIHPs are critically assessed in X-ray detection application, discussing the current understanding on the "dimensionality-property" relationship of OIHPs and the state-of-the-art progresses on the dimensionality-engineered OIHPs-based X-ray detector, and highlight the open challenges and future outlook of this field.

Enthalpy-driven synthesis of magnetic high entropy oxide catalyst for efficient oxidative desulfurization and high-value product recovery

High entropy metal oxides (HEOs) have shown remarkable catalytic potential owing to their multifaceted and tunable chemical composition, coupled with their exceptional thermodynamic stability. Specifically, magnetic HEOs demonstrate enhanced effectiveness in terms of catalyst separation and recovery owing to their magnetic properties. Nevertheless, current synthesis methods for magnetic HEOs often involve high-temperature conditions (typically > 1100 °C) to maximize the contribution of mixing entropy (ΔSmix) in the Gibbs equation (ΔGmix = ΔHmix - TΔSmix). Herein, unlike previous approaches, a reduction in the mixing enthalpy (ΔHmix) is proposed to result in a negative Gibbs free energy for the crystallization of HEOs. Based on this principle, a magnetic high entropy oxide, CoCrFeMnMoOx (MHEO), is successfully synthesized, at a relatively low temperature (900 °C). Notably, the MHEO catalyst demonstrated outstanding catalytic activity in the oxidative desulfurization (ODS) system utilizing O2 as the oxidant, achieving a rapid and complete sulfur removal of 100% within 3 h. Moreover, it demonstrates remarkable cycling durability, allowing for continuous operation over 20 cycles without significant loss in ODS efficiency. Furthermore, the magnetic properties of the MHEO catalyst facilitated the efficient separation and recovery of both the catalyst and high-value products. These findings offer significant insights into the design of high entropy catalysts and contribute to the advancement of sustainable green development.