Multiscale confinement nitridation in molybdenum carbide for efficient hydrogen production

The molybdenum carbide(Mo_(2)C)has been regarded as one of the most cost-efficient and stable electrocatalyst for the hydrogen evolution reaction(HER)by the virtue of its Pt-like electronic structures.However,the inherent limitation of high density of empty valence band significantly reduces its catalytic reactivity by reason of strong hydrogen desorption resistance.Herein,we propose a multiscale confinement synthesis method to design the nitrogen-rich Mo_(2)C for modulating the band structure via decomposing the pre-coordination bonded polymer in a pressure-tight tube sealing system.Pre-bonded c/N-Mo in the coordination precursor constructs a micro-confinement space,enabling the homogeneous nitrogenization in-situ happened during the formation of Mo_(2)C.Simultaneously,the evolved gases from the precursor decomposition in tube sealing system establish a macro-confinement environment,preventing the lattice N escape and further endowing a continuous nitridation.Combining the multiscale confinement effects,the nitrogen-rich Mo2C displays as high as 25%N-Mo concentration in carbide lattice,leading to a satisfactory band structure.Accordingly,the constructed nitrogen-rich Mo_(2)C reveals an adorable catalytic activity for HER in both alkaline and acid solution.It is anticipated that the multiscale confinement synthesis strategy presents guideline for the rational design of electrocatalysts and beyond.

DNA damage response-related immune activation signature predicts the response to immune checkpoint inhibitors: from gastrointestinal cancer analysis to pan-cancer validation

Objective: DNA damage response(DDR) deficiency has emerged as a prominent determinant of tumor immunogenicity. This study aimed to construct a DDR-related immune activation(DRIA) signature and evaluate the predictive accuracy of the DRIA signature for response to immune checkpoint inhibitor(ICI) therapy in gastrointestinal(GI) cancer.Methods: A DRIA signature was established based on two previously reported DNA damage immune response assays. Clinical and gene expression data from two published GI cancer cohorts were used to assess and validate the association between the DRIA score and response to ICI therapy. The predictive accuracy of the DRIA score was validated based on one ICI-treated melanoma and three pan-cancer published cohorts.Results: The DRIA signature includes three genes(CXCL10, IDO1, and IFI44L). In the discovery cancer cohort, DRIA-high patients with gastric cancer achieved a higher response rate to ICI therapy than DRIA-low patients(81.8% vs. 8.8%;P < 0.001), and the predictive accuracy of the DRIA score [area under the receiver operating characteristic curve(AUC) = 0.845] was superior to the predictive accuracy of PD-L1 expression, tumor mutational burden, microsatellite instability, and Epstein–Barr virus status. The validation cohort demonstrated that the DRIA score identified responders with microsatellite-stable colorectal and pancreatic adenocarcinoma who received dual PD-1 and CTLA-4 blockade with radiation therapy. Furthermore, the predictive performance of the DRIA score was shown to be robust through an extended validation in melanoma, urothelial cancer, and pan-cancer.Conclusions: The DRIA signature has superior and robust predictive accuracy for the efficacy of ICI therapy in GI cancer and pancancer, indicating that the DRIA signature may serve as a powerful biomarker for guiding ICI therapy decisions.

Stabilization of cathode electrolyte interphase for aqueous zinc-ion batteries

Aqueous zinc-ion battery systems are attractive for next-generation energy storage devices,however,the unstable electrode electrolyte interphase,especially cathode electrolyte interphase(CEI),has induced rapid capacity attenuation,insufficient cycle life,and severe safety issues.Evolving the researching of CEI formation,composition,dynamic structure,and reaction mechanisms would help in understanding the fundamental electrochemistry at CEI such as electron and ion transport processes,further strengthening the specific capacity,rate,and cycle performance of the cathode materials.In this review,we summarized the latest progress in understanding interfacial reaction mechanisms and ion dynamic behavior,emphasizing the impact of surface-specific adsorption and solvation behaviors on the interface's ultimate structure and chemical composition.Subsequently,the significant challenges that persist in CEI formation mechanisms,such as cathodic dissolution,by-product formation,electrostatic interactions,constrained electrochemical windows,oxygen evolution reaction,overpotentials,phase transitions,and additional factors,were discussed.These challenges are explored to identify triggers contributing to the depletion of active materials and alterations in the composition or state of the CEI.Ultimately,with a deep comprehension of interfacial behaviors,the review articulates innovative optimization strategies through a detailed categorization of approaches in electrolyte engineering,cathode engineering,and artificial CEI development.Furthermore,future challenges and development directions of CEI are presented.We hope to offer insights for constructing robust CEI films to achieve high performance aqueous zinc-ion batteries.

氢键有机框架材料在电化学能源存储和转换中的研究进展

作为一种新型的多孔材料,氢键有机框架(hydrogen-bonded organic frameworks,HOFs)结构因其丰富的孔道分布、可控的晶体构型以及易于调节的分子组成而表现出诸多优异的电化学特性,如快速的离子传输、特异性的离子筛分、可观的电化学活性面积、高暴露的催化活性位点等.这些特性促使研究者越来越多地关注其在电化学能源存储和转换技术中的应用,是能源领域研究的前沿和热点.尽管这些HOFs相关材料的结构和组成各不相同,总体上却可以分为HOFs和HOFs衍生物两大类.本文详细地介绍了HOFs及其衍生物作为电极材料或电催化剂在电化学领域,包括可充电离子电池、电化学超级电容器、电催化析氢、电催化析氧和氧还原反应中的应用原理与最新研究进展.在此基础上,重点阐述了HOFs相关材料的纳米形貌、晶体结构、孔道结构和分子组成对其电化学性能的影响,总结了克服HOFs相关材料氢键骨架稳定性和导电性差的相关方法,凝练了它们在该领域发展中的优势和挑战.基于上述讨论,希望对HOFs相关材料在电化学能源存储和转换技术中的发展提供新的研究方向.

Supramolecular assembly-derived carbon-nitrogen-based functional materials for photo/electrochemical applications: progress and challenges

Supramolecular chemistry during the synthesis of carbon-nitrogen-based materials has recently experienced a renaissance in the arena of photocatalysis and electrocatalysis.In this review,we start with the discussion of supramolecular assemblies-derived carbon-nitrogen-based materials’regulation from the aspect of morphology,chemical composition,and micro/nanostructural control.Afterwards the recent advances of these materials in energy and environment related applications,including degradation of pollutants,water splitting,oxygen reduction reactions,CO_(2) reduction reactions along with organic synthesis are summarized.The correlations between the structural features and physicochemical properties of the carbonnitrogen-based materials and the specific catalytic activity are discussed in depth.By highlighting the opportunities and challenges of supramolecular assembly strategies,we attempt an outlook on possible future developments for highly efficient carbon-based photo/electrocatalysts.

From borophosphate to fluoroborophosphate:a rational design of fluorine-induced birefringence enhancement

The introduction of oxofluoride anion into anionic group assists to tune optical properties owing to the change of coordination,electronegativity,and according anionic framework.Here,we proposed a rational design of new compounds by fluorine-driven structure and optical property evolution.A new borophosphate Ba_(2)BP_(3)O_(11)with the monoclinic space group P2_(1/c) has been synthesized in the sealed system.Ba_(2)BP_(3)O_(11)exhibits a rare P-O-P bridge formation,which is the first example in alkaline-earth metal borophosphates.By further substituting[BO_(4)]^(3-)with[BO_(3)F]^(4-),the first alkaline-earth metal/lead fluoroborophosphates M_(2)BP_(2)O_(8)F(M=Ba and Pb)with the same space group were designed.Since the scissors effect of fluorine,in M_(2)BP_(2)O_(8)F(M=Ba and Pb),a BO_(3)F tetrahedron corner-sharing with three PO_(4)tetrahedra forms 1D chains along the b-axial direction,which are filled by MO_(n)(M=Ba/Pb,n=5,6,8)distorted polyhedra.The first principles calculation shows that the borophosphate Ba_(2)BP_(3)O_(11)has a birefringence about 0.013@1,064 nm,while the fluoroborophosphates M_(2)BP_(2)O_(8)F(M=Ba and Pb)have the values of 0.035 and 0.043@1,064 nm,respectively.Such an apparent enhancement in birefringence is derived from synergies of the oxyfluoride and cation.The introduction of fluorine-containing heteroanionic groups provides a feasible strategy to design novel promising optical materials.

Modular Synthesis of Tetraurea and Octaurea Macrocycles Encoded with Specific Monomer Sequences

Intermolecular hydrogen bonding among urea units grants prominent mechanical strength to polyurea elastomer materials.However,such interactions can cause significant solubility problems when synthesizing oligourea macrocycles with a large number of urea units,and it remains unknown for macrocycles containing more than six urea units.Here,we demonstrate a two-step,modular strategy for making a new class of tetraurea and octaurea macrocycles using commercially available building blocks.Intramolecular hydrogen bonding within the fundamental o-phenylene bis(urea)unit is the key to overcoming intermolecular hydrogen bonding to form favorable conformations for ring-closure reactions.The size and monomer sequences can be controlled by varying the flexibility of the spacers.Rigid diphenyl methylene and diphenyl ether linkers selectively afford tetraurea macrocycles,whereas the flexible hexylene linker produces octaurea macrocycles.Macrocycles encoded with two different spacers were also made.All these macrocycles are confirmed by X-ray diffraction structural analysis of the complexed forms with sulfate anions.Interestingly,a unique“figure-eight”structure is observed for the complex of MUH octaurea macrocycle with two encapsulated sulfate anions.Our study shows a paradigm of making large oligourea macrocycles with designer properties in a programable manner with tunable monomer sequences.

Anion-Coordination-Driven Assembly of Anionic Hexagonal and Square Architectures and the Structural Interconversion

A biphenyl-bridged bis-tris(urea)ligand L was rationally designed with a favorable angle to construct a hexagon-shaped A_(6)L_(6)(A=anion)complex upon assembly with phosphate anions(PO_(4)^(3−))via anioncoordination-driven assembly(ACDA).Due to the moderate flexibility of L,another well-defined discrete architecture,a square-like A_(4)L_(4) complex,has also been obtained from ligand L and PO_(4)^(3−).Interconversion between these two self-assemblies can be readily realized by solvent regulation.In addition,the two anionic architectures display different binding abilities for selected cationic guest molecules,enabling the uptake of a desired guest from amixture of guests.