查看更多>>摘要：Coal mining and washing is accompanied by the production of large amounts of coal gangue,which exerts a notable influence on the natural environment.However,as a form of solid waste,coal gangue exhibits a wide range of potential applications in the field of recycling.Nowadays,'the utilization rate and quality of coal gangue are inadequate,and the disposal capacity and scale of coal gangue obviously cannot meet the current global low-carbon environmental protection requirements.The paper presents an overview of the present state of coal gangue production and utilization,and investigates the environmental impact caused by the practice of stacking coal gangue.We emphasize the current research status of gangue in various high-value application fields,including environmental materials,agricultural production,construction materials,recovery and extraction of valuable elements,and energy generation.It highlights the significance of pre-treatment methods like activation,modification,and innocuousness for the comprehensive utilization of gangue.Additionally,we briefly introduce and discusses the future directions of research and development in this area.Nevertheless,with regard to the environmental impact of secondary contamination and the efficiency of gangue utilization,there remain numerous obstacles and unresolved matters that merit further investigation.It is believed that this review can offer valuable insights into the utilization of gangue development methods,and expedite the successful imple-mentation and practical application of large-scale treatment and disposal of solid waste.
查看更多>>摘要：Metal-organic frameworks(MOFs)are a large class of crystalline porous materials that composed of organic li-gands and metal ions,of which zeolitic imidazolate frameworks(ZIFs)are a broad classification.The most well-known ZIF-like material is ZIF-8 crystals,which have been the subject of extensive research for decades.ZIF-8 crystals have been synthesized under various conditions for application in the fields of sensing,drug delivery,and catalysis.This paper provides a brief introduction to the preparation methods,formation processes,and formation mechanisms of ZIF-8 crystals in different media,and then explains the effects of different precursor conditions(type of Zn2+,ratio of raw materials,and type of solvent)on ZIF-8 crystals in terms of formation mechanisms.Subsequently,current reports on the application of ZIF-8-based chemiresistive gas sensors,elec-trochemical,fluorescent and colorimetric sensors are also summarized.Hopefully,ZIF-8 crystals with good cat-alytic properties will be obtained based on rational design for promoting the application in different fields of the sensors.
查看更多>>摘要：Clay minerals represent a class of hydrated phyllosilicates making up the fine-grained portions of rocks,sedi-ments,and soils.Due to the advantages of abundant reserves,low prices,and wide applications,the development and utilization of clay minerals have received increasing attention in recent years.Isomorphic replacement is a common phenomenon in clay minerals,which is one of the main causes of changes in mineral chemical composition and physical and chemical properties.This article briefly describes the crystal structure of several clay minerals such as montmorillonite,vermiculite,palygorskite,kaolinite,and halloysite.It summarized the research status of the effect of isomorphic replacement on their structure and application performance.The research results can provide theoretical basis for the structural research and efficient resource utilization of clay minerals.
查看更多>>摘要：Sodium-ion batteries(SIBs)are considered potential successors to lithium-ion batteries in the fields of energy storage and low-speed vehicles,thanks to their advantages such as abundant raw material sources,high energy density,and a wide operational temperature range.However,several scientific and engineering challenges still require attention in the development of sodium-ion batteries.Electrolyte salts,as a key component of sodium-ion battery electrolytes,play a critical role in battery performance.This paper provides a brief overview of the research progress on different electrolyte salt systems in sodium-ion batteries.It discusses characteristics such as ionic conductivity,electrochemical windows,electrochemical performance,and thermal safety in various solvent systems.Furthermore,the paper summarizes a series of strategies for controlling electrolyte and electrode in-terfaces,offering references for addressing the challenges in the mass production and application of sodium-ion batteries.
查看更多>>摘要：Layered LiNixCoyMnzO2(NCM)cathode materials have emerged as the best choice for high-energy-density lithium-ion batteries for powering electric vehicles.Despite significant research efforts,the understanding of complex structural dynamics during lithium(de-)intercalation still remains a subject of debate,especially in sce-narios where morphology and composition vary.In this study,we carried out in situ high-energy synchrotron X-ray diffraction experiments on commercial NCM523 cathode materials in both single crystal and polycrystalline forms to probe the structural changes during charging and discharging in detail.Our findings reveal that both single crystal and polycrystalline materials exhibit typical H1-H2-H3 phase transitions.However,in polycrystalline NCM532,a monoclinic intermediate phase emerges between the H1 and H2 phases.During this process,symmetry reduces from R-3m to C2/m,which is attributed to a shear distortion along the ab plane.In contrast,for single crystal materials,the H1 phase directly transforms into the H2 phase without the monoclinic phase.The observed monoclinic distortion signif-icantly impacts structural stability and material cycling performance.This study provides new insight into the structural dynamics in NCM532 cathode materials,particularly concerning morphology-dependent behaviors,which could deepen our understanding of the relationship between NCM material structures and their performance.
查看更多>>摘要：As a H2O2 electrochemical biomimetic enzyme sensor,the stability,repeatability and sensitivity of hemin-based composites are closely connected with the loading of hemin on high-performance matrix.Herein,polypyrrole/paper-derived carbon(PPy/PC)nanocomposite was used for the construction of a hemin-based non-enzymatic sensor to detect H2O2.Where the poplar wood is used to obtain crude cellulose through a straightforward paper-making process.This crude cellulose is then subjected to pyrolysis to yield the desired paper-based carbon ma-terial.The hemin-decorated PPy/PC was demonstrated possessing remarkable electrocatalytic activity for H2O2 reduction,and the possible mechanism of the reactions was discussed.The electrochemical sensor,utilizing the H-PPy/PC composite,achieved a low detection limit of 30 nM,along with enhanced selectivity and stability under optimized conditions.The favorable results observed can primarily be attributed to the superior electrochemical performance of PPy/PC,as well as its unique 3D interconnected structure.This structure effectively impedes the self-dimerization of hemin,thereby ensuring the generation of active catalytic species.
查看更多>>摘要：With the growing problem of water pollution caused by antibiotics,the development of photocatalysts with high photogenerated carrier separation efficiency is crucial.A high-efficiency microsphere Fe/BiOCl/BiVO4 with S-scheme heterojunction was synthesized by solvothermal method and its ciprofloxacin(CIP)degradation perfor-mance were investigated under visible light.XRD,FT-IR,SEM,EDS,HRTEM and XPS results show that the photocatalytic have good crystallization,morphology and the formed a microsphere.The photocatalytic perfor-mance of Fe/BiOCl/BiVO4 for CIP was superior to pure BiOCl and BiVO4 due to the microsphere and formed heterostructure between BiOCl and BiVO4.The influencing factors of CIP degradation by Fe/BiOCl/BiVO4 were investigated,and the results showed that Fe/BiOCl/BiVO4 had high degradation efficiency not only at pH 5-9,but also in the presence of inorganic Cl-,NO3-and metal ions.Under the optimal conditions,the degradation rate of CIP was up to 100%in 75 min.In addition to CIP,the Fe/BiOCl/BiVO4 photocatalysts degraded other organic pollutants,such as tetracycline,oxytetracycline,chlortetracycline,ofloxacin,levofloxacin,and rhodamine B,by more than 92%.The main active species were photogenerated holes(h+)and superoxide radicals(·O2-).In addition,possible intermediates and toxicity of intermediates were analyzed and five potential pathways for CIP degradation were proposed.
查看更多>>摘要：Hydrogen is now being used as a renewable clean energy carrier.One of the main issues with the application of hydrogen energy is a shortage of security and efficient hydrogen storage technology.TiMn-based alloys are considered promising hydrogen storage materials,but their comprehensive hydrogen storage properties and cyclic stable performance limit their further practical application.The hydrogen storage properties of alloys can be enhanced by substituting transition metal elements.Therefore,the comprehensive hydrogen storage perfor-mance of the Ti0.9Zr0.1Mn0.95Cr0.7V0.2M0.15(M=Fe,Co,Ni,Cu,Mo)alloys was systematically investigated ac-cording to the Mn element on the B side is partially replaced by variety of transition metal elements.The M=Ni alloy,which showed the highest hydrogen storage capacity among the group of alloys,was used to explore cycle stability.The plateau pressures of the series alloys decreased in order,Fe>Co>Ni>Cu>Mo.Aspects of hydrogen absorption kinetics,all of the alloys can reach full hydrogen absorption saturation within 400 s at 303 K.The Ti0.9Zr0.1Mn0.95Cr0.7V0.2Mo0.15 alloy possessed the fastest hydrogen absorption kinetic rate(t0.9=65 s)and the smallest hysteresis factor.This suggests that the substitution of Mo elements is effective in improving the hysteresis of the Laves phase alloys.Among the series of alloys,the M=Ni alloy exhibited the best overall hydrogen storage performance,which hydrogen storage capacity can reach 1.81 wt%and 97%of its capacity is kept after 100 cycles.
查看更多>>摘要：Due to the problems of low welding efficiency,large heat-affected zone,and poor welding quality in the process of welding thin-walled titanium tubes by argon arc welding,there are few studies on the use of high-frequency induction welding(HFIW)of thin-walled titanium alloy tubes.The evolution law of weld microstructure and mechanical properties of the thin-walled titanium tube needs to be further studied because of rapid welding speed and the small heat-affected zone of HFIW.Therefore,a novel manufacturing method via high-frequency induction welding is proposed in this paper to solve the existing problems.With an industrial-grade titanium TA2 tube(wall's thickness is 0.5 mm)as the research object,a comparative study is conducted in this research to examine the morphology,microstructure,microhardness,and tensile characteristics of welded joints at different welding power.The findings demonstrated a significant efficacy of HFIW in resolving these challenges.The mechanical properties and microstructue of heat-affected zone(HAZ)were characterized.The lowest hardness is measured at 202 HV,while the base material was recorded as 184 HV,when the welding speed of HFIW is set at 50 m/min.Meanwhile,the heat-affected zone has the highest hardness at 224 HV,a tensile strength of 446.8 MPa and a post-fracture elongation of 16%.The results showed that HFIW can not only greatly improve the welding efficiency,significantly improve the microstructure of weld joint and HAZ,and improve the mechanical properties of thin-walled titanium pipe,but also provide a highly feasible welding method for welding ultra-thin-walled pipes.
查看更多>>摘要：The conversion of chalcogen atoms into other types of chalcogen atoms in transition metal dichalcogenides ex-hibits significant advantages in tuning the bandgaps and constructing lateral heterojunctions.However,despite atomic defects at the atomic scale were inevitably formed during conversion process,the construction of dislo-cations remains difficult.Here,we conducted in-situ sulfurization to achieve structural transformation from monolayer WSe2 to WS2 successfully.We probe these transformations at atomic scale using high-angle annular dark field scanning transmission electron microscopy(HAADF-STEM)and study structural defects of sulfurized-WS2 by strain and displacement fields.We discovered that high-quality WSe2 flakes were completely sulfurized while dislocations were successfully constructed,manifesting atomic surface roughness and structural disorders.Our work provides insights into designing and optimizing customized Transition metal dichalcogenides(TMDs)materials in controlled synthesis and defect engineering.
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