查看更多>>摘要：Biomass,derived from plant photosynthesis that captures carbon dioxide to form carbohydrates,offers vast renewable reserves.The electrooxidation of biomass,coupled with the hydrogen evolution reaction,enables the simultaneous production of biomass-based plastic monomers and green hydrogen,attracting significant scholarly interest.However,ambiguity remains regarding the adsorption mechanism at the catalyst surface(Langmuir-Hinshelwood or Eley-Rideal)and the adsorbed substrate groups.To address this,we prepared a Ni/Co electrode for the electrooxidation of 5-hydroxymethylfurfural(HMF)into 2,5-furandicarboxylic acid(FDCA)through a corrosion reaction and electro-reduction pathway.HMF con-version reached 100.00％,FDCA yield reached 96.82％,and Faradic efficiency(FE)reached 92.14％.Meaningfully,utilizing in-situ spectroscopy and electrochemical methods,this work provided valuable insights into active sites and catalyst surface adsorption.
查看更多>>摘要：The implementation of pristine covalent organic polymer(COP)with well-defined structure as air elec-trode may spark fresh vitality to rechargeable zinc-air flow batteries(ZAFBs),but it still remains chal-lenges in synergistically regulating their electronic states and structural porosity for the great device performance.Here,we conquer these issues by exploiting N and S co-doped graphene with COP rich in metal-ligand nitrogen to synergistically construct an effective catalyst for oxygen reduction reaction(ORR).Among them,the N and S co-doped sites with high electronegativity properties alter the number of electron occupations in the d orbital of the iron centre and form electron-transfer bridges,thereby boosting the selectivity of the ORR-catalysed four-electron pathway.Meanwhile,the introduction of COP materials aids the formation of pore interstices in the graphene lamellae,which both adequately expose the active sites and facilitate the transport of reactive substances.Benefiting from the synergistic effect,as-prepared catalyst exhibits excellent half-wave potentials(E1/2=912 mV)and stability(merely 8.8％drop after a long-term durability test of 50000 s).Further,ZAFBs assembled with the N/SG@COP cat-alyst demonstrate exceptional power density(163.8 mW cm-2)and continuous charge and discharge for approximately 140 h at 10 mA cm-2,outperforming the noble-metal benchmarks.
查看更多>>摘要：Selective cleavage of Csp2—OCH3 bond in lignin without breaking other types of C—O bonds followed by N-functionalization is fascinating for on-purpose valorization of biomass.Here,a Co/Ni-based dual-atom catalyst CoNiDA@NC prepared by in-situ evaporation and acid-etching of metal species from tailor-made metal-organic frameworks was efficient for reductive upgrading of various lignin-derived phenols to cyclohexanols(88.5％-99.9％yields),which had ca.4 times higher reaction rate than the single-atom cat-alyst and was superior to state-of-the-art heterogeneous catalysts.The synergistic catalysis of Co/Ni dual atoms facilitated both hydrogen dissociation and hydrogenolysis steps,and could optimize adsorption configuration of lignin-derived methoxylated phenols to further favor the Csp2-OCH3 cleavage,as elabo-rated by theoretical calculations.Notably,the CoNiDA@NC catalyst was highly recyclable,and exhibited excellent demethoxylation performance(77.1％yield)in real lignin monomer mixtures.Via in-situ cas-cade conversion processes assisted by dual-atom catalysis,various high-value N-containing chemicals,including caprolactams and cyclohexylamines,could be produced from lignin.
查看更多>>摘要：Solid state lithium metal batteries(SSLMBs)are considered to be one of the most promising battery sys-tems for achieving high energy density and excellent safety for energy storage in the future.However,current existed solid-state electrolytes(SSEs)are still difficult to meet the practical application require-ments of SSLMBs.In this review,based on the analysis of main problems and challenges faced by the development of SSEs,the ingenious application and latest progresses including specific suggestions of various polymer fibers and their membrane products in solving these issues are emphatically reviewed.Firstly,the inherent defects of inorganic and organic electrolytes are pointed out.Then,the application strategies of polymer fibers/fiber membranes in strengthening strength,reducing thickness,enhancing thermal stability,increasing the film formability,improving ion conductivity and optimizing interface stability are discussed in detail from two aspects of improving physical structure properties and electro-chemical performances.Finally,the researches and development trends of the intelligent applications of high-performance polymer fibers in SSEs is prospected.This review intends to provide timely and impor-tant guidance for the design and development of polymer fiber composite SSEs for SSLMBs.
查看更多>>摘要：Optimizing the intrinsic activity of non-noble metal by precisely tailoring electronic structure offers an appealing way to construct cost-effective catalysts for selective biomass valorization.Herein,we reported a P-doping bifunctional catalyst(Ni-P/mSiO2)that achieved 96.6％yield for the hydrogenation rearrange-ment of furfural to cyclopentanone at mild conditions(1 MPa H2,150 ℃).The turnover frequency of Ni-P/mSiO2 was 411.9 h-1,which was 3.2-fold than that of Ni/mSiO2(127.2 h-1).Detailed characterizations and differential charge density calculations revealed that the electron-deficient Niδ+species were gener-ated by the electron transfer from Ni to P,which promoted the ring rearrangement reaction.Density func-tional theory calculations illustrated that the presence of P atoms endowed furfural tilted adsorb on the Ni surface by the C=O group and facilitated the desorption of cyclopentanone.This work unraveled the connection between the localized electronic structures and the catalytic properties,so as to provide a promising reference for designing advanced catalysts for biomass valorization.
查看更多>>摘要：Ni-Fe-based catalysts are considered to be among the most active catalysts for the oxygen evolution reac-tion(OER)under alkaline conditions,with Fe playing a crucial role.However,Fe leaching occurs during the reaction due to thermodynamic instability,which has resulted in conflicting reports within the liter-ature regarding its role.To clarify this point,we propose a strategy consisting of modulating the elec-tronic orbital occupancy to suppress the extensive loss of Fe atoms during the OER process.Theoretical calculations,in-situ X-ray photoelectron spectroscopy,molecular dynamics simulations,and a series of characterization showed that the stable presence of Fe not only accelerates the electron transfer process but also optimizes the reaction barriers of the oxygen evolution intermediates,promoting the phase tran-sition of Fe5Ni4S8 to highly active catalytic species.The modulated Fe5Ni4S8-based pre-catalysts exhibit improved OER activity and long-term durability.This study provides a novel perspective for understand-ing the role of Fe in the OER process.
查看更多>>摘要：Hydrogel electrolytes hold great potential in flexible zinc ion supercapacitors(ZICs)due to their high con-ductivity,good safety,and flexibility.However,freezing of electrolytes at low temperature(subzero)leads to drastic reduction in ionic conductivity and mechanical properties that deteriorates the perfor-mance of flexible ZICs.Besides,the mechanical fracture during arbitrary deformations significantly prunes out the lifespan of the flexible device.Herein,a Zn2+and Li+co-doped,polypyrrole-dopamine dec-orated Sb2S3 incorporated,and polyvinyl alcohol/poly(N-(2-hydroxyethyl)acrylamide)double-network hydrogel electrolyte is constructed with favorable mechanical reliability,anti-freezing,and self-healing ability.In addition,it delivers ultra-high ionic conductivity of 8.6 and 3.7 S m-1 at 20 and-30 ℃,respec-tively,and displays excellent mechanical properties to withstand tensile stress of 1.85 MPa with tensile elongation of 760％,together with fracture energy of 5.14 MJ m-3.Notably,the fractured hydrogel elec-trolyte can recover itself after only 90 s of infrared illumination,while regaining 83％of its tensile strain and almost 100％of its ionic conductivity during-30-60 ℃.Moreover,ZICs coupled with this hydrogel electrolyte not only show a wide voltage window(up to 2 V),but also provide high energy density of 230 Wh kg-1 at power density of 500 W kg-1 with a capacity retention of 86.7％after 20,000 cycles under 20 ℃.Furthermore,the ZICs are able to retain excellent capacity even under various mechanical defor-mation at-30 ℃.This contribution will open up new insights into design of advanced wearable flexible electronics with environmental adaptability and long-life span.
查看更多>>摘要：Early warning of thermal runaway(TR)of lithium-ion batteries(LIBs)is a significant challenge in current application scenarios.Timely and effective TR early warning technology is urgently required considering the current fire safety situation of LIBs.In this work,we report an early warning method of TR with online electrochemical impedance spectroscopy(EIS)monitoring,which overcomes the shortcomings of warn-ing methods based on traditional signals such as temperature,gas,and pressure with obvious delay and high cost.With in-situ data acquisition through accelerating rate calorimeter(ARC)-EIS test,the crucial features of TR were extracted using the RReliefF algorithm.TR mechanisms corresponding to the features at specific frequencies were analyzed.Finally,a three-level warning strategy for single battery,series module,and parallel module was formulated,which can successfully send out an early warning signal ahead of the self-heating temperature of battery under thermal abuse condition.The technology can pro-vide a reliable basis for the timely intervention of battery thermal management and fire protection sys-tems and is expected to be applied to electric vehicles and energy storage devices to realize early warning and improve battery safety.
查看更多>>摘要：Lead halide perovskite nanocrystals(PNCs)have received great research interests due to their excellent optoelectronic properties.However,high temperature,inert gas protection and insulating long-chain ligands are used during the conventional hot-injection synthesis of PNCs,which limits their practical applications.In this work,we first develop a simple and scalable polar-solvent-free method for the prepa-ration of full-component APbX3(A=Cs,methylammonium(MA),formamidinium(FA),X=Cl,Br,I)PNCs under ambient condition.Through an exothermic reaction between butylamine(BA)and propionic acid(PA)short ligands,the PbX2 precursors could be well dissolved without use of any polar solvent.Meanwhile,the relatively lower growth rate of PNCs in our room-temperature reaction enables us to modulate the synthetic procedure to enhance the scalability(40-fold)and achieve large-scale synthesis.The resultant short ligands passivated PNC inks are compatible with varying solution depositing tech-nique like spray coating for large-area film.Finally,we showcase that adopting the as-prepared MAPbI3 PNC inks,a self-powered photodetector is fabricated and shows a high photoresponsivity.These results demonstrate that our ambient-condition synthetic approach can accelerate the preparation of tunable and ready-to-use PNCs towards commercial optoelectronic applications.
查看更多>>摘要：Spinel cobalt oxide(Co3O4),consisting of tetrahedral Co2+(CoTd)and octahedral Co3+(CoOh),is considered as promising earth-abundant electrocatalyst for chlorine evolution reaction(CER).Identifying the cat-alytic contribution of geometric Co site in the electrocatalytic CER plays a pivotal role to precisely mod-ulate electronic configuration of active Co sites to boost CER.Herein,combining density functional theory calculations and experiment results assisted with operando analysis,we found that the CoOh site acts as the main active site for CER in spinel Co3O4,which shows better Cl-adsorption and more moderate inter-mediate adsorption toward CER than CoTd site,and does not undergo redox transition under CER condi-tion at applied potentials.Guided by above findings,the oxygen vacancies were further introduced into the Co3O4 to precisely manipulate the electronic configuration of Cooh to boost Cl-adsorption and opti-mize the reaction path of CER and thus to enhance the intrinsic CER activity significantly.Our work fig-ures out the importance of geometric configuration dependent CER activity,shedding light on the rational design of advanced electrocatalysts from geometric configuration optimization at the atomic level.
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