Herein,a series of manganese oxide catalysts with different valences(Mn_(3)O_(4),Mn_(2)O_(3),and MnO_(2))were designed and synthesized for the synthesis of ethylene urea(EU)from ethylenediamine(EDA)and carbon dioxide(...Herein,a series of manganese oxide catalysts with different valences(Mn_(3)O_(4),Mn_(2)O_(3),and MnO_(2))were designed and synthesized for the synthesis of ethylene urea(EU)from ethylenediamine(EDA)and carbon dioxide(CO_(2)).With a maximal EDA conversion of 82%and EU selectivity of 99%at 160℃ for 2 h,Mn_(2)O_(3) catalysts had the best catalytic activity among them,which was superior to the reported catalysts.In the following order:Mn_(2)O_(3)>MnO_(2)>Mn_(3)O_(4),the catalytic activity for the synthesis of EU from CO_(2) and EDA decreased.Further characterization showed the Mn_(2)O_(3) catalyst possessed a greater Mn^(3+)/Mn4+ratio and more surface oxygen vacancies than the MnO_(2) and Mn_(3)O_(4),which improved its capacity to adsorb and activate CO_(2) and EDA.After four recycling runs,the EDA conversion slightly declined from 82%to 56%on Mn_(2)O_(3) catalyst,while no obvious change in EU selectivity was observed.The loss of surface Ov contents and Mn^(3+)proportion were concluded as main reasons for the decrease in catalytic activity over Mn_(2)O_(3) catalyst.This work demonstrated a metal oxide catalyst that was efficient in producing EU from CO_(2) and EDA.展开更多
Transformation of urea and glycerol to glycerol carbonate is an environmental friendly and economical process.Catalysts play an indispensable role in the process.Although many catalysts have been developed,the perform...Transformation of urea and glycerol to glycerol carbonate is an environmental friendly and economical process.Catalysts play an indispensable role in the process.Although many catalysts have been developed,the performance of the catalysts still cannot meet the needs of industrialization.In this paper,research progress of the homogeneous and heterogeneous catalysts of the reaction over the past 20 years were reviewed systematically.According to the types and active centers of catalysts,the catalysts were classified systematically and analyzed in detail.The typical reaction mechanisms were also summarized.The research and development direction of catalysts is made more explicit through systematic classification and mechanism analysis.The article reveals more novel catalysts have been designed and used for the reaction,such as mixed metal oxides with special structures,solid wastes and non-metallic materials.This work summarized the current state of research and prospected possible routes for design of novel catalysts.It is hoped that this review can provide some references for developing efficient catalysts.展开更多
The conversion of urea-containing wastewater into clean hydrogen energy has gained increasing attention.However,challenges remain,particularly with sluggish catalytic kinetics and limited long-term stability of urea o...The conversion of urea-containing wastewater into clean hydrogen energy has gained increasing attention.However,challenges remain,particularly with sluggish catalytic kinetics and limited long-term stability of urea oxidation reaction(UOR).Herein,we report the loosely porous CoOOH nano-architecture(CoOOH LPNAs)with hydrophilic surface and abundant oxygen vacancies(Ov)on carbon fiber paper(CFP)by electrochemical reconstruction of the CoP nanoneedles precursor.The resulting three-dimensional electrode exhibited an impressively low potential of 1.38 V at 1000 mA·cm^(−2) and excellent durability for UOR.Furthermore,when tested in an anion exchange membrane(AEM)electrolyzer,it required only 1.53 V at 1000 mA·cm^(−2) for industrial urea-assisted water splitting and operated stably for 100 h without degrada-tion.Experimental and theoretical investigations revealed that rich oxygen vacancies effectively modulate the electronic structure of the CoOOH while creating unique Co3-triangle sites with Co atoms close together.As a result,the adsorption and desorption processes of reactants and intermediates in UOR could be finely tuned,thereby significantly reducing ther-modynamic barriers.Additionally,the superhydrophilic self-supported nanoarray structure facilitated rapid gas bubble release,improving the overall efficiency of the reaction and preventing potential catalyst detachment caused by bubble accumulation,thereby improving both catalytic activity and stability at high current densities.展开更多
Aqueous sodium-ion batteries(ASIBs)have garnered significant attention as promising candidates for large-scale energy storage applications.This interest is primarily due to their abundant resource availability,environ...Aqueous sodium-ion batteries(ASIBs)have garnered significant attention as promising candidates for large-scale energy storage applications.This interest is primarily due to their abundant resource availability,environmental friendliness,cost-effectiveness,and high safety.However,their electrochemical performance is limited by the thermodynamic properties of water molecules,resulting in inadequate cycling stability and insufficient specific energy density.To address these challenges,this study developed a hydrogen-bond enhanced urea-glycerol eutectic electrolyte(UGE)to expand the electrochemical stability window(ESW)of the electrolyte and suppress corresponding side reactions.The eutectic component disrupts the original hydrogen bonding network in water,creating a new,enhanced network that reduces the activity of free water and forms a uniform,dense passivation layer on the anode.As a result,the optimized composition of UGE exhibits a broad ESW of up to 3 V(-1.44 to 1.6 V vs.Ag/AgCl).The Prussian blue(PB)/UGE/NaTi_(2)(PO_(4))_(3)@C full cell exhibits an exceptionally long lifespan of 10,000 cycles at 10 C.This study introduces a low-cost,ultra-long-life ASIB system,utilizing a green and economical eutectic electrolyte,which expands the use of eutectic electrolytes in aqueous batteries and opens a new research horizon for constructing efficient electrochemical energy storage and conversion.展开更多
Background Previous studies have shown a relationship between elevated blood urea nitrogen(BUN)level and poor outcomes in several diseases,but data on the prognostic significance of postoperative BUN in elderly patien...Background Previous studies have shown a relationship between elevated blood urea nitrogen(BUN)level and poor outcomes in several diseases,but data on the prognostic significance of postoperative BUN in elderly patients undergoing valve replacement surgery(VRS)remained sparse.Methods BUN was measured immediately after VRS.A total of 3118 elderly patients were enrolled and divided into four groups according to the quartiles of postoperative BUN:Q1,<5.6 mmol/L;Q2,5.6-6.8 mmol/L;Q3,6.8-8.4 mmol/L and Q4,≥8.4 mmol/L.The associations of postoperative BUN with in-hospital and 1-year mortality were evaluated.Results The incidence of inhospital death(1.0%vs.3.3%vs.3.3%vs.8.4%,P<0.001)and major adverse clinical events(5.1%vs.7.8%vs.9.9%vs.19.1%,P<0.001)was significantly higher in patients with a high BUN level.BUN was independently associated with all-cause in-hospital mortality[odds ratio(OR):1.11,95%confidential interval(CI):1.07-1.16,P<0.001].The receiver operating characteristic(ROC)curve showed that BUN>9 mmol/L had a sensitivity of 48.4%and specificity of 81.8% for predicting in-hospital death[area under curve(AUC):0.705,95%CI:0.658-0.753,P<0.001].Kaplan-Meier survival curves showed that patients with BUN>9 mmol/L had a higher one-year mortality than those without(log-rank test:91.7,P<0.001).Multivariate analysis showed that BUN>9 mmol/L was an independent predictor for one-year mortality[hazard ratio(HR):1.67,95%CI:1.23-2.28,P=0.001].Conclusions This study provided strong evidence that increased postoperative BUN level was associated with poor prognosis in elderly patients undergoing VRS.展开更多
This study was conducted in two sections.Initially,the effects of NaCl,MgCl_(2),and urea were investigated on extracting copper and iron from chalcopyrite.Subsequently,CuFe_(2)O_(4)-based electrodes for supercapacitor...This study was conducted in two sections.Initially,the effects of NaCl,MgCl_(2),and urea were investigated on extracting copper and iron from chalcopyrite.Subsequently,CuFe_(2)O_(4)-based electrodes for supercapacitors were synthesized using the extracted solution.The first phase revealed that 3 mol/L NaCl achieved the highest extraction performance,yielding 60%Cu and 23%Fe.MgCl_(2)at 1.5 mol/L extracted 52%Cu and 27%Fe,while a combination of 0.5 mol/L MgCl_(2)and 1.6 mol/L urea yielded 57%Cu and 20%Fe.Urea effectively reduced iron levels.CuFe_(2)O_(4)-based electrodes were then successfully synthesized via a hydrothermal method using a MgCl_(2)-urea solution.Characterization studies confirmed CuFe_(2)O_(4)formation with a 2D structure and 45−50 nm wall thickness on nickel foam.Electrochemical analysis showed a specific capacitance of 725 mF/cm^(2)at 2 mA/cm^(2)current density,with energy and power densities of 12.3 mW·h/cm^(2)and 175 mW/cm^(2),respectively.These findings suggest that chalcopyrite has the potential for direct use in energy storage.展开更多
As a widely used fertilizer,urea significantly promotes the leaching of dissolved organic nitrogen(DON)in soils and aggravates nitrogen contamination in groundwater.Clayminerals are considered the most important facto...As a widely used fertilizer,urea significantly promotes the leaching of dissolved organic nitrogen(DON)in soils and aggravates nitrogen contamination in groundwater.Clayminerals are considered the most important factor in retaining DON.However,the effect of urea on the retention of DON with different molecular weights by clay minerals is unknown.In this study,the retention of both low-molecular weight DON(LMWD)and high-molecular weight DON(HMWD)by clay minerals in the presence of urea was investigated.For this purpose,batch adsorption and soil column leaching experiments,characterization analysis(Fourier transform infrared spectroscopy X-ray diffraction,and X-ray photoelectron spectroscopy),and molecular dynamics simulations were carried out.Urea had a positive effect on the adsorption of LMWD,whereas a competitive effect existed for the adsorption of HMWD.The dominant interactions among DON,urea,and clay minerals included H-bonding,ligand exchange,and cation exchange.The urea was preferentially adsorbed on clay minerals and formed a complex,which provided more adsorption sites to LMWD and only a few to HMWD.The presence of urea increased the retention of LMWD and decreased the retention of HMWD in clay minerals.The retention capacity of LMWD increased by 6.9%–12.8%,while that of HMWD decreased by 6.7%–53.1%.These findings suggest that LMWD tended to be trapped in soils,while HMWD was prone to be leached into groundwater,which can be used to evaluate the leaching of DON from soil to groundwater.展开更多
Ni-based electrocatalysts are considered a promising choice for urea-assisted hydrogen production.However,its application remains challenging owing to the high occupancy of d orbital at the Ni site,which suppresses th...Ni-based electrocatalysts are considered a promising choice for urea-assisted hydrogen production.However,its application remains challenging owing to the high occupancy of d orbital at the Ni site,which suppresses the reactant adsorption to achieve satisfactory urea oxidation reaction(UOR)and hydrogen evolution reaction(HER)activity.Herein,the WO_(3) site with empty d orbital is introduced into Ni_(3)S_(2) to construct dual active sites for regulating the adsorption of reactive molecules.Experimental and theoretical calculations indicate that the electron transfer from Ni_(3)S_(2) to WO_(3) forms electron-deficient Ni with sufficient empty d orbitals for optimizing urea/H_(2)O adsorption and tuning the adsorption behavior of the amino and carbonyl groups in urea.Consequently,the Ni_(3)S_(2)-WO_(3)/NF presents a remarkably low potential of 1.38 V to reach 10 mA cm^(-2) for UOR-assisted HER.This work highlights the significance of constructing synergistic dual active sites toward developing advanced catalysts for urea-assisted hydrogen production.展开更多
Electrocatalytic C—N coupling is an environmentally friendly pathway for reducing CO_(2)emissions,nitrate wastewater treatment,and urea production.CeO_(2)is a commonly used electrocatalyst for urea synthesis,but its ...Electrocatalytic C—N coupling is an environmentally friendly pathway for reducing CO_(2)emissions,nitrate wastewater treatment,and urea production.CeO_(2)is a commonly used electrocatalyst for urea synthesis,but its yield was restricted by the deficiency of active sites and the high barrier for C—N coupling.Herein,we employed transient heating to introduce oxygen vacancies as sites for the deposition of single metal atoms,thereby maximizing the atomic utilization as active sites for urea synthesis.The as-prepared CuFe-V-CeO_(2)electrocatalyst exhibits the outstanding urea yield rate(3553 mg h^(-1)g_(ca)^(t-1).)at-1.5 V versus reversible hydrogen electrode(RHE),surpassing the performance of previously reported electrochemical urea electrocatalysts.Theoretical calculation further revealed the roles of Ce,Cu,and Fe sites in active hydrogen(*H)generation,nitrate treatment,and CO_(2)stabilization,respectively.This work offers a novel and effective pathway for the design of electrocatalysts and developing an efficient C—N coupling system for urea production.展开更多
Urea is a major end product of nitrogen catabolism,serving as an osmolyte to regulate osmotic stress in fish exposed to varying water environments.It has been well known that urea transporters(UTs)facilitate the rapid...Urea is a major end product of nitrogen catabolism,serving as an osmolyte to regulate osmotic stress in fish exposed to varying water environments.It has been well known that urea transporters(UTs)facilitate the rapid movement of urea across cell membranes.However,researches on ut genes were predominantly focused on elasmobranchs and early developmental stages of fish.In this investigation,a total of three ut genes were identified in spotted sea bass.Phylogenetic,homology,and syntenic analyses were conducted to validate the annotation and assess the evolutionary relationships among ut genes.Both ut-a and ut-b genes have retained their evolutionary stability,demonstrating a significant level of homology between them.To gain deeper insights into the evolution of ut genes in spotted sea bass,we performed selective pressure analysis using site,branch,and branch-site models.The results suggested that positive selection likely played a significant role in shaping the evolution of the ut gene family.Furthermore,tissue-specific expression analyses revealed high expression levels of ut genes in osmoregulatory tissues such as the gill and kidney.Additionally,all three ut genes exhibited salinity-related expression patterns in gill and kidney tissues during both seawater-to-freshwater(SF)and freshwater-to-seawater(FS)adaptation.In situ hybridization results demonstrated the localization of both ut-a and ut-c mRNAs on the gill lamellae and adjacent gill filament epithelium.In summary,our study establishes a solid foundation for future research elucidating the evolutionary relationships and functional significance of ut genes during salinity acclimation in spotted sea bass and other teleost species.展开更多
Electrocatalytic urea wastewater treatment technology has emerged as a promising method for environmental remediation.However,the realization of highly efficient and scalable electrocatalytic urea wastewater treatment...Electrocatalytic urea wastewater treatment technology has emerged as a promising method for environmental remediation.However,the realization of highly efficient and scalable electrocatalytic urea wastewater treatment(SEUWT)is still an enormous challenge.Herein,through regulating the adsorption behavior of urea functional groups,the efficient SEUWT coupled hydrogen production is realized in anion exchange membrane water electrolyzer(AEMWE).Density functional theory calculations indicate that self-driven electron transfer at the heterogeneous interface(NiO/Co_(3)O_(4))can induce charge redistribution,resulting in electron-rich NiO and electron-deficient Co_(3)O_(4),which are superior to adsorbing C=O(electron-withdrawing group)and–NH_(2)(electron-donating group),respectively,regulating the adsorption behavior of urea molecule and accelerating the reaction kinetics of urea oxidation.This viewpoint is further verified by temperature-programmed desorption experiments.The SEUWT coupled hydrogen production in AEMWE assembled with NiO/Co_(3)O_(4)(anode)and NiCoP(cathode)can continuously treat urea wastewater at an initial current density of 600 mA cm^(-2),with the average urea treatment efficiency about 53%.Compared with overall water splitting,the H_(2) production rate(8.33 mmol s^(-1))increases by approximately 3.5 times.This work provides a cost-effective strategy for scalable purifying urea-rich wastewater and energy-saving hydrogen production.展开更多
BACKGROUND Increased blood urea nitrogen(BUN)levels have been demonstrated to be associated with broader metabolic disturbances and the incidence of type 2 diabetes(T2D),potentially playing a role in the development o...BACKGROUND Increased blood urea nitrogen(BUN)levels have been demonstrated to be associated with broader metabolic disturbances and the incidence of type 2 diabetes(T2D),potentially playing a role in the development of diabetic complications,including diabetic peripheral neuropathy.AIM To examine the relationship between BUN levels and peripheral nerve function in patients with T2D.METHODS This observational study involved the systematic recruitment of 585 patients with T2D for whom BUN levels and estimated glomerular filtration rate were measured.Electromyography was used to assess peripheral motor and sensory nerve function in all patients,and overall composite Z-scores were subsequently calculated for nerve latency,amplitude,and conduction velocity(NCV)across the median,ulnar,common peroneal,posterior tibial,superficial peroneal,and sural nerves.RESULTS Across the quartiles of BUN levels,the overall composite Z-score for latency(F=38.996,P for trend<0.001)showed a significant increasing trend,whereas the overall composite Z-scores for amplitude(F=50.972,P for trend<0.001)and NCV(F=30.636,P for trend<0.001)exhibited a significant decreasing trend.Moreover,the BUN levels were closely correlated with the latency,amplitude,and NCV of each peripheral nerve.Furthermore,multivariate linear regression analysis revealed that elevated BUN levels were linked to a higher overall composite Z-score for latency(β=0.166,t=3.864,P<0.001)and lower overall composite Z-scores for amplitude(β=-0.184,t=-4.577,P<0.001)and NCV(β=-0.117,t=-2.787,P=0.006)independent of the estimated glomerular filtration rate and other clinical covariates.Additionally,when the analysis was restricted to sensory or motor nerves,elevated BUN levels remained associated with sensory or motor peripheral nerve dysfunction.CONCLUSION Increased BUN levels were independently associated with compromised peripheral nerve function in patients with T2D.展开更多
To address the high cost and limited electrochemical endurance of Pt-based electrocatalysts,the appropriate introduction of transition metal-based compounds as supports to disperse and anchor Pt species offers a promi...To address the high cost and limited electrochemical endurance of Pt-based electrocatalysts,the appropriate introduction of transition metal-based compounds as supports to disperse and anchor Pt species offers a promising approach for improving catalytic efficiency.In this study,sub-1 nm Pt nanoclusters were uniformly confined on NiO supports with a hierarchical nanotube/nanosheet structure(Pt/NiO/NF)through a combination of spatial domain confinement and annealing.The resulting catalyst exhibited excellent electrocatalytic activity and stability for hydrogen evolution(HER)and urea oxidation reactions(UOR)under alkaline conditions.Structural characterization and density functional theory calculations demonstrated that sub-1 nm Pt nanoclusters were immobilized on the NiO supports by Pt–O–Ni bonds at the interface.The strong metal-support interaction induced massive charge redistribution around the heterointerface,leading to the formation of multiple active sites.The Pt/NiO/NF catalyst only required an overpotential of 12 and 136 mV to actuate current densities of 10 and 100 mA cm^(-2) for the HER,respectively,and maintained a voltage retention of 96%for 260 h of continuous operation at a current density of 500 mA cm^(-2).Notably,in energy-efficient hydrogen production systems coupled with the HER and UOR,the catalyst required cell voltages of 1.37 and 1.53 V to drive current densities of 10 and 50 mA cm^(-2),respectively—approximately 300 mV lower than conventional water electrolysis systems.This study presents a novel pathway for designing highly efficient and robust sub-nanometer metal cluster catalysts.展开更多
Interface chemical modulation strategies are considered as promising method to prepare electrocatalysts for the urea oxidation reaction(UOR).However,conventional interface catalysts are generally limited by the inhere...Interface chemical modulation strategies are considered as promising method to prepare electrocatalysts for the urea oxidation reaction(UOR).However,conventional interface catalysts are generally limited by the inherent activity and incompatibility of the individual components themselves,and the irregular charge distribution and slow charge transfer ability between interfaces severely limit the activity of UOR.Therefore,we optimized and designed a Ni_(2)P/CoP interface with modulated surface charge distribution and directed charge transfer to promote UOR activity.Density functional theorycalculations first predict a regular charge transfer from CoP to Ni_(2)P,which creates a built-in electric field between Ni_(2)P and CoP interface.Optimization of the adsorption/desorption process of UOR/HER reaction intermediates leads to the improvement of catalytic activity.Electrochemical impedance spectroscopy and ex situ X-ray photoelectron spectroscopy characterization confirm the unique mechanism of facilitated reaction at the Ni_(2)P/CoP interface.Electrochemical tests further validated the prediction with excellent UOR/HER activities of 1.28 V and 19.7 mV vs.RHE,at 10 mA cm^(-2),respectively.Furthermore,Ni_(2)P/CoP achieves industrial-grade current densities(500 mA cm^(−2))at 1.75 V and 1.87 V in the overall urea electrolyzer(UOR||HER)and overall human urine electrolyzer(HUOR||HER),respectively,and demonstrates considerable durability.展开更多
Urea-assisted water electrolysis offers a promising route to reduce energy consumption for hydrogen production and meanwhile treat urea-rich wastewater.Herein,we devised a shear force-involved polyoxometalate-organic ...Urea-assisted water electrolysis offers a promising route to reduce energy consumption for hydrogen production and meanwhile treat urea-rich wastewater.Herein,we devised a shear force-involved polyoxometalate-organic supramolecular self-assembly strategy to fabricate 3D hierarchical porous nanoribbon assembly Mn-VN cardoons.A bimetallic polyoxovanadate(POV)with the inherent structural feature of Mn surrounded by[VO_(6)]octahedrons was introduced to trigger precise Mn incorporation in VN lattice,thereby achieving simultaneous morphology engineering and electronic structure modulation.The lattice contraction of VN caused by Mn incorporation drives electron redistribution.The unique hierarchical architecture with modulated electronic structure that provides more exposed active sites,facilitates mass and charge transfer,and optimizes the associated adsorption behavior.Mn-VN exhibits excellent activity with low overpotentials of 86 m V and 1.346 V at 10 m A/cm^(2)for hydrogen evolution reaction(HER)and urea oxidation reaction(UOR),respectively.Accordingly,in the two-electrode urea-assisted water electrolyzer utilizing Mn-VN as a bifunctional catalyst,hydrogen production can occur at low voltage(1.456 V@10 m A/cm^(2)),which has the advantages of energy saving and competitive durability over traditional water electrolysis.This work provides a simple and mild route to construct nanostructures and modulate electronic structure for designing high-efficiency electrocatalysts.展开更多
AIM:To investigate whether blood urea nitrogen to serum albumin ratio(BAR)influences the onset and progression of diabetic retinopathy(DR)in diabetic patients.METHODS:The diabetic individuals were extracted from the N...AIM:To investigate whether blood urea nitrogen to serum albumin ratio(BAR)influences the onset and progression of diabetic retinopathy(DR)in diabetic patients.METHODS:The diabetic individuals were extracted from the National Health and Nutrition Examination Survey(NHANES)database spanning 1999 to 2018.The BAR was calculated as the ratio of blood urea nitrogen to serum albumin.To evaluate the association between BAR levels and DR,a generalized additive model and multivariate logistic regression analysis were performed.Additionally,subgroup analyses were conducted to determine whether other factors modified this association.RESULTS:The number of eligible individuals in the current research endeavor equaled 5798.The resulting data were indicative of the existence of a nearly linearly positive relationship between BAR levels and DR.Following confounding variable adjustment(age,gender,marital status,red blood cell,hemoglobin,lactate dehydrogenase,uric acid,creatinine,gender,red cell distribution width,highdensity lipoprotein,glucose,sodium,glycated hemoglobin,hypertension,and total cholesterol),the multivariate investigation implied that an elevated DR risk correlated with elevated levels of BAR(OR:1.46,95%CI:1.20-1.79).This relationship was noted to be reliable and stable across diverse analyses,following the conduction of sensitivity analysis(P for trend:0.0002).Subgroup analysis showed no statistically significant interactions between BAR and most other risk factors for DR.CONCLUSION:The study provides evidence of a positive association between elevated BAR levels and an increased risk of DR in diabetic individuals.展开更多
Urea holds promise as an alternative water-oxidation substrate in electrolytic cells.High-valence nickelbased spinel,especially after heteroatom doping,excels in urea oxidation reactions(UOR).However,traditional spine...Urea holds promise as an alternative water-oxidation substrate in electrolytic cells.High-valence nickelbased spinel,especially after heteroatom doping,excels in urea oxidation reactions(UOR).However,traditional spinel synthesis methods with prolonged high-temperature reactions lack kinetic precision,hindering the balance between controlled doping and highly active two-dimensional(2D)porous structures design.This significantly impedes the identification of electron configuration-dependent active sites in doped 2D nickel-based spinels.Herein,we present a microwave shock method for the preparation of 2D porous NiCo_(2)O_(4)spinel.Utilizing the transient on-off property of microwave pulses for precise heteroatom doping and 2D porous structural design,non-metal doping(boron,phosphorus,and sulfur)with distinct extranuclear electron disparities serves as straightforward examples for investigation.Precise tuning of lattice parameter reveals the impact of covalent bond strength on NiCo_(2)O_(4)structural stability.The introduced defect levels induce unpaired d-electrons in transition metals,enhancing the adsorption of electron-donating amino groups in urea molecules.Simultaneously,Bode plots confirm the impact mechanism of rapid electron migration caused by reduced band gaps on UOR activity.The prepared phosphorus-doped 2D porous NiCo_(2)O_(4),with optimal electron configuration control,outperforms most reported spinels.This controlled modification strategy advances understanding theoretical structure-activity mechanisms of high-performance 2D spinels in UOR.展开更多
基金supported by the National Natural Science Foundation of China(No.22278041)the Foundation of State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering(No.2022-K78)+1 种基金Jiangsu Province Key Laboratory of Fine Petrochemical Engineering(No.KF2107)the Advanced Catalysis and Green Manufacturing Collab-orative Innovation Center(No.ACGM2022-10-07)。
文摘Herein,a series of manganese oxide catalysts with different valences(Mn_(3)O_(4),Mn_(2)O_(3),and MnO_(2))were designed and synthesized for the synthesis of ethylene urea(EU)from ethylenediamine(EDA)and carbon dioxide(CO_(2)).With a maximal EDA conversion of 82%and EU selectivity of 99%at 160℃ for 2 h,Mn_(2)O_(3) catalysts had the best catalytic activity among them,which was superior to the reported catalysts.In the following order:Mn_(2)O_(3)>MnO_(2)>Mn_(3)O_(4),the catalytic activity for the synthesis of EU from CO_(2) and EDA decreased.Further characterization showed the Mn_(2)O_(3) catalyst possessed a greater Mn^(3+)/Mn4+ratio and more surface oxygen vacancies than the MnO_(2) and Mn_(3)O_(4),which improved its capacity to adsorb and activate CO_(2) and EDA.After four recycling runs,the EDA conversion slightly declined from 82%to 56%on Mn_(2)O_(3) catalyst,while no obvious change in EU selectivity was observed.The loss of surface Ov contents and Mn^(3+)proportion were concluded as main reasons for the decrease in catalytic activity over Mn_(2)O_(3) catalyst.This work demonstrated a metal oxide catalyst that was efficient in producing EU from CO_(2) and EDA.
基金supported by Fundamental Research Program of Shanxi Province(202203021221303)。
文摘Transformation of urea and glycerol to glycerol carbonate is an environmental friendly and economical process.Catalysts play an indispensable role in the process.Although many catalysts have been developed,the performance of the catalysts still cannot meet the needs of industrialization.In this paper,research progress of the homogeneous and heterogeneous catalysts of the reaction over the past 20 years were reviewed systematically.According to the types and active centers of catalysts,the catalysts were classified systematically and analyzed in detail.The typical reaction mechanisms were also summarized.The research and development direction of catalysts is made more explicit through systematic classification and mechanism analysis.The article reveals more novel catalysts have been designed and used for the reaction,such as mixed metal oxides with special structures,solid wastes and non-metallic materials.This work summarized the current state of research and prospected possible routes for design of novel catalysts.It is hoped that this review can provide some references for developing efficient catalysts.
基金supported by the Applied Basic Research Program of Yunnan Province(202101BE070001-032)Yunnan Major Scientific and Technological Projects(No.202202AG050001).
文摘The conversion of urea-containing wastewater into clean hydrogen energy has gained increasing attention.However,challenges remain,particularly with sluggish catalytic kinetics and limited long-term stability of urea oxidation reaction(UOR).Herein,we report the loosely porous CoOOH nano-architecture(CoOOH LPNAs)with hydrophilic surface and abundant oxygen vacancies(Ov)on carbon fiber paper(CFP)by electrochemical reconstruction of the CoP nanoneedles precursor.The resulting three-dimensional electrode exhibited an impressively low potential of 1.38 V at 1000 mA·cm^(−2) and excellent durability for UOR.Furthermore,when tested in an anion exchange membrane(AEM)electrolyzer,it required only 1.53 V at 1000 mA·cm^(−2) for industrial urea-assisted water splitting and operated stably for 100 h without degrada-tion.Experimental and theoretical investigations revealed that rich oxygen vacancies effectively modulate the electronic structure of the CoOOH while creating unique Co3-triangle sites with Co atoms close together.As a result,the adsorption and desorption processes of reactants and intermediates in UOR could be finely tuned,thereby significantly reducing ther-modynamic barriers.Additionally,the superhydrophilic self-supported nanoarray structure facilitated rapid gas bubble release,improving the overall efficiency of the reaction and preventing potential catalyst detachment caused by bubble accumulation,thereby improving both catalytic activity and stability at high current densities.
基金support by the Department of Science&Technology of Zhejiang Province under grant No.2024C01095the Fundamental Research Funds for the Provincial Universities of Zhejiang under grant No.RF-C2022008the National Natural Science Foundation of China(NSFC)under grant Nos.U20A20253,52372235,and 22279116。
文摘Aqueous sodium-ion batteries(ASIBs)have garnered significant attention as promising candidates for large-scale energy storage applications.This interest is primarily due to their abundant resource availability,environmental friendliness,cost-effectiveness,and high safety.However,their electrochemical performance is limited by the thermodynamic properties of water molecules,resulting in inadequate cycling stability and insufficient specific energy density.To address these challenges,this study developed a hydrogen-bond enhanced urea-glycerol eutectic electrolyte(UGE)to expand the electrochemical stability window(ESW)of the electrolyte and suppress corresponding side reactions.The eutectic component disrupts the original hydrogen bonding network in water,creating a new,enhanced network that reduces the activity of free water and forms a uniform,dense passivation layer on the anode.As a result,the optimized composition of UGE exhibits a broad ESW of up to 3 V(-1.44 to 1.6 V vs.Ag/AgCl).The Prussian blue(PB)/UGE/NaTi_(2)(PO_(4))_(3)@C full cell exhibits an exceptionally long lifespan of 10,000 cycles at 10 C.This study introduces a low-cost,ultra-long-life ASIB system,utilizing a green and economical eutectic electrolyte,which expands the use of eutectic electrolytes in aqueous batteries and opens a new research horizon for constructing efficient electrochemical energy storage and conversion.
基金supported by grants from the initial funding of National Natural Science Foundation of China(No.8227020480)。
文摘Background Previous studies have shown a relationship between elevated blood urea nitrogen(BUN)level and poor outcomes in several diseases,but data on the prognostic significance of postoperative BUN in elderly patients undergoing valve replacement surgery(VRS)remained sparse.Methods BUN was measured immediately after VRS.A total of 3118 elderly patients were enrolled and divided into four groups according to the quartiles of postoperative BUN:Q1,<5.6 mmol/L;Q2,5.6-6.8 mmol/L;Q3,6.8-8.4 mmol/L and Q4,≥8.4 mmol/L.The associations of postoperative BUN with in-hospital and 1-year mortality were evaluated.Results The incidence of inhospital death(1.0%vs.3.3%vs.3.3%vs.8.4%,P<0.001)and major adverse clinical events(5.1%vs.7.8%vs.9.9%vs.19.1%,P<0.001)was significantly higher in patients with a high BUN level.BUN was independently associated with all-cause in-hospital mortality[odds ratio(OR):1.11,95%confidential interval(CI):1.07-1.16,P<0.001].The receiver operating characteristic(ROC)curve showed that BUN>9 mmol/L had a sensitivity of 48.4%and specificity of 81.8% for predicting in-hospital death[area under curve(AUC):0.705,95%CI:0.658-0.753,P<0.001].Kaplan-Meier survival curves showed that patients with BUN>9 mmol/L had a higher one-year mortality than those without(log-rank test:91.7,P<0.001).Multivariate analysis showed that BUN>9 mmol/L was an independent predictor for one-year mortality[hazard ratio(HR):1.67,95%CI:1.23-2.28,P=0.001].Conclusions This study provided strong evidence that increased postoperative BUN level was associated with poor prognosis in elderly patients undergoing VRS.
文摘This study was conducted in two sections.Initially,the effects of NaCl,MgCl_(2),and urea were investigated on extracting copper and iron from chalcopyrite.Subsequently,CuFe_(2)O_(4)-based electrodes for supercapacitors were synthesized using the extracted solution.The first phase revealed that 3 mol/L NaCl achieved the highest extraction performance,yielding 60%Cu and 23%Fe.MgCl_(2)at 1.5 mol/L extracted 52%Cu and 27%Fe,while a combination of 0.5 mol/L MgCl_(2)and 1.6 mol/L urea yielded 57%Cu and 20%Fe.Urea effectively reduced iron levels.CuFe_(2)O_(4)-based electrodes were then successfully synthesized via a hydrothermal method using a MgCl_(2)-urea solution.Characterization studies confirmed CuFe_(2)O_(4)formation with a 2D structure and 45−50 nm wall thickness on nickel foam.Electrochemical analysis showed a specific capacitance of 725 mF/cm^(2)at 2 mA/cm^(2)current density,with energy and power densities of 12.3 mW·h/cm^(2)and 175 mW/cm^(2),respectively.These findings suggest that chalcopyrite has the potential for direct use in energy storage.
基金supported by the National Natural Science Foundation of China(No.42107052)Beijing Natural Science Foundation(No.JQ21031).
文摘As a widely used fertilizer,urea significantly promotes the leaching of dissolved organic nitrogen(DON)in soils and aggravates nitrogen contamination in groundwater.Clayminerals are considered the most important factor in retaining DON.However,the effect of urea on the retention of DON with different molecular weights by clay minerals is unknown.In this study,the retention of both low-molecular weight DON(LMWD)and high-molecular weight DON(HMWD)by clay minerals in the presence of urea was investigated.For this purpose,batch adsorption and soil column leaching experiments,characterization analysis(Fourier transform infrared spectroscopy X-ray diffraction,and X-ray photoelectron spectroscopy),and molecular dynamics simulations were carried out.Urea had a positive effect on the adsorption of LMWD,whereas a competitive effect existed for the adsorption of HMWD.The dominant interactions among DON,urea,and clay minerals included H-bonding,ligand exchange,and cation exchange.The urea was preferentially adsorbed on clay minerals and formed a complex,which provided more adsorption sites to LMWD and only a few to HMWD.The presence of urea increased the retention of LMWD and decreased the retention of HMWD in clay minerals.The retention capacity of LMWD increased by 6.9%–12.8%,while that of HMWD decreased by 6.7%–53.1%.These findings suggest that LMWD tended to be trapped in soils,while HMWD was prone to be leached into groundwater,which can be used to evaluate the leaching of DON from soil to groundwater.
基金supported by the National Natural Science Foundation of China(22162004)the Natural Science Foundation of Guangxi Province(2022JJD120011).
文摘Ni-based electrocatalysts are considered a promising choice for urea-assisted hydrogen production.However,its application remains challenging owing to the high occupancy of d orbital at the Ni site,which suppresses the reactant adsorption to achieve satisfactory urea oxidation reaction(UOR)and hydrogen evolution reaction(HER)activity.Herein,the WO_(3) site with empty d orbital is introduced into Ni_(3)S_(2) to construct dual active sites for regulating the adsorption of reactive molecules.Experimental and theoretical calculations indicate that the electron transfer from Ni_(3)S_(2) to WO_(3) forms electron-deficient Ni with sufficient empty d orbitals for optimizing urea/H_(2)O adsorption and tuning the adsorption behavior of the amino and carbonyl groups in urea.Consequently,the Ni_(3)S_(2)-WO_(3)/NF presents a remarkably low potential of 1.38 V to reach 10 mA cm^(-2) for UOR-assisted HER.This work highlights the significance of constructing synergistic dual active sites toward developing advanced catalysts for urea-assisted hydrogen production.
基金supported by the Hebei Natural Science Foundation(B2024205035)supported by the Fundamental Research Funds for the Central Universities+5 种基金the World-Class Universities(Disciplines)the Characteristic Development Guidance Funds for the Central Universities(1061-B23017010264)supported by the Fundamental Research Funds for the Natural Science Foundation of China(92047201,52102237)the Natural Science Foundation of Jiangsu Province(BK20220006)the National Major Projects of Water Pollution Control and Management Technology(2017ZX07204003)the Postdoctoral Science Foundations of China and Jiangsu Province(2021M690861,2022T150183,2021K065A)。
文摘Electrocatalytic C—N coupling is an environmentally friendly pathway for reducing CO_(2)emissions,nitrate wastewater treatment,and urea production.CeO_(2)is a commonly used electrocatalyst for urea synthesis,but its yield was restricted by the deficiency of active sites and the high barrier for C—N coupling.Herein,we employed transient heating to introduce oxygen vacancies as sites for the deposition of single metal atoms,thereby maximizing the atomic utilization as active sites for urea synthesis.The as-prepared CuFe-V-CeO_(2)electrocatalyst exhibits the outstanding urea yield rate(3553 mg h^(-1)g_(ca)^(t-1).)at-1.5 V versus reversible hydrogen electrode(RHE),surpassing the performance of previously reported electrochemical urea electrocatalysts.Theoretical calculation further revealed the roles of Ce,Cu,and Fe sites in active hydrogen(*H)generation,nitrate treatment,and CO_(2)stabilization,respectively.This work offers a novel and effective pathway for the design of electrocatalysts and developing an efficient C—N coupling system for urea production.
基金supported by the National Natural Science Foundation of China(No.32072947)the China Agriculture Research System(No.CARS-47)。
文摘Urea is a major end product of nitrogen catabolism,serving as an osmolyte to regulate osmotic stress in fish exposed to varying water environments.It has been well known that urea transporters(UTs)facilitate the rapid movement of urea across cell membranes.However,researches on ut genes were predominantly focused on elasmobranchs and early developmental stages of fish.In this investigation,a total of three ut genes were identified in spotted sea bass.Phylogenetic,homology,and syntenic analyses were conducted to validate the annotation and assess the evolutionary relationships among ut genes.Both ut-a and ut-b genes have retained their evolutionary stability,demonstrating a significant level of homology between them.To gain deeper insights into the evolution of ut genes in spotted sea bass,we performed selective pressure analysis using site,branch,and branch-site models.The results suggested that positive selection likely played a significant role in shaping the evolution of the ut gene family.Furthermore,tissue-specific expression analyses revealed high expression levels of ut genes in osmoregulatory tissues such as the gill and kidney.Additionally,all three ut genes exhibited salinity-related expression patterns in gill and kidney tissues during both seawater-to-freshwater(SF)and freshwater-to-seawater(FS)adaptation.In situ hybridization results demonstrated the localization of both ut-a and ut-c mRNAs on the gill lamellae and adjacent gill filament epithelium.In summary,our study establishes a solid foundation for future research elucidating the evolutionary relationships and functional significance of ut genes during salinity acclimation in spotted sea bass and other teleost species.
基金supported by the National Natural Science Foundation of China(Grant Nos.22162025,22168040)the Youth Innovation Team of Shaanxi Universities,the Open and Innovation Fund of Hubei Three Gorges Laboratory(SK232001)the Regional Innovation Capability Leading Program of Shaanxi(2022QFY07-03,2022QFY07-06).
文摘Electrocatalytic urea wastewater treatment technology has emerged as a promising method for environmental remediation.However,the realization of highly efficient and scalable electrocatalytic urea wastewater treatment(SEUWT)is still an enormous challenge.Herein,through regulating the adsorption behavior of urea functional groups,the efficient SEUWT coupled hydrogen production is realized in anion exchange membrane water electrolyzer(AEMWE).Density functional theory calculations indicate that self-driven electron transfer at the heterogeneous interface(NiO/Co_(3)O_(4))can induce charge redistribution,resulting in electron-rich NiO and electron-deficient Co_(3)O_(4),which are superior to adsorbing C=O(electron-withdrawing group)and–NH_(2)(electron-donating group),respectively,regulating the adsorption behavior of urea molecule and accelerating the reaction kinetics of urea oxidation.This viewpoint is further verified by temperature-programmed desorption experiments.The SEUWT coupled hydrogen production in AEMWE assembled with NiO/Co_(3)O_(4)(anode)and NiCoP(cathode)can continuously treat urea wastewater at an initial current density of 600 mA cm^(-2),with the average urea treatment efficiency about 53%.Compared with overall water splitting,the H_(2) production rate(8.33 mmol s^(-1))increases by approximately 3.5 times.This work provides a cost-effective strategy for scalable purifying urea-rich wastewater and energy-saving hydrogen production.
基金Supported by the Social Development Projects of Nantong,No.MS12019019,No.HS2022004 and No.MS2023083the Medical Research Project of the Jiangsu Health Commission,No.Z2022058the National Natural Science Foundation of China,No.32101027。
文摘BACKGROUND Increased blood urea nitrogen(BUN)levels have been demonstrated to be associated with broader metabolic disturbances and the incidence of type 2 diabetes(T2D),potentially playing a role in the development of diabetic complications,including diabetic peripheral neuropathy.AIM To examine the relationship between BUN levels and peripheral nerve function in patients with T2D.METHODS This observational study involved the systematic recruitment of 585 patients with T2D for whom BUN levels and estimated glomerular filtration rate were measured.Electromyography was used to assess peripheral motor and sensory nerve function in all patients,and overall composite Z-scores were subsequently calculated for nerve latency,amplitude,and conduction velocity(NCV)across the median,ulnar,common peroneal,posterior tibial,superficial peroneal,and sural nerves.RESULTS Across the quartiles of BUN levels,the overall composite Z-score for latency(F=38.996,P for trend<0.001)showed a significant increasing trend,whereas the overall composite Z-scores for amplitude(F=50.972,P for trend<0.001)and NCV(F=30.636,P for trend<0.001)exhibited a significant decreasing trend.Moreover,the BUN levels were closely correlated with the latency,amplitude,and NCV of each peripheral nerve.Furthermore,multivariate linear regression analysis revealed that elevated BUN levels were linked to a higher overall composite Z-score for latency(β=0.166,t=3.864,P<0.001)and lower overall composite Z-scores for amplitude(β=-0.184,t=-4.577,P<0.001)and NCV(β=-0.117,t=-2.787,P=0.006)independent of the estimated glomerular filtration rate and other clinical covariates.Additionally,when the analysis was restricted to sensory or motor nerves,elevated BUN levels remained associated with sensory or motor peripheral nerve dysfunction.CONCLUSION Increased BUN levels were independently associated with compromised peripheral nerve function in patients with T2D.
文摘To address the high cost and limited electrochemical endurance of Pt-based electrocatalysts,the appropriate introduction of transition metal-based compounds as supports to disperse and anchor Pt species offers a promising approach for improving catalytic efficiency.In this study,sub-1 nm Pt nanoclusters were uniformly confined on NiO supports with a hierarchical nanotube/nanosheet structure(Pt/NiO/NF)through a combination of spatial domain confinement and annealing.The resulting catalyst exhibited excellent electrocatalytic activity and stability for hydrogen evolution(HER)and urea oxidation reactions(UOR)under alkaline conditions.Structural characterization and density functional theory calculations demonstrated that sub-1 nm Pt nanoclusters were immobilized on the NiO supports by Pt–O–Ni bonds at the interface.The strong metal-support interaction induced massive charge redistribution around the heterointerface,leading to the formation of multiple active sites.The Pt/NiO/NF catalyst only required an overpotential of 12 and 136 mV to actuate current densities of 10 and 100 mA cm^(-2) for the HER,respectively,and maintained a voltage retention of 96%for 260 h of continuous operation at a current density of 500 mA cm^(-2).Notably,in energy-efficient hydrogen production systems coupled with the HER and UOR,the catalyst required cell voltages of 1.37 and 1.53 V to drive current densities of 10 and 50 mA cm^(-2),respectively—approximately 300 mV lower than conventional water electrolysis systems.This study presents a novel pathway for designing highly efficient and robust sub-nanometer metal cluster catalysts.
文摘Interface chemical modulation strategies are considered as promising method to prepare electrocatalysts for the urea oxidation reaction(UOR).However,conventional interface catalysts are generally limited by the inherent activity and incompatibility of the individual components themselves,and the irregular charge distribution and slow charge transfer ability between interfaces severely limit the activity of UOR.Therefore,we optimized and designed a Ni_(2)P/CoP interface with modulated surface charge distribution and directed charge transfer to promote UOR activity.Density functional theorycalculations first predict a regular charge transfer from CoP to Ni_(2)P,which creates a built-in electric field between Ni_(2)P and CoP interface.Optimization of the adsorption/desorption process of UOR/HER reaction intermediates leads to the improvement of catalytic activity.Electrochemical impedance spectroscopy and ex situ X-ray photoelectron spectroscopy characterization confirm the unique mechanism of facilitated reaction at the Ni_(2)P/CoP interface.Electrochemical tests further validated the prediction with excellent UOR/HER activities of 1.28 V and 19.7 mV vs.RHE,at 10 mA cm^(-2),respectively.Furthermore,Ni_(2)P/CoP achieves industrial-grade current densities(500 mA cm^(−2))at 1.75 V and 1.87 V in the overall urea electrolyzer(UOR||HER)and overall human urine electrolyzer(HUOR||HER),respectively,and demonstrates considerable durability.
基金supported by the National Natural Science Foundation of China(Nos.22322104,22171074)the Natural Science Foundation of Heilongjiang Province(No.YQ2021B009)+3 种基金the Reform and Development Fund Project of Local University supported by the Central Government(Outstanding Youth Program)Heilongjiang Province Young Scientific and Technological Talent Lifting Project(No.2023QNTJ019)the Basic Research Support Project for Outstanding Young Teachers in Heilongjiang Provincial University(No.YQJH2023129)the Outstanding Youth Science Foundation of Heilongjiang University(No.JCL202301)。
文摘Urea-assisted water electrolysis offers a promising route to reduce energy consumption for hydrogen production and meanwhile treat urea-rich wastewater.Herein,we devised a shear force-involved polyoxometalate-organic supramolecular self-assembly strategy to fabricate 3D hierarchical porous nanoribbon assembly Mn-VN cardoons.A bimetallic polyoxovanadate(POV)with the inherent structural feature of Mn surrounded by[VO_(6)]octahedrons was introduced to trigger precise Mn incorporation in VN lattice,thereby achieving simultaneous morphology engineering and electronic structure modulation.The lattice contraction of VN caused by Mn incorporation drives electron redistribution.The unique hierarchical architecture with modulated electronic structure that provides more exposed active sites,facilitates mass and charge transfer,and optimizes the associated adsorption behavior.Mn-VN exhibits excellent activity with low overpotentials of 86 m V and 1.346 V at 10 m A/cm^(2)for hydrogen evolution reaction(HER)and urea oxidation reaction(UOR),respectively.Accordingly,in the two-electrode urea-assisted water electrolyzer utilizing Mn-VN as a bifunctional catalyst,hydrogen production can occur at low voltage(1.456 V@10 m A/cm^(2)),which has the advantages of energy saving and competitive durability over traditional water electrolysis.This work provides a simple and mild route to construct nanostructures and modulate electronic structure for designing high-efficiency electrocatalysts.
基金Supported by the Wenzhou Municipal Basic Scientific Research Project(No.Y20220789).
文摘AIM:To investigate whether blood urea nitrogen to serum albumin ratio(BAR)influences the onset and progression of diabetic retinopathy(DR)in diabetic patients.METHODS:The diabetic individuals were extracted from the National Health and Nutrition Examination Survey(NHANES)database spanning 1999 to 2018.The BAR was calculated as the ratio of blood urea nitrogen to serum albumin.To evaluate the association between BAR levels and DR,a generalized additive model and multivariate logistic regression analysis were performed.Additionally,subgroup analyses were conducted to determine whether other factors modified this association.RESULTS:The number of eligible individuals in the current research endeavor equaled 5798.The resulting data were indicative of the existence of a nearly linearly positive relationship between BAR levels and DR.Following confounding variable adjustment(age,gender,marital status,red blood cell,hemoglobin,lactate dehydrogenase,uric acid,creatinine,gender,red cell distribution width,highdensity lipoprotein,glucose,sodium,glycated hemoglobin,hypertension,and total cholesterol),the multivariate investigation implied that an elevated DR risk correlated with elevated levels of BAR(OR:1.46,95%CI:1.20-1.79).This relationship was noted to be reliable and stable across diverse analyses,following the conduction of sensitivity analysis(P for trend:0.0002).Subgroup analysis showed no statistically significant interactions between BAR and most other risk factors for DR.CONCLUSION:The study provides evidence of a positive association between elevated BAR levels and an increased risk of DR in diabetic individuals.
基金financial support from the National Natural Science Foundation of China(52203070)the Open Fund of State Key Laboratory of New Textile Materials and Advanced Processing Technologies(FZ2022005)+2 种基金the Open Fund of Hubei Key Laboratory of Biomass Fiber and Ecological Dyeing and Finishing(STRZ202203)the financial support provided by the China Scholarship Council(CSC)Visiting Scholar Programfinancial support from Institute for Sustainability,Energy and Resources,The University of Adelaide,Future Making Fellowship。
文摘Urea holds promise as an alternative water-oxidation substrate in electrolytic cells.High-valence nickelbased spinel,especially after heteroatom doping,excels in urea oxidation reactions(UOR).However,traditional spinel synthesis methods with prolonged high-temperature reactions lack kinetic precision,hindering the balance between controlled doping and highly active two-dimensional(2D)porous structures design.This significantly impedes the identification of electron configuration-dependent active sites in doped 2D nickel-based spinels.Herein,we present a microwave shock method for the preparation of 2D porous NiCo_(2)O_(4)spinel.Utilizing the transient on-off property of microwave pulses for precise heteroatom doping and 2D porous structural design,non-metal doping(boron,phosphorus,and sulfur)with distinct extranuclear electron disparities serves as straightforward examples for investigation.Precise tuning of lattice parameter reveals the impact of covalent bond strength on NiCo_(2)O_(4)structural stability.The introduced defect levels induce unpaired d-electrons in transition metals,enhancing the adsorption of electron-donating amino groups in urea molecules.Simultaneously,Bode plots confirm the impact mechanism of rapid electron migration caused by reduced band gaps on UOR activity.The prepared phosphorus-doped 2D porous NiCo_(2)O_(4),with optimal electron configuration control,outperforms most reported spinels.This controlled modification strategy advances understanding theoretical structure-activity mechanisms of high-performance 2D spinels in UOR.
