Enhancing the stability of Ni Fe-layered double hydroxide nanosheet array for alkaline seawater oxidation by Ce doping

Electrocatalytic hydrogen production from seawater holds enormous promise for clean energy generation.Nevertheless,the direct electrolysis of seawater encounters significant challenges due to poor anodic stability caused by detrimental chlorine chemistry.Herein,we present our recent discovery that the incorporation of Ce into Ni Fe layered double hydroxide nanosheet array on Ni foam(Ce-Ni Fe LDH/NF)emerges as a robust electrocatalyst for seawater oxidation.During the seawater oxidation process,CeO_(2)is generated,effectively repelling Cl^(-)and inhibiting the formation of Cl O-,resulting in a notable enhancement in the oxidation activity and stability of alkaline seawater.The prepared Ce-Ni Fe LDH/NF requires only overpotential of 390 m V to achieve the current density of 1 A cm^(-2),while maintaining long-term stability for 500 h,outperforming the performance of Ni Fe LDH/NF(430 m V,150 h)by a significant margin.This study highlights the effectiveness of a Ce-doping strategy in augmenting the activity and stability of materials based on Ni Fe LDH in seawater electrolysis for oxygen evolution.

电催化合成氨的研究进展

氨是一种重要的工业原料,在化肥、染料、药品和炸药的制造中起着重要作用.由于氨的氢容量大、能量密度高且易于运输,被认为是一种潜在的无碳燃料.Haber-Bosch工艺实现了高附加值氨的大规模工业化生产,但其生产条件(400‒550ºC,15‒30 MPa)苛刻,且伴随着高能耗和CO_(2)排放.因此,开发绿色和可持续的氨合成方法,同时实现全球环境的可持续性势在必行.电催化氮还原合成氨(NRR)是近年来的研究热点,该技术可以在环境条件下进行,且可利用电子作为绿色还原剂,水作为质子源.此外,该过程具有实现分散和现场按需生产氨的巨大潜力,支持分布式肥料生产,从而降低运输成本.除了N2作为氮源,对环境有害且活性高于N2的氮物种(如NO,NO_(2)^(−)/NO_(3)^(−))已被认为是实现环境条件下生产氨的有吸引力的氮源,电催化NO还原(NORR)和NO_(2)−/NO_(3)^(−)(NO_(x)^(−))还原(NtrRR)合成氨具有应用潜力.本文综述了近年来电催化合成氨的研究进展.首先简要介绍了三种电催化合成氨路线(NRR,NORR和NtrRR)的研究背景和意义.然后,对环境条件下合成氨电催化剂的最新研究进展进行了详细讨论,主要涉及催化机理、理论计算和电化学性能.最后,对人工电催化合成氨当前面临的挑战和未来的研究需求作了总结和展望,包括:(1)注重理论计算,通过理论计算可以预测可能的活性位点、吸附能和反应途径,有助于快速筛选合适的催化剂,大大降低实验成本;(2)发展先进的原位表征技术来观察电催化剂表面上的动态变化和捕获/识别反应中间体,促进对真实反应机理的探索,从而进一步指导催化剂的设计;(3)确保数据的准确性和可重复性;(4)合理设计有效的电催化剂.为了进一步提高现有材料体系对氨合成的催化性能,需要开发更高效的材料设计策略(如精确调节单原子金属的配位环境、掺杂原子/空位的类型和浓度、合理暴露特定的晶体面等),以促进电催化剂的内在活性.此外,通过优化电催化剂的形态,构建特殊的结构(如尖刺),可以暴露丰富的活性位点,显著提高其表观活性;(5)研究特定的电极材料时,除材料工程外,扩展实验条件也至关重要,包括电解质的pH值、应用电位和氮物种初始浓度等,可能会影响催化活性和选择性;(6)文献报道的稳定性测试通常在50 h以下,对于工业运行(预计在高电流密度下可以稳定运行数千小时)来说,时间太短.因此,未来的催化剂设计需要以更长的测试时间为目标;(7)未来研究应进一步探索真实环境下NORR/NtrRR的催化活性,以实现更高效的氨合成;(8)应开发一种可替代的氨分离技术.在传统的Haber-Bosch工艺中,通过冷凝,氨从未反应的N2和H_(2)中分离出来,耗能大,因此应采用比冷凝工艺能量输入更少的分离技术;(9)从实际应用角度出发,还应考虑综合的技术经济评估,包括材料成本、总能源成本、设备维护成本和产品分离成本等,以评估氨电合成的大规模可扩展性和商业可行性.综上,开展电催化合成氨领域的研究有望以绿色和可持续的方式缓解环境污染和未来的能源问题.

自支撑过渡金属海水电解析氧催化剂研究进展

海水电解是一种很有前景的可持续绿氢生产技术。然而,由于受到缓慢的动力学、阳极上竞争性的氯释放反应、氯离子腐蚀和电极表面中毒等的影响,致使阳极材料的性能和耐久性下降,析氧反应(OER)的选择性降低。与传统的粉末催化剂相比,自支撑纳米阵列材料具有较低的界面电阻、较大的活性表面和优异的稳定性,已成为先进的催化剂。特别是在需要高电流密度的实际大规模制氢应用中,自支撑催化剂比粉末催化剂更具优势。电解过程中,在电极表面所产生气泡的强烈冲击下,粉末状纳米材料很容易剥离,导致催化活性降低,甚至频繁更换催化剂。相比之下,自支撑纳米材料的活性物质和基底之间具有很强的粘附性,确保了良好的电子导电性和高机械稳定性,有利于长期和循环使用。本文综述了用于海水电解自支撑过渡金属催化剂的最新进展,包括(氧)氢氧化物、氮化物、磷化物、硫族化物等。为确保OER过程中的高活性和高选择性,着重总结了各析氧催化剂在应对耐腐蚀性和屏蔽竞争反应方面所采取的策略。通常,构建具有高孔隙率和粗糙度的3D多孔纳米结构可以使催化剂具有较大的表面积和丰富的活性位点,是提高传质、OER活性和催化效率的有效策略。其次,催化剂表面的Cl−阻挡层,特别是兼具催化活性和保护作用的保护层,可以有效抑制Cl−的竞争性氧化和腐蚀,提高催化剂的催化活性、选择性和稳定性。此外,设计具有超亲水和超疏水表面的催化材料,以增加电解质的渗透性,促进活性位点的有效利用,并避免大量气泡的积累。最后,简要总结了OER催化剂在海水电解中的发展前景及建议。具体来说,海水电解的介质应从模拟盐水转移到天然海水中。鉴于天然海水电解中面临的诸多挑战,除了设计和合成具有高活性、高选择性和高稳定性的自支撑催化剂外,开发简单、低成本的天然海水预处理技术以最大限度地减少腐蚀和中毒问题也是海水电解未来发展的重要课题。更重要的是,应合理构建自支撑OER电催化剂的标准化评价体系。评估过程中应充分考虑催化剂内在活性、可达活性位点密度、尺寸、质量负荷、基质效应和试验条件等因素。

Construction of Air Quality Evaluation System Based on FCM Algorithm and BP Neural Network

In order to solve the limitations of existing air quality evaluation system, a new air quality evaluation system was established based on FCM, the BP neural network, with the aim to provide scientific bases for the targeted and efficient control of air pollution, formulation of prevention and control strategy, and improvement of living environment. Based on the existing data of 6 air quality indices, the air quality data were reclassified by using FCM algorithm, obtaining the clustering center, which minimized the cost function of non-similar index. Then, the reclassified 6 classes of data were proceeded with BP neural network training and simulation, so as to achieve the purpose of identification, thereby forming a new air quality evaluation system.

Plasma HGF and OPN as Potential Biomarkers of Pulmonary Arterial Hypertension in Congenital Heart Disease

Objectives:Pulmonary arterial hypertension in congenital heart disease(PAH-CHD)is the most common type of PAH and increases morbidity and mortality in patients with CHD.Right heart catheterization(RHC)is the standard method to diagnose PAH.However,RHC is an invasive and complicated method with relatively high cost.Noninvasive,feasible,and cost-efficient methods are urgently needed.The objective of this study was to evaluate three potential biomarkers of PAH-CHD:Hepatocyte growth factor(HGF),osteopontin(OPN),and suppression of tumorigenicity 2(ST2).Methods:Plasma samples were collected from patients with CHD(n=46)and healthy individuals(n=22)and divided into four groups according to the severity of PAH.The levels of HGF,OPN,and ST2 were then analyzed using an enzyme-linked immunosorbent assay.Correlations between HGF,OPN,ST2,and clinical parameters of PAH-CHD were analyzed.Results:The plasma HGF levels in the moderate to the severe group were significantly higher than those in the mild group,nonPAH group,and healthy control group(p<0.05).Derived from a receiver operating characteristic(ROC)curve analysis,a cut-off value of 356.75 ng/ml for the HGF concentration was able to predict PAH-CHD with 53%sensitivity and 89%specificity.The HGF level was positively related to pulmonary arterial systolic pressure(PASP)(r=0.36,p<0.05)and pulmonary vascular resistance(PVR)(r=0.36,p<0.05).Plasma OPN levels in the mild group were significantly higher than other groups and positively correlated with the pulmonary-systemic shunt ratio(Qp/Qs)(r=0.33,p<0.05).There was no statistically significant between-group difference in plasma soluble ST2(sST2)levels.Conclusion:The plasma HGF level was elevated in PAH-CHD patients and can be used as a potential biomarker.The plasma OPN level was positively correlated with the Qp/Qs.

A novel mutation in <i>NF1</i>gene in a Chinese patient with Legius syndrome like caféau lait spots

Neurofibromatosis type I (NF1) (OMIM, 162200) and Legius syndrome (OMIM, 611431) both have multiple café au lait spots. It is a challenge to differentiate the two diseases. Here we report a Legius syndrome-like patient who finally was identified as NF1 with a novel mutation in NF1 exon1 (c.55G > T). The mutation caused a substitution of a glutamic acid (GAG) with a terminator codon (TAG). For those patients with only multiple café au lait macules, axillary and inguinal freckling, but without any other clinical signs in NF1 and Legius syndrome, a gene testing is necessary to give a final diagnose. We suggested to use “Neurofibromatosis type 1—like syndrome” to describe those patients just like our patient reported here.

Fe-doped Co_(3)O_(4) nanowire strutted 3D pinewood-derived carbon: A highly selective electrocatalyst for ammonia production via nitrate reduction

Nitrate(NO_(3)^(-)),a nitrogen-containing pollutant,is prevalent in aqueous solutions,contributing to a range of environmental and health-related issues.The electrocatalytic reduction of NO_(3)^(-)holds promise as a sustainable approach to both eliminating NO_(3)^(-)and generating valuable ammonia(NH_(3)).Nevertheless,the reduction reaction of NO_(3)^(-)(NO_(3)^(-)RR),involving 8-electron transfer process,is intricate,necessitating highly efficient electrocatalysts to facilitate the conversion of NO_(3)^(-)to NH_(3).In this study,Fe-doped Co_(3)O_(4) nanowire strutted three-dimensional(3D)pinewood-derived carbon(Fe-Co_(3)O_(4)/PC)is proposed as a high-efficiency NO_(3)^(-)RR electrocatalyst for NH_(3) production.Operating within 0.1 M NaOH containing NO_(3)^(-),Fe-Co_(3)O_(4)/PC demonstrates exceptional performance,obtain an impressively large NH_(3) yield of 0.55 mmol·h^(-1)·cm^(-2) and an exceptionally high Faradaic efficiency of 96.5%at-0.5 V,superior to its Co_(3)O_(4)/PC counterpart(0.2 mmol·h^(-1)·cm^(-2),73.3%).Furthermore,the study delves into the reaction mechanism of Fe-Co_(3)O_(4) for NO_(3)^(-)RR through theoretical calculations.

Surface-derived phosphate layer on NiFe-layered double hydroxide realizes stable seawater oxidation at the current density of 1 A·cm^(−2)

Seawater electrolysis,especially in coastlines,is widely considered as a sustainable way of making clean and high-purity H2 from renewable energy;however,the practical viability is challenged severely by the limited anode durability resulting from side reactions of chlorine species.Herein,we report an effective Cl^(−) blocking barrier of NiFe-layer double hydroxide(NiFe-LDH)to harmful chlorine chemistry during alkaline seawater oxidation(ASO),a pre-formed surface-derived NiFe-phosphate(Pi)outerlayer.Specifically,the PO_(4)^(3−)-enriched outer-layer is capable of physically and electrostatically inhibiting Cl−adsorption,which protects active Ni^(3+)sites during ASO.The NiFe-LDH with the NiFe-Pi outer-layer(NiFe-LDH@NiFe-Pi)exhibits higher current densities(j)and lower overpotentials to afford 1 A·cm^(−2)(η1000 of 370 mV versusη1000 of 420 mV)than the NiFe-LDH in 1 M KOH+seawater.Notably,the NiFe-LDH@NiFe-Pi also demonstrates longer-term electrochemical durability than NiFe-LDH,attaining 100-h duration at the j of 1 A·cm^(−2).Additionally,the importance of surface-derived PO_(4)^(3−)-enriched outer-layer in protecting the active centers,γ-NiOOH,is explained by ex situ characterizations and in situ electrochemical spectroscopic studies.

Electrocatalytic synthesis of C-N coupling compounds from CO_(2) and nitrogenous species

The electrocatalytic synthesis of C-N coupling compounds from CO_(2) and nitrogenous species not only offers an effective avenue to achieve carbon neutral-ity and reduce environmental pollution,but also establishes a route to synthesize valuable chemicals,such as urea,amide,and amine.This innovative approach expands the application range and product categories beyond simple carbona-ceous species in electrocatalytic CO_(2) reduction,which is becoming a rapidly advancing field.This review summarizes the research progress in electrocatalytic urea synthesis,using N_(2),NO_(2)^(-),and NO_(3)^(-)as nitrogenous species,and explores emerging trends in the electrosynthesis of amide and amine from CO_(2) and nitro-gen species.Additionally,the future opportunities in this field are highlighted,including electrosynthesis of amino acids and other compounds containing C-N bonds,anodic C-N coupling reactions beyond water oxidation,and the catalytic mechanism of corresponding reactions.This critical review also captures the insights aimed at accelerating the development of electrochemical C-N coupling reactions,confirming the superiority of this electrochemical method over the traditional techniques.

Ambient electrosynthesis of urea from carbon dioxide and nitrate over Mo_(2)C nanosheet

Electrocatalytic synthesis of urea through C-N bond formation,converting carbon dioxide(CO_(2))and ni-trate(NO_(3)^(-)),presents a promising,less energy-intensive alternative to industrial urea production process.In this communication,we report the application of Mo_(2)C nanosheets-decorated carbon sheets(Mo_(2)C/C)as a highly efficient electrocatalyst for facilitating C-N coupling in ambient urea electrosynthesis.In CO_(2)-saturated 0.2 mol/L Na_(2)SO_(4)solution containing 0.05 mol/L NO_(3)^(-),the Mo_(2)C/C catalyst achieves an impres-sive urea yield of 579.13μg h^(-1)mg^(-1)with high Faradaic efficiency of 44.80%at-0.5 V versus the reversible hydrogen electrode.Further theoretical calculations reveal that the multiple Mo active sites enhance the formation of^(∗)CO and^(∗)NH_(2)intermediates and facilitate their C-N coupling.This research propels the use of Mo_(2)C-based electrodes in electrocatalysis and accentuates the capabilities of binary metal-based catalysts in C-N coupling reactions.

Cauliflower-like Ni_(3)S_(2) foam for ultrastable oxygen evolution electrocatalysis in alkaline seawater

It is of great importance to design and develop electrocatalysts that are both long-lasting and efficient for seawater oxidation.Herein,a three-dimensional porous cauliflower-like Ni_(3)S_(2) foam on Ni foam(Ni_(3)S_(2) foam/NF)is proposed as a high-performance electrocatalyst for the oxygen evolution reaction in alkaline seawater.The as-synthesis Ni_(3)S_(2) foam/NF achieves exceptional efficacy,achieving a current density of 100 mA·cm^(−2)at mere overpotential of 369 mV.Notably,its electrocatalytic stability extends up to 1000 h at 500 mA·cm^(−2).

N, O-doped carbon foam as metal-free electrocatalyst for efficient hydrogen production from seawater

Seawater electrolysis is the most promising technology for large scale hydrogen production due to the abundance and low cost of seawater in nature.However,compared with the traditional freshwater electrolysis,the issues of electrode poisoning and corrosion will occur during the seawater electrolysis process,and active and stable electrocatalysts for the hydrogen evolution reaction(HER)are thus highly desired.In this work,N,O-doped carbon foam in-situ derived from commercial melamine foam is proposed as a high-active metal-free HER electrocatalyst for seawater splitting.In acidic seawater,our catalyst shows high hydrogen generation performance with small overpotential of 161 mV at 10 mA·cm^(−2),a low Tafel slop of 97.5 mV·dec^(−1),and outstanding stability.

Biomimetic nanoparticles drive the mechanism understanding of shear-wave elasticity stiffness in triple negative breast cancers to predict clinical treatment

In clinical practice,we noticed that triple negative breast cancer(TNBC)patients had higher shear-wave elasticity(SWE)stiffness than non-TNBC patients and a higherα-SMA expression was found in TNBC tissues than the non-TNBC tissues.Moreover,SWE stiffness also shows a clear correlation to neoadjuvant response efficiency.To elaborate this phenomenon,TNBC cell membrane-modified polylactide acid-glycolic acid(PLGA)nanoparticle was fabricated to specifically deliver artesunate to regulate SWE stiffness through inhibiting CAFs functional status.As tested in MDA-MB-231 and E0771 orthotopic tumor models,CAFs functional status inhibited by 231M-ARS@PLGA nanoparticles(231M-AP NPs)had reduced the SWE stiffness as well as attenuated hypoxia of tumor as tumor soil loosening agent which amplified the antitumor effects of paclitaxel and PD1 inhibitor.Single-cell sequencing indicated that the two main CAFs(extracellular matrix and wound healing CAFs)that produces extracellular matrix could influence the tumor SWE stiffness as well as the antitumor effect of drugs.Further,biomimetic nanoparticles inhibited CAFs function could attenuate tumor hypoxia by increasing proportion of inflammatory blood vessels and oxygen transport capacity.Therefore,our finding is fundamental for understanding the role of CAFs on affecting SWE stiffness and drugs antitumor effects,which can be further implied in the potential clinical theranostic predicting in neoadjuvant therapy efficacy through non-invasive analyzing of SWE imaging.

CoSe_(2)nanowire array enabled highly efficient electrocatalytic reduction of nitrate for ammonia synthesis

The electrocatalytic reduction of nitrate(NO_(3)^(-))not only facilitates the environmentally sustainable production of ammonia(NH_(3))but also purifies water by removing NO_(3)^(-),thereby transforming waste into valuable resources.The process of converting NO_(3)^(-)to NH_(3)is complex,involving eight electron transfers and multiple intermediates,making the choice of electrocatalyst critical.In this study,we report a cobalt selenide(Co Se_(2))nanowire array on carbon cloth(CoSe_(2)/CC)as an effective electrocatalyst for the NO_(3)^(-)to NH_(3)conversion.In an alkaline medium with 0.1 mol/L NO_(3)^(-),CoSe_(2)/CC demonstrates exceptional NH_(3)Faradaic efficiency of 97.6%and a high NH_(3)yield of 517.7μmol h^(-1)cm^(-2)at-0.6 V versus the reversible hydrogen electrode.Furthermore,insights into the reaction mechanism of CoSe_(2)in the electrocatalytic NO_(3)^(-)reduction are elucidated through density functional theory calculations.

Significantly enhanced ion-migration and sodium-storage capability derived by strongly coupled dual interfacial engineering in heterogeneous bimetallic sulfides with densified carbon matrix

The development of highly efficient sodium-ion batteries depends critically on the successful exploitation of advanced anode hosts that is capable of overcoming sluggish reaction kinetics while also withstanding severe structural deformation triggered by the large radius of Na^(+)-insertion.Herein,a hierarchically hybrid material with hetero-Co_(3)S_(4)/NiS hollow nanosphere packaged into a densified N-doped carbonmatrix(Co_(3)S_(4)/NiS@N-C)was designed and fabricated utilizing CoNi-glycerate as the self-sacrifice template,making the utmost of the synergistic effect of hetero-Co_(3)S_(4)/NiS with strong electric field and rich reaction active-sites together with the densified outer-carbon scaffolds with remarkable electronic conductivity and robust mechanical toughness.As anticipated,as-fabricated Co_(3)S_(4)/NiS@N-C anode affords remarkable specific capacity,prolonged cycle lifespan up to 2400 cycles with an only 0.05%fading each cycle at 20.0 A g^(−1),and excellent rate feature(354.9 mAh g^(−1)at 30.0 A g^(−1)),one of the best performances for most existing Co_(3)S_(4)/NiS-based anodes.Ex situ structural characterizations in tandem with theoretical analysis demonstrate the reversible insertion-conversion mechanism of initially proceeding with Na^(+)de-/intercalation and superior heterogeneous interfacial reaction behavior with strong Na^(+)-adsorption ability.Further,sodium-ion full cell and hybrid capacitor based on Co_(3)S_(4)/NiS@N-C anode exhibit impressive electrochemical characteristics on cycling performance and rate capability,showcasing its outstanding feasibility toward practical use.