Hierarchically wood-derived integrated electrode with tunable superhydrophilic/superaerophobic surface for efficient urea electrolysis

Conferring surfaces with superhydrophilic/superaerophobic characteristics is desirable for synthesizing efficient gas reaction catalysts.However,complicated procedures,high costs,and poor interfaces hinder commercialization.Here,an integrated electrode with tunable wettability derived from a hierarchically porous wood scaffold was well designed for urea oxidation reaction(UOR).Interestingly,the outer surface of the wood lumen was optimized to the preferred wettability via stoichiometry to promote electrolyte permeation and gas escape.This catalyst exhibits outstanding activity and durability for UOR in alkaline media,requiring only a potential of 1.36 V(vs.RHE)to deliver 10 m A cm^(-2)and maintain its activity without significant decay for 60 h.These experiments and theoretical calculations demonstrate that the nickel(oxy)hydroxide layer formed through surface reconstruction of nickel nanoparticles improves the active sites and intrinsic activity.Moreover,the superwetting properties of the electrode promote mass transfer by guaranteeing substantial contact with the electrolyte and accelerating the separation of gaseous products during electrocatalysis.These findings provide the understanding needed to manipulate the surface wettability through rational design and fabrication of efficient electrocatalysts for gas-evolving processes.

Ambient Fast Synthesis of Superaerophobic/Superhydrophilic Electrode for Superior Electrocatalytic Water Oxidation

Developing cost-effective and facile methods to synthesize efficient and stable electrocatalysts for large-scale water splitting is highly desirable but remains a significant challenge.In this study,a facile ambient temperature synthesis of hierarchical nickel-iron(oxy)hydroxides nanosheets on iron foam(FF-FN)with both superhydrophilicity and superaerophobicity is reported.Specifically,the as-fabricated FF-FN electrode demonstrates extraordinary oxygen evolution reaction(OER)activity with an ultralow overpotential of 195 mV at 10 mA cm^(-2)and a small Tafel slope of 34 mV dec^(-1)in alkaline media.Further theoretical investigation indicates that the involved lattice oxygen in nickel-iron-based-oxyhydroxide during electrochemical self-reconstruction can significantly reduce the OER reaction overpotential via the dominated lattice oxygen mechanism.The rechargeable Zn-air battery assembled by directly using the as-prepared FF-FN as cathode displays remarkable cycling performance.It is believed that this work affords an economical approach to steer commercial Fe foam into robust electrocatalysts for sustainable energy conversion and storage systems.

Valence electronic engineering of superhydrophilic Dy-evoked Ni-MOF outperforming RuO_(2) for highly efficient electrocatalytic oxygen evolution

Tackling the problem of poor conductivity and catalytic stability of pristine metal-organic frameworks(MOFs) is crucial to improve their oxygen evolution reaction(OER) performance.Herein,we introduce a novel strategy of dysprosium(Dy) doping,using the unique 4f orbitals of this rare earth element to enhance electrocatalytic activity of MOFs.Our method involves constructing Dy-doped Ni-MOF(Dy@Ni-MOF) nanoneedles on carbon cloth via a Dy-induced valence electronic perturbation approach.Experiments and density functional theory(DFT) calculations reveal that Dy doping can effectively modify the electronic structure of the Ni active centers and foster a strong electronic interaction between Ni and Dy.The resulting benefits include a reduced work function and a closer proximity of the d-band center to the Fermi level,which is conducive to improving electrical conductivity and promoting the adsorption of oxygen-containing intermediates.Furthermore,the Dy@Ni-MOF achieves superhydrophilicity,ensuring effective electrolyte contact and thus accelerating reaction kinetics,Ex-situ and in-situ analysis results manifest Dy_(2)O_(3)/NiOOH as the actual active species.Therefore,Dy@Ni-MOF shows impressive OER performance,significantly surpassing Ni-MOF.Besides,the overall water splitting device with Dy@NiMOF as an anode delivers a low cell voltage of 1.51 V at 10 mA cm^(-2) and demonstrates long-term stability for 100 h,positioning it as a promising substitute for precious metal catalysts.

A Superaerophobic Bimetallic Selenides Heterostructure for Efficient Industrial-Level Oxygen Evolution at Ultra-High Current Densities

Cost-effective and stable electrocatalysts with ultra-high current densities for electrochemical oxygen evolution reaction(OER)are critical to the energy crisis and environmental pollution.Herein,we report a superaerophobic three dimensional(3D)heterostructured nanowrinkles of bimetallic selenides consisting of crystalline NiSe2 and NiFe2Se4 grown on NiFe alloy(NiSe2/NiFe2Se4@NiFe)prepared by a thermal selenization procedure.In this unique 3D heterostructure,numerous nanowrinkles of NiSe2/NiFe2Se4 hybrid with a thickness of ~100 nm are grown on NiFe alloy in a uniform manner.Profiting by the large active surface area and high electronic conductivity,the superaerophobic NiSe2/NiFe2Se4@NiFe heterostructure exhibits excellent electrocatalytic activity and durability towards OER in alkaline media,outputting the low potentials of 1.53 and 1.54 V to achieve ultra-high current densities of 500 and 1000 mA cm^−2,respectively,which is among the most active Ni/Fe-based selenides,and even superior to the benchmark Ir/C catalyst.The in-situ derived FeOOH and NiOOH species from NiSe2/NiFe2Se4@NiFe are deemed to be efficient active sites for OER.

Aluminum and phosphorus codoped “superaerophobic” Co3O4 microspheres for highly efficient electrochemical water splitting and Zn-air batteries

Multifunctional non-precious catalysts for hydrogen/oxygen evolution reaction(HER/OER) and oxygen reduction reaction(ORR) constitute the bottleneck in the applications in electrochemical overall water splitting(OWS) and Zn-air batteries. Herein, a trifunctional electrocatalyst of urchin-like Al,P-codoped Co3O4 microspheres supported on Ni foam(denoted as AP-CONPs/NF) was fabricated via a hydrothermal process and subsequent low-temperature annealing and phosphorization, exhibiting enhanced OER, HER and ORR activities compared with single-doped and undoped samples. Their surface self-organized microstructure and excellent "superaerophobic" feature make a high bubble repellency, which boost diffusion of reactants and electrolyte-electrode intimate contact. The codoping of Al and P elements into Co3O4 betters right the balance among surface chemical state, the increased oxygen vacancies and the promoted charge transfer. Encouraged by these synergistic advantages, the AP-CONPs/NF was further employed as excellent bifunctional electrodes for the OWS(low cell voltage of 1.57 V at 10 mA cm-2) and as air cathode for rechargeable Zn-air batteries(high power density of 89.1 mW cm-2), which demonstrates a great feasibility for practical applications.

Osteoconductivity of Superhydrophilic Anodized TiO₂Coatings on Ti Treated with Hydrothermal Processes

Surface hydrophilicity is considered to have a strong influence on the biological reactions of bone-substituting materials. However, the influence of a hydrophilic surface on osteoconductivity is not completely clear, especially for superhydrophilic surfaces. In this study, we conferred superhydrophilic properties on anodized TiO2 coatings using a hydrothermal treatment, and developed a method to maintain this surface until implantation. The osteoconductivity of these coatings was evaluated with in vivo tests. A hydrothermal treatment made the surface of as-anodized samples more hydrophilic, up to a water contact angle of 13 (deg.). Storage in both air and distilled water increased the water contact angle after several days because of the adsorption of hydrocarbon. However, storage in phosphate buffered solution led to a reduction in the water contact angle, because of the adsorption of the inorganic ions in the solution, and the sample retained its high hydrophilicity for a long time. As the water contact angle decreased, the hard tissue formation ratio increased continuously up to 58%, which was about four times higher than the hard tissue formation ratio on as-polished Ti.

Superhydrophilic–superhydrophobic patterned surfaces:From simplified fabrication to emerging applications

Superhydrophilic–superhydrophobic patterned surfaces constitute a branch of surface chemistry involving the two extreme states of superhydrophilicity and superhydrophobicity combined on the same surface in precise patterns.Such surfaces have many advantages,including controllable wettability,enrichment ability,accessibility,and the ability to manipulate and pattern water droplets,and they offer new functionalities and possibilities for a wide variety of emerging applications,such as microarrays,biomedical assays,microfluidics,and environmental protection.This review presents the basic theory,simplified fabrication,and emerging applications of superhydrophilic–superhydrophobic patterned surfaces.First,the fundamental theories of wettability that explain the spreading of a droplet on a solid surface are described.Then,the fabrication methods for preparing superhydrophilic–superhydrophobic patterned surfaces are introduced,and the emerging applications of such surfaces that are currently being explored are highlighted.Finally,the remaining challenges of constructing such surfaces and future applications that would benefit from their use are discussed.

Fully Superhydrophilic, Self-Floatable, and Multi-Contamination-Resistant Solar Steam Generator Inspired by Seaweed

Highly hydrophilic materials enable rapid water delivery and salt redissolution in solar-driven seawater desalination. However, the lack of independent floatability inhibits heat localization at the air/water interface. In nature, seaweeds with internal gas microvesicles can float near the sea surface to ensure photosynthesis. Here, we have developed a seaweed-inspired, independently floatable, but superhydrophilic (SIFS) solar evaporator. It needs no extra floatation support and can simultaneously achieve continuous water pumping and heat concentration. The evaporator resists salt accumulation, oil pollution, microbial corrosion, and protein adsorption. Densely packed hollow glass microbeads promote intrinsic floatability and heat insulation. Superhydrophilic zwitterionic sulfobetaine hydrogel provides a continuous water supply, redissolves the deposited salt, and endows the SIFS evaporator with excellent anti-fouling properties. With its unprecedented anti-contamination ability, this SIFS evaporator is expected to open a new avenue for designing floatable superhydrophilic materials and solving real-world issues of solar steam generation in complex environmental conditions.

Fabrication of superhydrophilic surface on copper substrate by electrochemical deposition and sintering process

Superhydrophilic surfaces were fabricated on copper substrates by an electrochemical deposition and sintering process. Superhydrophobic surfaces were prepared by constructing micro/nano-structure on copper substrates through an electrochemical deposition method. Conversion from superhydrophobic to superhydrophilic was obtained via a suitable sintering process. After reduction sintering, the contact angle of the superhydrophilic surfaces changed from 155° to 0°. The scanning electron microscope （SEM） images show that the morphology of superhydrophobic and superhydrophilic surfaces looks like corals and cells respectively. The chemical composition and crystal structure of these surfaces were examined using energy dispersive spectrometry （EDS） and X-ray diffraction （XRD）. The results show that the main components on superhydrophobic surfaces are Cu, Cu2O and CuO, while the superhydrophilic surfaces are composed of Cu merely. The crystal structure is more inerratic and the grain size becomes bigger after the sintering. The interracial strength of the superhydrophilic surfaces was investigated, showing that the interfacial strength between superhydrophilic layer and copper substrate is considerably high.

Wettability Control between Oleophobic/Superhydrophilic and Superoleophilic/Superhydrophobic Characteristics on the Modified Surface Treated with Fluoroalkyl End-Capped Oligomers/Micro-Sized Polystyrene Particle Composites

Fluoroalkyl end-capped vinyltrimethoxysilane-N,N-dimethylacrylamide cooligomer [RF-(CH2-CHSi(OMe)3)x-(CH2-CHC(=O)NMe2)y-RF;RF = CF(CF3)OC3F7: RF-(VM)x-(DMAA)y-RF] was synthesized by reaction of fluoroalkanoyl peroxide [RF-C(=O)O-O(O=)C-RF] with vinyltrimethoxysilane (VM) and N,N-dimethylacrylamide (DMAA). The modified glass surface treated with the cooligomeric nanoparticles [RF-(VM-SiO3/2)x-(DMAA)y-RF] prepared under the sol-gel reaction of the cooligomer under alkaline conditions was found to exhibit an oleophobic/superhydrophilic property, although the corresponding fluorinated homooligomeric nanoparticles [RF-(VM-SiO3/2)n-RF] afforded an oleophobic/hydrophobic property on the modified surface under similar conditions. RF-(VM-SiO3/2)n-RF/RF-(VM-SiO3/2)x-(DMAA)y-RF/PSt (micro-sized polystyrene particles) composites, which were prepared by the sol-gel reactions of the corresponding homooligomer and cooligomer in the presence of PSt particle under alkaline conditions, provided an oleophobic/superhydrophilic property on the modified surface. However, it was demonstrated that the surface wettability on the modified surface treated with the RF-(VM-SiO3/2)n-RF/RF-(VM-SiO3/2)x-(DMAA)y-RF/PSt composites changes dramatically from oleophobic/superhydrophilic to superoleophilic/superhydrophilic and superoleophilic/superhydrophobic characteristics, increasing with greater feed ratios (mg/mg) of the RF-(VM)n-RF homooligomer in homooligomer/cooligomer from 0 to 100 in the preparation of the composites. Such controlled surfac

Nanovilli electrode boosts hydrogen evolution:A surface with superaerophobicity and superhydrophilicity

Although tremendous efforts have been paid on electrocatalysts toward efficient electrochemical hydrogen generation,breakthrough is still highly needed in the design and synthesis of wonderful non-precious-metal electrocatalyst.Herein,a nanovilli Ni2P electrode,which with superaerophobic and superhydropholic can significantly facilitate the mass and electron transfer was constructed via a facial morphology control strategy.Meanwhile,the substitution of sluggish oxygen evolution with urea oxidation,lowering the two-electrode cell voltage to only 1.48 volts to achieve a current density of 10 mA·cm^(-2).Thus,the as-constructed electrode achieves the operation of hydrogen generation by an AA battery.This work sheds new light on the exploration of other high-efficient electrocatalysts for hydrogen generation by using intermittent clean energy.

飞秒激光选区微织构AlN超浸润平板热管

目的为了提升AlN基板的散热性能,研究嵌入式一体化AlN平板热管的激光加工方法。方法通过飞秒激光微织构技术结合热处理工艺制备出AlN亲疏水组合表面,并组装嵌入式一体化平板热管,测试其传热性能。通过三维表面轮廓仪、SEM、EDS和XPS分别分析表面的三维轮廓、形貌、元素含量和化学成分,研究表面亲、疏水的形成机理。结果楔形亲疏组合AlN平板热管的启动时间、启动温度均最低,相较于全超亲水样品,启动时间降低了14.9%,启动温度降低了6.0%。楔形亲疏组合热管的热阻最低,热流密度最高。相较于全亲水热管,热阻降低了33%,热流密度提升了2%。结论AlN陶瓷表面经过激光织构会产生AlOx(多价铝氧化物),具有较高的表面能,呈超亲水状态。热处理能使表面充分氧化,降低表面能,呈超疏水状态。嵌入一体化AlN平板热管的设计和无化学激光选区微织构方法,为电子陶瓷基板的散热提供了一种新思路。

聚丙烯织物表面超亲水涂层构筑及其油水分离性能

[目的]为得到具有优秀耐久性和高油水分离效率的超亲水性聚丙烯(PP)分离材料。[方法]通过将天然来源的羧甲基纤维素(CMC)与聚丙烯织物共价结合,制备出一种具有超亲水-水下超疏油性能涂层的改性PP织物。通过扫描电镜(SEM)、红外光谱(IR)、X射线光电子能谱(XPS)等手段对改性后的样品进行分析,利用接触角测量仪和自建油水分离装置测试了改性PP织物的润湿性及油水分离性能。[结果]改性PP织物在空气中的水接触角低至0°,在水下对不同油(包括正己烷、甲苯、煤油、柴油、汽油和石油醚)的接触角都不低于150°,对油水混合物的分离效率都可达到98%以上,分离时的水通量高达69449 L/(m^(2)·h)以上。经过50次循环分离、酸碱盐溶液腐蚀浸泡8 h、砂纸刮擦30次、高含沙量水冲刷2 h等多项测试后,改性PP织物均保持优异的水下疏油性和大于97%的油水分离效率。从微观结构与化学组成的角度揭示了是表面粗糙度与亲水基团的协同作用使PP织物由最初的疏水亲油转变为超亲水-水下超疏油。[结论]通过化学键连接的方式可以在PP织物表面成功构筑牢固结合的超亲水涂层。该改性过程绿色、简便、低成本,能赋予PP织物优异、耐久的油水分离性能。改性后的PP织物有望在复杂水体环境下的油水分离场景中应用。

特殊润湿性膜在油水分离中的应用进展

石油泄漏和含油废水排放严重污染生态环境,油水分离技术是涉油污染治理的重要手段。由于低耗能、简单高效等优点,特殊润湿性的膜材料在油水分离方面表现出巨大的应用潜力。基于润湿性相关理论和分离机理,总结了超疏水/超亲油膜、超亲水/水下超疏油膜、Janus膜和智能响应膜等油水分离膜的研究进展,并对油水分离膜的优缺点进行了分析,对将来的发展提出了展望。

仿生集水表面的研究进展及应用

淡水资源紧缺是当今全球面临的严峻挑战,随着全球人口增长和气候变化的影响,人类面临着日益严重的水资源短缺问题。近年的研究结果显示,通过仿生手段从大气中获取水资源,是一种备受关注的可行方法,仿生集水技术应运而生。仿生集水技术具有广泛的应用潜力,在大气水收集、海水淡化、工业废水回收和微流控等多个领域具备较好的应用前景。综述了近年来仿生集水技术的发展现状、制备工艺、集水原理和应用前景,总结了基于新型生物学水收集原理的仿生材料/结构/表面处理方法和应用研究现状,分析了仿生集水技术当前面临的问题,包括非均匀润湿集水表面相关理论的深入研究、集水表面耐久性提高及高效低成本制备工艺的开发等,未来的研究方向可集中在提高仿生材料集水性能的可持续性和制备成本的降低等方面,以推动该技术的商业化推广和规模化应用。通过持续的研究和创新,有望看到更多高效、经济的仿生集水技术出现,为人类面临的水资源短缺挑战提供有效的解决方案。

自清洁超亲水表面处理油田污水的研究进展

具有自清洁效应的超亲水表面因其简单的操作、高效的分离效率、绿色低廉的制作成本等优势而成为能源和环境领域备受关注的研究热点。对现阶段自清洁超亲水表面的研究进展进行了综述,首先介绍了自清洁超亲水表面的主流制备方法,并解释了自清洁超亲水表面的工作机制,然后阐述了其在处理油田污水方面的具体应用,最后总结了自清洁超亲水表面研究现阶段的成果和局限性,并对其未来发展方向做出了展望。

Superhydrophilic nickel hydroxide ultrathin nanosheets enable high-performance asymmetric supercapacitors

Superhydrophilic surfaces have been applied for supercapacitor;however,during energy storage reaction,how the wettability affects the process of electrochemical reaction specifically is still unclear.Herein,we demonstrate superhydrophilic surface for promotion of electrochemical reactions by liquid affinity and further explain the mechanism,where the transition of the wettability state caused by the change in surface free energy is the main reason for the obvious increase in specific capacitance.Through citric acid assistance strategy,an intrinsically hydrophobic Ni(OH)_(2)thick nanosheets(HNHTNs,16 nm)can be transitioned into superhydrophilic Ni(OH)_(2)ultrathin nanosheets(SNHUNs,6.8 nm),where the water contact angle was 0°and the surface free energy increased from 8.6to 65.8 mN·m^(-1),implying superhydrophilicity.Compared with HNHTNs,the specific capacitance of SNHUNs is doubled:from 1230 F·g^(-1)(HNHTNs)to 2350 F·g^(-1)(2A·g^(-1))and,even at 20 A·g^(-1),from 833 F·g^(-1)(HNHTNs)to 1670 F·g^(-1).The asymmetric capacitors assembled by SNHUNs and activated carbon show 52.44 Wh·kg^(-1)at 160W·kg^(-1)and excellent stability with~90%retention after5000 cycles(~80%retention after 9500 cycles).The promotion of electrochemical performances is ascribed to the change of surface wettability caused by surface free energy,which greatly increase affinity of electrode to the surrounding liquid environment to reduce the interface resistance and optimize the electron transport path.

超亲氮化碳-硅藻土复合滤层油包水乳液快速破乳

目的实现高黏度油品油包水乳液的快速高效破乳。方法以三聚氰胺为原料,通过热聚法制备超亲水材料氮化碳,采用制备的氮化碳混合硅藻土制备复合滤饼,通过抽滤实现高黏度油包水乳液快速破乳。结果含质量分数为1.5%氮化碳的0.5 cm氮化碳-硅藻土滤饼可实现水含量在6%(w)以内,乳滴粒径在2.32μm及以上,油包水乳液完全破乳,20 kPa真空度的破乳速率可达3.57 L/min,破乳效率为97.36%,油回收率为99.72%以上;增大破乳用滤饼厚度,可用于更高含水量乳液的破乳;破乳基于超亲氮化碳对水的强吸引力和硅藻土微孔破碎共同作用。结论氮化碳-硅藻土滤饼可实现油包水乳液快速高效破乳,具工业实用前景。

贻贝仿生矿化超亲水表面膜的制备及其油-水分离性能

频繁的海洋原油泄漏、无序且随意的工业含油污水排放催生出高效油-水分离材料迫切需求.融合膜分离技术和表面工程策略构建的超亲水膜实现了高效的油-水分离而引发广泛关注.本文利用贻贝仿生矿化的策略,结合贻贝启发快速沉积和层层自组装矿化两步法,在各种膜表面成功制备了界面稳定且具有优异抗污染性能的超亲水/水下超疏油涂层.由于其突出的超亲水和水下驱油能力,涂层膜能够高效分离油-水混合物以及表面活性剂稳定的水包油乳液.此外,由于优异的界面稳定性,超亲水表面膜实现了长效的油-水乳液分离.这些优异的性能加上其简便的制造工艺,使其成为油-水分离的理想材料.

超亲水表面喷雾冷却强化尿素钢带造粒换热性能研究

尿素钢带造粒工艺引入超疏水表面后可显著提高尿素颗粒球形度,改善壁面粘附现象,但同时减小了熔体与钢带接触换热面积和导热,导致造粒过程移热效率下降。在钢带正面进行超疏水改性同时,将背面改性为超亲水表面构成超疏水/超亲水双面不对称钢带,结合喷雾冷却技术,可有效增大喷雾微小液滴捕获效率、铺展速率和面积,显著提升液滴蒸发吸热效率,快速降低钢带及周边环境温度,并利用该技术实现了大颗粒尿素快速固化得到合格产品。