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Goode Harrell posted an update 1 day ago
Our work enables a scalable solution-processable approach for the generation of graphene-based FTE and functional devices.Liquid metals adhere to most surfaces despite their high surface tension due to the presence of a native gallium oxide layer. The ability to change the shape of functional fluids within a three-dimensional (3D) printed part with respect to time is a type of four-dimensional printing, yet surface adhesion limits the ability to pump liquid metals in and out of cavities and channels without leaving residue. Rough surfaces prevent adhesion, but most methods to roughen surfaces are difficult or impossible to apply on the interior of parts. Here, we show that silica particles suspended in an appropriate solvent can be injected inside cavities to coat the walls. This technique creates a transparent, nanoscopically rough (10-100 nm scale) coating that prevents adhesion of liquid metals on various 3D printed plastics and commercial polymers. Liquid metals roll and even bounce off treated surfaces (the latter occurs even when dropped from heights as high as 70 cm). Moreover, the coating can be removed locally by laser ablation to create selective wetting regions for metal patterning on the exterior of plastics. To demonstrate the utility of the coating, liquid metals were dynamically actuated inside a 3D printed channel or chamber without pinning the oxide, thereby demonstrating electrical circuits that can be reconfigured repeatably.Piezoelectric materials enable emerging self-powered wearable and implantable devices. The sol-gel technology with the lowest cost for large-scale production has shown its potential for producing high-quality PZT thin films. However, fabricating PZT films with a sufficient thickness for different application scenarios requires a long and repeated coating and heat-treatment process. The traditional solution-based method usually requires at least 20 coating cycles to fabricate 2 μm-thick PZT thin films. To save cost and improve fabrication efficiency, we develop a simplified thin-film fabrication method assisted by PZT powder. The new method can fabricate 2 μm-thick PZT films in a single step, one spin coating and annealing. Experiments indicate that the powder-based PZT thin films have porous structures and outstanding piezoelectric performances. The measured d33 of the powder-based PZT thin film is 47 pm/V. Both solution-based and powder-based PZT thin films show high flexibility and good fatigue resistance. Furthermore, we explore 2D mica as the substrate and achieve the transfer-free fabrication of flexible PZT thin-film nanogenerators that effectively simplify the complicated physical or chemical thin-film lift-off processes. The nanogenerator prototypes demonstrate the capability of accurately monitoring dynamic responses of flexible and soft human tissues.Despite the advantages of CO2 electrolyzers, efficiency losses due to mass and ionic transport across the membrane electrode assembly (MEA) are critical bottlenecks for commercial-scale implementation. In this study, more efficient electrolysis of CO2 was achieved by increasing cation exchange membrane (CEM) hydration via the humidification of the CO2 reactant inlet stream. A high current density of 755 mA/cm2 was reached by humidifying the reactant CO2 in a MEA electrolyzer cell featuring a CEM. Selleckchem MitoSOX Red The power density was reduced by up to 30% when the fully humidified reactant CO2 was introduced while operating at a current density of 575 mA/cm2. We reduced the ohmic losses of the electrolyzer by fourfold at 575 mA/cm2 by fully humidifying the reactant CO2. A semiempirical CEM water uptake model was developed and used to attribute the improved performance to 11% increases in membrane water uptake and ionic conductivity. Our CEM water uptake model showed that the increase in ohmic losses and the limitation of ionic transport were the result of significant dehydration at the central region of the CEM and the anode gas diffusion electrode-CEM interface region, which exhibited a 2.5% drop in water uptake.ConspectusExcessive use of fossil fuels has not only led to energy shortage but also caused serious environmental pollution problems due to the massive emissions of industrial waste gas. As the main component of industrial waste gas, CO2 molecules can also be utilized as an important raw material for renewable fuels. Thus, the effective capture and conversion of CO2 has been considered one of the best potential strategies to mitigate the energy crisis and lower the greenhouse effect simultaneously.In this case, CO2 electroreduction to high-value-added chemicals provides an available approach to accomplish this important goal. Nonetheless, the CO2 molecule is extremely stable with a high dissociation energy. With regard to the traditional electrocatalytic systems, there are three main factors that hinder their practical applications (i) sluggish carrier transport dynamics; (ii) high energy barrier for CO2 activation; (iii) poor product selectivity. Therefore, solving these three crucial problems is the key to reduction, thereby speeding up the development of CO2 conversion technology.In this Account, we summarize recent progress in tailoring the electronic structure of atomically thin two-dimensional electrocatalysts by different methods. Meanwhile, we highlight the structure-property relationship between the electronic structure regulation and the catalytic activity/product selectivity of atomically thin two-dimensional electrocatalysts, and discuss the underlying fundamental mechanism with the aid of in situ characterization techniques. Finally, we discuss the major challenges and opportunities for the future development of CO2 electroreduction. It is expected that this Account will help researchers to better understand CO2 electroreduction and guide better design of high-performance electrocatalytic systems.All solid-state Li metal batteries have drawn extensive attention because of the limited side reaction and consequent safety character. The applications of Li metal anodes are indispensable for realizing high energy density but still face many obstacles. One of the critical issues is the contact failure of the solid/solid interface. The rigid interface between a sulfide electrolyte and Li anode cannot afford the volume variation during cycling. Herein, we design an adhesive solid-state electrolyte film, which is supported by hot melt adhesive porous membranes for anode protection. The Li symmetric cells and all solid-state batteries based on adhesive electrolyte layers all exhibit enhanced long cyclic stability and suppressed voltage polarization. The peel strength tests confirm that the electrolyte layers decorated with adhesive components can offer intimate Li metal/electrolyte physical contact and withstand the volume variation of the Li anode. The adhesion force from porous membranes is believed to play a vital role in maintaining solid-solid interfacial contact stability.