3D Flower Research Articles

In-situ constructing oxygen-enriched vacancies BiOCl with 3D flower-structure for exceptional visible-light-driven photocatalytic properties

Bismuth oxychloride (BiOCl), emerging as a novel environmentally friendly nanomaterial, possesses considerable potential for photocatalytic degradation of organic wastewater. However, inadequate active sites and inhibited electron separation efficiency severely hinder its visible-light photocatalytic activity. To address this issue, herein we present a facile approach to in-situ construct BiOCl three-dimensional (3D) flower-structure (BOC-F) with oxygen-enriched vacancies for abundant active sites and effective electron separation efficiency through morphology control and vacancy engineering. The visible photocatalytic activity of BOC-F and BiOCl with 2D flaky-structure (BOC-S) was assessed through a systematic examination of the degradation efficiencies of tetracycline hydrochloride (TC-HCl) and rhodamine B (RhB). Under visible light irradiation, BOC-F exhibited superior visible photocatalytic activity, effectively degrading tetracycline hydrochloride (TC-HCl) (20 mg/L) and rhodamine B (RhB) (200 mg/L) within 90 min and 20 min of light exposure, respectively. The findings elucidate that BOC-F, possessing a 3D flower structure, manifests a heightened concentration of oxygen vacancies in contrast to BOC-S, consequently yielding excellent performance. Moreover, The ESR test showed that singlet oxygen (1O2) and hole (h+) were two main active species in the photocatalytic degradation of BOC-F. This work not only furnishes a facile method for constructing oxygen-rich vacancies in BiOCl but also provides fresh insights into the potential for enhancing the visible photocatalytic properties of Bi-based materials through vacancy engineering.

The phosphorous-doped 2D nanosheet assembled 3D Mn2V2O7 microflowers on Ni foam as a binder-free electrode for high energy density asymmetric supercapacitor application

In recent times, transition-metal oxides have been recognized as highly promising candidates for supercapacitor applications. Nevertheless, their progress in diverse fields has been hindered by challenges such as poor electrical conductivity and a shortage of active reaction centers. Doping heteroatoms would overcome these drawbacks and enhance the supercapacitor properties in transition metal oxides. Herein, the phosphorous-doped 2D nanosheet assembled 3D Mn2V2O7 micro flowers were grown on the Nickel foam using the hydrothermal method and successively phosphatized in a tube furnace, which was utilized as a binder-free supercapacitor electrode. The synthesis process involved varying the concentration of phosphorus (P), resulting in the successful formation of uniform P-decorated Mn2V2O7 microflowers. The unique microflower structure and doping P into the Mn2V2O7 material enhance the electrochemical properties with a specific capacity of 850C g−1 (1545 F g−1) at 1 A g−1 in a three-electrode cell. Moreover, the assembled Mn2V2O7–600/NF//AC device delivers a specific capacity of 258C g−1 (211 F g−1) at 1 A g−1 with a remarkable rate of 47 % at a high current density of 20 Ag −1. The device achieved a maximum energy density of 43.2 Wh kg−1 at a power density of 604.7 W kg−1, and it maintained 91 % of initial capacity after 10,000 charge/discharge cycles at 20 A g−1. These results suggest that the P-doping 2D nanosheet assembled 3D Mn2V2O7 could be promising electrode materials for supercapacitor applications.

High-performance Chinese ink flower-shaped evaporator: Intensified heat through light concentration to achieve water-energy balance

Maintaining a water-energy balance is crucial for maximizing efficiency in 3D interfacial solar-driven evaporation. Regrettably, the inherent flaw of 3D evaporators results in insufficient water supply capacity. Herein, taking inspiration from metals that can reflect light, aluminum foil (AF) was utilized to create a light-collecting device with internal reflection capabilities. A 3D sola flower (SF) evaporator with Chinese ink absorption coating and PDA surface hydrophilic treatment (IPSF) was designed. The experimental and simulated results show that by applying surface hydrophilic treatment and using a light-collecting device, a notable increase in temperature on the side of the 3D evaporator is visible, indicating the successful implementation of the spotlight effect. Therefore, it is possible to achieve a water-energy balance and attain a high evaporation rate. The evaporation rate of IPSF was 2.31 kg m−2 h−1 before concentrating light under one sun and 3.5 wt% brine. Comparably, it rose to 3.95 kg m−2 h−1 after concentrating (IPSFCL), marking a 71 % enhancement. This innovative light-collecting device and water-energy balance engineering provides a novel strategy and technique for designing 3D evaporators and can be applied in different environmental conditions.

Cathode|Electrolyte Interface Engineering by a Hydrogel Polymer Electrolyte for a 3D Porous High-Voltage Cathode Material in a Quasi-Solid-State Zinc Metal Battery by In Situ Polymerization.

This work highlights the development of a superior cathode|electrolyte interface for the quasi solid-state rechargeable zinc metal battery (QSS-RZMB) by a novel hydrogel polymer electrolyte using an ultraviolet (UV) light-assisted in situ polymerization strategy. By integrating the cathode with a thin layer of the hydrogel polymer electrolyte, this technique produces an integrated interface that ensures quick Zn2+ ion conduction. The coexistence of nanowires for direct electron routes and the enhanced electrolyte ion infiltration and diffusion by the 3D porous flower structure with a wide open surface of the Zn-MnO electrode complements the interface formation during the in situ polymerization process. The QSS-RZMB configured with an integrated cathode (i-Zn-MnO) and the hydrogel polymer electrolyte (PHPZ-30) as the separator yields a comparable specific energy density of 214.14Whkg-1 with that of its liquid counterpart (240.38Whkg-1, 0.5MZn(CF3SO3)2 aqueous electrolyte). Other noteworthy features of the presented QSS-RZMB system include its superior cycle life of over 1000 charge-discharge cycles and 85% capacity retention with 99% coulombic efficiency at the current density of 1.0Ag-1, compared to only 60% capacity retention over 500 charge-discharge cycles displayed by the liquid-state system under the same operating conditions.

Hierarchical structures of 2D g-C3N4 sheet supported 3D star-shaped flower CuO nanohybrids for improved photoelectrochemical water oxidation and visible light induced photodegradation of antibiotics

The interfacial interaction between different materials is favorable to the photoexcited charge separation, and it can also contribute complete performance to their individual benefits and create for the shortcomings to attain a complementary influence. But, it is still challenging to modify the preferred structure and heterojunction interface of catalyst materials using a facile and effective method. In this report, 2D g-C3N4 sheets supported 3D star-shaped flower like CuO nanohybrid p-n type heterojunction catalysts were prepared using simple facile synthesis technique and examined their catalytic activity and photoelectrochemical properties. The photocatalytic efficacies of TC using pure g-C3N4, CuO and CuO/g-C3N4 were 47.4%, 75.2% and 94.7% within the 30 min of visible light irradiation. The enhanced photodegradation performance of nanohybrids catalyst is due to the formation of heterojunction, subsequent in the photoexcited charge carrier’s active separation the improved ability of visible light absorption and development of p-n heterojunction. Moreover, PEC water oxidation properties were examined and CuO/g-C3N4 nanohybrid electrodes displays improved PEC properties than the pure CuO and g-C3N4. Furthermore, g-C3N4, CuO and CuO/g-C3N4 photoelectrode displays photocurrent density 0.85, 1.60 and 2.30 mA/cm−2, respectively. Therefore, 3D/2D nanohybrids with robust ability of visible light absorption could offer a novel method to create effective facilitating the growth of photoelectrodes for the PEC water oxidation and photodegradation for fast and effective antibiotic removal from the environment.

An acid-chromic luminescent lanthanide metallogel for time-dependent information encryption and anti-counterfeiting.

Luminescent materials with dynamic color transformation demonstrate significant potential in advanced information encryption and anti-counterfeiting. In this study, we designed multi-color luminescent lanthanide metallogels featuring time-dependent color transformation. These materials are based on Förster resonance energy transfer (FRET) platforms, facilitating cascade energy transfer from the ligand 4,4',4''-[1,3,5-benzenetriyltris (carbonylimino)]trisbenzoic acid (H3L) to Tb3+ ions and subsequently to Sulforhodamine 101. The emission color of the gels can be readily adjusted by the introduction of HCl, transitioning from initial green, yellow, light red, and red hues to blue, violet, pink, and deep red, respectively. Importantly, the color change in these gels is time-dependent, controlled by the hydrolysis time of glucono-δ-lactone, which modulates the luminescence intensity of H3L, Tb3+, and Sulforhodamine 101. Exploiting these characteristics, we developed methods for information encryption utilizing 3D color codes and anti-counterfeiting flower patterns. These patterns undergo time-dependent transformations, generating a series of 3D codes and flower patterns that can only be recognized in a predetermined manner. These findings highlight the promising application of lanthanide metallogels in advanced information protection strategies.

3D marigold flowers of copper–nickel oxide composite materials as a positive electrode for high-performance hybrid supercapacitors

3D marigold flowers of copper–nickel oxide via hydrothermal method as positive electrode for high-performance hybrid supercapacitor with specific capacitance of 2387.15 F g−1 and 93% cycling capacitive retention performance up to 10 000 cycles.

A signal "switch-on" photoelectrochemical sensor based on a 3D-FM/BiOI heterostructure for the sensitive detection of l-ascorbic acid.

A highly efficient 3D flower MoS2 (3D-FM)-based heterostructure photocatalyst (3D-FM/BiOI) was successfully obtained via a simple hydrothermal synthesis strategy. 3D-FM/BiOI showed prominent photoelectrochemical performance, distinguished stability and good selectivity. The introduction of 3D-FM, by promoting the photoelectric property attributed to it, facilitated the separation of photogenerated electron-hole pairs. Since the redox process of l-ascorbic acid (l-AA) resulted in an increasing photocurrent of 3D-FM/BiOI, a signal "switch-on" photoelectrochemical sensor (PECS) was designed to sensitively determine l-AA for the first time. Under optimized conditions, the 3D-FM/BiOI PECS worked over a wide range from 1 μM to 0.8 mM with a low detection limit of 0.05 μM (S/N = 3). The PECS was successfully exploited for l-AA sensing in human urine with excellent accuracy and applicability, demonstrating its practical precision and superb serviceability. Furthermore, the 3D-FM/BiOI PECS exhibited satisfactory selectivity and stability, providing a great potential platform for the construction of an l-AA sensor in various practical samples and complicated environments.

Boosted visible-light photocatalysis via p-n heterojunction synergy in 3D tin Sulfide-Graphitic carbon nitride nanohybrids

Creating superior nanohybrids with a narrow band gap to harness a larger portion of the solar spectrum is a contemporary necessity. In this study, we utilized a streamlined solvothermal approach to develop a three-dimensional, flower-like tin sulfide (3DF-SnS2) which was integrated atop graphitic nitride layers (g-C3N4). Using a suite of standardized characterization techniques, we delved deep into understanding the design intricacies, structural aspects, photophysical properties, chemical interplay, and surface dynamics of the produced nanohybrids. A noteworthy enhancement in the photocatalytic activity was observed in the p-n heterojunction (3DF-SnS2/g-C3N4) when tested under visible light using the benchmark organic pollutant, Rhodamine B (RhB). When pitted against other nanohybrids from this study, the optimized 3DF-SnS2/g-C3N4 structure displayed a remarkable aptitude for RhB degradation. This was largely due to its adept ability to segregate photo-generated charges efficiently and the harmonious synergy between the 3D and 2D structures, streamlining the charge transfer processes. This commendable photocatalytic efficacy can be attributed to several factors. First, band gap narrowing, the hybrid structure successfully reduces its band gap, allowing for a broader spectrum of solar energy absorption. Second, harmonized charge separation, the interplay between the 3D flower and the 2D sheet structures ensures an effective and efficient separation of photo-generated charges, optimizing their availability for catalytic reactions. 3D/2D Interface Dynamics: The interaction between the 3D floral configuration and the 2D sheet enhances charge mobility, further boosting efficiency. Third, enhanced surface area, the 3D flower-like design of SnS2, in conjunction with the planar nature of g-C3N4, offers abundant active sites for photocatalytic reactions.

Fabrication of a Novel Fluorescein Embedded Photocomposite Based on Interpenetrating Polymer Network (IPN) and Its Application in 4D Printing

AbstractWith the rapid development of the 3D printing technique, the concept of 4D has emerged, defining time as the fourth dimension. This concept allows for changes in the appearance, function, or other properties of 3D printed objects in response to certain controlled external stimuli over time. In this work, a new photocomposite containing fluorescein based is designed on an interpenetrating polymer network (IPN) system, this system can be generated by the simultaneous photopolymerization of acrylate and epoxide monomers under visible LED@405 nm irradiation. Unexpectedly, combining the reversible fluorometric turn‐on property of fluorescein and the deformation of the IPN in the presence of water, the 3D flower structure printed from this photocomposite would demonstrate a novel dual responsive behavior with both fluorescence and shape changes when it is exposed to water for a short time. This work would present a novel functional photocomposite material and also expand the application prospect of 4D printing.

Enhanced electromagnetic wave absorption of three-dimensional flower-like ZnO/TiO2/Ti3C2Tx composites

A novel strategy that selecting Ti3C2Tx MXene as the precursor of TiO2 and the support panel for ZnO crystal growth was reported for the synthesis of ZnO/TiO2/Ti3C2Tx hybrids with serial unique 3D architectures via a facile solvothermal method. The morphology changed from blooming flowers (especially for a regular 3D hexagon blooming rose) to ice-cream ball, macaron, hamburger, and urchin morphologies with an increase in the Ti3C2Tx concentration. The special morphologies were controlled by the direction and the support of ZnO growth that influenced by the functional groups and morphology of Ti3C2Tx. The distinctive in situ formation of multi-layered interphases was originated from the morphology of regular 3D flowers with separated 2D nanosheets, and the co-growth of the component simultaneously increased interfacial compatibility. Both of them were beneficial to enhance the electromagnetic wave absorption (EWA) performances. All the series of composites exhibited better EWA properties than TiO2/Ti3C2Tx without the hierarchical structure, manifesting that the synergistic effect of component design and hierarchical architectures played a crucial role in EWA performances. Among the composites, S4 that had a spherical blooming flower morphology exhibited the minimum reflection loss of −31.96 dB at a thickness of 2.5 mm, and the effective frequency bandwidth reached up to 2.24 GHz at a thickness of 5 mm. The reasons for the differences in EWA properties of the series of composites were discussed in detail from aspect of EWA mechanism. This work provides a new idea for the rational design of high-performance absorbers.

Hierarchical 3D flowers of 1T@2H-MoS2 assembled with an array of ultrathin nano-petals for high-performance supercapacitor electrodes

Hierarchical 3D flowers of 1T@2H-MoS2 assembled with an array of ultrathin nano-petals for high-performance supercapacitor electrodes

Efficient activation of peroxydisulfate by 3D flower spherical-like Fe–NC for organic contaminant removal: Fe(IV)=O as a dominant species

The high-valent iron-oxo species (Fe(IV)O) exhibit great prospects for the removal of organic contaminants in iron-mediated persulfate activation. Nevertheless, an adequate research of the mechanisms involved in Fe(IV)-based activation processes and organic degradation remains elusive. Here, an Fe encapsulated in N-doped carbons catalyst (2Fe–NC) with three-dimensional flower shape and mesoporous structure was developed, which can 100 % remove various organic pollutants such as chloramphenicol (CAP), sulfamethoxazole, amoxicillin, benzoic acid, and bisphenol A within 30 min by peroxydisulfate (PDS) activation. In the oxidation system, 2Fe–NC as an electron transfer medium was critical to mediate electron transfer from organic compound to PDS, accompanied by the redox cycle of Fe(IV)/Fe(II) and Fe(IV)/Fe(III). Multiple experiments reveal that the oxidation mechanism of 2Fe–NC@PDS system is similar to the dioxygen activation mechanism of binuclear active sites, which activates PDS to form surface-active Fe(IV)O species without producing radicals. The two pathways of CAP degradation simulated by density functional theory calculations release 6.92 and 4.23 eV, respectively, which is thermodynamically favorable. Overall, the new insights gained in this work offer a significant route to design more effective advanced oxidation processes for refractory contaminant treatment.

Fabrication of BiCuOS nanoflowers acting as nanoarrays on photonic nanoparticles for chemo-photothermal therapy

In recent years, 3D flower shaped nanostructures with an ability to improve internal photo reflections and absorptions is gaining popularity for the development of photo-thermal heat generating materials for cancer therapy. The use of bimetallic oxysulfide materials as photo-thermal agent is especially interesting as it is not only resulting in heat generation by absorbing laser light in the biological window but also participates in reactive oxygen species generation in tumor environment. In this work, we have reported a novel flower shaped BiCuOS nanostructures made of CuS base structures with vertical nanoarrays of bismuth oxide nanoplates for synergistic chemo-photothermal cancer therapy. Notably, 2D nanoplates (∼150 ± 50 nm in length and thickness of about ∼25 nm) could be seen grown in the form of nanoflowers (NFs) of 800 ± 100 nm in size on CuS base structures. The electronic structure, density of states, bond angle, bond length and thermal stability of formed NFs were investigated by density functional theory and molecular dynamic studies. The photo-thermal conversion efficiency was increased as a function of NF concentration. The percentage of doxorubicin released was estimated to be only ∼4% even after one day of incubation at pH 7.4 which increased to 38 and 45% at pH 5.5 without and with near infra-red light exposure, respectively. The cell viability experiments with fibroblast cells and red blood cells exhibited excellent biocompatibility of BiCuOS NFs. The synthesized BiCuOS NFs showed excellent anticancer activity against Hep-2 cells. Hence, the BiCuOS NFs reported here have huge potential for use as novel dual performing chemo-and-photothermal agent for advanced cancer therapy.

Pompom 3D flower like carbon-based Mn3O4 thin film electrodes for high performance supercapacitors

Manganese oxides have received a lot of attention as positive electrode materials for supercapacitors, but they still present challenges due to their weak electrical conductivity, lack of electroactive sites, and slow charge transfer kinetics. Herein, utilizing the electron beam evaporation technique, we effectively create pompom 3D flower-like C/Mn3O4 particles on Au/Ti/SiO2/(textured) Silicon (ATS) substrates with a few nanometers thickness. High accessibility to active species is provided by the linked carbon with Mn3O4 and the flower-shaped particles with multiple petals, which further enhance charge transfer kinetics. As a result, C/Mn3O4 thin film electrodes showed outstanding cycling stability of 89% even after 10,000 cycles and a reversible capacity of 1452 Fg−1 at 1 mVs−1 scan rate. The C/Mn3O4 thin film-based electrodes improved electrochemical performance is attributable to their unique surface topology.

Using geometric morphometrics to determine the "fittest" floral shape: A case study in large-flowered, buzz-pollinated Meriania hernandoi.

Floral shape (relative arrangement and position of floral organs) is critical in mediating fit with pollinators and maximizing conspecific pollen transfer particularly in functionally specialized systems. To date, however, few studies have attempted to quantify flowers as the inherently three-dimensional (3D) structures they are and determine the effect of intraspecific shape variation on pollen transfer. We here addressed this research gap using a functionally specialized system, buzz pollination, in which bees extract pollen through vibrations, as a model. Our study species, Meriania hernandoi (Melastomataceae), undergoes a floral shape change from pseudocampanulate corollas with more actinomorphically arranged stamens (first day) to open corollas with a more zygomorphic androecium (second day) over anthesis, providing a natural experiment to test how variation in floral shape affects pollination performance. In one population of M. hernandoi, we bagged 51 pre-anthetic flowers and exposed half of them to bee pollinators when they were in either stage of their shape transition. We then collected flowers, obtained 3D flower models through x-ray computed tomography for 3D geometric morphometric analyses, and counted the pollen grains remaining per stamen (male pollination performance) and stigmatic pollen loads (female pollination performance). Male pollination performance was significantly higher in open flowers with zygomorphic androecia than in pseudo-campanulate flowers. Female pollination performance did not differ among floral shapes. These results suggest that there is an "optimal" shape for male pollination performance, while the movement of bees around the flower when buzzing the spread-out stamens results in sufficient pollen deposition regardless of floral shape.

Reaction time influence on copper tin sulfide micro flowers for enhanced electrochemical hydrogen evolution reaction (HER) performance

Herein, we report the effective way to optimize the copper tin sulfide (Cu2SnS3) micro flowers via a simple hydrothermal method using different reaction times, which could enhance the fabricated electrocatalyst in electrochemical water splitting applications. The prepared Cu2SnS3 was identified by X-ray diffraction (XRD) analysis, which demonstrated the formation of triclinic phase Cu2SnS3 with a=0.664, b=1.151 and c=1.993 nm, respectively. Phase confirmation was further analyzed by using Raman and Fourier-transform infrared (FTIR) spectroscopy, which also demonstrated pure tetragonal copper tin sulfide (CTS) phase. The morphology of the copper tin sulfide (CTS) materials was explored with the help of scanning electron microscopy (SEM) and transmission electron microscopy (TEM) studies, which confirmed crystalline nature of triclinic copper tin sulfide (CTS) 3D hierarchical micro flowers. The prepared electrocatalyst was further characterized employing Energy-dispersive (EDX) and X-ray (XPS) spectroscopy. It exhibited chemical composition of Cu2p, Sn3d, and S2p in stoichiometric ratio with an atomic percentage of Cu, Sn, and S being 37.5, 40.7, and 21.7%, respectively. CTS-16 h exhibited 151 mV to afford 10 mA/cm2 and 139 mV/dec Tafel slope value, which was demonstrated by electrochemical characterizations. Moreover, the efficient electrocatalyst of CTS-16 h exhibited 131.5 cm2 electrochemical active surface area, while the other catalysts such as CTS-4 h, CTS-8 h and CTS-24 h were 49.25, 67.5, and 107.5 cm2 respectively. The CTS-16 h electrode shows excellent stability towards long-term CA test for one day with 94% retention. Therefore, the overall result suggests that the synthesized material provided a new approach for the noble metal catalysts substitute, and it is a potential material for clean energy systems.

Experimental and theoretical insights into colossal supercapacitive performance of graphene quantum dots incorporated Ni3S2/CoS2/MoS2 electrode

Transition metal sulfides (TMS) are promising electrode materials for supercapacitor applications due to their unmatchable advantages. To overcome the deficiency of individual metal sulfides, the combination of one or more pseudocapacitive transition metals with conductive carbon material can be a plausible solution. In this work, a simple and one-step hydrothermal synthesis method is used to fabricate the flower-like Ni3S2/CoS2/MoS2 (NCMS) and Ni3S2/CoS2/MoS2-GQDs (NCMS-G) directly on Ni foam and used it as a binder-free electrode for high-performance supercapacitor applications. The NCMS-G-2.5 electrode possessed colossal specific capacitance (2364 Fg−1 at the current density of 2 Ag−1), excellent rate capability (55 % at the current density of 10 Ag−1), as well as good cycling stability (93 % retention after 10,000 cycles at the current density of 20 Ag−1). Furthermore, assembled NCMS-G-2.5//rGO asymmetric supercapacitor (ASC) device delivered an excellent energy density of 84.8 Wh kg−1 and superior cycling performance (98 % capacitance retention after 10,000 cycles). We have investigated the interactions between Ni3S2/CoS2/MoS2 and carbon based nanostructure GQDs employing state-of-the-art Density Functional Theory (DFT) simulations. The interactions between Ni3S2/CoS2/MoS2 and GQDs is not only long range van der Waals interactions, but also chemical interactions involving charge transfer from metal 3d orbital to C 2p orbital of GQDs are also present. Due to this synergic effect, there is enhancement in electronic states near Fermi level which may improve the conductivity of the hybrid structure. Enhanced quantum capacitance, improved conductivity and increased surface area for the hybrid structure may attribute towards superior charge storage performance for the hybrid structures which support experimental data. It is expected that the fabricated, unique, 3D flower NCMS-G-2.5 has potential prospects for developing advanced and high-performance energy storage devices.

Morphology evolution of bimetallic Ni/Zn-MOFs and derived Ni3ZnC0.7/Ni/ZnO used to destabilize MgH2

Herein, 3D porous flower-like Ni/Zn-MOFs are synthesized via a simple solvothermal method. The reaction time shows obvious effects on the morphology evolution of Ni/Zn-MOFs, and the morphology evolution from plate to 3D flower is governed by a “nucleation–dissolution–renucleation” mechanism. Nonstoichiometric bimetallic carbide-containing composites (Ni3ZnC0.7/Ni/ZnO composites) are obtained through the simple calcination of Ni/Zn-MOFs under 4 MPa H2, suggesting that ZnO cannot be reduced and Ni3ZnC0.7 is stable even under 24 h of hydrogen treatment. The MgH2-5 wt% Ni3ZnC0.7/Ni/ZnO-3 composite began to dehydrogenate at 230 °C and 5 wt% H2 can still be released within the initial 1 h at 573 K. The hydrogen absorption capacity of the composite reached 2.57 wt% H2 at 423 K within 600 s. Interestingly, the composite can still absorb 0.78 wt% H2 at 353 K within 60 min. Compared to pure MgH2, the activation energy (Ea) of hydrogen absorption and dehydrogenation of the composite decreased to 44.85 and 93.06 KJ/mol, respectively. Comparing the cases of Ni3ZnC0.7, Ni, and ZnO addition clearly reveals that Ni3ZnC0.7 and Ni are the primary catalysts in these improvements. The Ni3ZnC0.7/Ni/ZnO-3 composite will react with MgH2 during the absorption–desorption cycle, and the in situ generated Mg2Ni/Mg2NiH4 acts as a “hydrogen pump” to reduce the potential barrier for the dissociation and recombination of H2. Trace amounts of MgZn2 can promote the formation of Mg/MgH2 and the resulting minor expansion and contraction during phase changes provides more paths for hydrogen diffusion. This study clearly demonstrates the efficient catalytic activity of nonstoichiometric bimetallic carbides and provides a promising catalyst design for Mg-based hydrogen storage materials.

A new technique for 3D printing dielectric structures using aerosol-jettable photopolymers

In this article, we report the development of a new method for the 3D printing of dielectrics. An aerosol-jet printer is used to deposit overlapping layers of photopolymer material under ultraviolet floodlight in the assembly of ramping microstructures in situ without the need for supporting structures. Printing is conducted using an in-house photodielectric ink, the development of which is presented with an emphasis on dielectric and mechanical bulk material characterization. Low dielectric loss at the X-band and structural strength are demonstrated, followed by print characterization wherein the driving mechanisms of the new method are explored, tied to print conditions, and related to specific material properties. Finally, a complex structure in the form of a 3D flower is printed to demonstrate the controlled and repeatable performance of the proposed technique.