1D Nanorods Research Articles

Design of hierarchical integration superbranched Ni–S clusters for efficient, stable hydrogen production

Transition metal sulfides (TMSs), especially iron-based metals (Fe, Co, Ni), were considered the most potential catalysts to replace noble metal-based materials for hydrogen evolution reaction (HER). This work selected metal ions as a variable to modulate the catalytic activity. Designing an electrode consisting of iron-based metal atoms sulfides sweeper-like hyperbranched clusters grown on nickel foam (NF) for HER. This particular structure consisted of 1D nanorods and adequate exposure of the lattice dislocation to exhibit enhanced electrocatalytic activity with low overpotential (135.9 mV) in alkaline conditions at 10 mA cm−2. In addition, stability test results showed that the electrode exhibited good durability. The enhanced electrocatalytic activity of Ni–S could be owing to high electrical conductivity characteristic, the hierarchical structure constituted with NF and the large active surface area of the self-grown electrode further facilitating the production of H2. The Ni sites on the Ni3S2 (110) crystal faces facilitated H adsorption, and all radical reactions under applied voltage proceed spontaneously. This work guides the selection and development of substrates for the design of synthetic transition metal catalysts, leading to cost-effective and efficient electrocatalytic hydrogen production.

From kesterite 2D nanosheets to wurtzite 1D nanorods: controllable synthesis of Cu−Zn−Sn−S and their application in electrocatalytic hydrogen evolution

As typical quarternary copper-based chalcogenides, Cu–Zn–Sn–S nanocrystals (CZTS NCs) have emerged as a new-fashioned electrocatalyst in hydrogen evolution reactions (HERs). Oleylamine (OM), a reducing surfactant and solvent, plays a significant role in the assisting synthesis of CZTS NCs due to the ligand effect. Herein, we adopted a facile one-pot colloidal method for achieving the structure evolution of CZTS NCs from 2D nanosheets to 1D nanorods assisted through the continuous addition of OM. During the process, the mechanism of OM-induced morphology evolution was further discussed. When merely adding pure 1-dodecanethiol (DDT) as the solvent, the CZTS nanosheets were obtained. As OM was gradually added to the reaction, the CZTS NCs began to grow along the sides of the nanosheets and gradually shrink at the top, followed by the formation of stable nanorods. In acidic electrolytic conditions, the CZTS NCs with 1.0 OM addition display the optimal HER activity with a low overpotential of 561 mV at 10 mA/cm2 and a small Tafel slope of 157.6 mV/dec compared with other CZTS samples. The enhancement of HER activity could be attributed to the contribution of the synergistic effect of the diverse crystal facets to the reaction.

Regulating Charge Carrier Dynamics in Stable Perovskite Nanorods for Photo-Induced Atom Transfer Radical Polymerization.

Semiconducting nanocrystals have attracted world-wide research interest in artificial photosynthesis due to their appealing properties and enticing potentials in converting solar energy into valuable chemicals. Compared to 0D nanoparticles, 1D nanorods afford long-distance charge carriers separation and extended charge carriers lifetime due to the release of quantum confinement in axial direction. Herein, stable CsPbBr3 nanorods of distinctive dimensions are crafted without altering their properties and morphology via grafting hydrophobic polystyrene (PS) chains through a post-synthesis ligand exchange process. The resulting PS-capped CsPbBr3 nanorods exhibit a series of enhanced stabilities against UV irradiation, elevated temperature, and polar solvent, making them promising candidates for photo-induced atom transfer radical polymerization (ATRP). Tailoring the surface chemistry and dimension of the PS-capped CsPbBr3 nanorods endows stable, but variable reaction kinetics in the photo-induced ATRP of methyl methacrylate. The trapping-detrapping process of photogenerated charge carriers lead to extended lifetime of charge carriers in lengthened CsPbBr3 nanorods, contributing to a facilitated reaction kinetics of photo-induced ATRP. Therefore, by leveraging such stable PS-capped CsPbBr3 nanorods, the effects of surface chemistry and charge carriers dynamics on its photocatalytic performance are scrutinized, providing fundamental understandings for designing next-generation efficient nanostructured photocatalyst in artificial photosynthesis and solar energy conversion.

N-doped carbon/TiO2 composites with enhanced photocatalytic performance for the removal of organic pollutants

A nitrogen doped carbon (NC) material, obtained via the camphor combustion technique, was used to develop a TiO2 based visible light photocatalyst. Various physical and analytical techniques were used to characterize the structural, morphological and photocatalytic study of the obtained catalyst. The results illustrate that N-doped carbon/TiO2 composites (NCT) exhibit NC spheroids embedded on the surface of 3D flower-like hierarchical TiO2 microspheres composed of 1D nanorods. The presence of C-N, C-C, N-Ti-O and Ti-O-C was successfully confirmed by the FTIR study. The UV–vis absorption spectra revealed the energy bandgap between 2.4 and 2.8 eV, confirming the enhanced visible light absorption ability for the NCT samples with increased wt% of N-doped carbon. The NCT sample has achieved 86% photodegradation of methyl orange in an aqueous solution within 25 min under mercury light irradiation and 85% within 10 min under natural sunlight irradiation. In addition, NCT3 composite degrades 30% of BPA (20 ppm) within 210 min under mercury light irradiation. The enhanced catalytic activity of the composite material was ascribed due to the high surface area, large pore size and high pore. Also, the high absorption in the visible range and efficient charge transfer of the charge carriers were credited for the enhanced photocatalytic activity of the NCT3 sample.

Shape Anisotropy-Governed High-Performance Nanomagnetosol for In Vivo Magnetic Particle Imaging of Lungs.

Caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), coronavirus disease 2019 (COVID-19) has shown extensive lung manifestations in vulnerable individuals, putting lung imaging and monitoring at the forefront of early detection and treatment. Magnetic particle imaging (MPI) is an imaging modality, which can bring excellent contrast, sensitivity, and signal-to-noise ratios to lung imaging for the development of new theranostic approaches for respiratory diseases. Advances in MPI tracers would offer additional improvements and increase the potential for clinical translation of MPI. Here, a high-performance nanotracer based on shape anisotropy of magnetic nanoparticles is developed and its use in MPI imaging of the lung is demonstrated. Shape anisotropy proves to be a critical parameter for increasing signal intensity and resolution and exceeding those properties of conventional spherical nanoparticles. The 0D nanoparticles exhibit a 2-fold increase, while the 1D nanorods have a > 5-fold increase in signal intensity when compared to VivoTrax. Newly designed 1D nanorods displayed high signal intensities and excellent resolution in lung images. A spatiotemporal lung imaging study in mice revealed that this tracer offers new opportunities for monitoring disease and guiding intervention.

Insights into the Relationship between the Microstructure and the Catalytic Behavior of Fe2(MoO4)3 during the Ethanolysis of Naomaohu Coal.

Ethanolysis is an effective method to depolymerize weak bonds in lignite under mild conditions, which can result in the production of high-value-added chemicals. However, improving ethanolysis yield and regulating its resulting product distribution is a big challenge. Hence, exploiting highly active catalysts is vital. In this work, Fe2(MoO4)3 catalysts with zero-dimensional nanoparticles, one-dimensional (1D) nanorods, two-dimensional (2D) nanosheets, and three-dimensional (3D) nanoflower structures were successfully prepared and applied in the ethanolysis of Naomaohu coal. The results showed that for all samples, the yield of ethanol-soluble portions (ESP) was significantly improved. The highest yield was obtained for the Fe2(MoO4)3 nanorods, with an increase from 28.84% to 47.68%, and could be attributed to the fact that the Fe2(MoO4)3 nanorods had a higher number of exposed active (100) facets. In addition, the amounts of oxygen-containing compounds, such as ethers, esters, and phenols, increased significantly. The mechanism of ethanolysis catalyzed by the Fe2(MoO4)3 nanorods was also studied using phenylbenzyl ether (BOB) as a model compound. BOB was completely converted at 260 °C after 2 h. It is suggested that Fe2(MoO4)3 nanorods can effectively break the C-O bonds of coal macromolecules, thus promoting the conversion of coal.

Photocontrolled Reversibly Chiral-Ordered Assembly Based on Cucurbituril.

Chirality transfer and regulation, accompanied by morphology transformation, arouse widespread interest for application in materials and biological science. Here, a photocontrolled supramolecular chiral switch is fabricated from chiral diphenylalanine (l-Phe-l-Phe, FF) modified with naphthalene (2), achiral dithienylethene (DTE) photoswitch (1), and cucurbit[8]uril (CB[8]). Chirality transfer from the chiral FF moiety of 2 to a charge-transfer (CT) heterodimer consisting of achiral guest 1 and achiral naphthalene (NP) in 2 has been unprecedented achieved via the encapsulation of CB[8]. On the contrary, chirality transfer from chiral FF to NP cannot be conducted in only guest 2. Crucially, induced circular dichroism of the heterodimer can be further modulated by distinct light, attributing to reversible photoisomerization of the DTE. Meanwhile, topological nanostructures are changed from one-dimensional (1D) nanofibers to two-dimensional (2D) nanosheets in the orderly assembling process of the heterodimer, which further achieved reversible interconversion between 2D nanosheets and 1D nanorods with tunable-induced chirality stimulated by diverse light.

Mono-coordinated defect toward metal-organic framework anode with remarkable electrochemical performance

The ultrahigh porosity and ligand tunability features of Metal organic frameworks (MOFs) make them excellent platforms for energy conversion and storage. Nevertheless, the practical applications of these materials are restricted due to their low conductivity and insufficient redox sites. Herein, a mono-coordinated ferrocenecarboxylic acid (Fc) was incorporated into MIL-53(Al) via a straightforward hydrothermal process to regulate the local coordination structure. In comparison to the MIL-53(Al) with a capacity of only 113 mAh/g, the MIL-53(Al)-Fc anode delivered an ultrahigh reversible capacity of 823 mAh/g over 700 cycles at 1 A·g−1. Furthermore, the developed MIL-53(Al)-Fc anode can exhibit a super high rate capacity of 489 mAh/g at 2 A/g. Importantly, it is discovered that the incorporation of Fc-doped MIL-53(Al) leads to a sustained increase in capacity throughout the process of charge/discharge cycling. Through a combination of experimental analysis and theoretical calculations, it has been demonstrated that the presence of unsaturated coordination metal sites into Fc-doped MIL-53(Al) not only improve its conductivity and the kinetics of Li+ storage, but also expose more reaction sites for Li+ facile desorption. This, in turn, facilitate the order–disorder transition during cycles. Meanwhile, the 1D nanorods morphologies can provide superior interaction between the active sites and electrolyte. Thus, this work will pave a new way to engineer advanced MOFs electrode materials for practical utilization of ultrahigh performance LIBs.

Superior cyclic stability and electrochemical performance of La supported Bi2S3@g-C3N4//rGO heterostructure composite for asymmetric supercapacitor devices

To improve the cyclic stability of Bi2S3 transition metal dichalcogenides (TMD), rare-earth lanthanum (La) supported Bi2S3@g-C3N4 was synthesized via a simple solvothermal method. The physicochemical properties of the electrode material were investigated by using various characterization techniques such as XRD, FTIR, FT Raman, HRSEM, XPS, BET, HRTEM and SAED. From HRTEM image that La doped Bi2S3@g-C3N4 heterostructure composite revealed in which the 2D layered g-C3N4 nanosheets decorated 1D nanorods of La doped Bi2S3. 10 mol% La doped Bi2S3@g-C3N4 heterostructure composite attained a higher specific capacity of 1880 C/g at 1 A/g by increasing active sites for diffusion ions due to enhanced surface area (131.4 m2/g). The aqueous asymmetric supercapacitor device was assembled using the La doped Bi2S3@g-C3N4 positive electrode and the rGO negative electrode with 1 M KOH electrolyte. This supercapacitor displayed a specific capacitance of 61 F/g at 2 mA/g, a maximum power density of 666 W/kg, an energy density of 1.7 W h/kg, and a capacitance preservation of 64% even after 10,000 cycles. 10 mol% La doped Bi2S3@g-C3N4 heterostructure composite persist excellent kinetic and electrochemical reversibility, intrinsic electrical conductivity, and remarkable cyclic stability.

Effect of perylene assembly shapes on photoelectrochemical properties and ultrasensitive biosensing behaviors toward dopamine.

In this study, a photoelectrochemical (PEC) sensor based on perylene diimide derivatives (PDIs) was developed for the ultrasensitive quantification of dopamine (DA). PDIs were able to form self-assembled semiconductor nanostructures by strong π-π stacking, suitable for photoactive substances. Moreover, the shape of the PDI significantly affected the PEC properties of these nanostructures. The results showed that amino PDI with two-dimensional (2D) wrinkled layered nanostructures exhibited superior PEC properties relative to one-dimensional (1D) nanorods and fiber-based nanostructures (methyl and carboxyl PDIs). Based on these results, a mechanism for PEC sensor action was then proposed. The presence of 2D amino-PDI resulted in accelerated charge separation and transport. Furthermore, dopamine acted as effective electron donor to cause an increase in photocurrent. The as-obtained sensor was then used to detect small molecules like DA. A blue light optimized sensor at an applied potential of 0.7V showed a detection limit of 1.67nM with a wide linear range of 5nM to 10μM. On the other hand, the sensor presented acceptable reliability in determining DA in real samples. A recovery rate between 97.99 and 101.0% was obtained. Overall, controlling the morphology of semiconductors can influence PEC performance, which is a useful finding for the future development of PEC sensors.

Nanoscale goldbeating: Solid-state transformation of 0D and 1D gold nanoparticles to anisotropic 2D morphologies.

Goldbeating is the ancient craft of thinning bulk gold (Au) into gossamer leaves. Pioneered by ancient Egyptian craftsmen, modern mechanized iterations of this technique can fabricate sheets as thin as ∼100 nm. We take inspiration from this millennia-old craft and adapt it to the nanoscale regime, using colloidally synthesized 0D/1D Au nanoparticles (AuNPs) as highly ductile and malleable nanoscopic Au ingots and subjecting them to solid-state, uniaxial compression. The applied stress induces anisotropic morphological transformation of AuNPs into 2D leaf form and elucidates insights into metal nanocrystal deformation at the extreme length scales. The induced 2D morphology is found to be dependent on the precursor 0D/1D NP morphology, size (0D nanosphere diameter and 1D nanorod diameter and length), and their on-substrate arrangement (e.g., interparticle separation and packing order) prior to compression. Overall, this versatile and generalizable solid-state compression technique enables new pathways to synthesize and investigate the anisotropic morphological transformation of arbitrary NPs and their resultant emergent phenomena.

Magnetocaloric properties of shape-dependent nanostructured Gd2O3 oxide particles

Single-phase Gd2O3 nanostructures with different morphologies, such as nanoparticles, nanorods, nanospheres, and nanoplates, were synthesised. Gd2O3 1D nanorods and 2D nanoplate architectures were prepared via the hydrothermal method, while 3D hollow nanospheres were synthesised via homogeneous precipitation. The magnetic and magnetocaloric properties of Gd2O3 nanostructured particles were studied as functions of temperature and field. The material demonstrated typical paramagnetic behaviour in the measured temperature range of 3–300 K. The magnetic entropy change (−ΔS M ) was determined from the magnetic isotherms measured in the 3–38 K temperature range in the field up to 5 T. The maximum change in magnetic entropy value 11.2 J kg−1 K−1 for the nanoplate, 9.4 J kg−1 K−1 for the nanorod, 9.2 J kg−1 K−1 for the nanosphere, and 10.7 J kg−1 K−1 for the nanoparticle sample was observed at temperature 5 K for the magnetic field of 5 T. Owing to large these Gd2O3 nanostructured particles would be considered promising materials for magnetic refrigeration at cryogenic temperatures.

Self-healing in CdTe nanostructures: Insights into their structural stability and optical properties using first principles theory

Herein, we report a first-principle density functional theory-based study on CdTe nanostructures in 1D (nanorods and nanotubes) and 2D (ultra-thin slabs, monolayers) systems created within the top-down approach in terms of various properties, such as electronic structure, structural stability, and optical properties, and the effect of surface passivation on these properties. A substantial quantum confinement effect is observed with the increase in the energy band gap observed when the thickness or diameter of the nanostructure becomes less than the excitonic Bohr radius of CdTe. For all of the nanostructures studied, the structural stability improves upon surface passivation. The dielectric properties suggest that all of the passivated and specific unpassivated nanostructures are suitable for optoelectronic applications. Among the nanostructures studied, the 2D system prepared in the <110> orientation and the nanotube derived from the <111> monolayer are the most stable and show the least enhancement (0.1–0.2 eV) in the energy band gap upon passivation. This minimal change may be due to significant self-healing in the pristine structures. The charge density plots obtained for the relaxed and unrelaxed pristine structures show the surface had undergone reconstruction as a self-healing mechanism. The stability, self-healing ability, and energy bandgap of these nanostructures suggest their applicability in optoelectronic devices.

Highly efficient electrooxidation of 5-hydroxymethylfurfural (HMF) by Cu regulated Co carbonate hydroxides boosting hydrogen evolution reaction

The biomass electrochemical oxidation has attracted worldwide attention owning to its carbon-neutral and sustainable nature. Here, different morphologies of CoCu-carbonate hydroxides (CH) electrodes are prepared through one-step hydrothermal method for 5-hydroxymethylfurfural electrocatalytic oxidation (HMF-ECO) to high-valued 2,5-furandicarboxylic acid (FDCA) for the first time. The results illustrate that Cu can regulate CoCu–CH morphologies from 1D nanorods to 2D ultra-thin nanosheets besides modulating the catalytic compositions. The optimal Co1Cu1–CH exhibits hybrid nanostructures containing the 1D nanorods and 2D ultra-thin nanosheets, which has the largest ECSA and specific surface area, as well as the smallest Tafel slope and impedance. The oxidation potential of HMF-ECO is 1.42 V vs RHE with the conversion of HMF 99.57%, the selectivity for FDCA 99.91%, and the FE 98.88%. In addition, Cu can promote the conversion of Co2+ to the favorable Co3+ for HMF-ECO on the catalyst surface. Density functional theory calculation indicates that Cu can improve charges transfer to HMF and lower its adsorption energy. In situ Raman spectra tests indicate that cobalt species is the active site for HMF-ECO. Furthermore, at 1.42 V vs RHE, the coupling of HMF-ECO and hydrogen evolution reaction shows that the cathodic hydrogen evolution rate is 92.33 L h−1 m−2, which is 3.69 times more than water splitting. This work provides a special structures material to process intensification of HMF electrooxidation coupling hydrogen production.

A study on structural and luminescence properties of novel orange-red emitting Sm3+ doped Sr3LiSbO6 nanorod phosphor with high color purity for W-LEDs

Being a simple synthesis technique, solid state reaction (SSR) method seldom generates 1D nanorod structured phosphors. In this article, we present a systematic study on the structural, morphological and spectroscopic properties of double perovskite type Sr3LiSbO6:Sm3+ phosphors prepared by the conventional SSR method. X-ray diffraction (XRD) analysis confirm the successful synthesis of hexagonal structured Sr(3−x)LiSbO6:xSm3+(x = 0,0.06,0.08,0.1,0.2,0.4 mol) phosphors and Fourier-Transform Infrared spectra (FTIR) revealed the molecular vibrations present in the samples. The surface morphology was confirmed by Field Emission Scanning Electron Microscopy (FE-SEM) and Transmission Electron Microscopy (TEM) analysis. The TEM images illustrate the one – dimensional nanorod structure of the phosphor with an average diameter of 35 nm and length of 350 nm. In photoluminescence (PL) spectroscopy, under an excitation of 406 nm the characteristic emissions at 564, 601, 649 and 710 nm, which correspond to the transitions from 4G5/2 to 6H5/2, 6H7/2, 6H9/2 and 6H11/2 respectively of Sm3+ were obtained with strong orange - red emission at 601 nm. The concentration quenching was observed at x = 0.1 mol and the critical distance for energy transfer between Sm3+ ions was calculated to be 14.32 Å. The energy transfer mechanism was determined to be dipole-dipole interaction. The decay analysis confirms the shorter life time of the activator ions in the microseconds (µs) range. The estimated CIE coordinates are (0.6057, 0.397) in the warm CCT region with 100 % color purity. Hence these results suggests that Sm3+ doped Sr3LiSbO6 to be a potential orange-red nanorod phosphor in the design of various photonic devices such as phosphor converted LEDs (pc- LEDs).

Enhanced electrocatalytic activity through facet engineering of single-crystal bimetallic hydroxide

Facet engineering is frequently employed to give catalysts the desired surface atom configurations and morphologies for enhanced catalytic performances. However, constructing single-crystal bimetallic hydroxides and understanding their facet effects are still challenging. Here, by adjusting the dissociated OH− concentration, 2D nanosheets (NSs) exposing (020) facet (CoCu(020) NS) and 1D nanorods mainly exposing (031) facet of single-crystal bimetallic kolwezite are precisely synthesized. CoCu(020) NS shows superior performances in alkaline hydrogen evolution and anion exchange membrane water electrolyzer. Combining characterizations and theoretical calculations shows that CoCu(020) NS exhibits a local geometric structure with low coordination number and an electron structure with appropriate d-band center level and charge density of active sites, both of which are strongly correlated with the adsorption properties of H2O and intermediates. This work might pave the way for development of single-crystal bimetallic hydroxides and further applications of facet engineering in electrocatalysis.

Grapefruit juice containing rich hydroxyl and oxygenated groups capable of transforming 1D structure of NiCo2O4 into 0D with excessive surface vacancies for promising energy conversion and storage applications

Fabrication of an efficient electrode material is highly demanded for obtaining high energy conversion electrochemical system. In this study, we describe a green and innovative approach of using grape fruit juice as a high carrier of reducing and surface modifying agents for manipulating the surface properties of nickel‑cobalt bimetallic oxide NiCo2O4 nanostructures. Different amounts of grape fruit juice were used to discern its role on the morphological and surface vacancies of NiCo2O4 nanostructures during oxygen evolution reaction (OER). Importantly, the physical characterization revealed the morphological transformation of NiCo2O4 nanostructures from 1D nanorods to short range 0D nanoparticles. Furthermore, the surface studies have shown that NiCo2O4 nanostructures prepared with grapefruit juice have high density of surface vacancies and higher amount of Ni2+ and a Co2+ metallic ions on the surface of NiCo2O4 compare to pure NiCo2O4 nanostructures. The OER of electrodes modified with NiCo2O4 nanostructures, particularly (sample-2, 2 mL of grape fruit juice) gave rise to an overpotential value of 260 mV at 10 mAcm−2 in 1.0 M KOH aqueous solution along with high durability/stability for 40 h. Additionally, the obtained electrochemical impedance spectroscopy value of 80 Ω and active surface area of 18.1 μFcm−2 attested for the excellent OER performance of NiCo2O4 nanostructures (sample-2). Eventually, the proven enhancement in surface vacancies, alternation in the mixed oxidation states of both Ni and Co together with the morphological transformation that have been accomplished via the green, simple, and low-cost strategy of using grape juice make it a suitable option for large scale production of wide range of multifunctional metal oxides and related nanostructured materials for plethora of energy conversion and storage applications.

Facile synthesis of 2D acid-etched g-C3N4 nanosheets with 1D ZnO nanorods as a promising electrode material for supercapacitor

A low-cost, non-toxic nanocomposite of two-dimensional (2D) nanosheets of acid-etched graphitic carbon nitride (TGCN) and one-dimensional (1D) nanorods of zinc oxide (ZnO NRs) is prepared using one-step calcination method. The average size and diameter of ZnO nanorods in TGCN/ZnO (T-ZnO) nanocomposite is reduced to 0.5 and 0.73 times than pristine ZnO NRs, respectively. After the acid-etching process, the size of the T-ZnO nanocomposite is further reduced which enhanced its specific surface area to 16.82 m2/g as compared to pristine ZnO NRs (3.56 m2/g). T-ZnO NRs shows a specific capacitance of 398.47 F/g using 0.5 M H2SO4 which is higher as compared to T-ZnO NRs using 0.5 M Na2SO4 (278.16 F/g) and 6 M KOH (106.10 F/g). Using Electrochemical impedance spectroscopy, diffusion coefficient (D) value 1.85 × 10−11 is obtained for T-ZnO NRs (0.5 M H2SO4). T-ZnO NRs also exhibits a higher specific capacitance of 311.80 F/g at 1 A/g using 0.5 M H2SO4. The nanocomposite shows superior energy density of 97.43 Wh/kg at 750 W/kg of power density. The superior capacitance retention (>95 %) and stable coulombic efficiency (>80 %) of T-ZnO NRs enables the nanocomposite for practical applications in energy storage devices. The electric double layer (EDL) and pseudocapacitive (PC) contribution of 6.04 % and 93.96 % to the total specific capacitance of T-ZnO NRs is evaluated using Trasatti method. The capacitive and diffusion-controlled contribution is also investigated for T-ZnO NRs using Dunn's method. The practical aspect of a supercapacitor using leakage current and self-discharge is also tested for the T-ZnO NRs. T-ZnO NRs is a promising energy storage material to fill the gap in the ongoing energy crisis.

Temperature-Driven Synthesis of 1D Fe2O3@3D Graphene Composite Applies as Anode of Lithium-Ion Batteries

A series of Fe2O3-anchored three-dimensional graphene (3DG) composites are synthesized via hydrothermal and annealing methods. The Fe2O3 nanocrystals in composites display nanocubes, one-dimensional (1D) nanorods and ellipsoids at hydrothermal temperatures of 120 °C, 150 °C and 180 °C, respectively. Notably, the composite synthesized at 150 °C shows 1D Fe2O3 uniformly embedded in 3DG, forming an interpenetrating 1D-3D (three-dimensional) structure. This combined structure is beneficial in improving the electrochemical stability and accelerating the Li+ diffusion rate. When used as anode for lithium-ion batteries (LIBs), the optimized 1D-3D Fe2O3@3DG composite delivers a reversible specific capacity of 1041 mAh g−1 at 0.1 A g−1 and maintains a high reversible specific capacity of 775 mAh g−1 after 200 cycles. The superior electrochemical properties of Fe2O3@3DG are a result of the stable interpenetrate structure, enhanced conductivity, and buffered volume change. These results suggest that Fe2O3@3DG composites have significant potential as advanced anode materials for LIBs and the combined 1D-3D structure also provides inspiration for other electrode material structure design.

FeOOH decorated Sb2Se3@CdxZn1-xS core-shell nanorod heterostructure photocathode for enhancing photoelectrochemical performance

In this work, a core-shell heterostructure Sb2Se3@CdxZn1-xS photocathode was constructed on the Fluorine-doped Tin Oxide (FTO) by Vapor Transport Deposition (VTD) and hydrothermal method, then β-FeOOH was deposited on the surface of Sb2Se3@Cd0.8Zn0.2S. The investigation indicates that Sb2Se3@CdxZn1-xS has a one-dimensional (1D) nanorod structure, which can provide a fast carrier transmission channel. The introduction of a CdxZn1-xS shell can accelerate the charge separation of Sb2Se3 and type-II heterojunction between them can enhance the electron migration efficiency of Sb2Se3. Using β-FeOOH as the protective layer can not only protect the ternary photocathode from photocorrosion, but also act as a cocatalyst to enhance surface reaction kinetics. Photoelectrochemical (PEC) tests found that the composite photocathode Sb2Se3@Cd0.8Zn0.2S/β-FeOOH achieves a higher photocurrent density (0.252 mA/cm2), which is about 21 times higher than that of pure Sb2Se3 nanorod photocathode (0.012 mA/cm2) under the same condition, besides, it also exhibited more excellent stability during 1 h hydrogen production. This work provides an effective way to design and fabrication of nanostructures for high-efficiency water splitting photoelectrodes.