Heterostructured Nanomaterials Research Articles

Interfacial Charge Transfer in One-Dimensional AgBr Encapsulated inside Single-Walled Carbon Nanotube Heterostructures.

The advent of one-dimensional van der Waals heterostructure (1D vdWH) nanomaterials has provided valuable opportunities for the advancement of electronic or optical devices, as well as for exploring various condensed matter phenomena. Electron transfer is a fundamental process in host-guest interactions, significantly influencing nanoscale physicochemical processes. Elucidating the mechanism by which the host influences the electronic structure of the guest is essential for elucidating these interactions. This study reports the successful synthesis of a material system consisting of precisely resolved AgBr nanowires encapsulated within single-walled carbon nanotubes (SWCNTs) that has been successfully synthesized and utilized to investigate the intrinsic electron transfer across 1D vdWHs. Cyclic voltammetry (CV) was employed to investigate the 1D vdWH interaction between AgBr and SWCNTs, which provided a more intuitive and accurate characterization of the charge transfer from SWCNTs to AgBr. Furthermore, Kelvin probe force microscopy showed a 149 mV reduction in the average surface potential of carbon nanotubes after AgBr filling, supporting the efficacy of CV in probing electron dynamics in 1D vdWHs. Finally, theoretical calculations indicated a charge transfer of 0.11 e- per simulation cell, reinforcing the effectiveness of CV in assessing the interactions within 1D vdWHs.

In Situ Driven Formation of Anatase/Brookite/Rutile Heterojunction N/TiO2 Nanocrystals as Sustainable Visible-Light Catalysts.

Visible-light active anatase/brookite/rutile (A/B/R) ternary N-doped titania (N/TiO2) crystals are successfully prepared by a facile sol-gel method using titanium butoxide and benign N-dopant source, guanidinium chloride. Systematically varying the aging time (1, 4, 8, and 12 d), its influence on physicochemical properties of as-obtained spherical heterojunction nanomaterials is studied. Detailed characterizations confirm that a substantial amount of anatase (88% to 50%) is transformed to rutile (2% to 38%) via intermediate brookite phase (9% to 25%) as the function of aging time; not only the A/B/R phase content of the samples is tuned by sol-gel aging time of the precursors solution but also their optical-response and methylene blue photocatalytic properties are profoundly dictated. Notably under visible-light irradiation, the photostable rutile rich mesoporous A/B/R triphasic N/TiO2 (50% A, 12% B, 38% R) aged for 12 d demonstrates higher degradation activity (97%) with a faster degradation rate (0.033 min-1) than both lesser aged N/TiO2 and undoped titania. This enhancement is attributed to the synergistic effect of interstitial-N-doping and optimal A/B/R interfacial charge transfer that leads to higher light absorption, lower bandgap energy and well-separated charge carriers. The current work provides a new perspective for designing highly active visible-light heterostructure nanomaterials with controllable phase composition.

(Invited) Tuning Selective CO2 Electrohydrogenation Under Mid Temperature and Pressure

To address rising environmental concerns and energy challenges, it is highly desirable to develop green technologies for a sustainable future. Hydrogenation reactions are essential processes in the chemical industry, giving access to a variety of valuable compounds. Electrochemical CO2 hydrogenation using renewable electricity is considered one of the most promising pathways to reach the environmental economics. Among various electrochemical devices, a solid state electrolyzer working at intermediate temperatures has the advantages of high reaction rates and low overpotentials. As CO2 molecules is quite stable, it is critical to develop electrocatalysts with high activity to reduce electricity engagement. Also, CO2 hydrogenation has multiple pathways which normally results in low selectivity for a target product. A tunable electrocatalyst with high selectivity to different products is desirable for CO2 conversion reactions. Heterostructured nanomaterials attracts great attentions in electrochemical systems. With careful design, they can show very high activity and selectivity towards an electrochemical reaction pathway. In this work, we combine theoretical simulations, including density functional theory (DFT) and ab initio molecular dynamics (AIMD) calculations, with experimental methods (characterizations and electrochemical measurements) for rational design of highly efficient heterostructured nanomaterials for CO2 hydrogenations. We studied the strong metal-support interaction (SMSI) in a doped CeO2 supported noble metal nanoparticles (NPs) system using theoretical calculations. The results indicate that SMSI largely depends on chemical conditions of the support and particle size of dispersed metal NPs. By tuning the SMSI, we can successfully change the catalytic activity and selectivity towards CO2 hydrogenation reactions. Based on these findings, we designed tunable heterostructured nanomaterials for efficient hydrogenation reactions at intermediate temperatures. These predictions were further confirmed by experimental method. By using a combination of high-throughput theoretical calculations and electrochemical measurements, we successfully developed highly active catalysts for electrochemical CO2 hydrogenation reactions. This framework is also applicable to other electrochemical systems using heterostructured materials.

Ultra-trace leakage detection of 1, 2-dimethoxyethane in Lithium-Ion battery electrolyte via lacunary polyoxometalates-driven synthesis of NiO/Si-NiWO4/WO3 heterostructure nanofibers

Early detection of electrolyte leakage is crucial to prevent thermal runaway in lithium-ion batteries (LIBs). Gas sensors offer a potential solution, however, designing sensing materials that can sensitively identify organic molecules from electrolyte leakage remains a great challenge. Herein, the heterostructured NiO/Si-NiWO4/WO3 nanofibers (NFs) were achieved as a sensing material for highly sensitive detection of 1, 2-dimethoxyethane (DME), a typical electrolyte organic molecule. This was accomplished using the highly negatively charged lacunary polyoxometalates (POMs) TBA4H6[SiW9O34]·2 H2O (α-SiW9) and Ni2+ as precursors, resulting in a series of uniform Si-NiWO4/WO3 decorated NiO NFs synthesized through a two-step process involving electrospinning followed by thermal oxidation. By utilizing the synergistic effect of abundant active interfaces, rapid carrier transfer, and a large specific surface area inherent to NFs, the sensor shows high sensitivity (1.87–300 ppb DME), reliable reproducibility and stability, and superior selectivity. Moreover, the sensor is highly responsive to electrolyte leakage simulations, making it a strong candidate for safety systems of LIBs. The study outlines a cost-effective method for preparing NiO/Si-NiWO4/WO3 NFs, setting a foundation for developing various heterostructured nanomaterials with POMs as precursors.

High-performance positive electrode material of MXene/FeNi2S4 nanocomposite for flexible supercapacitor with large potential window

Developing heterostructured nanomaterials with abundant active sites and excellent electronic conductivity is essential to enhance the electrochemical activity of supercapacitors. Herein, MXene/FeNi2S4 composites, as a high-performance electrode material for the flexible supercapacitor, were fabricated using a simple probe sonication method. The formation of a 3D architecture can create abundant electrochemical active sites, promoting the charge transfer as well as the redox reactions. Accordingly, a supercapacitor electrode based on MXene/FeNi2S4 exhibited excellent electrochemical performances, with a high specific capacitance of 673 F/g at 1 A/g. When MXene/FeNi2S4 was used as the electrode material of an asymmetric supercapacitor, the device showed an outstanding specific capacitance of 141 F/g at 1 A/g in a large potential window of 1.8 V. Up to 90 % of this high specific capacitance was retained after 2000 charge–discharge cycles. Furthermore, the device displayed high values of both energy density (63.37 Wh/kg) and power density (900.98 W/kg). The device also exhibited stable electrochemical performances under high flex at the bending angle of 135°. The exceptional electrochemical performances of MXene/FeNi2S4 highlight its great potential as an excellent electrode material for the next generation of flexible energy storage devices.

Avocado seed biomass-assisted synthesis of heterostructure bismuth vanadate nanomaterial by combustion method for the application of electrochemical lithium battery storage and supercapacitor

With the global demand for lithium-ion batteries (LIBs), research is focused on developing advanced energy storage materials with high energy and power densities. Hetero-structured nanomaterials have garnered significant interest in energy storage applications based on their unique architecture providing sites for improved electrochemical activity. This work reports a facile single-step combustion synthesis of bismuth vanadate nanoparticles (BVNPs) using avocado seed powder, an economical and eco-friendly fuel source. By optimizing the precursor-to-fuel ratio to 1:1, highly pure phase BVNPs were obtained as characterized via XRD, FT-IR, SEM-EDAX, TEM, UV-DRS, PL, BET, and DLS analyses. When assessed as an electrode material for LIBs, the BVNP1:1 delivered an exceptional initial discharge capacity of 2166 mAhg−1 and a retention of ∼53 mAhg−1 over 90 cycles with 99% Coulombic efficiency. The BVNP1:1 electrode exhibited a maximum specific capacitance of 545.65 mF/cm2 at 2 mA/cm2 current density as a supercapacitor. The combination of scalable green synthesis, excellent phase purity, and superior electrochemical performance makes these BVNPs a promising and sustainable electrode material for forthcoming energy storage technologies to meet the surging energy needs.

Lacunary polyoxometalates-induced controllable synthesis of Fe2O3/Si-FeWO4 heterostructure nanotubes for selective sensing of m-xylene

Metal oxide-based gas sensors encounter challenges in effectively detecting hazardous benzenes due to their stability and structural similarities. Here we report an innovative in situ growth method for synthesizing Fe2O3/Si-FeWO4 heterostructure nanotubes (NTs) using highly negatively charged multivacant lacunary TBA4H6[SiW9O34]·2H2O (α-SiW9) and Fe3+ as precursors. A two-step process involving electrospinning followed by a thermal oxidation method was employed to synthesize a series of the uniform Si-FeWO4 decorated Fe2O3 heterostructure NTs. Considering the rich Fe2O3/Si-FeWO4 active interfaces, rapid electron transfer, and high specific surface area, the optimal Fe2O3/Si-FeWO4 based sensors demonstrate significantly higher sensitivity (S = 27.5) towards 50 ppm m-xylene in comparison to pristine Fe2O3 (S = 1.8). Furthermore, the Fe2O3/Si-FeWO4 exhibits excellent stability, humidity resistance, and high selectivity for m-xylene. This work offers an efficient, cost-effective strategy to synthesize Fe2O3/Si-FeWO4 heterostructure NTs, with prospects for synthesizing other advanced sensing heterostructure nanomaterials with lacunary polyoxometalates as precursors.

Exploring the Contribution of Intelligent Nanomaterials in Gas Sensing

AbstractGas sensors are crucial in various industries like chemicals, food processing, pharmaceuticals, health monitoring through breath analysis, as well as in household and environmental monitoring to ensure human safety. Chemo‐resistive gas sensors based on metal oxides convert gas information into electrical signals by interacting with adsorption and desorption processes. For metal oxide semiconductor gas sensors, sensitivity and selectivity enhancements are achieved through doping, functionalization, composite formations, heterojunction creation, and morphological adjustments. The formation of heterojunctions notably boosts the efficacy of the sensing material, leveraging synergistic effects to reinforce adsorption rates, catalytic activity acceleration, and the depletion interface for electrons and holes. Over the past few decades, nanomaterials have played a critical role in gas sensing applications. They have enabled the detection of a wide array of harmful and polluting gases, as well as volatile organic compounds serving as disease biomarkers. Additionally, incorporating heterostructure nanomaterials into heterojunctions significantly impacts sensing performance and detection speed. This review discussed various types of gas sensing devices, categorizing them based on the sensing elements employed, each possessing its own set of unique advantages and disadvantages. Nevertheless, the review underscored the importance of several key parameters and factors that influence the performance of gas sensors. Additionally, recent advancements in the utilization of nanomaterial composites for gas sensor applications, particularly in the detection of gases such as ammonia, hydrogen sulphide, and sulphur dioxide vapours, were discussed. Furthermore, the review highlights recent research endeavours and fundamental parameters, including sensitivity, detection limits, selectivity, response times, and recovery times.

Bi2O3/ZnO heterostructured semiconductor nanocomposites: synthesis, characterization and its visible light-induced degradation of methylene blue dye

Abstract In this study, we describe the creation of linked semiconductor nanomaterials, which represents a significant development for photocatalytic applications. A Bi2O3–ZnO hetrostructured thin film was created using the SILAR-CBD deposition technique. In comparison to pure ZnO and Bi2O3, the produced heterostructured thin film showed greater photocatalytic (PCD) activity for the degradation of methylene blue (MB) dye under UV light. The formation of Bi2O3 (monoclinic lattice phase) and ZnO (hexagonal wurtzite phase) are the heterostructured nanomaterials that were generated, according to a powder XRD inspection. An image taken with HR-TEM demonstrates the mixing of nanoparticles and nanorod formations in the Bi2O3/ZnO. The vectorial movement of electrons (e−) and holes (h+) between ZnO and Bi2O3 is responsible for the boosted photocatalytic efficiency, which is in turn, accountable for the enhanced photocatalytic activities.

Tungsten Nitride/Tungsten Oxide Nanosheets for Enhanced Oxynitride Intermediate Adsorption and Hydrogenation in Nitrate Electroreduction to Ammonia.

Electrochemical NO3- reduction reaction (NO3RR) is a promising technique for green NH3 synthesis. Tungsten oxide (WO3) has been regarded as an effective electrocatalyst for electrochemical NH3 synthesis. However, the weak adsorption and the sluggish hydrogenation of oxynitride intermediates (NOx, e.g., *NO3 and *NO2) over WO3 materials hinder the efficiency of converting NO3- to NH3. Herein, we design a heterostructure of tungsten nitride (WN) and WO3 (WN/WO3) nanosheets to optimize *NO3 and *NO2 adsorptions and facilitate *NO2 hydrogenations to achieve a highly efficient electrochemical NO3RR to produce NH3. Theoretical calculations predict that locally introducing WN into WO3 will shorten the distance between adjacent W atoms, resulting in *NO3 and *NO2 being strongly adsorbed on W active sites in the form of bidentate ligands instead of the relatively weak monodentate ligands. Furthermore, WN facilitates H2O dissociation to supply the requisite protons, which is beneficial for *NO2 hydrogenations. Inspired by theoretical prediction, WN/WO3 nanosheets are successfully fabricated through a high-temperature nitridation process. The transmission electron microscopy, X-ray photoelectron spectroscopy, and X-ray absorption near-edge spectroscopy investigations confirm that the amorphous WN has been locally introduced in situ into WO3 nanosheets to form a composite heterostructure. The as-prepared WN/WO3 nanosheets exhibit a high Faraday efficiency of 88.9 ± 7.2% and an appreciable yield rate of 8.4 mg h-1 cm-2 toward NH3 production, which is much higher than that of individual WO3 and WN. The enhanced adsorption and hydrogenation behaviors of *NOx over WN/WO3 are characterized by in situ Fourier-transform infrared spectroscopy, consistent with the theoretical predictions. This work develops facile and effective heterostructure nanomaterials to tune the adsorption and hydrogenation of NOx for boosting the efficiency from NO3- to NH3.

Catalysts for hydrogen evolution in universal-pH medium: Construction and structural optimization of Ni3S2/Co9S8/WS2 interface synergies

The performance of heterostructure nanomaterials depends on both the individual components characteristics and the interfaces synergistic effect. In this paper, a high-activity universal-pH HER catalyst, Ti felt supported nanoporous Ni3S2/Co9S8/WS2 (NiCoW-S) is synthesized by electrodeposition and vulcanization. Compared with Ni3S2/Co9S8, Ni3S2/Co9S8/WS2 heterostructure catalyst exhibits enhancement of intrinsic catalytic active center, charge transfer rate and stability in a wide pH range. Benefiting from the 3D porous structure and high-density heterostructure active edge sites, NiCoW-S shows good stability. And Moreover, it only needs 35 and 145 mV to reach 10 mA cm−2 in 0.5 M H2SO4 and 1.0 M KOH, respectively. Based on the experimental analysis, the favorable synergistic effect of metal components and the formation of sulfur vacancies can enhance the conductivity of electron transfer, which promotes electron transfer at the active heterogeneous interface. It provides a reference for designing of advanced metal sulfide heterostructure for hydrogen production in the future.

Sandwich-like heterostructured nanomaterials immobilized laccase for the degradation of phenolic pollutants and boosted enzyme stability

A novel magnetic 2D/2D heterogeneous structure MXene@NiFe-LDH@Fe3O4 was prepared for immobilization of laccase. In this work, two-dimensional MXene nanosheets with abundant surface functional groups were heterogeneously assembled with layered double hydroxide (LDH) by in situ co-precipitation method, and magnetic nanoparticle Fe3O4 with excellent biocompatibility and rapid separation of materials and substrates was introduced subsequently, and then silane coupling agent was coated on the surface of MXene@NiFe-LDH@Fe3O4. The functionalized MXene@NiFe-LDH@Fe3O4 was employed as a carrier to immobilize laccase from Trametes-Versicolor. The enzyme loading of the nanocomposite material is as high as 167.9 mg/g. Compared with free enzymes, the immobilized laccase showed a notable improvement in stability in a wider range of pHs (2.0–8.0), temperatures (25–60 °C), and organic solvent concentration (1–5 M). The reusability study suggested that after 7 cycles of repeated catalysis, the degradation efficiency could reach 55.5% for 2,4-dichlorophenol, 92.1% for bisphenol A and70.9% for pyrocatechol. The results provide a new carrier preparation strategy for the efficient immobilization of laccase.

A Review on Gallium Oxide Materials from Solution Processes.

Gallium oxide (Ga2O3) materials can be fabricated via various methods or processes. It is often mentioned that it possesses different polymorphs (α-, β-, γ-, δ- and ε-Ga2O3) and excellent physical and chemical properties. The basic properties, crystalline structure, band gap, density of states, and other properties of Ga2O3 will be discussed in this article. This article extensively discusses synthesis of pure Ga2O3, co-doped Ga2O3 and Ga2O3-metal oxide composite and Ga2O3/metal oxide heterostructure nanomaterials via solution-based methods mainly sol-gel, hydrothermal, chemical bath methods, solvothermal, forced hydrolysis, reflux condensation, and electrochemical deposition methods. The influence of the type of precursor solution and the synthesis conditions on the morphology, size, and properties of final products is thoroughly described. Furthermore, the applications of Ga2O3 will be introduced and discussed from these solution processes, such as deep ultraviolet photodetector, gas sensors, pH sensors, photocatalytic and photodegradation, and other applications. In addition, research progress and future outlook are identified.

Hollow Heterostructured Nanocatalysts for Boosting Electrocatalytic Water Splitting.

The implementation of electrochemical water splitting demands the development and application of electrocatalysts to overcome sluggish reaction kinetics of hydrogen/oxygen evolution reaction (HER/OER). Hollow nanostructures, particularly for hollow heterostructured nanomaterials can provide multiple solutions to accelerate the HER/OER kinetics owing to their advantageous merit. Herein, the recent advances of hollow heterostructured nanocatalysts and their excellent performance for water splitting are systematically summarized. Starting by illustrating the intrinsically advantageous features of hollow heterostructures, achievements in engineering hollow heterostructured electrocatalysts are also highlighted with the focus on structural design, interfacial engineering, composition regulation, and catalytic evaluation. Finally, some perspective insights and future challenges of hollow heterostructured nanocatalysts for electrocatalytic water splitting are also discussed.

The role of Al2O3 interlayer in the synthesis of ZnS/Al2O3/MoS2 core-shell nanowires

During the synthesis of heterostructured nanomaterials, unwanted structural and morphological changes in nanostructures may occur, especially when multiple sequential growth steps are involved. In this study, we describe a synthesis strategy of heterostructured ZnS/Al2O3/MoS2 core-shell nanowires (NWs), and explore the role of the Al2O3 interlayer during synthesis. Core-shell NWs were produced via a four-step route: 1) synthesis of ZnO NWs on a silicon wafer, 2) deposition of thin Al2O3 layer by ALD, 3) magnetron deposition of MoO3 layer, and 4) annealing of the sample in the sulphur atmosphere. During sulphurization, ZnO is converted into ZnS, and MoO3 into MoS2, while the Al2O3 interlayer preserves the smooth surface of an NW required for the growth of a continuous MoS2 shell. The resulting ZnS/Al2O3/MoS2 core-shell NWs were characterized by transmission electron microscopy, X-ray diffraction and photoelectron spectroscopy, Raman spectroscopy, and optical photoluminescence spectroscopy. A reported strategy can be used for the synthesis of other core-shell NWs with a transition metal dichalcogenides (TMDs) shell to protect the NW core material that may otherwise be altered or damaged by the reactive chalcogenides at high temperatures.

Hierarchical Hollow CoWO4-Co(OH)2 Heterostructured Nanoboxes Enabling Efficient Water Oxidation Electrocatalysis.

Rational design and construction of well-defined hollow heterostructured nanomaterials assembled by ultrathin nanosheets overtakes crucial role in developing high-efficiency oxygen evolution reaction (OER) electrocatalysts. Herein, a reliable metal-organic framework-mediated and cation-exchange strategy to tune the geometric structure and multicomponent heterostructures has been proposed for the fabrication of hollow CoWO4-Co(OH)2 hierarchical nanoboxes assembled by rich ultrathin nanosheets. Benefiting from the hierarchical hollow nanostructure, the CoWO4-Co(OH)2 nanoboxes offer plenty of metal active centers available for reaction intermediates. Moreover, the well-defined nanointerfaces between CoWO4 and Co(OH)2 can function as the bridge for boosting the efficient electron transfer from CoWO4 to Co(OH)2. As a consequence, the optimized CoWO4-Co(OH)2 nanoboxes can exhibit outstanding electrocatalytic performance toward OER by delivering 10 mA cm-2 with a low overpotential of 280 mV and a small Tafel slope of 70.6 mV dec-1 as well as outstanding electrochemical stability. More importantly, this CoWO4-Co(OH)2 heterostructured nanocatalyst can couple with Pt/C to drive overall water splitting to achieve 10 mA cm-2 with a voltage of 1.57 V.

Mesoporous WS2/MoO3 Hybrids for High-Performance Trace Ammonia Detection.

Mesoporous WS2/MoO3 hybrids were synthesized by a facile two-step and additive-free hydrothermal approach and employed for high-performance trace ammonia gas (NH3) detection. Compared with single WS2 and MoO3 counterparts, WS2/MoO3 sensors exhibited an improvement in NH3-sensing performance at room temperature (22 ± 3 °C). Typically, the optimal WS2/MoO3 sensor showed a higher and quicker response of 31.58% within 57 s toward 3 ppm of NH3, which was 17.7- and 57.4-fold larger than that of pure MoO3 (1.78% within 251 s) and WS2 (0.55% within 153 s) ones. Meanwhile, good reversibility, sensitivity, and selectivity, reliable long-term stability, and the lowest detection limit of 9.0 ppb were achieved. These superior properties were probably ascribed to numerous heterojunctions favorable for additional carrier-concentration modulation via the synergetic effect between WS2 and MoO3 components and the large specific surface area beneficial for richer sorption sites and faster molecular transfer at room temperature. Such achievements also imply that the designed WS2/MoO3 heterostructure nanomaterials have the potential in achieving trace NH3 recognition catering for the requirements of high sensitivity and low power consumption in future gas sensors.

Crystalline Domains Nested on Two-Dimensional Nanosheets as Heterogeneous Nanomachineries for the Sustainable Production of Bioactive Compounds from Chlorella sorokiniana

Naturally occurring bioactive compounds have attracted significant interest from the perspective of scientific and industrial aspects owing to the wide range of technological, economic, and healthcare benefits. Their synthetic origin still suffers from several impeding challenges, such as expensive extraction and low yield. To address these critical issues, a unique hybridized system termed “algal-nanohybrids” was established by integrating green microalgae, Chlorella sorokiniana, with carbon-based heterostructured nanomaterials (CHNs), enhancing the microalgal growth for the sustainable augmentation of bioactive compounds as renewable sources of secondary metabolites. Hitherto, this work presents a new avenue in the formation of CHNs comprising propene-bridged cyanurate tetramer crystals nested on two-dimensional (2D) nanosheets, possessing excellent photocatalytic activity along with biocompatibility for the sustainable production of bioactive compounds. Mechanistic insights into the formation of CHNs and their plausible interaction with the algal cells were deciphered using a suite of characterization techniques. The conceptual significance of CHNs was elaborated, as an efficient nanomachinery for bolstering the enhanced production of lutein (97%) from C. sorokiniana, which is higher than that reported for other lutein-producing microalgae grown under photoautotrophic conditions. Interestingly, CHNs not only promoted microalgal biomass by 88% but also enhanced the production of chlorophyll a and carotenoids by 42 and 75%, respectively. This unprecedented work advances the synthesis of biocompatible CHNs, which can provide a breakthrough in the industry for the production of natural lutein and other bioactive compounds from microalgae.

Construction of three‐dimensional marigold flower‐shaped Ni3V2O8 for efficient solid‐state supercapacitor applications

AbstractDevelopment of binary spinel‐type mixed metal oxide and fabrication various morphological heterostructure nanomaterials having two distinct metals paid a wide attention in emerging field. Here, we prepared three‐dimensional (3D) marigold flower‐like Ni3V2O8 structure via a simple and facile technique for electrochemical supercapacitor applications. 3D Ni3V2O8 with thick petals as cathode materials exhibits high specific capacitance of 263.12 F g−1 at a scan rate of 0.5 mA cm−2. The high energy density of 32.98 W h kg−1 at power density of 189.96 W kg−1 is obtained by the cathode formation of marigold flower‐shaped Ni3V2O8, indicating excellent ions accessibility and large charge storage ability of Ni3V2O8 structure. It is also observed that even after 5000 cycles charging‐discharging profile analysis, Ni3V2O8 cathode retains 32% of its initial capacitance along with 100% Coulombic efficiency. This higher capacitance retention strengthens its adoption as a potential candidate for supercapacitor application.

Nanoarchitectonics of Sn3O4/g-C3N4 Heterostructure Materials for Better Photocatalytic and Electrochemical Performance

Sn3O4/g-C3N4 heterostructure nanomaterials were prepared by calcining melamine and the hydrothermal method. The microstructure and morphology of the synthesized specimen were characterized by X-ray diffraction (XRD), electron microscope (SEM and TEM) and nitrogen adsorption and desorption (BET). The photocatalytic activity was evaluated by the photodegradation of methylene blue (MB) under visible light irradiation and the electrochemical performance was tested under a typical three-electrode configuration. The results show that the Sn3O4/g-C3N4 heterojunctions exhibit more superior photocatalytic performance for degrading MB compared with single Sn3O4 and g-C3N4. The degradation rate of MB reaches up to a maximal 90.30% within 75[Formula: see text]min, which is far higher than that of Sn3O4 (61.30%). It is attributed to the effective interfacial contact between Sn3O4 and g-C3N4, which increases charge transfer and prolongs electron-hole separation time. The specific capacitance of Sn3O4/g-C3N4 is 28.6% higher than that of Sn3O4 due to the formation of a heterostructure.