Enlarged Surface Area Research Articles

Fabrication of Triblock Elastomer Foams for Oil Absorption Applications: Effects of Crosslinking, Composition, and Rheology Factors

Oil spill accidents and oil-contaminated wastewater release from industries cause severe environmental pollution, resource waste, and economic loss. Thus, there is a dire need for an efficient oil/water separation approach to mitigate the challenge. Among the various oil/water separation technologies, employing oil-absorbing materials is one of the most effective strategies. In this work, a highly effective elastomer foam based on styrene–ethylene–butylene–styrene (SEBS) and ethylene propylene diene monomer (EPDM) blend was developed. Dicumyl peroxide was employed as a radical initiator for the crosslinking of the elastomer blend. The crosslinking of the blend significantly increased the melt strength of the SEBS/EPDM blend and therefore allowed them to expand extensively (up to 1200 vol %) with substantial volume increase (expansion ratio 12.8–13.1) and created pores with well-defined structures. As a result, the material exhibited outstanding oil absorption (up to 1030 wt %) due to an enlarged surface area and blend constituents. The incorporation of EPDM and radical-mediated crosslinking prevented the dissolution of SEBS in the oil and maintained the structural integrity of the foam in the oil, paving the way for recyclability. Also, the inherent hydrophobicity of employed polymers led to poor interaction with water and, thus, outstanding oil/water separation ability of the developed elastomer foams. Additionally, the foaming of triblock polymers, including SEBS, remained largely unexplored. This study has elucidated the impact of crosslinking and rheological factors on the successful foaming of SEBS.

Efficient and reliable detection of rhodamine B using SERS from silver-decorated photonic crystal silicon nanoscale pores

Porous silicon photonic crystal (PSi PhC) decorated with silver nanoparticles (AgNPs) is shown to provide a new substrate for the improvement of SERS. AgNPs are obtained through immersion of PSi PhC samples in AgNO3 solutions and successive thermal annealing. The nanocomposite material generated by adding AgNPs inside the silicon nanoscale pores, integrates the ability of metal surfaces to amplify Raman scattering signals and an enlarged surface area. Besides, PhC structure formed by multilayer PSi increases interaction time of light and matter of the multilayer structure. The experimental results show that the AgNPs-decorated PSi PhC has the largest Raman intensity in comparison with other SERS substrates based on Si. The enhancement of Raman signals also reduces the threshold of the detection down to below 10-10 M. The analytical enhancement factor of AgNPs/PSi PhC SERS substrate for the detection of Rhodamine B (RhB) reaches 1010. This proposed AgNPs/PSi PhC SERS substrate could serve as a potential candidate for detecting RhB in foodstuffs at very low concentrations.

In-situ Construction of Sulfur-doped g-C3N4/defective g-C3N4 Isotype Step-scheme Heterojunction for Boosting Photocatalytic H2 Evolution

The rational construction of a high-efficiency step-scheme heterojunctions is an effective strategy to accelerate the photocatalytic H2. Unfortunately, the variant energy-level matching between two different semiconductor confers limited the photocatalytic performance. Herein, a newfangled graphitic-carbon nitride (g-C3N4) based isotype step-scheme heterojunction, which consists of sulfur-doped and defective active sites in one microstructural unit, is successfully developed by in-situ polymerizing N,N-dimethyl-formamide (DMF) and urea, accompanied by sulfur (S) powder. Therein, the polymerization between the amino groups of DMF and the amide group of urea endows the formation of rich defects. The propulsive integration of S-dopants contributes to the excellent fluffiness and dispersibility of lamellar g-C3N4. Moreover, the developed heterojunction exhibits a significantly enlarged surface area, thus leading to the more exposed catalytically active sites. Most importantly, the simultaneous introduction of S-doping and defects in the units of g-C3N4 also results in a significant improvement in the separation, transfer and recombination efficiency of photo-excited electron-hole pairs. Therefore, the resulting isotype step-scheme heterojunction possesses a superior photocatalytic H2 evolution activity in comparison with pristine g-C3N4. The newly afforded metal-free isotype step-scheme heterojunction in this work will supply a new insight into coupling strategies of heteroatoms doping and defect engineering for various photocatalytic systems.

Surface enlargement of tantalum capacitor foils by pulsed direct current etching and laser cladding

Electrochemical etching for the surface enlargement of tantalum capacitor foils has always been a challenge, due to the ultra-high chemical stability of tantalum foils. Herein, pulsed direct current etching of tantalum capacitor foils assisted by laser cladding was investigated and high surface area enlargement was achieved. The effects of electrolyte composition, power supply parameters and external environment on the etching process of tantalum foil were systematically studied, to screen out the best experimental conditions. Furthermore, iron particles with diameters of 3–5 μm were successfully laser cladded on the surface of tantalum foils. These particles will be easily etched in the electrochemical process to form more previous pores, which can serve as etching sites for further tantalum foil etching. Under the best conditions, high-specific capacitance tantalum foils with a capacitance of 155.1 nF/mm2 were obtained at a high forming voltage of 100 V, which were 8 times larger than the unetched light foils. The surface enlargement of tantalum capacitor foils is expected to realize the development of novel tantalum capacitors with both high operating voltage and high capacitance.

Self-powered health monitoring with ultrafast response and recovery enabled by nanostructured silicon moisture-electric generator

Humidity sensors have been widely applied in health management, including respiration monitoring and non-contact sensing for human–machine interaction. Nevertheless, most existing monitoring systems hinging on moisture-sensitive materials require an additional external power source. In addition, the inferior sensitivity and long response/recovery time of the sensors still hinder their desirable healthcare applications. Here, we developed a self-powered humidity sensor built on the moisture-directly triggered electricity generation (MEG) effect, where silicon nanowire arrays (SiNWs) function as the sensing element, exhibiting an ultrafast response to humidity changes with high-level sensitivity. Humidity gradients induce charge directional transport in SiNWs nanochannels, directly actuating electricity signals generation without any additional power units for sensing. The enlarged surface area, oriented nanochannel structure, and superior electrical conductivity of SiNWs facilitate a robust dependence of the output voltage on humidity, enabling the sensor with quick response/recovery (∼0.10 s/∼0.17 s), ultra-high sensitivity, and broad detection range (3.94 mV/1% for 50–95% RH/1.13 mV/1% for 0–50% RH). Furthermore, we designed a smart respiratory monitoring system that can extract various respiration patterns and distinguish different language commands. We also constructed a non-contact human–machine interface leveraging the SiNWs sensor that can effectively disrupt virus propagation and bacterial infection. The elaborate self-powered humidity sensor proposed in our work could as well potentially be exploited for establishing wearable and integrated health monitoring platforms in the future.

Synergetic modulation of a hierarchical nanoflower-like NiMoO4/Ni(OH)2 composite toward efficient alkaline water oxidation

Electrocatalysts with densely exposed sites and high intrinsic activity are desired for high-efficiency oxygen evolution reaction (OER). In this paper, we report the microwave assisted solvothermal growth of NiMoO4 nanoflowers on electrodeposited Ni(OH)2 nanosheets, forming a high specific surface area (132.5 m2g-1) nanoflower-like NiMoO4/Ni(OH)2 configuration supported on a conductive nickel foam (NF) substrate. The as-prepared NiMoO4/Ni(OH)2/NF behaved efficiently as a self-supported 3D catalyst electrode for alkaline OER, compared with commercial RuO2 (298 mV overpotential at 10 mA cm−2 and Tafel slope of 88.6 mV dec−1), needing a low overpotential of 292 mV to attain 10 mA cm−2, with a small Tafel slope of 85.0 mV dec−1 and good stability for 100 h running at 10 mA cm−2 in 1.0 M KOH. Aside from enlarged surface area for more exposed edge sites for catalysis, the modulated synergy between Ni and Mo atoms probably contributes to enhanced intrinsic activity. A more electronegative Mo increases the electron density of Ni, thus accelerating the deprotonation of intermediates and driving the transition from Ni to NiOOH, leading to modulated thermodynamics and kinetics for OER catalysis.

Development of a novel colorimetric sensor array based on oxidized chitin nanocrystals and deep learning for monitoring beef freshness

Food spoilage not only causes food waste, but also leads to serious foodborne illnesses. To address these concerns, a novel colorimetric sensor array (CSA) fabricated from oxidized chitin nanocrystals (O-ChNCs) combined with convolutional neural network (CNN) had been developed for real-time monitoring of beef freshness. The oxidation procedure downsized chitin to the nanoscale with enlarged surface areas and more sites that are reactive. It also converted hydroxyl groups to carboxyl groups, giving chitin nanocrystals high negative charges. These enhanced electrostatic interactions of O-ChNCs with ammonium cations, which was validated with three representative food spoilage gases (methylamine (MA), trimethylamine (TMA), and ammonia (NH3)). The detection limits reached 100, 70, and 70 ppm for MA, TMA, and NH3, respectively. All four CNN architectures succeeded with over 96 % accuracy in discriminating freshness when monitoring real beef samples stored at room temperature for 4 days in real time. The highest accuracy of 99.27 % was achieved by ResNet-50. The overall results indicated that the newly developed O-ChNCs-based CSA coupled with CNN achieved fast and reliable monitoring of beef freshness.

One-pot preparation of layered double oxides-engineered biochar for the sustained removal of tetracycline in water

Tetracycline (TC) and sugarcane bagasse had both exerted enormous strain on environmental security. In this work, new composite adsorbent designed by impregnating bio-waste bagasse with magnesium–aluminum layered double oxides (BC-MA) was innovatively brought forward for TC removal. Benefiting from the abundant adsorption sites supplied by developed pores structure (0.308 cm3·g−1), enlarged surface area (256.8 m2·g−1) and reinforced functional groups, the maximum adsorption amount of BC-MA for TC reached 250.6 mg g−1. Moreover, BC-MA displayed desirable adsorption capacity in diverse water environments coupled with excellent sustainable regeneration ability. The absorption process of TC by BC-MA was spontaneous and endothermic, and the pivotal rate-limiting stage pertained to intraparticle diffusion. The mechanisms proposed here mainly concerned π-π interactions, pore filling, complexation and hydrogen bonding. These findings suggested that the synthesis of modified biochar from bagasse would offer new opportunities for simultaneous waste resource reuse and water pollution control.

Pre-applied underfill Technique for Fine-pitch Cu Pillar 3D Die Stacking to Enable 2.5/3D Advanced Packaging

Increased performance and smaller form factor have driven demand for next generation architectures for integrated circuit 3D (IC) chip packaging. Advanced chip packaging technologies, such as 2.5D and 3D, offer greater chip compatibility and lower power consumption. Given these advantages, the adoption of advanced packaging is inevitable. One key driver is the copper pillar interconnect technology which offers several benefits such as improved electromigration resistance, improved electrical and thermal conductivity, simplified under bump metallization (UBM), and higher input/output (I/O) density. The fine pitches that copper pillars are capable of helps the technology to supersede solder bump technology, which reaches its lowest pitch around 40 microns. Finer pitches allow for a higher I/O count, which enhances performance. One of the major innovations has been 2.5/3D integration, a technique of vertically stacking multiple dies. However, traditional encapsulation techniques become challenging because traditional capillary underfill methods become restrictive as enlarged surface area is required in order to provide underfill protection on multiple surfaces. Here, we discuss a novel approach of vertically stacking dies with an integrated underfill process that minimizes the required area for underfilling in fine-pitch IC chip packages by creating a technique to apply underfill during thermo-compression bonding. This process offers a reliable method for vertical stacking of multiple chips and eliminates post-processing need for underfill application. Additionally, the process provides precise temperature control to both the substrate and die by using a mechanism of dual heat application. This is used in combination with a controlled variable application of compressive force on the package. Through fine-tuning of the force and temperature applied to the IC components, the bonding process can be tailored to simultaneously provide the ideal underfill curing conditions while forming solder joints. In this work, we used dies with 80µm pitch Cu pillar flip chip copper pillars with tin/silver caps bonded to Electroless Nickel and Immersion Gold (ENIG) pads in conjunction with commercially available pre-applied underfill material. The interconnect strength was determined though destructive shear testing and cross-sectional analysis to evaluate for the bonding quality and strength. A scanning electron microscope was used to visually examine joint properties, and X-ray analysis was conducted to review for underfill voiding. Finally, completed assemblies were thermal-cycled to evaluate for the degradation of joint strength and voiding of underfill under induced stress.

The modification of MnO2·0.5H2O by Al/Mg doping to enhance lithium adsorption and reduce manganese dissolution with application to brines

Lithium extraction by ion sieve adsorption possesses the merits of a simple, low cost process of less pollution. In this article, lithium ion sieve MnO2·0.5H2O modified by doping with Al/Mg was obtained by hydrochloric acid pickling of precursor, which was formed by hydrothermal reaction of Mn2O3 with LiOH·H2O followed by a sintering process with Al2O3/MgO. The structure analysis indicated that the spinel structure of [MnO6] framework was observed in MnO2·0.5H2O. The lithium adsorption process reached equilibrium within 24 h and obeyed the pseudo second-order and Langmuir isotherm models. Attribute to the expanded surface area and increased Mn4+ proportion, the ion sieve doped with Al or Mg exhibited better performance in terms of lithium adsorption capacity and extent of manganese dissolution than undoped sample, and the best doping ratio were both 4%. Through doping 4% Al and 4% Mg, the adsorption capacity of doped samples in LiOH solution (CLi+ = 600 mg/L) was increased to 46.8 mg/g and 45.8 mg/g, respectively, from 40.1 mg/g, and the extent of manganese dissolution in the pickling dropped to 3.67% and 3.58% from 4.42%, respectively. Generally, adsorption capacity and selectivity of 4% Al-doped ion sieve is better than 4% Mg-doped ion sieve, therefore 4% Al-doped ion sieve is an ideal adsorbent. This study can provide a reference value to further research on efficient lithium adsorption.

Facile in-situ grown spinel MnCo2O4/MWCNT and MnCo2O4/Ti3C2 MXene composites for high-performance asymmetric supercapacitor with theoretical insight

The logical construction of electrode materials along with greater electrochemical features and solid architectural design is a strategic approach for boosting the electrochemical performance of supercapacitors. However, it is tough and complicated to develop diverse composite materials with better electronic conductivity and greater specific capacitance via rapid and cost-effective synthesis procedures. Herein, we propose a straightforward and simple approach by employing the hydrothermal technique for the synthesis of spinel MnCo2O4 composite nanostructures using 1D MWCNT and 2D MXene (Ti3C2Tx) materials with detailed analysis of the supercapacitor performance as compared to existing literature on similar studies. The MCO/TCX (MnCo2O4/Ti3C2Tx) composite shows an impressive capacitance of 860.22 F/g at a current density of 2 A/g after electrochemical optimization. Furthermore, an asymmetric supercapacitor device (ASCs) was constructed using MCO and its composites MCO/MWCNT and MCO/TCX as a positive, and AC was employed as a negative electrode to test its device capability. Comparatively, the MCO/TCX//AC SC device demonstrated exceptional energy storage properties with a better specific capacitance value of 126.58 F/g at 0.8 A/g of current density, an elevated energy density of 40 Wh/kg, with a power density of 4828 W/kg along a capacitance retention rate of 87 % over 5000 cycles, suggesting better cycle life. Whereas, the MCO/MWCNT//AC device shows a better cycling performance of 91 % after 5000 cycles with a superior energy and power density of 27.04 Wh/kg and 1448 W/kg respectively. Also the theoretical insight for further understanding of the charge-storage mechanism through DFT calculations provides an estimate of electronic properties and quantum capacitance calculated for the pristine MCO and its hybrids with CNT and Ti3C2Tx MXene and information on the interactions between orbitals, the bonding process, and the charge transfer capabilities of each electrode material. The theoretical studies also confirm that the electronic properties and therein charge storage performance have an increasing trend in the order of MCO < MCO/CNT < MCO/TCX consistent with the experimental findings. Additionally, these simulations conclude that the hybrid MCO/TCX has the largest quantum capacitance which is in accordance with the findings of the experiments. The improved performance of MCO/TCX is due to the enlarged surface area that allows higher charge transfer from TCX to MCO. The charge transferred from the C 2p orbital of TCX to the Mn 3d orbital of MCO is the leading cause for the capacitance improvement mechanism of hybrid MCO/TCX. This work offers a simple procedure for developing energy storage devices using spinel MnCo2O4-based composite electrode materials supported by 1D carbon nanotube and 2D MXene that offer superior electrochemical performance and the fabricated electrodes that could be employed further for energy storage-based applications.

Direct Urea/H2O2 Fuel Cell with a Hierarchical Porous Nanoglass Anode for High-Efficiency Energy Conversion

Direct urea/H2O2 fuel cells (DUFCs) constitute a sustainable bifunctional energy conversion technique devoted to simultaneously eliminating environmental wastewater with urea and generating clean energy. However, exploring an efficient anode material for DUFCs still remains a huge challenge. In this work, a Ni-P hierarchical porous nanoglass (HPNG) catalytic electrode was developed via a low-cost, industrially available electrodeposition technique, which exhibits one of the best performances reported so far in the urea oxidation reaction (UOR), with a potential of 1.330 V at a current density of 10 mA cm-2 and a Tafel slope of 9.77 mV dec-1. The superior UOR performance of the HPNG electrode is attributed to the excellent intrinsic catalytic activity of NG with a high-energy state and an extremely enlarged surface area from the unique 3D hierarchical porous structure. Furthermore, a DUFC system with the HPNG anode shows a performance breakthrough as indicated by the maximum power density of 38.15 mW cm-2 for 0.5 M urea, representing one of the best yet reported DUFCs. Our work demonstrates the feasibility of the scalable production of HPNG electrodes and is expected to be a great contribution to the development of the practical use of DUFCs in the near future for bifunctional energy conversion.

Facile Formation of Metal–Oxide Nanocraters by Laser Irradiation for Highly Enhanced Detection of Volatile Organic Compounds

Although various fabrication methods for metal–oxide nanostructures have been well developed for enlarged surface area, numerous efforts to further enhance the effective surface area for their chemical sensor applications are still being studied. Herein, a high‐power laser is irradiated on the existing metal–oxide nanostructures to expose the hidden inner surface of the nanostructures for full participation in the surface gas‐sensing reactions, resulting in extraordinary gas‐sensing performance. In addition, noble metal catalyst decoration at both the inner and outer surfaces of the nanostructures records extremely high gas response and selectivity to volatile organic compounds. The numerical simulation and experimental verification of the effects of high‐power laser irradiation for morphological evolution of the metal–oxide nanostructures can provide a new perspective toward the time‐efficient development of nanostructure‐based electronic devices.

Multistage SrBaTiO3 /PDMS Composite Film-Based Hybrid Nanogenerator for Efficient Floor Energy Harvesting Applications.

Triboelectric nanogenerators are an emerging energy-scavenging technology that can harvest kinetic energy from various mechanical moments into electricity. The energy generated while humans walk is the most commonly available biomechanical energy. Herein, a multistage consecutively-connected hybrid nanogenerator (HNG) is fabricated and combined with a flooring system (MCHCFS) to efficiently harvest mechanical energy while humans walk. Initially, the electrical output performance of the HNG is optimized by fabricating a prototype device using various strontium-doped barium titanate (Ba1- x Srx TiO3 , BST) microparticles loaded polydimethylsiloxane (PDMS) composite films. The BST/PDMS composite film acts as a negative triboelectric layer that operates against aluminum. Single HNG operated in contact-separationmode could generate an electrical output of ≈280V, ≈8.5µA, and ≈90 µC m-2 . The stability and robustness of the fabricated HNG are confirmed and eight similar HNGs are assembled in a 3D-printed MCHCFS. The MCHCFS is specifically designed to distribute applied force on the single HNG to four nearby HNGs. The MCHCFS can be implemented in real-life floors with an enlarged surface area to harvest energy generated while humans walk into direct current electrical output. The MCHCFS is demonstrated as a touch sensor that can be utilized in sustainable path lighting to save enormous electricity waste.

Porous carbon nanofibers supported Zn@MnOx sorbents with high dispersion and loading content for hot coal gas desulfurization

Sorbent with a great quantity of highly dispersed active components is of importance to achieve excellent desulfurization performance. Thus, Zn@MnOx/porous carbon nanofibers (PCNFs) sorbent has been constructed via electrospinning, carbonization and hydrothermal techniques in this study. The as-prepared sorbent realizes a sulfur capacity of 9.63 g S 100 g−1 sorbent and a utilization 117% of ZnO, which can be attributed to the synergetic effects of the enlarged surface area of PCNFs and the uniformly distributed active components. The specific surface area of modified PCNFs is nearly five times higher than that of the pristine CNFs, providing larger loading area and more attachment sites for metal oxides. Activation with KMnO4 not only generates active component MnOx but also presets ‘seed’ for the attachment of Zn2+, which is beneficial for the high dispersion of active components. The presented method is beneficial to producing sorbents with better structure and promotes desulfurization performances.

Interfacial Engineering Boosts Highly Reversible Zinc Metal for Aqueous Zinc-Ion Batteries.

Zinc metal is emerging as the promising anode for aqueous Zn-ion batteries. However, corrosion and undesirable Zn dendrite growth limit their practical application in the large-scale energy storage area. Herein, a mountain-valley micro/nanostructure is successfully fabricated on the surface of the Zn anode via a femtosecond-laser filament texturing (FsLFT) technique. Beneficial from the large surface area and spontaneously generated ZnO coating layer, the FsLFT-Zn electrode demonstrates a slow corrosion rate with a current density of 0.62 mA cm-2 and a stable cycle life over 3000 h under 1 mA cm-2, superior to the original Zn anode. Simulation of the electric fields reveals that the enlarged surface area is responsible for the outstanding performance of the FsLFT-Zn electrode. This study not only proposes a novel strategy to suppress dendrite growth toward highly stable AZIBs but also opens a new avenue to solve similar issues in other metal batteries.

Application of an Eco-Friendly Adhesive and Electrochemical Nanostructuring for Joining of Aluminum A1050 Plates

In adhesive joints used in several industrial applications, the adherends' bonding is made using an adhesive, which is usually an epoxy resin. However, since these adhesives are derived from petroleum fractions, they are harmful to the environment, due to the pollutants produced both during their manufacture and subsequent use. Thus, in recent years, effective steps have been made to replace these adhesives with ecological (green) ones. The present work focuses on the study of aluminum A1050 joints bonded with a green adhesive; the study also involves the electrochemical anodization method applied to adherends for nano-functionalization. The nanostructured aluminum adherends allow the formation of an expanded surface area for adhesion, compared to the non-anodized adherends. For comparison reasons, two different adhesives (Araldite LY1564 and Green Super Sap) were used. In addition, for the same reasons, both anodized and non-anodized aluminum adherends were joined with both types of adhesives. The lap joints were subsequently tested under both shear-tension and three-point bending conditions. The major findings were that aluminum A1050 anodization in all cases resulted in shear strength enhancement of the joints, while joints with both aluminum anodized and non-anodized adherends and bonded with the eco-friendly adhesive showed a superior shear behavior as compared to the respective joints bonded with Araldite adhesive.

In-situ preparation of Cu-BTC modified with organic amines for H2S removal under ambient conditions

Amine modification is an effective strategy to improve the H2S removal performance of Cu-BTC. In order to avoid the problem of pore blockage after amine modification in post synthesis impregnation, herein a series of Cu-BTC modified with organic amine adsorbents were prepared via an in-situ one-pot method and the H2S removal performance under ambient conditions was tested. It is found that the introduced organic amines, depending on the types of amine selected, have a significant influence on the growth of Cu-BTC and its textural properties. The H2S removal performance on the as-prepared materials suggested that the amine modified samples remarkably improved the H2S removal capacities with an order of BA-Cu-BTC > TEA-Cu-BTC > TEOA-Cu-BTC > Cu-BTC. Besides the enlarged surface area and the increased mesopores volumes, BA has the advantages of smaller steric hindrance and –NH2 groups, among which the former increased the accessibility of Cu active sites while the latter acted as additional active sites for H2S capturing, thus affording BA-Cu-BTC highest breakthrough capacity of 77.3 mg S/g. Overall, this study elaborates the effect of organic amines in-situ modification on the Cu-BTC structure and desulfurization.

FeV LDH Coated on Sandpaper as an Electrode Material for High-Performance Flexible Energy Storage Devices

Recently, considerable research efforts to achieve advanced design of promising electroactive materials as well as unique structures in supercapacitor electrodes have been explored for high-performance energy storage systems. We suggest the development of novel electroactive materials with an enlarged surface area for sandpaper materials. Based on the inherent micro-structured morphologies of the sandpaper substrate, nano-structured Fe-V electroactive material can be coated on it by facile electrochemical deposition technique. A hierarchically designed electroactive surface is covered with FeV-layered double hydroxide (LDH) nano-flakes on Ni-sputtered sandpaper as a unique structural and compositional material. The successful growth of FeV-LDH is clearly revealed by surface analysis techniques. Further, electrochemical studies of the suggested electrodes are carried out to optimize the Fe-V composition as well as the grit number of the sandpaper substrate. Herein, optimized Fe0.75V0.25 LDHs coated on #15000 grit Ni-sputtered sandpaper are developed as advanced battery-type electrodes. Finally, along with the negative electrode of activated carbon and the FeV-LDH electrode, it is utilized for hybrid supercapacitor (HSC) assembly. The fabricated flexible HSC device indicates high energy and power density by showing excellent rate capability. This study is a remarkable approach to improving the electrochemical performance of energy storage devices using facile synthesis.

Molten salt-lithium process induced controllable surface defects in titanium oxide for efficient photocatalysis

The efficiency of photoabsorption, photo-generated charge separation, and surface redox reaction determine the overall efficiency of photocatalysts. Therefore, exploring ways to simultaneously optimize the parameters is key to improving the photocatalytic performance. Herein, a novel low-temperature ternary molten salt-lithium reduction method is designed to create controllable oxygen vacancies (Ovs) as well as to manipulate the surface microstructure of the classic photocatalyst TiO2. The optimized TiO2 exhibits a 10-fold increase in the photocatalytic RhB breakdown rate and H2 generation quantity compared to pristine TiO2. The dual surface defects result in synergistic effects: i) Ovs lower band gap, enhance the charge separation efficiency as capture centers, and facilitate hydrogen adsorption; ii) the enlarged surface area enhances light-harvesting and provides more active sites. This research proposes a novel strategy for manipulating surface defects in a controlled manner and highlights the synergistic optimization of the thermodynamical and kinetical parameters to promote the photocatalytic performance.