Wet Chemical Method Research Articles

Atomically Dispersed Metal‐Nitrogen‐Carbon Electrocatalysts for the Oxygen Reduction Reaction

AbstractThe quest for alternatives to Pt as an oxygen reduction electrocatalyst, possessing high activity, stability, and abundant reserves, holds great significance for H2/O2 fuel cells. Recently, metal‐nitrogen‐carbon (M‐N‐C) electrocatalysts have garnered substantial attention as promising substitutes. These electrocatalysts not only exhibit well‐defined structures but also offer the flexibility to adjust the central metal atoms and coordination atoms. It is beneficial in elucidating the active sites during the catalytic process and in the design of highly active electrocatalysts. In this review, the real active site of M‐N‐C electrocatalyst‐driven ORR is investigated in depth by in situ characterization techniques such as X‐ray absorption spectroscopy, Raman spectroscopy, Fourier‐transform infrared spectroscopy. It′s worth noting that the catalytic activity of M‐N‐C electrocatalysts originates from the dynamic evolution of electrocatalyst structure. Subsequently, we review various synthetic strategies, including the wet chemistry method, spatial confinement, and template‐assisted method, aimed at the rational design of M‐N‐C electrocatalysts. Moreover, recent progresses of M‐N‐C electrocatalysts with varying configurations, encompassing single‐atom, and double‐atom electrocatalysts are discussed, Finally, summary and perspectives on the development of M‐N‐C are provided.

Clean and accurate soil quality monitoring in mining areas under environmental rehabilitation in the Eastern Brazilian Amazon.

Soil quality monitoring in mining rehabilitation areas is a crucial step to validate the effectiveness of the adopted recovery strategy, especially in critical areas for environmental conservation, such as the Brazilian Amazon. The use of portable X-ray fluorescence (pXRF) spectrometry allows a rapid quantification of several soil chemical elements, with low cost and without residue generation, being an alternative for clean and accurate environmental monitoring. Thus, this work aimed to assess soil quality in mining areas with different stages of environmental rehabilitation based on predictions of soil fertility properties through pXRF along with four machine learning algorithms (projection pursuit regression, PPR; support vector machine, SVM; cubist regression, CR; and random forest, RF) in the Eastern Brazilian Amazon. Sandstone and iron mines in different chronological stages of rehabilitation (initial, intermediate, and advanced) were evaluated, in addition to non-rehabilitated and native forest areas. A total of 81 soil samples (26 from sandstone mine and 55 from iron mine) were analyzed by both traditional wet-chemistry methods and pXRF. The available/exchangeable contents of K, Ca, B, Fe, and Al, in addition to H+Al, cation exchange capacity at pH = 7, Al saturation, soil organic matter, pH, sum of bases, base saturation, clay, and sand were accurately predicted (R2 > 0.70) using pXRF data, with emphasis on the prediction of Fe (R2 = 0.93), clay content (R2 = 0.81), H+Al (R2 = 0.81), and K+ (R2 = 0.85). The best predictive models were developed by RF and CR (86%) and when considering pXRF data + mining area + stage of rehabilitation (73%). The results highlight the potential of pXRF to accurately assess soil properties in environmental rehabilitation areas in the Amazon region (yet scarcely evaluated under this approach), promoting a more agile and cheaper preliminary diagnosis compared to traditional methods.

Bi/BiVO4 tailoring molecular oxygen activation for SPR-promoted photocatalytic contaminant removal

In recent years, photocatalytic technology has been gained widespread attention in contaminants removal due to its green, low-carbon, sustainable properties. Bismuth vanadate (BiVO4) with decahedral shapes has emerged as a promising photocatalyst with unique photoinduced charges directional transfer. In this study, a simple wet chemical reduction method was used to load stable Bi0 nanoparticles in situ on the surface of decahedral BiVO4 to enhance the charges movement for molecular oxygen activation and tetracycline photodegradation. The formed Bi0 nanoparticles induced abundant oxygen vacancy defect states and surface plasmon resonance effects on BiVO4 nanoparticles surface. In aid of the special function of a surface heterojunction, decahedral BiVO4 can be photoexcited to produce more photogenerated carriers, and its separation efficiency is greatly improved, thus enhancing both the oxidative activity and photocatalytic activity. In the photocatalytic degradation process, superoxide radicals (∙O2−) showed the most significant contribution, and singlet oxygen (1O2) played junior role in tetracycline hydrochloride (TC) removal. 1O2 is obtained by ∙O2− and hole energy conversion, and some of it is produced by tetracycline photodecomposition under alkaline conditions. The BBV0.4 photocatalytic system has the best catalytic activity under weakly alkaline conditions, and the synergistic effect of photocatalysis and photodecomposition greatly improves the mineralization rate of TC. The large numbers of ∙O2− and 1O2 reactive oxygen species produced by BBV0.4 activation of oxygen play a crucial role in the photodegradation of TC via demethylation, deoxidation, deamination, ring-opening, and carbonylation to complete mineralization. This work studies in depth the change in the decahedral BiVO4 photocatalytic mechanism caused by the in situ introduce of bismuth metal, providing an efficient and environmentally friendly reference method for the rapid removal of tetracycline hydrochloride under alkaline conditions.

Fabrication of Novel 3-D Nanocomposites of HAp-TiC-h-BN-ZrO2: Enhanced Mechanical Performances and In Vivo Toxicity Study for Biomedical Applications.

Due to excellent biocompatibility, bioactivities, and osteoconductivity, hydroxyapatite (HAp) is considered as one of the most suitable biomaterials for numerous biomedical applications. Herein, HAp was fabricated using a bottom-up approach, i.e., a wet chemical method, and its composites with TiC, h-BN, and ZrO2 were fabricated by a solid-state reaction method with enhanced mechanical and biological performances. Structural, surface morphology, and mechanical behavior of the fabricated composites were characterized using various characterization techniques. Furthermore, transmission electron microscopy study revealed a randomly oriented rod-like morphology, with the length and width of these nanorods ranging from 78 to 122 and from 9 to 13 nm. Moreover, the mechanical characterizations of the composite HZBT4 (80HAp-10TiC-5h-BN-5ZrO2) reveal a very high compressive strength (246 MPa), which is comparable to that of the steel (250 MPa), fracture toughness (14.78 MPa m1/2), and Young's modulus (1.02 GPa). In order to check the biocompatibility of the composites, numerous biological tests were also performed on different body organs of healthy adult Sprague-Dawley rats. This study suggests that the composite HZBT4 could not reveal any significant influence on the hematological, serum biochemical, and histopathological parameters. Hence, the fabricated composite can be used for several biological applications, such as bone implants, bone grafting, and bone regeneration.

Nano FeCoNi-based high-entropy alloy for microwave absorbing with high magnetic loss and corrosion resistance

With the development of modern communication and military technology, the protection of electromagnetic wave pollution and radar stealth technology have been widely concerned. In this background, the magnetic metals were widely used due to the strong ferromagnetism, which can induce strong magnetic loss to the electromagnetic wave. However, it remains challenging to precisely control the wave-absorbing performance of individual magnetic metals, and there are issues with poor corrosion resistance and high temperature resistance. Therefore, the alloy powders based on Fe, Co, and Ni in this work were prepared by wet chemical method at room temperature. Different from most of the traditional powder metallurgy methods, the wet chemical method enables us to obtain binary, ternary and quaternary alloys with a nanometer-scale and uniform distribution, all products have a microscopic morphology of 300–500 nm spheres. The FeCoNi alloy powder shows an effective absorption band (RL<-10 dB) of 7 GHz in the high frequency electromagnetic wave range at an ultrathin thickness of 1.5 mm, which has a high temperature magnetism (Tc >900 K) and excellent corrosion resistance. Further doping of Cu to form a quaternary alloy can improve the corrosion resistance and maintain the original wave-absorbing properties, while doping of Mo and Sn can adjust the position of the effective absorption bandwidth.

Agro-waste mediate to synthesize the solar light active titanium dioxide nanoparticles with enhanced efficacy of pollutant removal

In this research work, Titanium dioxide (TiO2) nanoparticles were prepared from green waste by Wet Chemical method. Titanium tetraisopropoxide (TTIP) precursor is converted to TiO2 nanoparticles by using the Musa-paradisiaca L. (Banana crop) pseudo stem extract as a capping agent. The non-dopant, anatase phase crystalline TiO2 nanoparticles were synthesized and characterized by using analytical techniques like TEM, HR-TEM, SAED, BET, FTIR, SEM, EDX, XRD, XPS, DRS, UV-Visible spectrophotometer and Zeta Potential. The green synthesized TiO2 nanoparticles with band gap energy 2.95 eV were used as a photocatalyst for the degradation of Indigo Carmine (IC) dye under solar radiation with an intensity of 1200*100 lux. Optimization process was carried out for three factors such as catalyst dosage, pH and concentration of the dye solution at constant time. TiO2 nanoparticles photocatalyst showed 99% degradation efficiency in 30 minutes (min) for the IC dye under optimum condition. This experimental work was confirmed by comparing with the theoretical results obtained from Response Surface Methodology (RSM). The RSM of the quadratic model produces a theoretical layout for the optimization process and provides the Analysis of Variance (ANOVA) data which evaluate the importance of each experimental factor. The RSM results are well matched with the R2 value obtained from the experimental method. The biogenic TiO2 nanoparticles had greater efficacy in the degradation of IC dye for five cycles of reaction.

Fabrication of biomimetic scaffold through hybrid forming technique

AbstractBone tissue engineering procedures require the use of a scaffold with a sufficiently porous structure, which serves as a three‐dimensional template for cell attachment, followed by tissue regeneration and vascularization both in vitro and in vivo. This study aimed to create scaffold material with a unique hybrid forming that met these parameters. Slip casting and freeze‐drying processes were used with a hybrid forming approach to create a bone scaffold based on hydroxyapatite (HA) mimicking the structure of cortical and cancellous bones, respectively. HA was synthesized by the wet chemical precipitation method. Fourier‐transform infrared spectroscopy, dynamic light scattering, X‐ray diffraction, thermogravimetric analysis‐differential thermal analysis, Brunauer‐Emmett‐Teller, He Pycnometer, and scanning electron microscope analyses were performed to characterize the scaffold. According to analysis results, HA particle size was found at 137.8 nm. The optimum sintering temperature was determined to be 1300°C. The specific surface area of the HA powder was measured as 55.11 m2/g. The total open porosity of the hybrid scaffold was calculated as 70%. Scaffold successfully substituted both cancellous and cortical layers of bone regarding structural characteristics, porosity, and mechanical strength. Considering morphological characteristics, a hybrid scaffold might facilitate vascularization, osteoinduction, and osteoconduction. Research findings suggest that the hybrid design strongly resembled natural bone and is suitable for both load‐bearing and non‐bearing bones.

Synthesis of highly efficient ternary phase graphene/Bi/SnO2 photocatalyst for degradation of organic dye pollutants

In this work, graphene nanosheets (GNs) are prepared from graphite rods obtained from waste dry-cell batteries using the electrochemical exfoliation (ECE) method. Then GNs used as a matrix to modify tin oxide (SnO2) and Bismuth (Bi) nanoparticles to prepare a binary phase SnO2@G and ternary-phase Bi@SnO2@G nanocomposite materials by wet-chemical method and used as a photocatalysts for degradation of organic dye pollutants. XRD diffraction pattern clearly confirmed the presence of tetragonal crystal system of SnO2 which was maintaining its structure in SnO2@G and G/Bi/SnO2. The stretching and bending vibrations of the functional groups were analyzed using FTIR analysis. FESEM images demonstrated the surface morphology and the texture of the as synthesized sample. Raman Spectroscopic investigation was carried out to confirm the in-plane blending of SnO2 and graphene inside the composite matrix. The as-prepared ternary-phase Bi@SnO2@G-based photocatalyst showed high degradation efficiency of 99.6% and 94.5% for direct blue (DB) and methyl blue (MB) dyes, respectively, under visible light irradiation by (i) minimizing the hole and electron recombination, (ii) providing a high surface area, and (iii) reducing the band gap energy. This study provides an effective, low-cost, and smart approach for producing GNs on a wide scale from battery waste along with nanohybrid composites with high photocatalytic efficiency.

Integrated photocatalysis adsorption processes for oxytetracycline removal: using volborthite and its composite with g-C3N4.

The photocatalytic-adsorption performance of the composites of volborthite (CuVA) and graphitic carbon nitride (g-C3N4) was studied in this work using oxytetracycline (OTC) as model pollutant under LED light irradiation. CuVA at different weight percentages (10, 30, 50), namely, C10, C30, and C50, were loaded onto graphitic carbon nitride using wet chemical method. The physical, chemical, and optical properties were evaluated via various analytical techniques. Through integrated adsorption-photocatalytic process, no significant photocatalytic reaction occurred in g-C3N4 and the composite even after 4h of irradiation. The setup was modified such that each run was conducted in the presence and absence of light. Aside from photolysis and g-C3N4, all composites performed better under the presence of light in which CuVA improved the most from ~ 50% down to ~ 20% of initial concentration. CuVA performed almost identically (80% removal of OTC) under the presence of light irradiation at ambient temperature (22°C) and in the dark at 32°C, confirming that temperature was the contributing factor to the improvement instead of light. CuVA exhibited excellent adsorption capacity of 171mg/g and adsorption rate of 90% towards the removal of highly concentrated OTC (100mg/L) under optimized parameters of pH 5.0 and at 42°C after 3h of adsorption process. Life cycle assessment revealed that close to 50% of fresh 100ppm OTC could be removed after five cycles without any desorption process.

Multiwalled carbon nanotubes decorated with molybdenum sulphide (MoS2@MWCNTs) for highly selective electrochemical picric acid (PA) determination

Nitrophenols are industrially versatile yet environmentally detrimental compounds. Herein, we have synthesised molybdenum sulphide based dichalcogenide supported multiwalled carbon nanotubes i.e. MoS2@MWCNTs electrocatalyst by simple wet chemical method for PA determination. The successful decoration of MoS2 over MWCNTs were confirmed by various characterizations techniques including scanning electron microscopy (SEM) shows MoS2 layers grown on MWCNTs and having average size is –80 nm. Energy dispersive X-ray analysis (EDAX) reveals elements are homogenously distributed in nanocomposite. High resolution-transmission electron microscopy (HR-TEM) shows increase in average diameter after decoration of MoS2 over MWCNTs from 30 nm to 70 nm. The Fourier transform infrared (FT-IR) analysis suggests the presence of Mo-S stretching frequency at 605 cm−1 in addition to hydroxyl, carbonyl, C–C, C–O stretching frequencies are also observed. In Raman spectrum from apart D and G bands, the characteristic intense bands E2g1 and A1g of MoS2 were pointed towards presence of molybdenum and sulphur. The X-ray diffraction (XRD) confirms synthesised electrocatalyst is in hexagonal crystal structure with P63/mmc space group. The X-ray photoelectron spectroscopy (XPS) reveals that for Mo 3d is found to be two characteristics peaks at 231.2 eV and 233.2 eV corresponds to Mo4+ 3d3/2 and 3d5/2 respectively. The peak at 229 eV corresponds to S 2s. Whereas, the signal appears at 162.7 eV, 165 eV, 169 eV and 170 eV shows sulphur is in 2S3/2 and 2S5/2 states. Electrochemical performance was examined by cyclic voltammetry (CV) tests. The Electrocatalyst is highly selective, having appreciable anti-interference property, lower limit of detection (LoD), i.e., 0.5 μM with wide linear range. The low Rct and high k⁰ pointed that MoS2@MWCNTs performed better towards electrochemical detection of PA.

Performance improvement of vapor compression heat pump with superhydrophobic finned-tube evaporator

Residential buildings frequently employ vapor compression heat pump for winter heating. Its advantages over electric and coal-fired heating include great energy effectiveness and low emissions. However, the outside evaporator's frosting negatively impacts the performance of heat pump systems in low-temperature and high-humidity environments. To ameliorate the frosting problem, a finned-tube heat exchanger with superhydrophobic surface wettability prepared by the wet chemical etching method was applied to a vapor compression heat pump in this study. The performance of a commercial evaporator unit and the superhydrophobic evaporator unit under five frosting conditions was investigated through experiments. The maximum heat transfer rate of the superhydrophobic heat exchanger unit was increased by 17%–44% compared with that of the commercial unit. The COP improvement of the superhydrophobic unit reached 11.2%, 14.3%, 18.8%, 20.9% and 31.9%, respectively. The total mass of frost formation of the superhydrophobic unit experienced a 59.2%–76.3% decrease. The operation time of the superhydrophobic evaporator unit before defrosting determination was significantly extended, reducing the number of defrosting times during a long-time operation. This study proves the advantages of superhydrophobic finned-tube evaporators used in heat pumps in terms of heat transfer performance and frost suppression performance, promoting the application of superhydrophobic finned-tube evaporators in heat pump air-conditioning systems.

ZnO/ZIF-8 nanocomposite for orange G dye degradation: synthesis, characterization, photocatalytic activity, and mechanism

Textile dyes are one of the dominant reasons for water pollution. Among these dyes, Orange G is toxic, carcinogenic, and non-biodegradable and can cause a severe threat to humans and marine life. Therefore, in this present work, a novel photocatalyst was synthesized, and systematic degradation of Orange G dye was investigated. The novel ZnO/ZIF-8 nanocomposite has been successfully synthesized via a two-step method, thermal decomposition for ZnO and wet-chemical method for ZnO/ZIF-8 nanocomposite. The band gap of the nanocomposite was calculated using a KM plot and found to be 3.5 eV. The surface charge of the materials was examined using zeta potential measurement, which was found to be suitable for dye degradation. The recombination time of the materials was investigated using Time-Resolved Photoluminescence (TRPL) study, and it was found that nanocomposite has a lower recombination rate than pristine materials. The degradation efficiency of materials towards Orange G dye was calculated to be ∼95% after 120 min illumination. The photocatalysis mechanism was proposed on the basis of Mott–Schottky measurements, which were supported by the scavenger test. Furthermore, to evaluate the reusability of the nanocomposite, a photocatalytic experiment was conducted several times. The ZnO/ZIF-8 nanocomposite could be used for the degradation of textile dye wastewater.

Zinc ion storage abilities of Mo3WOx nano-ceramic under extreme-cold environments

It is imperative to develop new electrode materials for aqueous multivalent metal ion batteries with electrochemistry abilities at extreme-low temperatures due to the possible extreme-cold operating conditions of batteries in the present or the future. Herein, as a proof-of-concept experiment, a new orthorhombic molybdenum-tungsten oxide (Mo3WOx) is synthesized by a wet-chemical method and tested as anode material for aqueous zinc ion batteries at extreme-cold temperatures (−40, −60 and −75 °C) for the first time. Two anti-freezing electrolytes are selected to examine the related half-cell performances, and 7.5 m ZnCl2 aqueous solution is more suitable for Mo3WOx half-cells than 2 m Zn(BF4)2 aqueous solution. At −40 °C, Mo3WOx exhibits reversible charge capacity of 104.1 mAh g−1 at 100 mA g−1 and the charge capacity can still maintain 82.3 mAh g−1 after 100 cycles; and under further test at 5000 mA g−1, Mo3WOx shows a high initial charge capacity of 42.5 mAh g−1 together with a capacity retention ratio of 81.6 % after 10,000 cycles. It is worth highlighting that the high capacities of Mo3WOx delivered at −40 °C are even comparable with the capacities of some “new-type” anode materials for aqueous zinc ion batteries exhibited at ambient temperature. At colder temperatures of −60 and −75 °C, the as-prepared compound still owns certain zinc ion storage abilities, especially high discharge/charge capacities of 48.9/48.7 mAh g−1 can be still achieved in the 100th cycle at −75 °C (100 mA g−1). Furthermore, a full-cell with operational capability at −40 °C is also built here, and it can exhibit discharge capacity of 66.1 mAh g−1 (coulombic efficiency of 99.7 %) in the 3rd cycle and discharge capacity of 48.2 mAh g−1 (coulombic efficiency of 99.7 %) in the 50th cycle.

ZSM‐5‐Promoted Co‐Based Light‐Assisted Thermocatalytic Fischer–Tropsch Synthesis Catalyst for Production of Liquid Fuel

Light‐assisted thermocatalytic Fischer–Tropsch synthesis (FTS) provides a more efficient and sustainable approach to synthesizing high‐value chemicals compared to the thermal‐driven FTS. However, producing liquid fuel via cobalt‐based light‐assisted thermocatalytic FTS catalyst poses a challenge since photogenerated electrons increase CO conversion simultaneously with a significant reduction in the selectivity of C5+ product. Herein, a cobalt‐based light‐assisted thermocatalytic FTS catalyst containing ZSM‐5 molecular sieve promoter is prepared by a unique wet chemical reduction method, and the constructed 15%Co/Ta3N5‐ZSM‐5 catalyst exhibits nearly 90% C5+ product selectivity and 63% CO conversion under photothermal condition. Further characterization indicates that the simultaneous increase in the number of active sites and the density of acidic sites in the catalyst is crucial to achieve a simultaneous increase in CO conversion and C5+ product selectivity, which enables the catalyst to produce liquid fuel via light‐assisted thermocatalytic FTS reaction. This work provides an approach to introduce solar energy into the process of liquid fuel production, which can improve the sustainability of the liquid fuel production process.

Improving performance of cathode NMC-811 by CeO2-coating for Li-ion battery

The high energy density layered oxide LiNi0.8Mn0.1Co0.1O2 (NMC811) holds great promise as a cathode material for future Li-ion batteries. However, its application in electric vehicles is hindered by issues such as inadequate cycle performance and rate capability. Additionally, the corrosion caused by the electrolyte poses limitations on high voltage operation. In this study, Cerium Oxide (CeO2) was used to coat NMC811 using wet chemical method followed by heat treatment. Distilled water was used to dissolve Ce salt instead of ethanol so that it can reduce coating costs and is more environmentally friendly. XRD analysis showed no significant change in the hexagonal crystal structure of NMC811 material but the appearance of small CeO2 peaks in patterns. Electrochemical test of CeO2 coated NMC811 exhibited 18% and 9% higher cyclic and rate performance, respectively in comparison to pristine material.

Blue light emissive zero-dimensional hybrid cadmium bromide as fluorescence sensor toward benzaldehyde

Organic-inorganic hybrid low-dimensional metal halides have been widely studied as a new class of luminescence materials due to abundant structural diversity and intriguing photophysical property. Herein, we explored two new Cd-based 0D halides of [BHEPZ]CdBr4 (BHEPZ = 1,4-Bis(2-hydroxyethyl) piperazine) and [EPIPZ]CdBr4 (EPIPZ = 1-ethylpiperazine) through facile wet-chemistry method. These 0D halides exhibit blue light emissions derived from radiative recombination of self-trapped excitons (STEs) based on detailed spectroscopy investigations. More interestingly, [BHEPZ]CdBr4 exhibits rapid luminescence off switching toward benzaldehyde but fails in any other organic solvents. In-depth investigations demonstrate that the detection limit can fall to 2.65 ppm indicating perfect real-time fluorescent probe to detect benzaldehyde with high sensitivity and selectivity. This work enriches the cadmium halide materials and provide a new perspective for potential applications of 0D hybrid metal halides.

Edge interface microenvironment regulation of CoOOH/commercial activated carbon nano-hybrids enabling PMS activation for degrading ciprofloxacin

Peroxymonosulfate (PMS) is widely employed to generate oxygen-containing reactive species for ciprofloxacin (CIP) degradation. Herein, cobalt oxyhydroxide @activated carbon (CoOOH@AC) was synthesized via a wet chemical sedimentation method to activate PMS for degradation of CIP. The result suggested AC can support the vertical growth of CoOOH nanosheets to expose high-activity Co-contained edges, possessing efficient PMS activation and degradation activity and catalytic stability. In the presence of 3.0 mg of optimal CoOOH@AC and 2 mM PMS, 96.8 % of CIP was degraded within 10 min, approximately 11.6 and 9.97 times greater than those of CoOOH/PMS and AC/PMS systems. Notably, it was disclosed that the optimal CoOOH@AC/PMS system still exhibited efficient catalytic performance in a wide pH range, different organics and common co-existing ions. Quenching experiments and electron paramagnetic resonance indicated that both radical and non-radical processes contributed to the degradation of CIP, with 1O2 and direct electron transfer accounting for the non-radical pathway and SO4•− and •OH serving as the main radical active species. Finally, possible CIP degradation pathways were proposed based on high-performance liquid chromatography-mass spectrometry. This study provided an alternate method for wastewater treatment based on PMS catalyzed by cobalt-based hydroxide.

Amorphous LaWOx nanoparticles with rich O defects for photocatalytic RhB degradation

Water containing organic pollutants is posing an increasingly serious challenge to the clean water resources on which human beings depend. As a promising environmental purification technology, photocatalytic degradation can directly use solar energy to purify polluted wastewater without any secondary pollution. Synthesized via the wet chemical method, LaWOx nanoparticles display ultraviolet light responsiveness, large surface area, amorphous features, and abundant surface oxygen defects. These characteristics empower LaWOx NPs to efficiently degrade Rhodamine B, achieving a 92.76 % degradation efficiency in 105 min and a rate constant (Kap) of 0.02215 min−1 under full-spectrum irradiation. This study offers insights into developing new amorphous nano-photocatalysts.

Fabrication of highly sensitive memristive device using NiO nanoparticles synthesized by single step wet chemical method

Single step wet chemical method is used to prepare molar concentration varied NiO nanoparticle using PVP as the capping agent. Structural, optical and electrical properties are investigated on the prepared samples and are correlated with growth. TEM shows particle size distribution ∼ 3–4 nm synthesized in the range 0.001–1 M which agrees with XRD and optical measurements. Red shift in absorption is observed in optical measurement with enhancing molarity. Because of lesser size distribution of NiO nanoparticles, larger native defect in the form of oxygen vacancies is expected which may beutilized in fabrication of memristive devices. The sensitivity of the devices is estimated through Roff/Ron and area of pinched hysteresis loopwhich shows promising result. Higher sensitivity is explained due to incorporation of more oxygen vacancies during the growth of NiO nanoparticles synthesized at higher concentration. The experimental memristive characteristics are validated through theoretical model fitting using different window functions.

Rational Electrochemical Design of Cuprous Oxide Hierarchical Microarchitectures and Their Derivatives for SERS Sensing Applications.

Rational morphology control of inorganic microarchitectures is important in diverse fields, requiring precise regulation of nucleation and growth processes. While wet chemical methods have achieved success regarding the shape-controlled synthesis of micro/nanostructures, accurately controlling the growth behavior in real time remains challenging. Comparatively, the electrodeposition technique can immediately control the growth behavior by tuning the overpotential, whereas it is rarely used to design complex microarchitectures. Here, the electrochemical design of complex Cu2O microarchitectures step-by-step by precisely controlling the growth behavior is demonstrated. The growth modes can be switched between the thermodynamic and kinetic modes by varying the overpotential. Cl- ions preferably adhered to {100} facets to modulate growth rates of these facets is proved. The discovered growth modes to prepare Cu2O microarchitectures composed of multiple building units inaccessible with existing methods are employed. Polyvinyl alcohol (PVA) additives can guarantee all pre-electrodeposits simultaneously evolve into uniform microarchitectures, instead of forming undesired microstructures on bare electrode surfaces in following electrodeposition processes is discovered. The designed Cu2O microarchitectures can be converted into noble metal microstructures with shapes unchanged, which can be used as surface-enhanced Raman scattering substrates. An electrochemical avenue toward rational design of complex inorganic microarchitectures is opened up.