Facile Wet Chemical Method Research Articles

Stabilization and Surface Functionalization of Palladium Disulfide Nanoparticles with Acetylene Derivatives.

Metal chalcogenide nanoparticles have been attracting extensive attention in diverse fields. Traditionally these nanoparticles are stabilized by organic ligands such as thiols and amines involving nonconjugated core-ligand interfacial interactions. In the present study, a facile wet-chemistry method is described for the synthesis of palladium disulfide (PdS2) nanoparticles capped with acetylene derivatives. Spectroscopic and electrochemical measurements suggest that conjugated Pd-C≡ linkages are formed at the core-ligand interface and facilitate electronic coupling and hence manipulation of the nanoparticle optical and electronic properties. The unique interfacial linkages also allow further functionalization of the nanoparticles by metathesis reaction with olefin derivatives, as manifested in the reaction with vinylferrocene. This research opens new avenues for the structural engineering and functionalization of metal chalcogenide nanoparticles.

Effect of Ag doping on the structural, morphological, optical and antibacterial activity of ZnS nanoparticles

In this study Ag-doped ZnS nanostructures for antibacterial activity were prepared by means of a facile wet-chemical method. XRD study reveals a decrease in the intensity of XRD peaks and the presence of an additional peak for silver which further affirms the incorporation of silver ions in ZnS matrix. The synthesized 1% Ag-doped ZnS nanostructures have the average particle size distribution of 16.45 ± 0.13 nm based on the TEM image. The antimicrobial activity of pure ZnS and Ag-doped ZnS were evaluated against Staphylococcus aureus and Escherichia coli. The results show that the bacterial inhibition was enhanced due to the doping of Ag into ZnS matrix in contrast to ZnS. This results obtained from the antibacterial study could be capitalized to be administered as a potent antibacterial drug for biomedical application.

Robust Dual-Color Electrochromism of Vanadium Oxide Nanorods Embedded on Reduced Graphene Oxide: Unraveling the Mechanism

Vanadium pentoxide (V2O5), associated with both cathodic and anodic coloration, is considered as one of the best electrochromic (EC) materials for energy-saving smart electronics. Here we present the fabrication and detailed mechanism analysis for improving the electrochromic properties of V2O5 incorporated in a reduced graphene oxide (rGO) matrix using a facile wet chemical method. The microstructural study disclosed the formation of prominent V2O5 nanorods embedded in the rGO matrix. The optimized electrochromic film resulted in coloration (tc) and bleaching time (tb) of ∼6.2 and ∼4.8 s, respectively, much faster than the color switching kinetics of the pristine V2O5 sample (tc ∼ 19.4 s, tb ∼ 15.3 s). The more dispersed structure also ensured an approximate 400% enhancement in the optical modulation of EC film and reflected a noticeable improvement in the coloration efficiency (∼347 cm2/C) of V2O5 film. Modification with rGO resulted in an outstanding improvement in the electrochemical redox stability of V2O5 up to 5000 CV cycles with minimum deterioration in the curve area. The formation of nanorod structure was the prime factor for better ion diffusion and thereby facilitating enhanced performance.

Facile synthesis, morphological, optical, catalytic and photocatalytic properties of Ag nanoparticles decorated Ce doped ZnO hybrid plasmonic nanorods

Designing plasmonic metal–semiconductor hybrid nanostructures for photodecomposition of industrial textile effluent has been considered as a great way to boost the catalytic and photocatalytic capability by promoting effective separation of photoexcited charge carriers. Herein, fabrication of Ag nanoparticles decorated Ce doped ZnO nanostructures were demonstrated via facile wet chemical method. The morphology and structure of the fabricated photocatalysts were analysed using FESEM, XRD and Raman spectroscopy whereas PL, TRPL and UV–vis absorption spectroscopy were employed to examine their optical behaviour. Catalytic response of the synthesized catalysts was studied for 4-NP to 4-AP reduction and the results are more favourable for Ag loaded Ce doped ZnO catalysts and achieved 96.4 % reduction of 4-NP in only 4 min. Photocatalytic measurements showed that higher Ag NP loading onto Ce doped ZnO nanostructures led to superior photodegradation ability over other photocatalysts for the degradation of synthetic dyes and levofloxacin antibiotic. The sunlight driven photodecolorization of harmful synthetic dyes and levofloxacin were studied and efficacy of 97.5, 97.1, 85.1, and 70.9 % were achieved for MG, MB, RhB and MO dyes, respectively in 12 min and 97.2 % efficiency for degradation of levofloxacin was achieved in 20 min of sunlight exposure. Furthermore, the key reactive species was identified and tentative photodegradation process was explained. This work provides an excellent plasmonic-semiconductor catalyst and photocatalyst with good photostability and practical applicability indicating its enormous potential for application in environmental remediation.

High Power Factor Flexible Ag2Te Film on Nylon by a Wet Chemical Method for Power Generator.

Herein, we develop a facile wet chemical method for the synthesis of Ag2Te powders at room temperature and flexible Ag2Te/nylon thermoelectric (TE) films are prepared by vacuum-assisted filtration of the synthesized Ag2Te powders and then hot pressing. Because of the good crystallinity of Ag2Te grains and continuous grain boundaries, an optimized film exhibits a power factor of 513 μW m-1 K-2 at 300 K, which stands among the highest values reported for Ag2Te-based films to date. In addition, the film also has good flexibility. A four-leg flexible TE device assembled with the film generates a power density of 5.46 W m-2 at a temperature gradient of 31.8 K. This work provides a facile and environmentally friendly method for preparing flexible Ag2Te films.

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.

A highly stable and conductive cerium‐doped Li7P3S11 glass‐ceramic electrolyte for solid‐state lithium–sulfur batteries

AbstractIn this report, a facile wet chemical method using acetonitrile combined with thermal annealing was used to prepare Li2S‐P2S5 (LPS) based glass‐ceramic electrolytes with (1 wt%, 3 wt%, and 5 wt% Ce2S3) and without Ce2S3 doping. The crystal structure, ionic conductivity, and chemical stability of Li7P3S11 glass‐ceramic electrolytes were examined at varying temperatures (250–350°C). The results indicated that the highest ionic conductivity of 3.15 × 10−4 S cm−1 for pure Li7P3S11 was observed at a temperature of 325°C. By incorporating 1 wt% Ce2S3 and subjecting it to a heat treatment at 250°C, the glass ceramic electrolyte attained a remarkable ionic conductivity of 7.7 × 10−4 (S cm−1) at 25°C. Furthermore, it exhibited a stable and extensive electrochemical potential range, reaching up to 5 volts when compared to the Li/Li+ reference electrode. By tuning the glass transition and crystallization temperature, cerium doping seems to make Li7P3S11 more chemically stable, compared to its original 70Li2S‐30P2S5 counterpart. According to Raman and X‐ray photoelectron spectroscopy analyses, cerium doping inhibits the decomposition of highly conductive P2S74‐ (pyro‐thiophosphate) to PS43− and P2S64−. Doped LPS has a greater crystallinity and more uniform microstructure than pure LPS, according to XRD, Raman spectroscopy, and scanning electron microscopy analysis. Consequently, Li7P2.9Ce0.1S11 electrolyte shows great potential as a solid‐state electrolyte for constructing high‐performance sulfide‐based all‐solid‐state batteries.

Free‐standing Stanene for High Selectivity of Formate in Electrocatalytic Carbon Dioxide Reduction Reaction

AbstractAs well‐known electrocatalysts with good catalytic efficiency for carbon dioxide reduction reaction (CO2RR) towards the production of formate, tin (Sn)‐based catalysts have aroused broad concern. Here, free‐standing porous stanene is synthesized for the first time by a facile wet chemical method, and its excellent electrocatalytic performance for formate (HCOO−) formation in CO2RR is demonstrated. High Faradaic efficiency (F.E., 93% at −930 mV versus reversible hydrogen electrode (RHE)) can be achieved in the CO2RR catalyzed by stanene in 0.5 m KHCO3 aqueous solution. The in situ Mössbauer spectra reveal that zero‐valent Sn aids in improving the selectivity of formate production. Furthermore, density functional theory calculations suggest that the high selectivity of HCOO− of CO2RR on stanene mainly originates from the edge sites on Sn (100). To further explore the practicability of the stanene‐based catalysts for CO2RR, stanene decorated by 3 wt% BP‐2000 is prepared, showing an excellent F.E. of 98% at −930 mV versus RHE due to the higher exposure of catalytic active sites. These new findings of the activity origination and reaction mechanism of stanene contribute to the deeper understanding of Sn‐based catalysts for CO2RR, which is beneficial for the future designation of highly efficient CO2RR catalysts.

Coupling of two-dimensional MXenes and graphene for boosting the hydrogen storage performance of MgH2.

MgH2 used in solid-state hydrogen storage still suffers from high thermal stability and slow hydrogen absorption-desorption kinetics. Here, we report a hybrid of MgH2-Ti3C2/graphene prepared through a facile wet chemical method followed by a ball-milling method. It was confirmed that the coupling of Ti3C2 and graphene possesses a synergistic effect on the hydrogen desorption and absorption reactions of MgH2/Mg. The initial temperature of MgH2-Ti3C2/graphene to desorb hydrogen was reduced to 169 °C significantly and it could desorb 6.8 wt% H2 within 6 min at a constant temperature of 300 °C. Moreover, the desorbed sample could start to absorb hydrogen at room temperature and achieve a capacity of 6.0 wt% when the temperature was gradually increased to 350 °C. These results are far superior to pristine MgH2, disclosing that the addition of two-dimensional Ti3C2/graphene is an efficient strategy to boost the hydrogen storage performance of MgH2.

Fabrication of a PCN/BiOBr 2D hybrid with improved photocatalytic performance of 2,4-dichorophenol degradation.

Photocatalysis has received much attention as an environmentally friendly route to manage the emerging organic pollution problems. Herein, BiOBr nanosheets have been synthesized by a hydrothermal method, and then PCN/BiOBr hybrids are designed via a facile wet chemical method. The as-prepared PCN/BiOBr hybrids are characterized by X-ray diffraction (XRD), UV-vis diffuse reflectance spectra (UV-vis DRS), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). The PCN/BiOBr composite exhibits remarkable improved activity in the degradation of 2,4-dichlorophenol (2,4-DCP) as compared to the pristine BiOBr. Based on the ·OH amount-related fluorescence spectra fluorescence and the photoelectrochemistry (PEC) tests, it is confirmed that the enhanced photocatalytic performance of PCN/BiOBr is attributed to the promoted charge separation. Moreover, by means of the radical-trapping experiments it is demonstrated that the formed ·O2- species, as the electron-modulated direct products, are the primary active species during the photocatalytic degradation of 2,4-DCP. This work would provide a feasible design strategy to fabricate high-activity photocatalysts for 2,4-DCP degradation.

Highly air-stable magnesium hydrides encapsulated by nitrogen-doped graphene nanospheres with favorable hydrogen storage kinetics

Severe surface oxidation and sluggish kinetic rates of Mg hydrides (MGHs) are the main bottlenecks for their industrial applications. Herein, we present a strategy to simultaneously tackle these problems. The nano-size MGHs were encapsulated in nitrogen-doped graphene nanospheres (NGNSs) via a facile wet-chemical method. This configuration not only prevented the MGHs from oxidation when exposed to air even after a long duration, but also stimulated faster kinetic rates of hydrogen absorption and desorption owing to the nano-size effect of MGHs and the unique electronic structure of NGNSs. As a result, MGHs of ca. 20 nm were coated by a few layered NGNSs to form MGH@NGNSs nanocomposite. A high hydrogen absorption capacity of 6.5 wt% was achieved at 200 °C within 0.4 h, with a releasing hydrogen capacity of 5.5 wt% at 300 °C within 0.5 h, indicating that this composite has obtained remarkably hydrogen storage performance. Density Functional Theory (DFT) based calculations suggested that the hydrogen adsorption/desorption kinetics were significantly fast at the interface of Mg surface and NGNSs with pyridinic configuration. This strategy paves a way for the development of high-performance Mg-based hydrogen storage materials for industrial applications.

Facile fabrication of regenerable spherical La0.8Ce0.2MnO3 pellet via wet-chemistry molding strategy for elemental mercury removal

Perovskite-based sorbents have received extensive attention in the field of mercury abatement. However, the excellent Hg0 adsorption performance on the lab scale hardly transforms into industrial-scale utilization because of the elutriation and microcrystalline nature of powdery perovskite sorbent. Hence, the granulation of perovskite into pellets is a strongly solicited and urgent demand. In this work, a universal granulation strategy is exploited for fabricating perovskite sorbent pellets for Hg0 capture from coal combustion flue gas (CCFG) based on a facile wet-chemistry method. This route takes advantages of the unique thermal sensitivity and thermal decomposition characteristics of agar powder and surface tension of medium to simultaneously trade off the molding, pore creation, and mechanical property of perovskite-based sorbent pellets. Besides, silica sol was also added to further enhance the physical strengths of sorbent pellets. The obtained perovskite sorbent pellet (i.e., LCMO-A-Z-2) with a favorable BET surface area of 113.16 m2 g−1 and pore diameter of 8.81 nm, largely facilitating Hg0 diffusion and capture over sorbent pellets. LCMO-A-Z-2 was further employed to Hg0 adsorption experiment under simulated CCFG, which exhibited satisfactory Hg0 adsorption capacity of 2.07 mg g−1 and nearly identical Hg0 adsorption performance after 5 cycles. The weight loss was approximately 13 % after 1000 rotations in the anti-attrition ability experiment suggesting its outstanding mechanical strength. It is reasonable to deduce this granulation method can be readily extended to other powdery sorbents. This work makes first step towards the application of sorbent pellets under application-relevant conditions and support the ultimate implementation of traditional sorbents in various large-scale industrial scenarios.

Anchoring PdAu nanoclusters inside aminated metal-organic framework for fast dehydrogenation of formic acid

Liquid sunshine formic acid (FA), which is obtainable through CO2 hydrogenation with green H2 or biomass processing, is regarded as a prospective liquid organic hydrogen carrier (LOHC) owing to its high volumetric capacity (53 g H2 L−1), stability, and renewability. The search for effective catalysts to produce H2 from additive-free FA under ambient conditions is necessary but remains a challenge. Herein, highly dispersed and ultrafine PdAu nanoclusters (NCs) (1.2 nm) anchored by the aminated metal–organic framework (NH2-MIL-101) were successfully fabricated using a facile wet-chemical method and employed as a superior catalyst for formic acid dehydrogenation (FAD). The resulting PdAu/NH2-MIL-101 catalyst demonstrates 100 % H2 selectivity and superior performance with a turnover frequency value reaching 2921.0 h−1 at 323 K without any additive. Under similar conditions, this value is higher than the majority of published MOF-based FAD heterogeneous catalysts. The superior performance of PdAu/NH2-MIL-101 originates from a synergistic combination of the promoting effect of amino groups, the effective electronic coupling of Pd and Au, and the strong metal-support interaction between PdAu NCs and NH2-MIL-101, which promote the formation of reactive PdAu NCs and thus greatly improve catalytic performance. This work may provide important inspiration for developing highly efficient catalysts and strongly promote FA as a promising LOHC for chemical H2 storage.

Controlled Synthesis of Lead-Free Double Perovskite Colloidal Nanocrystals for Nonvolatile Resistive Memory Devices.

Although lead-free double perovskites such as Cs2AgBiBr6 have been widely explored, they still remain a daunting challenge for the controlled synthesis of lead-free double perovskite nanocrystals with highly tunable morphology and band structure. Here, we report the controlled synthesis of lead-free double perovskite colloidal nanocrystals including Cs2AgBiBr6 and Cs2AgInxBi1-xBr6 via a facile wet-chemical synthesis method for the fabrication of high-performance nonvolatile resistive memory devices. Cs2AgBiBr6 colloidal nanocrystals with well-defined cuboidal, hexagonal, and triangular morphologies are synthesized through a facile wet-chemical approach by tuning the reaction temperature from 150 to 190 °C. Further incorporating indium into Cs2AgBiBr6 to synthesize alloyed Cs2AgInxBi1-xBr6 nanocrystals not only can induce the indirect-to-direct bandgap transition with enhanced photoluminescence but also can improve its structural stability. After optimizing the active layers and device structure, the fabricated Ag/polymethylene acrylate@Cs2AgIn0.25Bi0.75Br6/ITO resistive memory device exhibits a low power consumption (the operating voltage is ∼0.17 V), excellent cycling stability (>10 000 cycles), and good synaptic property. Our study would enable the facile wet-chemical synthesis of lead-free double perovskite colloidal nanocrystals in a highly controllable manner for the development of high-performance resistive memory devices.

Boosting glycerol electrooxidation over palladium catalyst driven by boron-incorporation

The incorporating of metalloid elements into the interstices of Pd lattice is a powerful strategy to manipulate the binding strength of surface adsorbates and thereby to boost its electrocatalytic activity and anti-poisoning for many electrocatalytic reactions. In present work, a novel nanocomposite, the boron-incorporated palladium nanoparticles anchored on the three-dimensional nitrogen-doped graphene (PdBx/NG), was firstly fabricated through a simple hydrothermal synthesis followed by a facile wet chemical reduction method. Extensive physicochemical analyses were conducted to unveil the effects of the boron-incorporation on the properties of the as-synthesized electrocatalyst. More strikingly, the PdBx/NG displayed considerably boosted electrocatalytic behavior towards glycerol oxidation reaction (GOR), which largely outperformed the Pd/NG and benchmark Pd/C. The NG endowed PdBx/NG with three-dimensional architecture, rich pores and abundant nitrogen-containing functional groups. Furthermore, the boron-incorporation enabled the electronic effect (electronic modification) and strain effect (lattice expansion) for Pd. The superior contribution of NG and boron-incorporation enhanced electrocatalytic activity and reinforced stability of PdBx/NG for GOR. This study provides an alternative way for fabricating the boron-incorporated catalysts for electrochemical reactions and beyond.

Porous carbon nanosheets derived from two-dimensional Fe-MOF for simultaneous voltammetric sensing of dopamine and uric acid

It is of great significance for electrochemical sensors to simultaneously detect dopamine (DA) and uric acid (UA) related to biological metabolism. In this work, two-dimensional (2D) porous carbon nanosheets (CNS) was prepared as electrocatalysts to improve the sensitivity, the selectivity, and the detection limit of the simultaneous detection. First, 2D amorphous iron-metal organic frameworks (Fe-MOF) was synthesized with Fe3+ and terephthalic acid via a facile wet chemistry method at room temperature. And then, CNS was prepared by pyrolysis and pickling of Fe-MOF. CNS had large specific surface area, good electrical conductivity and lots of carbon defects. The response currents of the CNS modified electrode was larger than those of the control electrodes in the simultaneous determination. The simultaneous determination was measured via differential pulse voltammetry to reduce the effect of capacitive currents on quantitative analysis. The CNS modified electrodes showed high sensitivity and low detection limit for the simultaneous detection of DA and UA. The modified electrodes have been successfully used to detect DA and UA in normal human serum.

Copper oxide-anchored ZnO nanoflakes for the enhanced photocatalytic degradation performance and mechanistic investigations

An efficient CuO anchored ZnO nanoflakes were synthesized through facile wet chemistry method and the catalysts were well characterized using various sophisticated instruments. CuO nanoparticle incorporation was found to have a direct linear relationship with light absorbance. The degradation ability of the ZnO/CuO p-n junction was studied on the degradation of methyl orange. Under UV–Vis light illumination, the photocatalytic removal efficacy of methyl orange over CuO/ZnO p-n junction is up to 89%, which is greater than that of barecatalysts. The maximized photocatalytic degradation performance might be ascribed to the augmented visible light harvesting capacity and reduced the rate of photogenerated electron-hole pair recombination. The efficient photoinduced electron and hole pair charge separation upon excitation is aided by the effective formation of p-n junctions between ZnO and CuO. Based on the findings, a plausible photocatalytic mechanism for the as-synthesized CuO anchored ZnO nanoflake was proposed.

Palladium Nanoparticles Grown by Using Successive Ionic Layer Adsorption and Reaction Method: Ethanol Electrooxidation and Electrochemical Quartz Crystal Microbalance Studies

A facile wet chemical method namely successive ionic layer adsorption and reaction (SILAR) is implemented to grow palladium nanoparticles on graphite substrate. The grown Pd nanoparticles are successfully applied for electrooxidation of ethanol in alkaline solution. The electrocatalytic activity of grown Pd nanoparticles is studied by performing cyclic voltammetry (CV) measurements. Electrooxidation of ethanol by Pd nanoparticles is shown to be affected by growth parameters such as precursor concentration and number of SILAR growth cycles. Excessive growth of Pd nanoparticles due to large number of SILAR growth cycles shifts the pattern of cyclic voltammograms from period-one cyclic voltammograms to high order periodic/aperiodic cyclic voltammograms. Pd nanoparticles are also grown on gold coated quartz crystal and implemented to track any mass changes that occur during electrochemical surface oxidation/reduction over Pd nanoparticles, with and without ethanol in alkaline solution. To measure the mass changes occurring during CV measurements electrochemical quartz crystal microbalance (EQCM) is implemented in situ along with potential scanning.

Peroxymonosulfate activation by Co@TiO2 for high-efficiency organic removals

Here we demonstrated that the Co doped anatase titanium dioxide (Co@TiO2) prepared by a facile wet chemical method could activate peroxymonosulfate (PMS) for efficiently degrading a wide range of refractory organic pollutants. The characterization results demonstrated that the doped Co replaced partial Ti while did not bring obvious structural change. The Co@TiO2/PMS system can efficiently remove about 100 % chlortetracycline (CTC) within 40 min and 100 % Rhodamine B (RhB) within 15 min. The Co@TiO2/PMS/CTC system maintained a good catalytic performance over a wide pH range from 3 to 11 and the removal efficiency of CTC improved with increasing pH. The Co@TiO2/PMS system had a good anti-interference ability, which was free from interference by inorganic ions (such as H2PO42-, NO3- and SO42-, etc.) and HA, and also in the different real water matrixes and refractory organic pollutants. Quenching experiments and electron spin resonance (EPR) measurements confirmed that the system had a typical radical process as hydroxyl radical (•OH), sulfate radical (SO4•−) and superoxide radical (O2•−) were the main reactive species for the degradation of CTC. Furthermore, the Co@TiO2 also showed excellent stability and low metal leaching during long-term use because of the excellent chemical and physical stability of TiO2.

Porous Indium Nanocrystals on Conductive Carbon Nanotube Networks for High‐Performance CO2‐to‐Formate Electrocatalytic Conversion

Ever‐increasing emissions of anthropogenic carbon dioxide (CO2) cause global environmental and climate challenges. Inspired by biological photosynthesis, developing effective strategies NeuNlto up‐cycle CO2 into high‐value organics is crucial. Electrochemical CO2 reduction reaction (CO2RR) is highly promising to convert CO2 into economically viable carbon‐based chemicals or fuels under mild process conditions. Herein, mesoporous indium supported on multi‐walled carbon nanotubes (mp‐In@MWCNTs) is synthesized via a facile wet chemical method. The mp‐In@MWCNTs electrocatalysts exhibit high CO2RR performance in reducing CO2 into formate. An outstanding activity (current density −78.5 mA cm−2), high conversion efficiency (Faradaic efficiency of formate over 90%), and persistent stability (~30 h) for selective CO2‐to‐formate conversion are observed. The outstanding CO2RR process performance is attributed to the unique structures with mesoporous surfaces and a conductive network, which promote the adsorption and desorption of reactants and intermediates while improving electron transfer. These findings provide guiding principles for synthesizing conductive metal‐based electrocatalysts for high‐performance CO2 conversion.