Thiourea Research Articles

IMPACT OF FOLIAR SPRAY OF BIOREGULATORS IN TERMINAL HEAT STRESS CONDITION ON TEST WEIGHT, OIL CONTENT AND SEED VIABILITY OF MUSTARD (BRASSICA JUNCEA L.)

The experiment was conducted during the years 2019-20 & 2020-21 at Oil Seed Farm of C. S. Azad University of Agriculture & Technology Kanpur. Two varieties namely Kanti (V1) and Maya (V2) seeds were sown in Rabi 2019 and 2020 and seven chemicals concentrations of bioregulators were applied as foliar spray treatments at vegetative stage, at anthesis stage and at both stage viz., Salicylic acid (SA) 800 ppm (T1 , T8 and T15), Salicylic acid spray at vegetative stage @ 400 ppm (T2 , T9 and T16), Ascorbic acid (AA) 10 ppm (T3 , T10 and T17), Potassium chloride (KCl) 1% (T4 , T11 and T18), thiourea (TU) 400 ppm (T5 , T12 and T19), Cycocel (CCC) 800 ppm (T6 , T13 and T20), Cycocel 400 ppm (T7 , T14 and T21) and T0 -Control (without spray). Freshly harvested seeds were investigated for test weight (1000 seed weight), oil content % and seed viability % and significantly maximum test weight (4.57g) and seed viability (98.46%) recorded from the treatment T19 followed by treatment T16 as compared to control, while on oil content % no significant effect of treatment was recorded. Variety Maya showed significantly superior performance on test weight and oil content over variety Kanti but seed viability did not differ signicantly.

Study of percent degradation of copper complex with various solvents

Transition metal soaps have their vast area of different fields like industry, technology and in allied science. Recently their complexes have greatly attracted the attention of industries and are finding increasing their application in different fields. The photocatalytic degradation of copper (II) soap complex have been studied spectrophotometrically in non- aqueous and non polar solvent benzene. Copper (II) Mustard complex was synthesized with N and S containing ligands. The aim of this study to observe the percent degradation of copper soap complex which increases with increasing amount of methanol solvent and further decrease with some extent. Zinc oxide (ZnO) was used in the photocatalytic decolourisation and degradation study of copper (II) Mustard thio urea complex. Intensity of light is measured with the help of solar meter (CEL India Model SM 201). Absorption of light is recorded by U.V. visible spectrophotometer (SYSTRONIC MODEL 106) at different time intervals. The various thermodynamic and kinetic parameters of the process were evaluated. Photo degradation has been considered in many reaction of biological, synthetic and industrial importance where energy received from sun can be better utilized for converting the pollutants into less toxic or almost harmless materials. The best way for the overall treatment of dyestuff effluent, is photo degradation. Photo-catalysis has proven as a booming field of chemistry due to its numerous potential applications. An attempt has been made to focus on anti-microbiological activity of copper (II) mustard thiourea complex at different concentrations with Staphylococcus aureus which may causes skin infections.

Antioxidant enzymes and transporter genes mediate arsenic stress reduction in rice (Oryza sativa L.) upon thiourea supplementation

Thiourea (TU) is a chemo-priming agent and non-physiological reactive oxygen species (ROS) scavenger whose application has been found to reduce As accumulation in rice grains along with improved growth and yield. The present field study explored TU-mediated mechanistic changes in silicon (Si) assimilation in root/shoot, biochemical and molecular mechanisms of arsenic (As) stress amelioration in rice cultivars. Gosai and Satabdi (IET-4786) rice cultivars were selected for field experiment at three different places; control field and two other As contaminated experimental fields (EF1 and EF2) in West Bengal, India. The average As reduction was observed to be 9.5% and 19.8% whereas the yield increment was 8.8% and 17.7% for gosai and satabdi, respectively among all the three experimental fields. The positive interrelation was also observed between improved internal ultrastructure anatomy and enhanced Si assimilation (36%–423%) upon TU application. The level of photosynthetic pigments was increased by 29.8%–99.2%. Further, activities of antioxidant enzymes were harmonically altered in TU supplemented plants. The expression of various As related transporter genes in flag leaf and developing grains (inflorescence) was changed in both the rice cultivars (gosai and satabdi). It was also presumably responsible for observed As reduction in grains. Thus, TU application was found to be an efficient and sustainable agronomic practice for amelioration of As toxicity in rice plants in As contaminated field conditions.

Effect of Thiourea Containing Composite Additives on Nickel Electrodeposition in Ammoniacal Solution

Composite additives have an important influence on the process of metal electrodeposition and the quality of a metal deposited layer. In this work, the additive thiourea (TU) was compounded with cetyltrimethyl ammonium chloride (CTAC), sodium dodecyl sulfate (SDS) and polyethylene glycol 20,000 (PEG20000), and their effect on the cyclic voltammetric behavior, electrochemical nucleation mechanism, crystallographic orientations and surface morphology of the nickel electrodeposition in ammoniacal solution were experimentally investigated. The results show that the introduction of composite additives resulted in a stronger cathodic polarization and increased the nucleation overpotential (NOP) values significantly, which had an important impact on forming compact and smooth nickel deposits. The chronoamperometry analysis indicated that the reduction in nickel followed the 3D progressive nucleation mechanism in the presence of composite additives at the step potential of −1.16 V and −1.18 V. Smoother and finer nickel films were found using scanning electron microscopy (SEM) images as the composite additives were used. X-ray diffraction revealed that all nickel deposit samples had the face-centered cubic structure, and five main crystal planes were displayed by the presence of composite additives in the electrolyte. Furthermore, the diffraction peaks of (111) and (200) crystal planes were slightly shifted toward lower 2θ values when thiourea was used in combination with additive CTAC or PEG20000. These results were beneficial for understanding the mechanisms and facilitating the rational design of additives for metal nickel electrodeposition.

A Sensitive Capacitive Biosensor for Protein a Detection Using Human IgG Immobilized on an Electrode Using Layer-by-Layer Applied Gold Nanoparticles.

A capacitive biosensor for the detection of protein A was developed. Gold electrodes were fabricated by thermal evaporation and patterned by photoresist photolithography. A layer-by-layer (LbL) assembly of thiourea (TU) and HAuCl4 and chemical reduction was utilized to prepare a probe with a different number of layers of TU and gold nanoparticles (AuNPs). The LbL-modified electrodes were used for the immobilization of human IgG. The binding interaction between human IgG and protein A was detected as a decrease in capacitance signal, and that change was used to investigate the correlation between the height of the LbL probe and the sensitivity of the capacitive measurement. The results showed that the initial increase in length of the LbL probe can enhance the amount of immobilized human IgG, leading to a more sensitive assay. However, with thicker LbL layers, a reduction of the sensitivity of the measurement was registered. The performance of the developed system under optimum set-up showed a linearity in response from 1 × 10−16 to 1 × 10−13 M, with the limit detection of 9.1 × 10−17 M, which could be interesting for the detection of trace amounts of protein A from affinity isolation of therapeutic monoclonal antibodies.

Highly selective recognition of acrylamide in food samples using colorimetric sensor based on electrochemically synthesized colloidal silver nanoparticles: Role of supporting agent on cross-linking aggregation

Acrylamide (AA) which occurs during carbohydrate-rich foods processed at high temperatures has been known as a neurotoxic, genotoxic, and probable carcinogenic compound to humans. In this study, thiourea (TU) is used as a supporting agent for the direct recognition of AA based on the cross-linking aggregation of electrochemically synthesized colloidal silver nanoparticles (e-AgNPs). The effect of TU on the AA recognisability was investigated using UV–vis absorption spectra, TEM, DLS, FTIR, and Raman analysis. The obtained results show that the partial substitution of the citrate layer on the surface of e-AgNPs by TU plays an important role in the AA recognisability of colorimetric sensors. At the concentration of 1 μΜ, TU can replace the citrate layer capped on the surface of e-AgNPs leading to the large changes in the dispersion state of e-AgNPs in acid conditions. This replacement helped AA easily adsorb and interact with the e-AgNPs via the amine group, resulting in a change in color and absorbance of the e-AgNPs-TU solution. This new design selectively responds to AA but does not show a color change with other agents. Under optimized conditions, the analysis of the dispersion state variation of e-AgNPs showed excellent sensing performance toward AA with a good linear in the range of 0.1–1000 μΜ (R2 = 0.99) and a limit of detection (LOD) of 0.024 μΜ. Our study also reveals that the e-AgNPs-TU-based colorimetric sensor can be effectively utilized for the determination of AA in the real biscuit and snack samples with an RSD value of 4.1%.

Effects of foliar applied thiourea on maize physiology, growth and yield (Zea mays L.) under shaded conditions

Adverse climatic conditions lead toward reduction in agricultural crop production that is a serious threat for global food security. Reduced irradiance in crop season affects plant physiology, growth and yield. To alleviate shade stress, foliar application of thiourea (TU) has not been comprehensively tested on maize. In this regard, a greenhouse study on maize crop was established with different TU application (as foliar) rates; CK (0 mg L−1), T4 (400 mg L−1), T8 (800 mg L−1) and T16 (1600 mg L−1) under shaded and non-shaded conditions. The results indicated that TU increased physiologically photosynthetic rate (Pn), biochemically chlorophyll a, chlorophyll b and leaf water content. In term of nutrient concentration, stem and leaf nitrogen contents were increased by 18.30% and 23.55% respectively in T16 as compared to CK. Overall, higher amount of TU (T16) increased plant height (5.10%), stem diameter (11.90%), stem fresh weight (5.16%), stem dry weight (5.22%), 100-kernel weight (23.58%) and grain yield (9.08%) than that of CK. However, TU application under shaded environment could not produce similar yield as that of non-shaded plants. Overall, non-shaded plant had 9.71% higher grain yield than that of shaded conditions. But it can be concluded that foliar application of TU at higher concentration could be a promising option to maintain maize productivity under shaded conditions. Furthermore, combination of TU with other plant nutrients should be tested to improve maize growth under shaded conditions.

Investigation on flame retardancy of sulfur/nitrogen-based compounds for polyamide 6 fabric through facile exhaustion route

Improving the flame retardancy and anti-dripping ability of polyamide 6 (PA6) fabrics through facile textile finishing technique is of great interest. This study focused on the flame retardant (FR) modification of PA6 fabric using three sulfur/nitrogen-containing compounds with different sulfur valence through exhaustion process. We further explored and compared the thermal stability, heat release ability, FR performance and mechanism of guanidine sulfamate (GAS), thiourea (THU), ammonium sulfate (AMS) on PA6 fabric. The modified PA6 fabrics displayed self-extinguishing ability without dripping action. They also possessed the low damaged length of 8–12 cm and high LOI of about 31.0%, suggesting good flame retardancy. As a comparison, GAS and AMS with positive sulfur valence had higher FR efficiency than THU with negative sulfur valence on PA6 fabric. GAS and AMS modification also decreased the heat release of PA6 fabric by about 20.1% and 16.2%, respectively. According to the thermal stability and char residue analyses, GAS, THU and AMS mainly worked through the gas-phase FR mechanism. A condensed FR action also occurred for THU modified PA6 fabric. Besides, no obvious influence on mechanical performance of PA6 fabric was observed.

Effects of various media on micellization, adsorption and thermodynamic behaviour of imipramine hydrochloride and antimicrobial surfactant mixtures.

The effect of various media (aqueous, NaCl, urea (U) and thiourea (TU)) on the micellization and adsorption activity of varied mixtures of imipramine hydrochloride (IMP) and benzethonium chloride (BZCl) is investigated via tensiometry. In an aqueous medium, the interactions between IMP and BZCl are also evaluated using UV–visible and FTIR spectroscopy. The interaction between components increases with increased mole fraction (α1) of BZCl in the mixed system (IMP + BZCl). Different parameters, such as micellar and the mixed monolayer component composition, the interaction parameters of the solution and the interface, the activity coefficients of the components in solution and at the interface, and thermodynamic parameters, are computed using different proposed theoretical models (i.e. Clint, Motomura, Rubingh and Rosen). The cmc values obtained for the pure components and mixtures (IMP + BZCl) of all the compositions are found to be less in NaCl than in the aqueous solution while found more in the presence of U or TU. TU is more effective in increasing the cmc of the pure and mixed systems than U. The Gibbs free energy values of the studied pure and mixed systems are negative, showing the spontaneous nature of the reaction.

Plant growth promoters mediated quality and yield attributes of milk thistle (Silybum marianum L.) ecotypes under salinity stress

Silybum marianum (L.) Gaertn (Astraceae) is a well-reputed medicinal plant mostly utilized for silymarin (Sily) content and oil production, however, the information about Sily contents in achene part is still fragmented under different climatic conditions. In this study four milk thistle ecotypes from Faisalabad (FSD), Gujranwala (GUJ), Quetta (QTA), and Kallar kahar (KK) having an altered achene color were analyzed under salt stress. Application of plant growth promoters (PGPs) is one of the solution for ameliorating the effect of salinity and increasing the quantity and quality traits of milk thistle, so ascorbic acid (AsA), thiourea (TU), and moringa leaf extract (MLE) were soil supplied after developing salinity stress (120 mM with irrigation) at germination stage. Predetermined levels were selected for PGPs such as AsA (500 µM), MLE (3%), and TU (250 µM). Results revealed that all yield related attributes were significantly decreased, while secondary metabolites, pericarp epidermis, pericarp parenchyma, and pericarp seed integument increased under salinity stress. Data suggested that PGPs treatment was helpful to alleviate the deleterious effects of salinity stress and enhance the milk thistle quality and quantity parameters. The ecotypic variations with altered achene color patterns represent an advantage for QTA ecotypes for higher Sily extraction under salt stressed conditions.

Novel method of one pot preparation of thiourea self-assembled monolayers over gold nanoparticles-carbon nanotubes composite for sensing application of phenolic compounds

A novel method based on a one pot preparation of thiourea (TU) self-assembled monolayers (SAMs) over gold nanoparticles (Aunano) mixed with carbon nanotubes (CNTs) is presented. The sensor is fabricated by casting a thin layer from CNT-Aunano-TU mixture over a GC electrode surface for concurrent determination of hydroquinone (HQ), catechol (CC), phenol (PH), and p-nitrophenol (PNPH) in real water samples. The one pot preparation method of TU-SAMs is advantageous for simplicity, efficiency and time saving as it takes 45 min for preparation compared to 12 or 24 h with other cited electrochemical methods. Gold nanoparticles increase the stability of TU-SAMs via the strong Au–S bond and significantly raise the number of immobilized S-functionalized compounds i.e., establishment of an interface with amine groups which form hydrogen bonds with the target compounds. Voltammetry concurrent determination of HQ, CC, PH, and PNPH in wastewater sample is successfully accomplished in the concentration ranges (0.01 to 80 µM), (0.01 to 80 µM), (0.01 to 90 µM) and (0.05 to 90 µM) with low detection limits of 0.165 nM, 0.112 nM, 0.732 nM and 3.687 nM, respectively. The GC/CNT-Aunano-TU sensor is practically used in wastewater samples for HQ, CC, PH, and PNPH determination with satisfactory recoveries, outstanding interference resistance and long-time stability.

Sensitive Detection of Thiourea Hazardous Toxin with Sandwich-Type Nafion/CuO/ZnO Nanospikes/Glassy Carbon Composite Electrodes.

In this research study, we developed a voltammetric electrochemical sensor probe with a copolymer Nafion (Sulfonated Tetrafluoroethylene-based Fluoro-polymer) decorated with hydrothermally prepared sandwich-type CuO/ZnO nanospikes (NSs) onto a glassy carbon electrode (GCE) for reliable thiourea (TU) detection. The detailed characterizations in terms of structural morphology, binding energy, elemental compositions, grain size and crystallinity for synthesized NSs were performed by field emission scanning electron microscopy (FESEM), X-ray photoelectron spectroscopy (XPS), energy-dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD) analysis, respectively. The differential pulse voltammetric (DPV) analysis for TU showed good linearity at current-versus-TU concentration on the calibration plot in the 0.15~1.20 mM range, which is defined as a dynamic detection range (LDR) of TU in a phosphate buffer solution. Considering the slope of LDR over the GCE-coated NSs surface area (0.0316 cm2), the TU sensor sensitivity (0.4122 µA µM−1 cm−2) was obtained. Besides this, the low limit (LOD) for TU detection was calculated and found to be 23.03 ± 1.15 µM. The fabricated Nafion/CuO/ZnO NSs/GCE sensor probe was created as a reliable sensor based on reproducibility, interference effect, stability and response time. Real bio-samples were investigated and the results confirm the anticipated reliability of the TU sensor probe. Thus, this is a noble way to develop enzyme-free electrochemical sensors that could be an alternative approach for the detection of chemicals in the field of enzyme-free biosensor development technology.

Dye-sensitized solar cell using nickel sulfide-reduced graphene oxide counter electrode: Effect of sulphur content

The influence on sulphur content in term of thiourea (TU) concentration on the properties of nickel sulphide (NiS)-reduced graphene oxide (rGO) has been reported in this paper. The effect of sulphur content on the performance of dye-sensitized solar cell (DSSC) using NiS-rGO counter electrode (CE) has also been investigated. The source of sulphur is TU. The sample has been prepared via modified Hummers’s method assisted with spin coating technique. The cell using NiS-rGO CE prepared with 1.20 M TU yielded the highest power conversion efficiency (η) of 1.42%. This is due to this cell has the lowest series resistance (Rb) and charge transfer resistance at the interface of NiS-rGO CE/electrolyte (Rct) with the value of 0.44 and 4.09 Ω, respectively. It is also due to the sample with 1.20 M TU owns the highest reduction current (J). The finding of this work reveals that NiS-rGO is able to substitute platinum as CE for DSSC.

Bifunctional hydrogen-bonding cross-linked polymeric binders for silicon anodes of lithium-ion batteries

The optimization of polymeric binders has been considered as an effective strategy to accommodate the huge volume change of Si anodes during lithiation and delithiation processes. In this work, three dimensional polymeric binders (CMC/TU) with multiple hydrogen bonds were designed and fabricated through the copolymerization reaction between carboxymethylcellulose sodium (CMC) and thiourea (TU), which possess bifunctional effects on Cu current collectors and Si active materials. On the one hand, similar to the interaction mechanism at rubber-metal boundary in tire industry, the formation of dendritic CuxS layers results in physical interlocked forces to strengthen the binding forces of CMC/TU binders with Cu current collectors. On the other hand, the generation of hydrogen bonds between polymeric binders and Si oxide layers can enhance the binding forces of CMC/TU binders with Si active materials and stabilize the electrode/electrolyte interface. When served as binders to Si microparticles (1–5 μm), they exhibited initial coulomb efficiency of 89.9% and reached 1059 mAh g−1 after 150 cycles, which results from the bifunctional roles of CMC/TU binders for maintaining electrode integrity during the discharge and charge processes. The developed synthetic method provides a strategy to enhance the electrochemical properties of Si-based materials, and can be widely applied to other electrode materials.

Application of sewage sludge combined with thiourea improves the growth and yield attributes of wheat (Triticum aestivum L.) genotypes under arsenic-contaminated soil.

Arsenic (As) contamination is a serious threat to agriculture and human health worldwide. It can adversely affect the growth attributes of food crops. On the other hand, using thiourea (TU) to ameliorate As stress is an economically consistent approach. However, there is a knowledge gap regarding the combined use of TU and Sewage sludge (SS). SS is considered important, unutilized biomass. It can be used as a fertilizer that has high organic matter and nutrients. Therefore, the current study was performed to evaluate TU and SS sole and combined responses under As toxicity on two wheat genotypes (Markaz 19 and Ujala 16). There were four treatments control (As 50 mg kg-1), SS (30 g kg−1)+TU (6.5 mM)+As, TU+As and SS+As applied with four replications. Results revealed that SS+TU performed significantly better over SS, TU and control for improvement in root and shoot fresh and dry weight of wheat varieties Markaz 19 and Ujala 16 under As toxicity. A significant decrease in POD, SOD and APX of Markaz 19 and Ujala 16 also validated the effective functioning of SS+TU over control. The maximum increase of 71 and 77% was noted in phosphorus, where SS+TU was applied over control in Markaz 19 and Ujala 16, respectively. In conclusion, SS+TU is a better approach than the sole application of SS and TU under As contamination for improvement in wheat growth attributes. More investigations are recommended at the field level under different As contamination and agro-climatic zones to declare SS+TU an effective amendment to mitigate As toxicity in wheat.

Effect of Exogenous Application of Some Growth Regulators on Growth and Yield of Maize(Zea mays L.) Cultivars

Maize being subtropical crop is sensitive to low temperature at early growth stages. Exogenous application of humic acid (HA), ascorbic acid (AsA), and thiourea (TU) can improve the growth of maize. This experiment was conducted to investigate the effect of different plant growth regulators to as a foliar spray to two (pioneer 1543 and monsanto 8441) maize cultivars. Main objective of this research is exogenous application of plant growth regulators that significantly increase the growth parameters, plant biomass and yield of plant. A total of 3 treatments TO = control, T1 = 20ml/L HA, AsA and TU, T2 = 30ml/L HA, AsA and TU and T3 = 50ml/L HA, AsA and TU were tested in a randomized complete block design with three replications. All the treatments improved the yield, growth and biomass of maize. Although, various treatments, thiourea showed the maximum leaf length, root length and cobe length of the plant. Results declared that foliar spray of plants growth regulators increased the growth parameters viz; plant height, Number of leaves per plant, Leaf area, Number of nodes and Fresh weight of plant.

Rosin imidazoline as an eco-friendly corrosion inhibitor for the carbon steel in CO2-containing solution and its synergistic effect with thiourea

Rosin is known as an eco-friendly raw material from natural plants. The main component of rosin is abietic acid. Abietic acid has a carboxyl and a tricyclic phenanthrene skeleton in which conjugated double bonds are present. Conjugation structure will lead to local enrichment of electrons, thereby creating sites that can be used for adsorption. In this case, it is expected that a better performance could be obtained if an inhibitor is synthesized from rosin. In this work, rosin was used to synthesize an imidazoline derivative as a corrosion inhibitor, then the corrosion inhibition performance and synergistic effect with thiourea (TU) of rosin imidazoline (RI) for carbon steel in test solution were studied using weight loss measurement, electrochemical techniques and surface characterization. The results show that the inhibition efficiency of RI reaches 83.8% at 200 mg/L. A further increase in RI concentration does not effectively improve the inhibition performance since the critical micelle concentration of RI is present at around 200 mg/L. The molecular characteristics of RI was analyzed by quantum chemical calculations. It clearly shows that multiple adsorption sites exists in the RI molecular structure, hence RI could offer a good inhibition performance. With the compounding of 200 mg/L RI and 10 mg/L TU, the inhibition efficiency could increase as high as 89.8%, demonstrating a good synergistic effect between RI and TU. The corresponding synergistic mechanisms are also proposed.

Ground electronic state description of thiourea coordination in homoleptic Zn2+, Ni2+ and Co2+ complexes using sulfur K-edge X-ray absorption spectroscopy.

Sulfur K-edge X-ray absorption spectroscopy (XAS) was employed to experimentally characterize the coordinative bond between the thiourea (TU) or thiocarbamide ligand and transition metal (TM) ions Zn2+, Co2+ and Ni2+ in distorted tetrahedral and octahedral homoleptic coordination environments. Comparisons of XAS spectra of the free TU ligand and [Zn(TU)4]2+, [Co(TU)4]2+ and [Ni(TU)6]2+ complexes clearly identify spectral features unique to TM2+-S(TU) bonding. Quantitative analysis of pre-edge intensities describes the covalency of Ni2+-S(TU) and Co2+-S(TU) bonding to be at most 21% and 9% as expressed by the S 3p contributions per TM 3d electron hole. Using relevant Ni2+ complexes with dithiocarbamate and thioether ligands, we evaluated the empirical S 1s → 3p transition dipole integrals developed for S-donor ligands and their dependence on heteroatom substitutions. With the aid of density functional theory-based ground electronic state calculations, we found evidence for the need of using a transition dipole that is dependent on the presence of conjugated heteroatom (N) substitution in these S-donor ligands.

Significantly enhanced capacitance of symmetrical supercapacitor based on Cu-CuxS@S-C electrode by thiourea electrolyte additive

Metal sulfides have been considered to be excellent electrode materials for supercapacitors (SCs) due to their high conductivity and electrochemical activity. Meanwhile, the addition of redox additives to the electrolyte can increase the pseudocapacitance of SCs. Herein, the composite (Cu-CuxS@S-C) of Cu nanocrystals and CuxS embedded in S-doped carbon matrix was prepared through impregnation method followed by high-temperature pyrolysis. The optimal Cu-CuxS@S-C-600 has an extremely high capacitance of 9607 mF cm−2 at 5 mA cm−2 in the alkaline electrolyte with thiourea (TU), which is due to the good conductivity of Cu and CuxS, large crystal plane spacing of CuxS, and the redox reaction caused by the addition of TU. The symmetrical SC based on Cu-CuxS@S-C-600 electrode was fabricated, its pseudocapacitance (960 mF cm−2) in the electrolyte with TU is 4.6 times that (208 mF cm−2) in the electrolyte without TU. The energy density (E) of SC reaches 261 µ Wh cm−2, and the power density (P) is 2800 µW cm−2 at 4 mA cm−2 in the gel electrolyte with TU.

A Modulation QCM Applied to Copper Electrodeposition and Stripping

AbstractA fast electrochemical quartz crystal microbalance with dissipation monitoring (EQCM−D) was applied to copper electrodeposition and subsequent stripping. Accumulation brings the frequency noise down to the mHz range, corresponding to 0.1 % of a monolayer. With this precision, the apparent mass transfer rate as determined from the time‐derivative of the frequency shift can be directly compared to the current. Small but systematic deviations between the two can be attributed to nanoscale roughness. In the voltage range of underpotential deposition (UPD), the apparent mass transfer rate shows peaks and shoulders. The plating additive benzotriazole (BTA) leaves the magnitude of electrogravimetric signals unchanged, but shifts the UPD onset potential. The additive thiourea (TU) promotes UPD and strongly increases the bandwidth.