Alkaline Reaction Research Articles

Electroless deposited NiP-fabric electrodes for efficient water and urea electrolysis for hydrogen production at industrial scale

Herein, an advanced approach for transforming ordinary cotton-polyester fabric into a flexible and catalytic current collector is demonstrated for water and urea electrolysis for industrial-scale H2 production, addressing challenges in energy and environmental sustainability. A controlled electroless plating is adopted to deposit conducting metallic Ni-nanoparticles together with NixPy-catalytically active phase on an open macroporous framework of fabric. NiP-fabric electrodes exhibit exceptional hydrogen evolution reaction (HER) in alkaline, acidic, and in artificial Sea-water with overpotential values of 159 mV, 127 mV, and 94 mV at 10 mA/cm2 current density respectively. These electrodes also demonstrate the outstanding oxidation reaction for oxygen evolution and urea oxidation with the potential of just 1.509 V vs RHE (at 20 mA/cm2) and 1.312 V vs RHE (at 10 mA/cm2), with the in-situ formation of more active NiOOH species. A self-supported and macro-porous electrode configuration regulates the adsorption/desorption of intermediates species, enhanced charge and mass transport, and easier desorption of oxygen molecules. Finally, a two-electrode water and urea electrolyzer is constructed by NiP-fabric, which can deliver an H2-production at 100 mA/cm2 at a potential of 1.883 V and 1.611 V, respectively.

Factors affecting compressive strength and expansion due to alkali-silica reaction of fly ash-based alkaline activated mortar

The development of environmentally friendly alkaline-activated materials (AAMs) holds promise, as AAMs can be derived from waste materials. This study aims to investigate the factors influencing (i) compressive strength and (ii) expansion due to alkali-silica reaction (ASR) in AAMs. These factors include alkaline concentration, heat curing conditions, fineness of fly ash, and the liquid alkaline-to-binder (L/B) ratio. The findings indicate that the higher concentrations of NaOH solution led to an increase in AAM compressive strength due to the enhanced dissolution and polymerization rates in a more alkaline environment. Heat curing stimulated chemical reactions and structure formation, while the reduced water content resulted in lower porosity and higher compressive strength in the hardened cement. Finer fly ash yielded greater compressive strength than coarser ash, as its smaller spherical particles contributed to denser and firmer structures. The presence of calcium minerals, from both Ordinary Portland Cement (OPC) and high-calcium fly ash, bolstered the strength of hardened products. Moreover, calcium minerals like CaO, Ca(OH)2, and CaSO4 were found to induce ASR expansion by promoting gel formation, leading to later-stage expansion in the hardened cement or concrete. However, finely milled fly ash as a precursor significantly reduced ASR expansion in AAMs, by approximately 40% compared to ordinary Portland cement. This study provides valuable insights for civil engineers for better understanding of AAM behavior and makes contributions to the safety and sustainability of cement and concrete systems.

Potassium in brown soils of mountain pastures of Uzbekistan

The studied mountain brown soils are characterized by loamy granulometric composition, nutty-cloddy structure, slightly acidic or slightly alkaline reaction. The total potassium content in the upper horizon varies from 1.240 to 1.685 %. Exchangeable potassium ranges from 265 to 1028 mg/kg of soil. The share of clay fraction varies from 2.9 to 18.3 %. In silty fractions, the con- tent of potassium is 2-3 times higher than in the soil as a whole and ranges from 1.26 to 3.02 %. Potassium reserves were identified - near, immediate and potential. Fluctuations in the content of potassium reserves in the humus horizon of the total content were: immediate from 1.5 to 8.31 %, near ө from 5.40 to 32.85 %, potential, dominant in the total content 65.12 to 93.0 %. It has been established that the distribution of potassium and its reserves in the pasture mountain brown soils of Uzbekistan is uneven and depends on many natural factors. It was revealed that potassium of a potential reserve is presented in a sufficiently large amount, and in a slightly smaller amount - near and immediate. Losses of near and immediate reserves of potassium lead to a decrease in the content of total potassium in general.

Assessment of the soil buffer capacity in the green plantings of the megalopolis parks

Land degradation poses a serious challenge to food security, livelihood sustainability, ecosystem services and biodiversity conservation, while inefficient land management leads to widespread loss of soil biodiversity. The soil buffer capacity is actively involved in the mechanisms of implementing such an ecosystem service as the development and stabilization of soil fertility. Buffering determines the share of the soil potential that determines the processes of immobilization (deposition) and mobilization (release, loss) of a particular element of fertility – first of all, mineral nutrients required by plants, productive moisture, thermal energy of the soil, gas composition of soil air, acidity. The soils in parks on the territory of megacities are an integral component of them determining the conditions for the growth and development of green spaces. We assessed the acid-base (pH) buffer capacity of urban areas in a park area covered with tree stands of such introduced tree species as horse chestnut (Aesculus hippocastanum), sugar maple (Acer saccharum), small-leaved elm (Ulmus parvifolia), common hackberry (Celtis occidentalis), honey locust (Gleditsia triacanthos) and Japanese pagoda tree (Styphnolobium japonicum) growing on the territory of the T. G. Shevchenko Park (Dnipro city, Ukraine). Soil samples were collected under the crowns of these tree species. The acid-base buffering capacity of urban soils was determined by the Arrhenius method, which includes adding certain volumes of acid and alkaline components to the sample, and further calculating the buffering area within acid and base intervals. Buffering areas were calculated using the Simpson formula. The results were processed with statistical methods (arithmetic mean and standard deviation were calculated, and the difference in means was found according to the Tukey's comparison test). Initially the samples of the studied soils were found to have mostly a slightly alkaline reaction of the soil solution. Within the acid range of external influences, the buffer capacity of urban soils under introduced tree species was determined to establish the following descending series: horse chestnut, common hackberry, small-leaved elm, honey locust, Japanese pagoda tree, sugar maple. The same series was established for the total acid-base buffering capacity. The results show the greater acid-base buffer capacity of soils sampled under horse chestnut, common hackberry, small-leaved elm and honey locust trees, and therefore these soils were resistant to degradation compared to the soils sampled under Japanese pagoda tree and sweet maple. The environment-forming role of introduced tree species in the implementation of buffer properties of urban soils in the park on the megalopolis territory can be assumed.

Elucidating key mechanistic processes during acidic CO2 electroreduction on gas diffusion electrodes towards stable production of formic acid

The electrochemical reduction of CO2 using renewable electricity could be a sustainable alternative to produce formic acid. Although using bulk acidic electrolyte offers system and downstream processing benefits, neutral to alkaline electrolyte systems prevail due to challenge suppressing hydrogen evolution in acidic environment. In recent years, it has been shown that HER could be mitigated by confining the OH- being generated and constraining the movement of H3O+ towards reaction surface, thereby producing an alkaline reaction environment within the electrode. Herein, we have demonstrated how a porous and highly hydrophobic Bi-based gas diffusion electrode enables remarkably efficient bulk acidic electrolysis. Importantly, the local alkaline reaction environment has been proven via electrochemical impedance spectroscopy and pH visualization. Furthermore, optical monitoring of electrolyte conditions through a transparent cell sheds light on the CO2 recovery process in the acidic system, promoting a better technical practice in handling with electrochemical cells and CO2 recirculation. Finally, HCOOH accumulation as the key degradation reason is unveiled through investigation into the impact of operating modes on the stability at high current density, where earlier studies failed to adequately address. It is believed that this valuable insight could facilitate stable and efficient formic acid production in future work.

Salinization and Solonetsization of Soils in River Valleys of the Kulunda Plain

The surface of the Kulunda Plain is dissected by a system of ancient wide valleys, former runoff hollows, which have a very small slope (less than 1°). Rivers flow along these weakly expressed valleys, redistributing readily soluble salts throughout the territory. The regime of these rivers is characterized by a sharp and high flood wave and low (up to complete drying) runoff in the summer. The purpose of this work is to study the ion-salt system of soils of ancient runoff troughs of the Kulunda Plain, groundwater and river waters in order to identify modern processes of soil salinization. During floods, river water feeds close-lying groundwater, influencing its chemical composition. Studies of three key sites in the valleys of the Bagan (Novosibirsk region), Burla and Kulunda (Altai Territory) rivers took place in 2021–2022. Ground waters of varying degrees of mineralization (from 3.4 to 63.0 g/l) and lie close to the surface (2–5 m), which causes a wide distribution of saline hydromorphic soils in the study area. Differences in the salt state of soils in different valleys, groundwater and river waters are discussed. The degree of salinization of soils depended on their granulometric composition. The high content of physical clay contributed to the rise of salts with groundwater and their accumulation in the soil profile. A large amount of exchangeable sodium in the soil absorbing complex of the studied soils (more than 3–5 cm (eq)/kg), the predominance of easily soluble sodium salts in the soil solution with its low mineralization, as well as the alkaline reaction of the soil medium indicates the manifestation of the process of soil salinization.

PROPERTIES OF EKRANOSEMS OF THE CITY OF LVIV

Ekranozems are urban soils that occupy a significant area of cities and play an important role in urban ecosystems, because they have a wide range of properties. One of the main features of ekranozems is the presence of a closed impermeable layer - a screen, that is, an artificial surface, which includes asphalt concrete, paving stones, sidewalks, etc. At the same time, thanks to the processing of scientific and literary sources, it should be noted that ekranozems are still little-studied and under-researched due to their inaccessibility. They are the result of a variegated relief, the influence of zonal and climatic conditions of soil formation and anthropogenic factors. It is clear that these interactions varied depending on the location and age characteristics of the city. The structure, composition and properties of ekranozems, as well as their functioning, are determined by the structural features of roads, driveways, footpaths, etc., as well as the features of anthropogenic impact (before sealing) on the soil, taking into account its natural features in certain conditions of soil formation. Ekranozems occupy a significant part of the territory of the city of Lviv and are characterized by a great variety of properties. As a result of their stay under asphalt concrete and pavement surfaces, such negative processes as a decrease in water permeability, a decrease in the concentration of oxygen in the soil, and a change in the water regime occur. There is also soil compaction and a decrease in general sparability during the improvement of the territory. These soils are united by their lack of humus throughout the profile. The studied ekranozems are characterized by the presence of calcium carbonates throughout the profile, which are brought, for the most part, during the construction and laying of networks, as well as various repair works on the road. The acid-base properties of ekranozems are represented by the alkaline reaction of the soil environment, which is caused by the presence of carbonate salts (pH ranges from 7.7 to 8.1), which causes a slowdown in soil-forming processes and, as a result, a change in soil quality. Keywords: ekranozem; urban soil; sealed soil; urban ecosystem; anthropogenic soil; Lviv plateau; cultural layer.

Mitigation of alkali-silica reaction in blast-furnace slag-based alkaline activated material through incorporation of alum water treatment residue

Alkaline-activated materials (AAMs) have been developed as an alternative binder for cement in an effort to reduce the carbon footprint. However, due to the high alkaline contents in AAMs, these materials, particularly ground granulated blast-furnace slag (GGBS)-based AAM, may have a high potential of detrimental alkali-silica reaction (ASR) when amorphous silica-rich aggregates are used. This study utilised alum water treatment residue (AWTR), a waste from drinking water treatment, as an additional precursor in slag-based AAM to mitigate ASR in mortars with high reactive glass aggregate. The results showed that incorporating 40% AWTR in the precursor improved the compressive strength from 47 to 64 MPa and reduced ASR-induced expansion from 0.9% to 0.2% after 28 days of the accelerated test. The characteristics of the ASR gels were analysed using backscattered electron images coupled with energy-dispersive x-ray spectroscopy. Microscopic observations revealed that the ASR products formed in two stages. In the earlier stage, amorphous ASR gels precipitated surrounding the aggregates, exerting pressure on them and the matrix, resulting in initial cracking. In the latter stage, ASR products extruded into the open cracks, and crystalline products were formed, causing additional damage to the matrix. The quantitative elemental analysis demonstrated that incorporating AWTR could slow down silica dissolution by forming an Al layer in the aggregate surface, prevent the ASR gel calcification and reduce the growth of the harmful crystalline ASR products.

Features of achieving compensation of hypothyroisis in pregnant women

BACKGROUND: Hypofunction of the thyroid gland in women at the pre-pregnancy stage and during pregnancy is associated with a high risk of congenital hypothyroidism in children, as a result of which irreversible changes in the nervous system are formed. Despite the mandatory intake of potassium iodide preparations, pregnant women often develop gestational hypothyroidism, which requires the appointment of levothyroxine. Many women have episodic hypofunction of the thyroid gland before pregnancy, associated with various factors. Diagnosed hypothyroidism requires hormonal correction. The recommended dose of levothyroxine calculated by the patient’s weight is not always adequate to achieve TSH targets. In addition, there are pharmacological factors. Levothyroxine sodium preparations differ in bioavailability. The stability of drugs is affected by external factors and the composition of fillers from different manufacturers of drugs.AIM: To assess the dependence of TSH reduction on the method of taking levothyroxine in a population of pregnant women.MATERIALS AND METHODS: Statistical analysis and prospective study was carried out from 2019 to 2021. On the basis of the «Perinatal Center», Tyumen, women’s consultative and diagnostic department. Pregnant women with diagnosed primary subclinical and manifest hypothyroidism in the first trimester of pregnancy (n=76) were selected for cohort observation. All pregnant women were prescribed L-thyroxine Berlin-hemi. Other levothyroxine preparations were not used in order to exclude distortion of the results of the study.RESULTS: Pregnant women with hypothyroidism were divided into two groups according to the method of taking L-thyroxine: oral (n=54) and sublingual (n=22). A month later, TSH normalization was observed in 41 pregnant women in the oral group (76%) and in 22 pregnant women in the sublingual group (100%). Women who did not achieve hypothyroidism compensation were recommended sublingual administration without increasing the dose of L-thyroxine, provided that TSH was no higher than 4.0 mcME / ml. A TSH study a month later showed that all pregnant women achieved compensation. CONCLUSION: Based on the conducted research, it is shown that the more rational administration of levothyroxine sodium preparations is sublingual, since there is a slightly alkaline reaction in the oral cavity, which does not have a destructive effect, like gastric juice.

Effective Hydrogen Production from Alkaline and Natural Seawater using WO3-x@CdS1-x Nanocomposite-Based Electrocatalysts.

Offshore hydrogen production through water electrolysis presents significant technical and economic challenges. Achieving an efficient hydrogen evolution reaction (HER) in alkaline and natural seawater environments remains daunting due to the sluggish kinetics of water dissociation. To address this issue, we synthesized electrocatalytic WO3-x@CdS1-x nanocomposites (WCSNCs) using ultrasonic-assisted laser irradiation. The synthesized WCSNCs with varying CdS contents were thoroughly characterized to investigate their structural, morphological, and electrochemical properties. Among the samples tested, the WCSNCs with 20 wt % CdS1-x in WO3-x (Wx@Sx-20%) exhibited superior electrocatalytic performance for hydrogen evolution in a 1 M KOH solution. Specifically, the Wx@Sx-20% catalyst demonstrated an overpotential of 0.191 V at a current density of -10 mA/cm2 and a Tafel slope of 61.9 mV/dec. The Wx@Sx-20% catalysts demonstrated outstanding stability and durability, maintaining their performance after 24 h and up to 1000 CV cycles. Notably, when subjected to natural seawater electrolysis, the Wx@Sx-20% catalysts outperformed in terms of electrocatalytic HER activity and stability. The remarkable performance enhancement of the prepared electrocatalyst can be attributed to the combined effect of sulfur vacancies in CdS1-x and oxygen vacancies in WO3-x. These vacancies promote the electrochemically active surface area, enhance the rate of charge separation and transfer, increase the number of electrocatalytic active sites, and accelerate the HER process in alkaline and natural seawater environments.

ACIDITY OF DEGRADED SOILS OF AGRICULTURAL LANDS OF THE DONETSK PEOPLES REPUBLIC

The purpose of this work was to study the acidity of degraded agricultural soils. The main objectives of the research were to study the actual and potential soil acidity of agricultural lands of the Donetsk Peoples Republic on the example of agricultural farms in the northern part of the Shakhtyorsky district. It was established that the studied model sites are characterized by a slightly acidic, neutral or slightly alkaline medium reaction, which creates favorable conditions for the formation of crops and plant growth. When studying the exchangeable acidity of soils, the ambiguity of changes in its values was established, depending on the location of the model sites, the system of soil content in the crop rotation, the horizon, and other factors. Th e most exceeding the control values of the exchange acidity are characteristic of the slope surfaces of sites where the intensity of erosion processes reaches a maximum (exceeding the indicator compared to the control by average of 8,6%). In the future, increased values of exchangeable acidity may adversely affect the formation of crop yields. Changes in the values of hydrolytic acidity of soils follow the same regularity as the variation in the indices of exchangeable acidity. The most significant excess of the hydrolytic acidity index in comparison with the control was recorded on the slope sites of the fields (increase by 11-17%). The conducted studies confirm the need for constant agroecological monitoring of these lands with the regulation of mineral fertilizers to increase the absorption capacity of soils due to increased values of exchangeable and hydrolytic acidity.

Enhancing Effect of Boron-Doping on the Activity of Nife-MOF-74 Towards Oxygen Evolution Reaction in Alkaline

Water splitting has drawn significant attention due to the capability of mass-producing hydrogen, which is considered a promising alternative to fossil fuels in the future.[1] The development of electrochemical energy conversion and storage technologies, such as water electrolyzers, metal-air batteries, and regenerative fuel cells, is of great importance to support the transition to clean and renewable energy.[2] Based on the merits of high surface area, 3D periodic porous structure, large porosities, diverse composition and well-defined metal centers, metal–organic frameworks (MOFs) and their derivatives have been widely exploited as OER electrocatalysts.[3]However, MOFs have some limitation to be used as a OER catalysts, considering their poor stabilities (in water, especially basic/acidic conditions) and low electrical conductivities. Incorporation of boron atoms into an aromatic carbon framework offers a wide variety of functionalities. [4] In this work, the flower-like bimetallic NiFe-MOF-74 dopped with boron were fabricated, and they exhibit superior catalytic activity with a very low overpotential of 318 mV for OER at a laboratory grade current density of 10 to 100 mA/cm2 and fast reaction kinetics with a small Tafel slope of 89 mV dec-1 in 1.0 M KOH using a catalyst fabrication process that is scalable to commercial levels. Additional work is required to demonstrate current densities at commercial levels. Reference [1] L. Fan, Z. Kang, M. Li, D. Sun, Recent progress in pristine MOF-based catalysts for electrochemical hydrogen evolution, oxygen evolution and oxygen reduction, Dalton Trans. 50 (2021) 5732–5753. https://doi.org/10.1039/D1DT00302J.[2] Bimetallic metal–organic frameworks and MOF-derived composites: Recent progress on electro- and photoelectrocatalytic applications - ScienceDirect, (n.d.). https://www.sciencedirect.com/science/article/pii/S0010854521005385 (accessed April 27, 2022).[3] J. Du, F. Li, L. Sun, Metal–organic frameworks and their derivatives as electrocatalysts for the oxygen evolution reaction, Chem. Soc. Rev. 50 (2021) 2663–2695. https://doi.org/10.1039/D0CS01191F.[4] Y. Xie, Z. Meng, T. Cai, W.-Q. Han, Effect of Boron-Doping on the Graphene Aerogel Used as Cathode for the Lithium–Sulfur Battery, ACS Appl. Mater. Interfaces. 7 (2015) 25202–25210. https://doi.org/10.1021/acsami.5b08129.

Uniformly Dispersed Cobalt Catalyst on the Coffee Waste-Derived Carbon Support for Hydrogen Evolution Reaction

The research interests in transition metal catalysts on carbon support have increased last decade for expensive noble metal catalyst replacement. Because those catalysts have a large surface area, good chemical stability, and are cheap and earth-abundant. Mainly structured with Co-N-C catalysts such as Cobalt (Co) nanoparticle embedded N-doped carbon, Co single-atom catalyst on carbon, etc., are highly efficient for hydrogen evolution reaction (HER) in acidic and alkaline electrolytes.Here, we report the uniformly dispersed cobalt catalysts (Co-SCC-N) on nitrogen (N)-doped spent coffee grounds (SCG) derived carbon support, which was further utilized as HER electrocatalyst. In the first step, SCG-derived carbon is synthesized by simple pyrolysis with ZnCl2. Then, the cobalt catalyst is prepared by adsorption of the complex Co ion with 1,10-phenanthroline on the SCG-derived carbon support, followed by pyrolysis at 800°C under a nitrogen atmosphere. Uniform and high dispersions of cobalt on the carbon substrate have been confirmed by scanning transmission electron microscopy (STEM) and energy dispersive X-ray (EDX) elemental mapping analysis. X-ray photoelectron spectroscopy (XPS) determined that the catalyst contained Co2+ ions and had nitrogen-doped. Also, X-ray diffraction (XRD) and Raman spectroscopy revealed carbon materials disorders, crystallinity, and no metal-related peaks that validated no metal clusters on the carbon. Electrochemical tests were examined by linear sweep voltammetry, Tafel, electrochemical impedance spectroscopy, and chronopotentiometry (CP) in alkaline and acidic electrolytes. Co-SCC-N exhibited excellent HER performance in an alkaline medium, which needed 0.246 V to reach 10 mA cm-2. And the CP test confirmed better stability at 10 mA cm-2 for 12 hours. The result recommends a simple synthesis method for uniformly dispersed metal catalysts on biomass-derived carbon support by a simple pyrolysis technique.

Continuum Modeling of Gas and Ions Transport in a High-Surface-Area Carbon (HSC) Nanopore

PEM fuel cell (PEMFC) is one of the promising energy conversion devices for emission-free transportation applications. It is beneficial in faster charging and better scalability compared to battery-powered vehicles, making PEMFC a viable option for heavy-duty vehicles which require higher efficiency and longer lifetimes. To economically compete with the combustion engine and improve commercialization, the PEMFC cathode desires optimization in enhancing the utilization of the expensive Pt catalyst. Integration of high-surface-area carbon (HSC) has shown to increase accessible Pt surface by diminishing ionomer poisoning as Pt particles can be loaded inside the nanoscale micropores (<5 nm) that ionomer cannot penetrate due to size restriction. However, separating Pt catalysts from ionomers requires a water pathway to deliver the proton to the interior catalyst surface, leading to RH-dependent electrochemical surface area (ECSA). In this work, we develop a steady-state, isothermal continuum model to study the gas and ions transport within HSC nanopores. The pore is represented as a straight cylindrical channel filled with water with an ionomer domain at the pore mouth serving as a proton reservoir. The ionomer phase contains H+, OH-, and background stationary SO3 - while the water phase only includes H+ and OH-. The Poisson-Nernst-Plank equations describe the flux of ions, and O2 transport is described by Fick’s law. Non-ideal behaviors including nanoconfinement effects and dielectric saturation are considered in the pore water phase, reflected by corrections in ion chemical potentials, diffusion coefficients of transport species, and dielectric constant. The electrical double layer (EDL) at the water-electrode interface is depicted as discrete finite domains applying the Gouy-Chapman-Stern (GCS) theory, with the oxygen reduction reaction (ORR) occurring at a finite reaction plane at the outer Helmholtz plane (OHP) through both acidic and alkaline reaction pathways. Donnan potential drop is solved at the ionomer-pore water interface and governs potential distribution in the pore water phase, further determining ionic concentrations at the catalyst surface and thus the kinetic region of polarization curves. The strong-adsorbed water adlayers due to nanoconfinement effects create a transport barrier for O2 approaching the catalyst surface, leading to higher mass transport resistance. A comparison between a flooded pore scenario (only a water phase exists in the pore) and a wetted pore scenario (the pore wall is covered by a water film while a gas phase also exists in the pore) shows that mass transport is hindered in the flooding pore as O2 dissolves in the pore water through a limited pore-ionomer interfacial area, while pore gas phase in the wetted pore serves as an extra O2 resource. This suggests that the management of HSC water uptake needs to avoid pore flooding while ensuring enough wettability to allow proton transport. The model is expected to couple with HSC pore size distribution measured from experiments and upscale to a cell-level model in future work.

Alkali-Activated Brick Aggregates as Industrial Valorized Wastes: Synthesis and Properties

In recent works, many industrial by-products were employed as solid precursors for the synthesis of alkali-activated binders and as alternatives to Portland cement for the immobilization of hazardous, toxic and nuclear wastes. Among industrial wastes, alkali-activated brick was found to be an interesting porous composite for removing very toxic heavy metals (Pb2+, Cd2+, Co2+) and radio-nuclides (Sr2+, Cs+, Rb+) from aqueous solutions. The starting material is very attractive due to the presence of metakaolinite as a geo-polymer precursor and silica for increasing material permeability and facilitating water filtration. The alkaline reaction gave rise to geo-polymerization followed by partial zeolitization. Elemental surface micro-analysis was performed by Scanning Electron Microscopy (SEM) equipped with an Energy-Dispersive X-ray Spectrometer (EDS). The formation of crystalline phases was corroborated by X-ray diffraction (XRD) analysis. Information about 29Si, 27Al and 1H nuclei environments in crystallized and amorphous aluminosilicates was obtained by 29Si, 27Al and 1H MAS NMR. 27Al–1H dipolar-mediated correlations were investigated by employing dipolar hetero-nuclear multiple quantum coherence (D-HMQC) NMR, highlighting Al–O–H bonds in bridging hydroxyl groups (Si–OH–Al) that are at the origin of adsorptive properties. Aqueous structural stability and cationic immobilization characteristics before and after material calcination were investigated from acid-leaching experiments.

Hydrogenation versus hydrogenolysis during alkaline electrochemical valorization of 5-hydroxymethylfurfural over oxide-derived Cu-bimetallics

The electrochemical conversion of 5-Hydroxymethylfurfural, especially its reduction, is an attractive green production pathway for carbonaceous e-chemicals. We demonstrate the reduction of 5-Hydroxymethylfurfural to 5-Methylfurfurylalcohol under strongly alkaline reaction environments over oxide-derived Cu bimetallic electrocatalysts. We investigate whether and how the surface catalysis of the MOx phases tune the catalytic selectivity of oxide-derived Cu with respect to the 2-electron hydrogenation to 2.5-Bishydroxymethylfuran and the (2 + 2)-electron hydrogenation/hydrogenolysis to 5-Methylfurfurylalcohol. We provide evidence for a kinetic competition between the evolution of H2 and the 2-electron hydrogenolysis of 2.5-Bishydroxymethylfuran to 5-Methylfurfurylalcohol and discuss its mechanistic implications. Finally, we demonstrate that the ability to conduct 5-Hydroxymethylfurfural reduction to 5-Methylfurfurylalcohol in alkaline conditions over oxide-derived Cu/MOx Cu foam electrodes enable an efficiently operating alkaline exchange membranes electrolyzer, in which the cathodic 5-Hydroxymethylfurfural valorization is coupled to either alkaline oxygen evolution anode or to oxidative 5-Hydroxymethylfurfural valorization.

STUDY ON EUTROPHICATION CHANGE AND THEIR CONSEQUENCES IN PALIASTOMI LAKE

Background: The article describes the study of chlorophyll concentration dynamics in Paliastom lake and its surrounding area. The research covers the period from 2015 to 2022. The study uses remote sensing satellite images obtained from Landsat 8, Sentinel-2, as a result of processing in the SNAP application. At the same time, in situ researches was performed. Aims: This study aims to research chlorophyll concentration in Paliastom lake and its adjacent area through remote sensing methods and in situ data. Methods: For our research and historical data collection, satellite remote sensing was applied, which generates data on spatial and temporal variations of suspended particles in estuaries and coastlines. In situ studies, Chlorophyll concentration and promoting chemical agents were measured, water temperature, pH, total hardness, alkalinity, acidity, and others. Total turbidity was determined, and qualitative reactions were performed to define the presence of phosphates and nitrates. Results: The results received through remote sensing, and in situ studies were compared. Paliastom lake and its adjacent area are prone to eutrophication processes. Natural phenomena and human industrial activity cause the process. Discussion: According to in situ studies and the data obtained from sensors, the water in Paliastom lake is prone to a weak alkaline reaction. The water of the lake can be considered as having medium turbidity. Phosphate and nitrate ion detection reactions performed with qualitative analysis protocols showed positive samples. The intensity of the obtained color indicated their high concentration. Conclusions: The annual evolution of Chl-a in Paliastom lake reaches the maximum value in the summer months. Compared to previous years, a decrease in chlorophyll concentration was observed during the lockdown period of 2020 due to the Covid Pandemic.

Grand canonical DFT based constant charge method for electrochemical deuterium/hydrogen evolution reaction micro-kinetics on Pt (1 1 1)

Applied external potential is considered to have significant impact on the reaction mechanisms and kinetic behaviors for electrochemical reactions. The electrochemical isotope deuterium/hydrogen (D/H) evolution shows significant different kinetic behavior under applied potential conditions, but the intrinsic mechanisms from the electrochemical isotope effect remains unclear. In this work, the grand canonical density functional theory (GC-DFT) based constant charge method was used to systematically investigate the electrochemical D/H evolution reactions (DER/HER) on the Pt (111) surface. By using this method, the linear and quadratic relationship between charge distribution (q), electronic energy (Eelect) and applied potential (U) were observed respectively, which are resulted from solving of linear Poisson-Boltzmann equation and Kohn-Sham-Mermin equations in combination of solvent modification. Equilibrium Pourbaix diagrams of D/H adsorbing on Pt (111) surface was subsequently investigated to revealed the electrode structure in real reaction condition, with θD/H coverages on the cathode surface calculated to be 0.0 monolayer (ML) and 1/6 ML for alkaline and acidic solvent at −1.23 V to 0.0 V vs. SHE. Mechanistic studies of HER/DER on the Pt (111) surface revealed that Volmer-Tafel reaction pathway is more favorable than the Volmer-Heyrovsky pathway. Analysis of the applied potential effect on the reaction energy barriers show that the acidic Volmer step is very sensitive toward the applied potential condition, with the structure of transition state likely to shift. Comparisons of the calculated current–potential polarization curves between HER and DER revealed that in the acidic condition, the calculated current density of HER is close to DER, revealing that the H*/D* migration and coupling on the electrode is comparable to each other when the solution is saturated with H3O+/D3O+. In the alkaline reaction condition, discrepancies of j value between DER and HER becomes slightly larger, revealing that jointly control effect from Volmer and Tafel step was enhanced. This work provides the new insight for investigating the microkinetic properties of electrochemical isotope reaction.

Response of Nitrogen and Plant Growth Regulators on Growth and Yield of Wheat (Triticum aestivum L.)

A research trial was conducted during Rabi season, 2022 at crop research farm, Department of Agronomy at Sam Higginbottom University of Agriculture, Technology and Sciences, Prayagraj Uttar Pradesh India. The soil in experimental field was sandy loam in texture, having alkaline reaction (pH 7.7) with very low organic carbon (0.44%), available higher-level N (171.48 kg/ha), P (27.0 kg/ha) and higher level of K (291.2 kg/ha). To evaluate the response of nitrogen and different plant growth regulators on growth and yield of wheat (Triticum aestivum) the experiment was laid out in Randomized Block Design (RBD) with ten treatments each replicated thrice. The treatment consists three levels of nitrogen (120 kg/ha, 140 kg/ha and 160 kg/ha), in combination with two sprays of Plant growth regulators viz. [Chlormequat chloride (0.2%), Tebuconazole (0.1%) and chlormequat chloride (0.2%) + tebuconazole (0.1%)] applied at 40 DAS followed at 55 DAS whose effect was observed on wheat. The results revealed that, higher plant height (98.70 cm), was recorded with treatment nitrogen 160 kg/ha along with Tebuconazole (0.1%). However, maximum number of tillers/running row meter (78.33), maximum dry weight (23.01 g), higher crop growth rate (0.0059 g/m2/day), more number of effective tillers/m2 (271), highest spike length (15.10 cm), maximum number of grains/spike (60.05), higher test weight (39.75 g), maximum grain yield (4.66 t/ha),) and straw yield (6.98 t/ha) were recorded with treatment nitrogen -160 kg/ha along with CCC (0.2%) and Tebuconazole (0.1 %) in wheat. Application of both nitrogen and plant growth regulators improved the growth and yield of wheat significantly.

Impact of the use of biological preparations «Tumat» and «Bioecohum» on soil fertility and rice yield

The article presents the results of testing the biopreparations «Tumat» and «BioEkoHum» for fertility and productivity of rice-marsh soils of the Akdala irrigation array of the Balkhash district of the Almaty region. It was established that the fertility of the original soil according to the existing agrochemical gradations was characterized by an alkaline reaction of the environment, a very low supply of mobile forms of phosphorus and potassium, and the content of easily hydrolysable nitrogen was average. The content of organic matter was at the level of 1.1 %. At the same time, fluctuations in agrochemical parameters in the experimental plots were significant. So, for organic matter, the extreme values were 0.7÷1.3 %, for easily hydrolysable nitrogen 36.4÷75.6 %, for phosphorus content - 8÷14 and potassium - 70÷160 mg/kg of soil.It was revealed that the introduction of «Tumat» into the soil + sowing with rice seeds treated by them had a positive effect on the stabilization of the humus state, mobile phosphorus and exchangeable potassium in the tillering phase. Due to the change in the redox environment, the content of easily hydrolysable nitrogen in this phase decreased in all variants of the experiment, since the dynamics of nitrogen content is determined by the transformation of nitrogen compounds and their consumption. In the next phases of rice development, bioameliorants contributed to an increase in effective fertility, positively influencing the content of mobile mineral forms of nitrogen. Apparently, these are very promising options in terms of maintaining soil fertility. For all variants of the experiment, there is a slight increase in the mobile form of phosphorus, and the content of exchangeable potassium decreased compared to their content in the tillering phase. As the obtained data on the biological yield showed, the largest increase was obtained in option 4 with the introduction of «Tumat» into the soil + planting of rice seeds untreated with this biomeliorant - 30.3 c/ha (36.1 %), when sowing the seeds treated with it, the increase was 30.6 %. An increase of 9 q/ha (25 %) and 7 q/ha (19.4 %) was obtained in the variants with planting seeds treated with «BioEcoHum», and planting them when it was introduced into the soil, respectively.