Hydrothermal Treatment Method Research Articles

SMALL-PIECE SEMI-DRY-COMPACTED CONCRETE PRODUCTS BASED ON WASTE FROM ENERGY GENERATING ENTERPRISES

The article investigates the fly ash from Burshtyn TPP for its use as a component of binding raw material compositions for the production of small-piece concrete products. Based on the integrated characteristics of chemical and phase composition, it was found that the ash is ultra-acidic, is an amorphous substance and is characterized by low hydraulic activity. Calcium-containing additives (slag cement and/or hydrated lime) and an alkaline aggregate (soda solution) were used to activate the ash glass. The charges compositions using ash at the level of 75–90 wt. %, in which the type and amount of activator and the type of aggregate (alkaline solution or water) were subject to variation in order to optimize the technological parameters of the materials. For materials formed at a pressing pressure of 25 kgf/cm2 and hardened under steaming conditions, a positive effect of cement, alkaline aggregate and combined hardening activator on the properties of materials, their appearance and geometric dimensions was established. Such materials have a low level of mechanical properties; only certain charge compositions allow for a mechanical strength grade of M50 to M75. In order to improve the final mechanical strength of materials, the influence of pressing pressure, moulding moisture and hydrothermal treatment methods (steaming or parboiling) on the properties of materials of individual compositions was investigated. It has been determined that increasing the pressure up to 300 kgf/cm2 and autoclave treatment of semi-finished products can significantly improve the level of mechanical properties. The rational compositions of binder compositions with a high degree of fly ash use (75 and 77 wt. %) were determined, on the basis of which water-resistant samples of asphalt concrete grades M 125 and M200 in terms of mechanical strength and grade F25 in terms of frost resistance were obtained by semi-dry pressing. The materials are recommended for the manufacture of products for the construction of sidewalk elements, as well as wall small-piece concrete products.

Research on a harmless treatment method for oily sludge in coal chemical wastewater and the pollutant transformation mechanism of oily sludge during the treatment process

This study developed an ultrasound synergistic subcritical hydrothermal treatment method (U-SHT) to address the challenges posed by the high oil and water content, complex composition, and hazardous nature of oily sludge (OS) generated during the pretreatment of coal chemical wastewater. The study investigated the efficiency of this method for the harmless disposal and resource recovery of OS, and the migration-transformation mechanism of hazardous organic pollutants in OS. The findings revealed that U-SHT achieved a removal efficiency of chemical oxygen demand in OS of 91.16 %, an oil resource recovery efficiency of 96.60 %, and a residual oil rate of 0.28 %, meeting API emission standards. Further research indicated that the solubilizing effect of the surfactant on the oil enhanced the demulsifying effect of ultrasonic cavitation on the emulsified structure of OS, enabling ultrasound to efficiently release and disperse pollutants within OS. This promoted the decomposition and transformation of pollutants under subcritical hydrothermal conditions, with synergistic removal efficiencies for typical pollutants such as long-chain alkanes, polycyclic aromatic hydrocarbons, and phenols reaching 96.61 %, 97.63 %, and 97.76 %, respectively. Economic evaluation indicated that the cost of OS treatment was $29.66/m3, significantly lower than existing methods, demonstrating promising practical application prospects.

KHCO3 chemical-activated hydrothermal porous carbon derived from jackfruit inner skin for supercapacitor applications

The reuse of waste biomass resources had become a hot spot in the sustainable development of human society. Due to the complexity of biomass composition and microstructure, the quality reproducibility of biomass porous carbon was poor. Therefore, it was of great significance to develop a reliable method for preparing porous carbon from biomass. In this paper, a combination of hydrothermal carbonization treatment and mild activation of KHCO3 was used to prepare iron-modified porous carbon with carbon spheres/nanoplates structure, which promoted ion/electrolyte diffusion and increased the accessibility between surface area and electrolyte ions. Therefore, the active porous carbon from the Jackfruit inner skin has good specific capacitance (273.2 F/g at 1 A/g) and good cycle stability, and the capacitance loss is only 6.6 % after 10,000 charge discharge cycles. The above results showed that hydrothermal treatment and mild activation methods provided an effective way to transform waste biomass into high-performance electrode material.

Study on Effects of Hydrothermal Heat Treatment Method on Fertilizer Efficiency of Biomass Waste

This study explores a new way of utilizing biomass waste as fertilizer based on the hydrothermal heat treatment method. Hydrothermal heat treatment was carried out on common biomass waste, including corn stalks, livestock manure, and vegetable waste. by heating them to 120°C and then to 240°C respectively, while measuring the contents of organic matter, total nutrients, and humus in hydrothermal solid products. The experimental results are as follows. With the increase in temperature, the pH of three kinds of biomass waste hydrothermal products is reduced to different degrees. The content of organic matter in the solid products of corn stalk increased with the increase of temperature, the content of organic matter in the hydrothermal products of vegetable waste was opposite to that of corn stalk, and the content of organic matter in the hydrothermal solid products of pig manure was higher than 30% at different temperatures. The total nutrient content of the hydrothermal product of corn stalk decreased first and then increased with the increase of temperature, and reached the minimum value of 10.12 g/L at 180°C. The total nutrient content of the solid product of vegetable waste showed a negative correlation with temperature, and the total nutrient content of the raw material of pig manure was 60.55 g/kg. The total nutrient content of solid products after different hydrothermal temperature treatments was 41.8–59.03 g/kg, which was lower than that of raw materials. With the increase of temperature, the humic acid content of the solid product of corn stalk first increased and then decreased, the humic acid content of hydrothermal product of pig manure continued to increase with the increase of temperature, and the humic acid content of hydrothermal product of vegetable continued to increase with the increase of temperature. At 210°C, the contents of humic acid and fulvic acid reached the maximum, and the humification rate reached the maximum of 0.856.

RGO/In2O3 heterostructures based gas sensor for efficient ppb-level n-butanol detection

The real-time and effective detection of n-butanol gas is particularly important in production and daily life due to its flammability, toxicity, and potential hazards to the environment. This article reports the preparation of hollow indium oxide spheres and rGO/In2O3 composites through a simple hydrothermal and subsequent heat treatment method. Test results indicate that the gas sensitivity of n-butanol can be significantly improved through rGO composites. The prepared hollow indium oxide spheres are composed of nanosheets with a diameter of probably 500 nm. After combination by rGO, the specific surface area and the proportion of adsorbed oxygen of the material are increased, both of which are advantageous for enhancing gas sensitivity abilities. At the optimum operating temperature of 160 °C, the response value of rGO/In2O3 complex sensor is 51–50 ppm of n-butanol, which is 3.6 times the response of pure In2O3. Gas sensors composed of rGO/In2O3 exhibit ultra-fast response time and low detection limit. Even for ppb grade (100 ppb) n-butanol gas, the response value is still 2.3. These characteristics make rGO/In2O3 a promising material for the preparation of high-performance n-butanol gas sensors. Besides, the gas-sensitive mechanism of the enhanced n-butanol sensing performances is also analyzed.

Electron spin-states reconfiguration induced by alternating temperature gradient for boosting photocatalytic hydrogen evolution on hollow core-shell FeS2/CuCo2O4 Z-scheme heterostructure

The pyroelectric effect and electron spin-state reconfiguration play a critical role in photocatalysis but are seldom investigated. This work is the first to exploit the fluctuating temperature (ΔT) between the cold-hot alternation in photocatalysis to drive the pyroelectric effect and electron spin-sate reconfiguration. FeS2/CuCo2O4 (FS/CCO) hollow core-shell heterojunctions were prepared using hydrothermal and heating treatment methods. The FeS2 (FS) can generate heat under near-infrared (NIR) light to provide the elevated temperature end required for the pyroelectric effect of CuCo2O4 (CCO) under the influence of ΔT. With this thermoelectric and pyroelectric effect, CCO can release surface charges, generating spontaneous polarization, changing the electron (eg) filling number on Co surface sites, reversing the spin electron state, thus controlling the carriers' migration direction and enhancing their separation and migration rate, and finally prolonging their lifetime. As a result, the as-designed FS/CCO-15 composites yielded up to 19.5 mmol g−1 h−1 extraordinary photocatalytic performance, i.e., 10.2 and 6.45-fold of the pure FS (1.92 mmol g−1 h−1) and CCO (3.02 mmol g−1h−1) under simulated sunlight, respectively. It also yielded up to 19.8% average apparent quantum yield. This work thoroughly explored the distinctive impact of the pyroelectric effect, electron spin-state reconfiguration, orbital coupling effect, and hydrogen evolution, guiding us and creating more possibilities for photocatalytic technology and efficiency using NIR light.

Magnesium Alloy Composite Water‐Repellent Surface with Durable Corrosion Resistance and Self‐Cleaning Behavior

Magnesium (Mg) alloys have poor corrosion resistance, higher requirements for corrosion resistance of the coating, and the changes in the environment in the actual application are complicated and diverse. Therefore, it is urgent to develop bio‐inspired water‐repellent surfaces (WRSs) with long‐lasting corrosion resistance and multiple excellent properties for Mg alloys. In this study, a composite water‐repellent surface (CWRS) with long‐lasting corrosion resistance and self‐cleaning behavior is prepared by combining laser processing, hydrothermal treatment, and immersion method on the Mg alloy surface. The effect of ambient temperature changes on the wettability and corrosion resistance of the CWRS is investigated. The experimental results showed that a uniform and dense CWRS with a film thickness of 36 μm could be prepared on the Mg alloy surface at an ambient temperature of 180 °C, demonstrating excellent corrosion resistance and self‐cleaning behavior. In addition, in the harsh salt spray test, it is found that even if the superhydrophobicity of the CWRS was lost, the surface still has good corrosion resistance. Multifunctional CWRSs have become a research hotspot, and it is of great significance to promote the application of Mg alloys in actual working conditions.

Method of hydrothermal treatment for coal spontaneous combustion inhibition and its application

The use of coal combustion inhibitors, which are mostly sprayed on the surface of the coal that remains in the mining region (post-mining inhibition), has a significant effect on preventing spontaneous burning of coal, although their duration of action is limited. Pre-inhibition (pre-mining inhibition) prolong the inhibition duration and offers the chance to change the temperature of the inhibition fluid. This results in the suggestion of a hydrothermal inhibition strategy that emphasises the influence of inhibition fluid temperature on the inhibitory effect in order to achieve accelerated inhibition. Infrared tests and temperature-programmed oxidation are used to explore the inhibition law and mechanism of inhibition temperature on the spontaneous combustion of different coal orders. The findings demonstrated that when the inhibition temperature increased to 30 °C, 40 °C, 50 °C, 60 °C and 70 °C, the average inhibition rate and cross point temperature increased dramatically while the rates of oxygen consumption, exothermic rate, and CO production continuously dropped. Simultaneously, the coal's content of more reactive groups, such methyl and methylene, dropped, and the coal's risk to self-heat reduced. At the 70 °C inhibition temperature, the lignite coal showed the maximum inhibition rate (65.28%). This research is crucial to advancing the inhibitor's application technology and efficiency of inhibition.

Effect of Hydrothermal Treatment on the Mechanical and Microscopic Properties of Moso Bamboo

In this study, moso bamboo was used as a raw material. To increase the plasticity of bamboo to achieve a greater softening effect, the softening method of hydrothermal treatment was used. Hardness and the flexural elastic modulus were used as the evaluation indices, and the crystallinity and main functional groups of the softened bamboo were analysed using X-ray diffraction and Fourier-transform infrared spectroscopy. Combined with the examination of timber colour, micromorphology, bending strength, and nanomechanical tests, our analysis showed the effects of the hydrothermal treatment on bamboo. The results showed that the hardness and flexural moduli of bamboo decreased with the increase in hydrothermal treatment temperature. However, cracking occurred after 3.5 and 4 h of treatment at 180 °C and 190 °C. This indicated that the softening effect was most pronounced when the treatment temperature and time were 180 ℃ and 3 h, respectively. The cellulose crystallinity of bamboo increased and then decreased with the increase in treatment temperature. Cracks were produced in the cell structure, starch locally disappeared, and the hardness and the elasticity modulus of the thin-walled bamboo cells first increased and then decreased with the increase in treatment temperature.

Enhanced dielectric properties of poly(vinylidene fluoride) matrix nanocomposites incorporated with one–dimensional structure of titanate nanotubes

The dielectric properties of polymer nanocomposites based on a poly(vinylidene fluoride) (PVDF) matrix, filled with a one–dimensional nanostructure of titanate nanotubes (TNTs), were investigated. These studies demonstrated significant improvements in the energy storage capability of the application. The TNTs were synthesized through an alkali hydrothermal treatment method at 130 °C for 24 h, using a 10 M NaOH solution. The TNTs exhibited a large dielectric permittivity of approximately 1.2 × 104 with a low loss tangent of approximately 0.12 at 1 kHz and 25 °C. TNTs/PVDF polymer nanocomposites were studied and fabricated using liquid phase–assisted dispersion and hot–pressing methods. By introducing TNTs into the PVDF polymer, both the dielectric permittivity and loss tangent increased. Notably, the polymer nanocomposite containing 50 wt. % TNTs exhibited a dielectric permittivity of 5.3 × 103 at 1 kHz, which is ∼530 times greater than that of pure PVDF (10.78), while the loss tangent remained at 0.572. The low–frequency dielectric permittivity increased with an increase in relative humidity from 50 to 95 % due to enhanced interfacial polarization at the surface and electrode interface. However, at frequencies greater than 1 kHz, the dielectric permittivity was independent of relative humidity. The improvement in the enhanced dielectric permittivity of polymer–based nanocomposites with incorporated TNTs was ascribed to these factors.

Titanium-based substrate modified with nanoenzyme for accelerating the repair of bone defect

Titanium (Ti) and titanium alloy are the most common metal materials in clinical orthopedic surgery. However, in the initial stage of surgery and implantation, the production of excessive reactive oxygen species (ROS) can induce oxidative stress (OS) microenvironment. OS will further inhibit the growth of new bone, resulting in surgical failure. In this study, based on the fact that nanoscale manganese dioxide (MnO2) can show H2O2-like enzyme activity, a MnO2 nanocoating was prepared on mciro-nano structured surface of Ti substrate via a two-step method of alkaline thermal and hydrothermal treatment. The results of scanning electron microscopy (SEM), X-ray diffractometer (XRD) and X-ray photoelectron spectroscopy (XPS) showed that the nano-MnO2 coating was successfully fabricated on the surface of Ti substrate. The results of measurement of H2O2, dissolved O2 and intracellular ROS in vitro showed that the treated Ti substrate could efficiently eliminate H2O2 and reduce ROS. Furthermore, the modified Ti substrate could promote the early adhesion, proliferation and osteogenic differentiation of MSCs, which was demonstrated by experimental results of cell morphology, cell viability, alkaline phosphatase, collagen, and mineralization deposition. The results of quantitative real-time polymerase chain reaction (qRT-PCR) of MSCs adhered the modified Ti substrate showed that the expression of genes related to osteogenic differentiation significantly increased. More importantly, the modified Ti implant could eliminate ROS at the injury site, reduce OS and promote the regeneration of bone tissue, which was demonstrated via hematoxylin/eosin, Masson's trichrome and immunohistochemical staining. In conclusion, the modified Ti implant presented here had the effect of reducing OS and promoting osseointegration. Relevant research ideas and results provide new methods for the research and development of functional implants, which have potential application value in the field of orthopedics.

RuSe2/CeO2 heterostructure as a novel electrocatalyst for highly efficient alkaline hydrogen evolution

Constructing heterojunction to adjust the electronic structure of catalysts is a promising strategy for synergistically improving electrocatalytic activity. In addition, RuSe2 is recognized as an effective alternative to Pt for boosting alkaline hydrogen evolution reaction (HER) on account of its outstanding catalytic properties. Herein, novel RuSe2/CeO2 heterojunction electrocatalysts are fabricated through hydrothermal and thermal treatment methods. The optimal 50% RuSe2/CeO2 heterojunction electrocatalyst exhibits a low HER overpotential of 16 mV to attain 10 mA cm−2 current density and Tafel slope of 66.1 mV dec−1 for hydrogen evolution in 1.0 M KOH. At the same time, the 50% RuSe2/CeO2 heterojunction electrocatalyst also maintains a stable HER activity for 50 h or 3000 CV cycles. The experimental results show that formation of heterogeneous interface between RuSe2 and CeO2 results in the redistribution of electrons at the RuSe2/CeO2 interface, thereby changing the electronic structure of RuSe2 and enhancing the performance of the RuSe2/CeO2 electrocatalyst. This work may provide a feasible way to design efficient hydrogen evolution heterojunction electrocatalysts by modulating the electronic structure in alkaline electrolytes.

Construction of 2D/3D g-C3N4/BiOI Photocatalysts with p-n Heterojunction and Their Performance in Photocatalytic Degradation of Amaranth Dye.

The g-C3N4 (graphitic carbon nitride)/BiOI (bismuth oxyiodide) photocatalysts, boasting a unique nanomicrosphere architecture, were synthesized through a tripartite process involving heat polycondensation, hydrothermal treatment, and hybrid methods, using melamine, bismuth nitrate, and potassium iodide as starting materials. The photocatalyst was comprehensively characterized and analyzed while its efficacy in photocatalytic degradation of amaranth (AR) under various lighting conditions was investigated, and the catalytic mechanism was determined by kinetic analysis and free radical scavenging experiments. The results showed that g-C3N4 formed a strong bond with BiOI. The resulting composite catalyst retains the inherent 2D lamellar structure of g-C3N4, as well as the 3D microsphere structure of BiOI, thereby creating heterojunctions via p-n interactions. Under visible light exposure, g-C3N4/BiOI-15% demonstrated optimal catalytic performance, achieving a degradation rate of 74.64% for AR and exhibiting the highest rate constant. Radical tests confirmed that -O2- (superoxide anion) plays a crucial role as active species in the photocatalytic reaction.

Synthesis, characterization and dielectric relaxation studies of graphene quantum dots prepared by hydrothermal treatment method

Zero dimensional graphene quantum dots (GQDs) exhibit fascinating chemical and physical properties discovered by Pan et al., in 2010, due to the quantum confinement and edge effect. GQDs have been synthesized by hydrothermal treatment method from graphite powder as low cost, easy process, and large amount with high production yield. The functional groups of GQDs on the surface sites of carbon atoms have been studied through Fourier transform infrared spectroscopy (FTIR) analysis. X-ray diffraction (XRD) pattern of GQDs shows the broad diffraction at 2 θ = 24.47 ° with 0.36 nm an interlayer distance confirming the formation of the GQDs. Raman analysis reveals that GQDs show both D and G bands mostly the armchair edges. UV–visible spectra show absorption peak at 287 and 330 nm credited to π → π * and n → π * transitions due to the presence of conjugated carbon–carbon bonds and carbonyl groups. The particle size of GQDs is found below 5 nm from high- resolution transmission electron microscopy (HR-TEM) image. Scanning electron microscopy shows the surface morphology of GQDs are crumpled and aggregated thin sheets. Dielectric properties of synthesized GQDs have been studied in the range frequency between 0.01 and 105 Hz at different temperatures (25, 50, 75, and 100 °C). The dielectric relaxation mechanism is explained in the framework of dielectric loss tangent (tanδ), permittivity and electrical conductivity. The dielectric loss tangent increases with frequency and maximum peak decreases with frequency at all different temperatures due to present of polar groups in GQDs. Dielectric permittivity decreases with frequency at all different temperatures due to charge orientation and rotation of dipole moments. The electrical conductivity increases with frequency at all different temperature due to the GQDs is highly conductive nature. So synthesized GQDs can be used in electrical and electronic materials.

Examination of the influence of hydrothermal treatment of textile materials on their physical and mechanical properties and development of innovative technology

Relevance. Investigation in the field of textile materials and the effect of processing on their properties, is relevant, as it helps to develop more effective processing methods and increase the resistance of textile materials to the influence of various factors, which is important for both manufacturers and consumers. Purpose. The purpose of the study was to examine the effect of hydrothermal processing of textile materials on their physical and mechanical properties, develop a technology for the production of clothing using a new method (device) of press equipment for hydrothermal processing of composite material. Methodology. The analysis method was used during the study, and an experiment was also conducted in which the temperature of the steam that did not fall below 160°C was used when processing the selected fabric samples, and the temperature of the working bodies of the press for forming the back was at least 110°C. Results. As a result, the influence of hydrothermal treatment on the properties of textile materials was examined in detail and established. Having analysed the existing method of hydrothermal treatment using a vacuum unit, it was established that the conventional method of treatment leads to a substantial decrease in fabric thickness, breaking load and air permeability. It was also noted that during the hydrothermal treatment of the material, it is exposed under the influence of pressure. This leads to densification and flattening of the threads inside the material, creating flat areas, which causes adverse changes in the physical and mechanical characteristics of the fabric. Conclusions. These factors indicate a potential deterioration in the quality and durability of textile products, which can increase the percentage of defects and negatively affect consumer satisfaction. This study also points to the prospects of using a vacuum installation in hydrothermal treatment, which allows preserving the desired properties of materials, improving the quality of the final products. The practical importance of the results of this study lies in the possibility of improving the quality of textile products and reducing the damage to materials, which is important for ensuring longer operation of textile products and increasing consumer satisfaction

Recycling of hazardous jarosite residues based on hydrothermal crystal transformation

Jarosite [MeFe3(SO4)2(OH)6] is a typical non-ferrous smelting slag produced in the process of iron removal from hydrometallurgical solution, which contains a large number of valuable and toxic metal elements. Treating the complex and hazardous jarosite residue in an economically and environmentally sound way has always been an urgent problem. A novel one-step hydrothermal treatment method was proposed in this paper for recycling of jarosite residues. It can be seen from the XRD and TEM results that jarosite residues could be completely transformed into hematite crystal particles under hydrothermal conditions at temperature above 220℃. Meanwhile, other valuable metal components (such as nickel sulfate hexahydrate) entrained in the residue will be dissolved in the aqueous solution, which can be reused in the hydrometallurgical process. Through phase composition analysis of the hydrothermal process, it is concluded that jarosite was firstly pyrolyzed to generate Fe3+. The obtained Fe3+ was then hydrolyzed to Fe (OH)3, which was transformed into Fe2O3 through dehydration condensation and directional arrangement. Further roasting the hematite particles, the obtained product contained 62.57 % of Fe, but only 0.21 % of S and 0.04 % of As, which meets the requirements of raw materials for iron making. In addition, compared with the current international standard ISO 1248:2006 (E), the obtained hematite particles with nanometer size and single crystal structure can be used as iron oxide red pigment. Overall, the one-step hydrothermal treatment of jarosite residues followed by reduction roasting not only realizes the economic recycling of the metal resources, but also solves the stacking problem of those hazardous residues.

Hydrothermal synthesis of high-purity zeolite X from coal fly ash for heavy metal removal: Kinetic and isotherm analysis

Treated fly ash (TCFA) yielded high-purity, single-phase zeolite-X, efficiently removing Ni and V ions from aqueous solutions. The pretreatment process of raw fly ash (RCFA) involved magnetic fraction separation, followed by acid washing. Zeolites were synthesized by the fusion prior step to the hydrothermal treatment method. The VSM test shows that the MS value dropped from 2.19 to 1.43 emu/g due to removing the magnetic fraction. These findings align with XRF results showing a 98 % reduction in Fe2O3 content, while acid washing lowered other metal oxide content to below 12 %. XRD results indicate the successful synthesis of high-crystallinity, single-phase zeolite X-TCFA, achieved at 90 °C for 12 h. SEM images further confirm the purity of the product, revealing pyramidal octahedral-shaped single crystals. Additionally, BET analysis shows a high surface area of 452 m2/g, featuring mesopores from 2 to 50 nm. The FTIR spectrum displayed the characteristic peaks of Zeolite X, confirming the success of the preparation process. TCFA-zeolite X has high thermal stability based on TGA analysis. The pseudo-second-order model fits the kinetic data, suggesting that chemical adsorption mechanisms control Ni and V adsorption. Langmuir isotherm best-explained results, with max adsorption of 41.55 mg/g Ni and 32.38 mg/g V.

Optimization of the method of hydrothermal treatment of mogar grain for production of food concentrate "Talkan"

The possibility of using mogar grain for the production of food concentrates based on the traditional national dish "Talkan" is considered. "Talkan" is a national food concentrate for Republic of Kazakhstan, which has been used as a staple food in long-distance trekking by various cultures for centuries. Traditionally, talkan is prepared from various cereals, particularly millet, wheat and barley. When boiling water and oil are added, it turns into a hearty porridge, and when oil and sugar are added, it becomes a delicious dessert. The difficulty lies in the careful handling and preparation of the mogar grain. During intensive cooking, the grain can easily overcook, resulting in all the valuable nutrients being leached into the broth. In addition, improperly prepared mogar can burn during further roasting. To determine the optimal parameters of mogar hydrothermal treatment and to create a high-quality food concentrate based on the national dish "Talkan", a complex experiment was conducted using modern methods of experiment planning. A number of variables were tested during the experiment, including temperature limits and duration of cooking, as well as temperature, duration and intensity of stirring during drying and roasting of mogar. The study showed that the most favourable conditions for mogar grain involve cooking at an initial temperature of between 15–20 °C for about 60 minutes, gradually reaching 100 °C. The drying and roasting processes are best carried out for 25 minutes, with a layer thickness of 25 mm and a surface temperature of 250 °C. The determined of hydrothermal treatment serve as a basis for the design of specialised equipment for preparation of mogar grain for the purpose of making Talkan

Study of Metal–Graphene Aerogel for Efficient Solar Energy Interface Evaporation Based on One‐Step Thermal Reduction Method

Freshwater resources can be sustainably harvested through interfacial evaporation by solar energy. To enhance the efficiency of solar interfacial evaporation, a metal–graphene alcohol gel is synthesized using a one‐step thermal reduction technique. Subsequently, a metal–graphene aerogel (GA) is produced using freeze‐drying technology. The hydrothermal treatment method is applied to introduce asymmetric moisture and roughness on the upper and lower surfaces of the aerogel. The unique structure of the aerogel plays a significant role in facilitating continuous water transport to the interface for evaporation. The top layer, being hydrophobic, and the bottom layer, being hydrophilic, contribute to this process. Importantly, the top layer's design ensures that an excessively thick water film does not form, thereby preventing any adverse effects on light‐absorption efficiency. The aerogel exhibits that an outstanding water‐evaporation rate is 1.75 kg m−2 h−1 and a remarkable photothermal conversion efficiency (PTCE) is 93.17% under one solar radiation intensity. This is because the aerogel has a unique 3D structure. This special 3D structure has an interconnected microporous‐like appearance inside, which increases the evaporation area. Metal–GA is based on the electric field dielectric evaporation mechanism of metal nanoparticles localized surface plasmon resonance effect and the thermal mediated evaporation mechanism of graphene full spectrum. Under the double action, the PTCE is significantly improved. The meticulously created metallic GA performs exceptionally well at evaporating water. As a result, it presents a promising and practical avenue for exploring effective solar interfacial evaporation.

Facile synthesis of ZnIn2S4/Cu2O hierarchical heterostructures for enhanced selectivity and sensitivity of NH3 gas at room temperature

The development of an effective and reliable sensor with the capability to detect ammonia (NH3) gas at room temperature exerts a significant influence on the sensor industry. The gas sensing performance is notably improved by the formation of a heterostructure between metal oxide with metal sulfides. In this study, pure ZnIn2S4 (ZIS), Cu2O and heterostructures of ZIS with 5, 10 and 20 wt% of Cu2O were successfully prepared using hydrothermal, co-precipitation and heat treatment methods, respectively. A thorough investigation has been carried out to examine the sensing capabilities of all the materials upon exposure to NH3 with different concentrations (1, 5, 10, 15, 20, 25 and 50 ppm) at room temperature (RT). Impressively, the composite material 0.9ZnIn2S4/0.1Cu2O (ZIS-10) has exhibited remarkable gas sensitivity compared to pristine ZIS and Cu2O towards 25 ppm NH3, low limit of detection (1 ppm) with fast response/recovery times (37/25 sec). The improved performance of the ZIS-10 composite sensor may be ascribed to the synergistic effect between ZIS and Cu2O, which facilitates the electron transfer from ZIS to the Cu2O at the interface. The plausible gas-sensing mechanism and the pathways responsible for enhanced sensing are also discussed in detail.