Amount Of MgO Research Articles

Discovery of the Late Jurassic-Early Cretaceous Lamprophyres in Western Songliao Basin of Northeast China and Their Constraint on Regional Lithospheric Evolution

Contrary to the commonly accepted notion that the lithosphere in NE China thinned from the Late Jurassic through to the Early Cretaceous period, we report the discovery of a thickening episode in the backdrop of this long-term thinning. A series of lamprophyre dikes have been recently discovered in the Tuquan Basin of the western Songliao Basin that have been dated to 156.0 ± 2.3 Ma, 132.9 ± 1.2 Ma, and 126.2 ± 2.5 Ma by using the zircon U–Pb technique. These lamprophyres are subdivided into biotite orthoclase lamprophyre (BOL) from the Late Jurassic and quartz magnetite lamprophyre (QML) from the Early Cretaceous. The BOL and QMLs are shoshonite and calc-alkaline in series, are characterized by large amounts of FeOT, TiO2, MgO, and Mg#, and are rich in LREEs and LILEs but poor in HREEs and HFSEs. They have high ratios of (La/Yb)N, La/Ta, La/Nb, Th/Y, Ba/Nb, Ba/Ta, and Ba/Th, and low ratios of Zr/Ba, La/Sm, and Nb/Zr. These features collectively point to the derivation of dike magmas from the partial melting of the enriched lithospheric mantle that had been previously metasomatized by subduction-related fluids. The BOL has high ratios of Rb/Sr (0.42) and K/Yb*1000 (28.3), and low ratios of Ba/Rb (13.5) and Dy/Yb (2.35), suggesting the derivation of magma from a high degree of partial melting of the phlogopite-bearing lherzolite mantle in the spinel–garnet transition zone at a depth of about 60 km. The QMLs have low ratios of Rb/Sr (0.02–0.06) and K/Yb*1000 (8.13–19.73), and high ratios of Ba/Rb (17.6–42.6) and Dy/Yb (3.48–4.09), indicating that the magmas were derived from a low degree of partial melting of the lherzolite mantle in the garnet zone at a depth of ca. 85 km. The younger QML (126.2 ± 2.5 Ma) has a lower Dy/Yb ratio (3.48–3.92) than the older QML (132.9 ± 1.2 Ma), with a Dy/Yb ratio of 4.09 implying that the younger magma was formed at a shallower depth of the mantle (<85 km) than the older one. These observations indicate that in 156–132 Ma, the lithosphere thickened by approximately 25 km at a rate of approximately 1.0 km/Myr. This is used to propose a model of geodynamic evolution in three stages.

Temperature-driven phase transformation of Ca-rich boron waste into CaB2O4: Investigation of microstructure, crystallinity and thermal characteristics

Large-scale mining and mineral processing, as well as increasing industrialization, generate a significant volume of boron wastes (BWs), necessitating waste recycling management. This research proposes a conceptual framework for circular production design based on the increased utilization of commercially valuable BWs including large amounts of B2O3, CaO, and MgO. In this study, BW is a non-calcined waste, whereas BW40, BW50, BW60 and BW90 are boron wastes calcined at 400 °C, 500 °C, 600 °C and 900 °C, respectively. Chemical, structural, thermal, and morphological characteristics and alterations depending on the calcination temperatures of BWs are investigated using XRF, XRD, FTIR, TG-DTA, and SEM techniques. BW which is non-calcined boron waste comprises Ca[B(OH)4]2.2H2O and HCaBO3 crystalline phases, whereas BW40 treated at 400 °C has HCaBO3 and CaCO3 crystalline phases as well as amorphous structure. CaCO3 and Ca2B2O5 crystalline phases and amorphous structure are present in the BW50 and BW60 samples, calcined at 500 and 600 °C. At 900 °C, all phases were transformed into Ca2B2O5 and CaB2O4 crystalline phases. We demonstrated that BW40, BW50, and BW60 have comparable chemistry and morphologies, but increasing calcination temperature to 900 °C resulted in a fundamentally different microstructure.

MgO as promoter for electrocatalytic activities of Co3O4–MgO composite via abundant oxygen vacancies and Co2+ ions towards oxygen evolution reaction

Oxygen evolution reaction (OER) is known as bottleneck problem during the water splitting process due to high energy barrier and non-availability of efficient nonprecious electrocatalysts. The cobalt oxide (Co3O4) in the spinel phase has limited OER activity and stability in the alkaline media. For this purpose, we have carried out the synthesis of Co3O4–MgO (CM) composite by wet chemical method and it offers abundant oxygen vacancies and Co2+ concentration for the efficient OER reaction. The effect of different amounts of MgO on the OER activity of Co3O4 was also studied. Despite inactivity of MgO towards OER, it creates high density of oxygen vacancies and favored the formation Co2+ ions at the surface, thus accelerated the OER kinetics. The physical studies were performed to investigate the morphology, crystalline structure, surface information and chemical composition using several analytical techniques. The optimized CM-0.1 composite produced an overpotential of 274 mV at 10 mAcm−2 which is lower in value than the pristine Co3O4. The significant enhancement in the OER activity was verified by the large value of electrochemical active surface area values 12.8 μFcm−2 and the low charge transfer resistance of 45.96 Ω for the optimized CM-0.1 composite. The use of abundance materials for the synthesis of CM composite revealed an enhanced OER performance, suggesting the dynamic role of MgO, therefore it could be used for improving the electrochemical properties of extended range of metal oxides for specific application especially energy conversion and storage devices.

Reaction mechanism between MgO crucible and AerMet100 steel during vacuum induction melting

AerMet100 steel has strict composition and inclusion requirements. Therefore, its reaction with MgO refractory during vacuum induction melting cannot be ignored. In this study, the reaction mechanism between the MgO refractory and AerMet100 steel during the refining stage was investigated using a MgO crucible. The influence of the MgO crucible on AerMet100 steel composition and inclusions under refining vacuum pressures of 50–100 and 5–10 Pa was compared. The results indicate that SiO2, Al2O3, and MgO in the crucible decompose and are reduced by C in the liquid steel, which results in the increase of Si, dissolved Al (Als), and dissolved Mg (Mgs) content in the liquid steel. The increase of Ca content is due to the reduction of CaO in the crucible by C in the liquid steel. The reaction of Al2O3 inclusions and Mgs in the liquid steel is the primary generation method of MgO·Al2O3 spinel inclusions. As the Mgs content in the liquid steel increases, Al2O3 inclusions transform into MgO·Al2O3 spinel inclusions along the path Al2O3 + Mgs → Al2O3 with a small amount of MgO + Mgs → MgO·Al2O3 spinel. In contrast, the vacuum pressure of 50–100 Pa is more effective at controlling the composition and inclusions of AerMet100 steel and is a more appropriate choice for the refining vacuum pressure.

Stability of a Mixed‐Valence Hydrous Iron‐Rich Oxide: Implications for Water Storage and Dynamics in the Deep Lower Mantle

AbstractIncorporation of water into mantle compositions can have significant effects on the phase relations in the systems. In this study, we synthesized an iron‐rich hexagonal hydrous phase (referred to as “HH1‐phase”) under the high pressure‐temperature (P‐T) conditions of the deep lower mantle and determined the crystal structure of the HH1‐phase at 79 GPa using the multigrain crystallography method. The chemical formula obtained was Fe12.76O18Hx (x ∼ 4.5) in the Fe‐O‐H system. To demonstrate the role of HH1‐phase for water storage in multicomponent systems relevant to mantle compositions, we investigated the stability of HH1‐phase in both MgO‐rich pyrolitic and SiO2‐rich basaltic compositions. Our results indicate that the HH1‐phase serves as major water storage in a pyrolitic composition, whereas the Al‐rich CaCl2‐type δ‐phase and SiO2 phase are major water storage phases in a SiO2‐rich basaltic composition. Incorporation of considerable amounts of SiO2, MgO, and Al2O3 into the HH1‐phase expands its stability field from 98 GPa in the Fe‐Al‐O‐H system to at least 108 GPa (corresponding to ∼2,400 km depth) in the Mg‐Si‐Al‐Fe‐O‐H system. Plumes of hot upwelling rock rooted at the base of the lower mantle have been proposed as a possible origin of hotspot volcanoes. The hydrous Fe‐rich HH1‐phase, if included into the material of upwelling plumes, will decompose on its rising to the upper part of the lower mantle and release water. Our results should provide constraints on water storage in the deep lower mantle and have implications for deep mantle dynamics.

Effect of MgO on physicochemical property and phase transformation in copper slag

The cleaning of copper slag is an important way to realize the sustainable development of the copper metallurgy industry. MgO is a commonly used additive in the cleaning process and has an important impact on the physicochemical properties of copper slag. However, there are few studies on the mechanism of the phase transformation of the ISASMELT copper slag with different additive amounts of MgO. In this study, the mechanism of the phase transformation of copper slag with different additive amounts of MgO and the effect of MgO on the mass action concentration of slag component, physicochemical properties of copper slag and copper loss were elucidated. The results showed that when the MgO was added to copper slag, high melting point hortonolite was formed in the slag. When the additive amount of MgO was more than 4%, high melting point pleonaste was formed. With increasing MgO additive amount, the slag viscosity increased, and the silicate structure tended to be complex. Adding MgO to slag was not conducive to the recovery of matte from copper slag. The results provide a theoretical basis for selecting the most reasonable slag type in the cleaning process of ISASMELT copper slag and selecting the reasonable raw material in the ISASMELT process of copper concentrate.

Synthesis of NiO/MgO/ZrO2 catalyst for syngas production from partial oxidation and dry reforming of biogas

This work focuses on a facile NiO/MgO/ZrO2 synthesis protocol for syngas production via partial oxidation and dry reforming of biogas. Herein, performance of the developed catalysts with different amounts of MgO (0–40 %wt. of support) and NiO (10–50 %wt.) on %CH4 conversion, %CO2 conversion, H2/CO ratio, and carbon formation are studied. The results reveal the presence of monoclinic ZrO2 and tetragonal ZrO2 phases with 50%NiO/ZrO2 catalyst synthesized by surface modification technique using carbon derived from urea. Addition of MgO in the catalyst shows ability to stabilize tetragonal ZrO2 phase as well as enhance basic surface of the catalyst. These properties render the adsorption of CO2 molecules on the surface, which subsequently are reduced by carbon, leading to CO production. Appropriated amount of NiO and MgO, which is 30 %wt. NiO and 20 %wt. MgO (relative to ZrO2) can produce syngas having quality (H2/CO molar ratio) of ca. 2.

The effect of slag chemistry on the reactivity of synthetic and commercial slags

In this paper, both synthetic slag and commercial slag covering the common composition range were employed to estimate the correlation between slag chemistry and reactivity through hydraulicity and dissolution tests. It was found that slag reactivity was favorably affected by increasing Al2O3 and MgO contents, while the adverse effect of decreasing CaO/SiO2 ratio could be compensated by higher amounts of Al2O3 and/or MgO. When calorimetric measurement was used to assess the reactivity of slag, the effect of sulfur species incorporated in commercial slag should be taken into consideration as a small quantity of it could lead to a major difference of cumulative heat release due to the formation of ettringite. Moreover, a novel graphical method was proposed to estimate the reactivity of slag considering its chemical composition from a new perspective, i.e. a cartesian coordinate system based on (CaO/SiO2)−(MgO + Al2O3).

Influence of micro Fe2O3 and MgO on the physical and mechanical properties of the zeolite and kaolin based geopolymer mortar

Geopolymer binders can be used as a sustainable alternative to Portland cement. Despite the extensive research regarding the influence of different parameters on the properties of geopolymers, the studies investigating the effect of Fe2O3 and MgO on the performance of geopolymer concrete are minimal. This study investigates the impact of micro Fe2O3 and MgO additives on the physical and mechanical properties of the geopolymer binder. For this reason, the binder was developed by replacing 10%, 20%, and 30% kaolin with zeolite. In addition, Fe2O3 and MgO amounts in the binder were increased by substituting 4%, 6%, and 8% Fe2O3 and MgO with zeolite. The binder was activated with NaOH containing 15% Na (Na/binder) by weight. Geopolymer mortar specimens were prepared by mixing binder, sand, and NaOH-water solution, and the physical and mechanical properties of geopolymer specimens were investigated. Results show that replacing zeolite with kaolin and adding micro Fe2O3 and MgO increase the geopolymer specimens' unit weight, compressive strength, flexural strength, and ultrasonic pulse velocity (UPV). Fourier transform infrared spectroscopy (FTIR) and x-ray diffraction (XRD) spectra show no significant difference between the zeolite and zeolite + kaolin based geopolymer specimens. However, hematite mineral phases and periclase and forsterite mineral phases are prominent in geopolymer specimens incorporating micro Fe2O3 and MgO, respectively. Scanning electron microscopy (SEM) analysis shows a dense structure in the zeolite + kaolin based geopolymer specimens than zeolite based geopolymer specimens. Energy dispersive spectroscopy (EDS) analysis shows sodium aluminosilicate and calcium silicate hydrates as the main hydration products of all the geopolymer specimens. Based on the results, adding Kaolin, Fe2O3, and MgO in a zeolite-based geopolymer improves the physical and mechanical properties of the specimens.

Substitution of ‘small’ divalent cations (e.g. Mg) for Si and Al in the nepheline tetrahedral framework: 2. The occurrence of Mg-rich nepheline and kalsilite

AbstractNatural nepheline usually contains very small amounts of MgO (<0.1 wt.%), although these examples are mainly from Mg-poor alkaline igneous rocks such as nepheline syenites. However, this work shows that nepheline and kalsilite with much higher MgO concentrations can occur in the groundmass of strongly SiO2-undersaturated, feldspar-free, mafic volcanic rocks (i.e. olivine-rich foidites). Furthermore, a strong positive correlation is evident between their Mg and Fe contents. The occurrence of Mg-rich nepheline and kalsilite seems to be related to their derivation from Mg-rich magmas when compared to most of the host rocks investigated to date. Additionally, the physicochemical conditions of crystallisation seem to have an important role in the incorporation of ‘small’ divalent cations by these minerals. The prevalence of Mg-rich nepheline and kalsilite as late magmatic phases and the divergent Mg and Fe relationships for phenocrysts and ‘quenched’ groundmass crystals support this hypothesis. The positive correlation between Mg and Fe contents reflects their strong geochemical affinity and the entrance of Fe3+, Fe2+ and Mg2+ cations into the same crystallographic site of nepheline and kalsilite structures. The calculation of atomic formulae and stoichiometry parameters for nepheline-group minerals where data for the T2+ cations (e.g. Mg2+) are incorporated gives more reliable compositional parameters (see Paper 1). Calculated excess silica values (Si′) are affected significantly when the coupled substitution 2Al3+ = Mg2+ + Si4+ is considered. Thus, specific analyses of ‘small’ divalent cations are essential to obtain more realistic values of excess Si′, in particular, for nepheline and kalsilite that crystallised from Mg-rich, Si-poor, mafic–ultramafic alkaline lavas.

Three-dimensional carbon architectures with O doping and rich defects for catalytic conversion of polysulfides

Abstract To deal with the notorious shuttle behavior and sluggish conversion of lithium polysulfides (LiPSs), heteroatoms doping and defects creating are practical strategies for improving capture and catalytic conversion of LiPSs. In this work, O doped porous carbon materials (OPC) with a 3D hierarchical structure, consisting of 2–4 μm carbon sheets decorated with macrospores of 0.2–0.4 μm, was fabricated with MgO template. It is found that the increasing the carbonization temperature and the amount of MgO will make OPC rich in oxygen functional groups and defect sites. Electrochemical measures show that the OPC12–800 achieves reversible capacity (an initial discharge specific capacity of 1448.4 mAh g−1 at current density of 0.1 C) and cycling performance (717.7 mAh g−1 at 2 C over 200 cycles). The excellent electrochemical performance is attributed to the hierarchical porous structure, abundant C–O/C=O and defects, which effectively adsorbs polysulfides and promote faster redox reaction of LiPSs. This study provides an alternative to improve the performance of carbon materials as host of Li–S batteries by regulating the types of oxygen-containing functional groups and defects on carbon surface.

Size Effect of MgO on the Ionic Conduction Properties of a LiBH4·1/2NH3-MgO Nanocomposite.

A solid-state electrolyte (SSE) is the core component for fabricating solid-state batteries competitive with the currently commercial Li-ion batteries. In the present study, a LiBH4·1/2NH3-MgO nanocomposite has been developed as a fast Li-ion conductor. The conductive properties depend strongly on the size of MgO nanopowders. By adding MgO nanoparticles, the first-order transition at 55 °C observed in the crystalline LiBH4·1/2NH3 is suppressed due to the conversion of LiBH4·1/2NH3 into the amorphous state. When the size of MgO decreases from 163.6 to 13.9 nm, the MgO amount required for the phase-transition suppression of LiBH4·1/2NH3 decreases linearly from 92 to 75 wt %, accompanied by a significant enhancement of ionic conductivity. The optimized nanocomposite with 75 wt % MgO of size 13.9 nm exhibits a pronouncedly high conductivity of 4.0 × 10-3 S cm-1 at room temperature, which is 20 times higher than that of the crystalline LiBH4·1/2NH3. Furthermore, a smaller size MgO contributes to a higher electrochemical stability window (ESW) owing to the stronger interfacial interaction via B-O bonds, i.e., an ESW of 4.0 V is achieved with the addition of 75 wt % MgO of size 13.9 nm.

Room temperature Raman spectroscopy and 29Si MAS NMR combined with high temperature Raman spectroscopy and DFT calculation of xMgO-(1-x)CaO–SiO2 glasses and melts

In order to study the effect of MgO on the microstructure and macroscopic thermos-physical properties of calcium silicate melt, quantitative analysis of the various silicon-oxygen Q i species in magnesium-calcium silicate glasses and melts at a constant alkalinity has been performed by in-situ high temperature Raman spectroscopy, 29 Si MAS NMR and DFT (Density Functional Theory) calculation. Several cluster models, probably existed in magnesium-calcium silicate glasses and melts, modified by Ca 2+ or Mg 2+ have been designed, their Raman vibrational modes and scattering activities were thus simulated and calculated. A function correlating the wavenumbers of Si-O nb (non-bridge oxygen) of various SiOTs (silicon-oxygen tetrahedrons) with their RSCS (Raman scattering cross sections) was constructed and used to calibrate the experimental Raman spectra. The abundance of each primary Q i species of various magnesium-calcium silicate glasses can be composed by all the deconvoluted hyperfine peaks within the same Q i species. The quantitative description for glasses was proven to be consistent with the result from 29 Si MAS NMR. Thus, Q i species distributions for melts were also quantitatively derived. It demonstrated that the abundances of Q 1 and Q 3 species increased while Q 2 species decreased with the increasing replacing amount of MgO. The relationship between the viscosity and Q i species distributions as well as different cations has been investigated and correlated. Q 3 species was predominantly responsible for the contribution of viscosity of melt.

Effects of steel slag on the microstructure and mechanical properties of magnesium phosphate cement

The effects of steel slag (SS) addition on the strength and water resistance of magnesium phosphate cement (MPC) are investigated, and the hydration mechanism is proposed in this paper. With the addition of SS, the strength and water resistance of MPC were significantly enhanced. The compressive strength of MPC with 10 wt% SS (SS 10) cured in air for 60 d reached 56.7 ± 4.2 MPa. Interestingly, the strength loss rate of the sample cured in water for 14 d was only 6.6%. In addition, the microstructure and hydration products of MPC specimens were investigated via X-ray diffraction and scanning electron microscopy. There was a significant amount of unreacted MgO after MPC curing, and the main hydration product was struvite-K. The amount of struvite-K (KMgPO4·6H2O) of MPC with 0 wt% SS decreased after curing in water. However, no significant changes in the amount of hydration products was evident for SS 10, and the compactness was enhanced. This work provides a new approach for the resource utilization of SS.

The Effects of MWCNT Addition to Physical Properties of ZTA-MgO Cutting Tool

The purpose of this study is to develop ZTA-MgO-MWCNT cutting insert with enhanced properties and excellent tool performance that is suitable for high-speed machining. The effects of MWCNT addition on the physical properties of ZTA-MgO composites were investigated. The samples were fabricated using 80:20 composition (80 wt.% of Al2O3: 20 wt.% of YSZ) with fixed amount of MgO at 1.1 wt.% and MWCNT ranging from (0.1 – 0.5 wt.%) as secondary additives. The CNT was pre-treated in ethanol for 1 hour using an ultrasonic homogenizer before mixing and ball milled with Al2O3, YSZ and MgO compositions for 24 hours. The mixture is then pressed at 100 MPa into round-shaped cutting inserts mold after being dried at 100°C for 24 hours. The pressed samples were sintered at 1600 oC for 4 hour soaking time. XRD, density, porosity and shrinkage analysis performed on the samples. The XRD analyses indicate the presence of major phases were α-Al2O3, ZrO2, Zr0.963Y0.037O1.982 and MgAl2O4. The effect of MWNT addition on density, porosity and shrinkage of ZTA-MgO shows that density (4.210 g/cm3) and percentage of shrinkage (8.05%) obtained the highest value by 0.2 wt.% MWCNT compared with samples without CNT additives which is only 4.020 g/cm3 and 7.05% respectively. High density value indicates that the shrinkage percentage is also high, which corresponds to the densification of the composites. Poor dispersion of MWCNT within the matrix is highly accounted for agglomeration around Al2O3 grain boundaries and decreases in densification.

Role of MgO in lowering glass transition temperature and increasing hardness of lithium silicate glass and glass-ceramics

The effect of variation of MgO (1.5, 4.5 and 7.5 mol%) content on glass structure, crystallization behavior, microstructure and mechanical properties in a Li2O–K2O–Na2O–CaO–MgO–ZrO2–Al2O3–P2O5–SiO2 glass system has been reported here. Increased amount of MgO enhanced the participation of Al2O3 as a glass network former along with [SiO4] tetrahedra, reducing the amount of non-bridging oxygen (NBO) and increasing bridging oxygen (BO) amount in glass. The increased BO in glass resulted in a polymerized glass structure which suppressed the crystallization and subsequently increased the crystallization temperature, bulk density, nano hardness, elastic modulus in the glasses as well as the corresponding glass-ceramics. MgO addition caused phase separation in higher MgO (7.5 mol%) containing glass system which resulted in larger crystals. The nano hardness (∼10 GPa) and elastic modulus (∼127 GPa) values were found to be on a much higher side in 7.5 mol% MgO containing glass-ceramics as compared to lower MgO containing glass-ceramics.

Study on oxidation behavior of Al-Mg-Sc alloy

The high temperature oxidation behavior of Al-Mg-Sc alloy has been investigated. The structure and composition of oxide layer of Al-Mg-Sc alloy were analyzed by SEM, XRD and ARXPS. The microstructure evolution of Al substrate near the interface between Al-Mg-Sc alloy and oxide layer was explored by EBSD. The results showed that the oxide layer was mainly composed of MgO and small amounts of MgAl2O4. The formation of MgAl2O4, which was mainly distributed at the bottom of the oxide layer, was followed by formation of MgO. The phenomenon of grain boundary wetting by the second solid phase was observed. After being oxidized at 600 °C, the Al substrate near the interface was recrystallized thoroughly and the dislocation density of the oxidized sample was about an order of magnitude lower than that of the original sample.

Binder effect on ZnAl2O4-containing high-alumina refractory castables

In situ spinel (MgAl2O4, ZnAl2O4, etc.) formation in alumina-based castables has been pointed out as a key issue in the refractory area, as it may enhance the mechanical properties and corrosion resistance of such materials. Nevertheless, the generation of these compounds is usually accompanied by a large volume expansion, which may induce crack formation in the resulting microstructure. Aiming to investigate the influence of zinc and magnesia spinel generation on the properties of alumina-based castables, three vibratable compositions, containing calcium aluminate cement or hydratable alumina as binders, were designed and characterized in this work. Different experimental tests were carried out to analyze the produced samples, such as: cold flexural strength, apparent porosity, hot elastic modulus, assisted sinterability, corrosion cup-tests, etc. According to the results, ZnAl2O4 was mainly formed above 800 °C, favoring an earlier sintering of the samples. The addition of high amounts of ZnO or MgO (3 wt% to 9.4 wt%) to the castables resulted in the expansion of the samples during their first thermal treatment up to 1500 °C, reaching dL/L0 values equivalent to 1.16% up to 2.35%. Thermodynamic simulations indicated that spinel phase presented higher chemical stability when in contact with the evaluated synthetic slag at 1500 °C. Depending on the corrosion cup-test procedure (free or under constraint), different results of the slag infiltrated area were obtained (13.7%–20.5%) and, the combination of two different spinel phases (MgAl2O4 and ZnAl2O4) in a castable composition resulted in a refractory with enhanced corrosion behavior when the tests were carried out under constraint.

Adsorption and Photocatalytic Degradation Properties of Bimetallic Ag/MgO/Biochar Nanocomposites

The Ag/MgO/biochar nanostructures were fabricated using a solvent-free ball milling process as an effective adsorbent. Development of functional materials capable of completely removing organic pollutants from water and their adequate adsorption present challenges. The addition of MgO nanoparticles diffused equally on biochar surfaces in the biochar matrix, according to various characterization data. In decomposing biochar and compressing MgO, powdered metal enhanced mesopores and macropores of nanocomposites. XPS analysis indicates the potential synthesis of modified biochar nanocomposites. Adequate amounts of MgO added to biochar improved the ability of the nanocomposites to remove methylene blue (M.B.) through photosynthesis and adsorption. Photocatalytic analysis was carried out for the proposed novel composites to remove tetracycline (T.C.) subjected to different conditions. The photodegradation efficiency was found 80.26% for TC concentration, 50 ppm, H2O2 of 100 mM pH: 5-6 of Ag/MgO/biochar (0.01 g) at 25° temperature. Treatment of various organic wastewaters by metal oxide/biochar nanocomposites with strong adsorption and photocatalytic degradation capabilities is made possible by this research.

Performance analysis of dye-sensitized solar cells with various MgO-ZnO mixed photoanodes prepared by wet powder mixing and grinding

In this study, photoanodes of a dye-sensitized solar cell (DSSC) were made by adding various weight percentages (0∼9 wt%) of MgO nanopowder to ZnO nanopowder with a different wet powder mixing and grinding method. For the MgO/ZnO DSSCs, the addition of 1 wt% MgO can achieve maximum short-circuit current density (4.00 mA/cm2) and maximum photovoltaic conversion efficiency (1.03%), which was 39% and 27% better than those of the reference ZnO DSSCs, respectively. When a small amount of MgO was added, the electron transport rate or the efficiency of electron injection into photoanodes was improved. However, when a large amount of MgO was added, the number of carriers generated by light was lowered, which led to performance degradation in DSSCs. Preparing photoanodes by adding a small amount of MgO to ZnO can thus effectively improve the photovoltaic performance of ZnO DSSCs.