Amorphous materials and heterointerface engineering have been widely used in the field of electrocatalytic water splitting due to their unique electronic structures and surface properties. However, the development of low-cost bifunctional catalysts simultaneously possessing high activity and robust stability remains a substantial challenge. Herein, we have realized the deep optimization of catalytic activity by constructing the crystalline-amorphous NiMgPO4.8H2O/a-FeNiMgPOx heterojunction. Theoretical analysis and experimental characterization collectively demonstrate that this composite structure significantly enhances catalytic performance through a triple synergistic effect: (1) interfacial electronic reconstruction optimizes the d-band center position; (2) abundant defect sites within the amorphous phase increase the electrochemical active area; (3) the resultant built-in electric field at the interface substantially enhances transfer efficiency of protons and charges. Benefiting from these advantages, the catalyst exhibits outstanding bifunctional activity in the alkaline electrolyte. The optimized electrocatalyst shows extremely low hydrogen evolution reaction (HER) and low oxygen evolution reaction (OER) overpotentials of 61 and 222 mV, respectively, at a current density of 10 mA cm-2. The NiMgPO4.8H2O/a-FeNiMgPOx electrolyzer utilizing the electrocatalyst as both anode and cathode demonstrates remarkable overall water-splitting activity, requiring a cell potential of only 1.525 V at 10 mA cm-2 and retains over 97% of its initial activity during a continuous 12-h stability test. This work provides not only a novel design strategy for hydrated metal phosphate systems but a new mechanism for synergistically enhancing intrinsic catalytic activity through crystalline-amorphous heterojunction engineering.

The energy storage density of dielectric ceramics is governed by both the dielectric breakdown strength and the dielectric permittivity. Glass, as a sintering additive, can effectively enhance the breakdown strength by reducing porosity and refining grain size; however, it often severely reduces the permittivity. In this study, a novel BaO-B2O3-SiO2-ZnO (BBSZ) glass additive was synthesized and incorporated into Ba0.3Sr0.7TiO3 (BST) ceramics. The resulting ceramics not only achieved a dense microstructure with fine main grains but also facilitated the formation of a secondary crystalline phase, Ba2TiSi2O8 (BTS). This BTS phase significantly enhanced the dielectric breakdown strength while effectively mitigating the reduction in permittivity. Specifically, the ceramic with 12 wt

Abstract During the long-term preservation of ancient books, acidic substances will continuously erode and cause them to suffer severe damage. As a mild deacidification agent, nano-MgO is often dispersed in organic solvents for large-scale deacidification. This study is based on small-scale deacidification in the laboratory, using cheaper and safer water as the carrier, and aiming at the problem that nano-MgO is easy to agglomerate, through the combination of ultrasonic dispersion and dispersant, the nano-MgO aqueous suspension with improved dispersion and acceptable stability was prepared. The results indicate that ultrasonication in an ice-bath at 600 W for 10 min was optimal, and the mass ratio of dispersant to MgO is 1:5 can meet the dispersion requirements. The average particle size of MgO under the optimal dispersion conditions measured by a nanometer particle size analyzer is below 400 nm. The AFM picture shows that the particle size of MgO was observed to be approximately 100 nm. SEM pictures show that MgO appears to be relatively evenly distributed on the fiber surface, the deacidification behavior appears relatively uniform across the treated samples, and the effect is better than that of the deacidification solution without dispersion treatment.

Multilayer piezoelectric ceramics employing base metals such as copper as inner electrodes are ideal for components like micro-displacement actuators and ultrasonic motors, which require materials possessing high piezoelectric performance, high Curie temperature, and low sintering temperature. In this study, by introducing a ternary composite additive of Li2CO3-CuO-Nb2O5 into the 0.075Pb(Mn1/3Sb2/3)O3-0.925Pb(Zr0.48Ti0.52)O3 (PMSPZT) system, PMS-PZT ceramics with excellent overall properties were successfully fabricated at a sintering temperature of 950 degrees C, exhibiting d33= 361.2 pC/N, Tc= 339.8 degrees C, tans= 0.6%, Qm= 668.8, kp= 0.65. The effects of sintering temperature on the structure and properties of the ceramics were systematically investigated. The synergistic action of Li2CO3 and CuO effectively reduced the sintering temperature and facilitated the incorporation of Nb into the B-site at relatively low temperatures, thereby significantly enhancing the piezoelectric performance and Curie temperature of the material. This work not only provides an effective low-temperature sintering approach for the PMS-PZT ceramic system, but also offers important references for the selection of material systems and additives in the development of multilayer piezoelectric devices.

This research aimed to compare the fruit storability and quality differences between the 'Fuyan' and 'Dongbi' varieties of longan (Dimocarpus longan Lour.) by assaying their antioxidant system and disease defense systems. The results showed that, compared to 'Fuyan' fruit, during storage, 'Dongbi' fruit exhibited superior storability and appearance, characterized by lower levels of fruit disease, pulp breakdown, pericarp browning, and weight loss, alongside higher pericarp color, brightness, pigments, pulp nutrient content, and commercial acceptability of fruit. Additionally, 'Dongbi' longans exhibited lower ROS accumulation and MDA level, higher levels of antioxidants (AsA, GSH), antioxidant enzymes (SOD, CAT, APX), reducing power, and DPPH center dot scavenging ability. Besides, 'Dongbi' longans retained higher levels of secondary metabolites (lignin, total phenolics, flavonoid), PRMEs (PAL, C4H, 4-CL, CAD, POD), and PRs (CHI, GLU). Therefore, the enhanced storage stability of 'Dongbi' longans may be attributed to the synergistic effects of an improved antioxidant system, phenylpropanoid pathway, and PRs.

In natural environments, amorphous Al(OH)s often combines with natural organic matter, such as humic acid, to form complexes through coprecipitation. The adsorption and reduction characteristics and mechanisms of humic acid-Fe(III) coprecipitates with Cr(VI) are well understood, however, research on humic acid-Al(III) coprecipitates is limited. This study aims to investigate the adsorption and reduction characteristics and mechanisms of humic acid-Al(III) coprecipitates with varying initial C/M ratios (carbon to metal ratio 1-20) on Cr(VI). The adsorption of Cr(VI) on the coprecipitates decreased from 0.49 to 0.03 mmol/g with C/M ratios increasing from 1 to 20. The structure of the coprecipitates transformed from "mineral-like" to "organic-like" as the C/M ratio increased, with approximately the C/M ratio being equal to 5 as the turning point. When the C/M ratio was below 5, the coprecipitates exhibited a significant "mineral-like" structure. In this state, the humic acid component blocked the pore space of amorphous Al(OH)s, favoring Cr(VI) adsorption via surface complexation, resulting in an antagonistic effect on the intra-particle diffusion of Cr(VI). Conversely, when the C/M ratio exceeded 5, the coprecipitates adopted a significant "organic-like" structure. This structural change led to a significant decrease in the coprecipitation pHpzc, increasing the electrostatic repulsion between Cr(VI) anions and negatively charged surface of coprecipitates, manifesting an antagonistic effect on the surface complexation process of Cr(VI). As the C/M ratio continued to rise, the high concentration of humic acid components inhibited the hydrolysis and precipitation of Al(III), reducing the formation of amorphous Al(OH)3 with a porous structure, which has impacts on the surface complexation of Cr(VI) and reinforced the antagonistic effect on intra-particle diffusion. The reduction of Cr(VI) by coprecipitates with varying C/M ratios is driven by humic acid as the sole electron donor. The induction effect and molecular fractionation enhance humic acid's synergistic reduction of Cr(VI), while Al3 + complexation with humic acid's reducing groups reduces the contact between Cr(VI) and humic acid's reducing functional groups, leading to an antagonistic reduction effect.

Designing and constructing highly efficient, cost-effective, and durable non-precious metal bifunctional catalysts remains a challenge. In this work, by constructing crystalline/amorphous Co3(PO4)2-MoO3-x/NF in turn, a significant optimization of the catalytic activity is achieved. The amorphous state provides an abundance of active sites with unsaturated electronic structures, while the crystalline state offers high conductivity, which synergistically improves overall water-splitting kinetics. The alkaline hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) can achieve current densities of 100 mA cm-2 with overpotentials of 101 and 321 mV, respectively. At this current density, the material also demonstrates excellent long-term stability for long-term operation of 100 hours and 80 hours, respectively. In addition, the assembled two-electrode electrolyzer requires a low voltage of 1.51 V to reach a current density of 10 mA cm-2. This study illustrates the value of crystalline/amorphous heterojunctions in optimizing catalytic activity and provides a new approach for the design and construction of crystalline/amorphous electrocatalysts.

Exploiting high-entropy rare-earth monosilicates (HEREMs) with simultaneously improved corrosion resistance and thermophysical properties is vital for their use as next-generation environmental barrier coating materials. Herein, a new dual-phase strategy has been developed to regulate the comprehensive properties of HEREMs. Specifically, by adding 20% Lu2Si2O7 (LuD) into (Ho0.1Er0.1Yb0.4Lu0.4)2SiO5 (HEREM-0.1), novel (Ho0.1Er0.1Yb0.4Lu0.4)2SiO5/Lu2Si2O7 (HEREM-0.1/LuD) dual-phase rare-earth silicates have been successfully fabricated to exhibit a synergistic enhancement in both thermophysical properties and calcium-magnesium-aluminosilicate (CMAS) corrosion resistance, including excellent high-temperature stability without phase transformation up to 1973 K, well-matched coefficients of thermal expansion (3.5-5.7 x 10-6 K-1) with SiCf/SiC composites (4.0-5.5 x 10-6 K-1) across 473-1573 K, extremely low thermal conductivity of 0.8-1.4 W m-1 K-1 from room temperature to 1273 K, and further enhanced CMAS corrosion resistance at 1673 K for 60 h (ultralow corrosion depth of 47 mu m). Such superior properties can be attributed to the introduction of the dual-phase structure and the enhanced stability of the formed apatite structure. Our work provides an alternative way to developing HEREMs with outstanding comprehensive properties.

Ubiquitous amorphous ferrihydrite (Fh) and humic substances (HSs) combining into co-precipitates fundamentally alters the processes by which they reduce the mobility and toxicity of Cr(VI) contaminants in groundwater and soil. However, the kinetic characteristics of the interactions between Fh-humic acid (HA) coprecipitates and Cr(VI) remain poorly understood. In this study, the kinetics of Cr(VI) adsorption and reduction by Fh-HA co-precipitates were examined under mildly acidic experimental conditions (pH 4-5). Compared to Fh and HA in their pure phases, Cr(VI) adsorption by Fh in co-precipitates was inhibited (antagonistic adsorption), whereas Cr(VI) reduction by HA in co-precipitates was enhanced (synergistic reduction). A successful multistep kinetic model was developed to simulate this complex reaction process involving both adsorption and reduction and effectively overcome the limitations of classical kinetics. The antagonistic adsorption effect ranged between 2 %-11 % mainly because of HA competing for adsorption sites on Fh, whereas the synergistic reduction effect varied between 116 %-518 % mainly because the highly reductive active components within the HA molecules preferentially bind to Fh during co-precipitate formation (molecular fractionation). Both the antagonistic adsorption and synergistic reduction effects are influenced by the structural types of the Fh-HA co-precipitates, being particularly pronounced in Fh-like co-precipitates characterized by a low C/Fe ratio. Our findings provide a comprehensive perspective for quantitatively assessing the role of Fh-HS co-precipitates regarding Cr(VI) contamination in groundwater, contributing to its evaluation, management, and remediation.

To understand the underlying mechanism of the organic acid accumulation of postharvest longan fruit, integrative analyses of transcriptome and metabolome were performed in the fruit of two longan varieties ('Fuyan' and 'Dongbi') with different storability. Compared with 'Dongbi' longan, the 'Fuyan' cultivar exhibited higher fruit respiration rate, pulp breakdown index, and TA content, but a lower TSS content during storage. Targeted metabolomic analysis revealed that, in comparison to 'Dongbi' longan, during storage, 'Fuyan' longan accumulated higher levels of four organic acids, including 3-phenyllactic acid, lactate, succinic acid, and oxaloacetate. Transcriptomic analysis showed that DEGs between 'Fuyan' and 'Dongbi' longans were primarily enriched in respiration metabolism pathways, including glycolysis, gluconeogenesis, and the TCA cycle. Additionally, WGCNA identified hub genes involved in these metabolic pathways. RT-qPCR analysis indicated that the expression of related genes (DlLDH, DlACL, DlPEPC, DlMDH, DlAST and DlSCS) was upregulated in 'Fuyan' longan compared with 'Dongbi' longan during storage. These findings suggest that the increase in longan pulp acidity is attributed to organic acid accumulation and an enhanced respiration metabolism, resulting in the poor storability of 'Fuyan' longan during storage.

Exploiting high‐entropy rare‐earth monosilicates (HEREMs) with simultaneously improved corrosion resistance and thermophysical properties is vital for their use as next‐generation environmental barrier coating materials. Herein, a new dual‐phase strategy has been developed to regulate the comprehensive properties of HEREMs. Specifically, by adding 20% Lu 2 Si 2 O 7 (LuD) into (Ho 0.1 Er 0.1 Yb 0.4 Lu 0.4 ) 2 SiO 5 (HEREM‐0.1), novel (Ho 0.1 Er 0.1 Yb 0.4 Lu 0.4 ) 2 SiO 5 /Lu 2 Si 2 O 7 (HEREM‐0.1/LuD) dual‐phase rare‐earth silicates have been successfully fabricated to exhibit a synergistic enhancement in both thermophysical properties and calcium–magnesium–aluminosilicate (CMAS) corrosion resistance, including excellent high‐temperature stability without phase transformation up to 1973 K, well‐matched coefficients of thermal expansion (3.5–5.7 × 10 −6 K −1 ) with SiC f /SiC composites (4.0–5.5 × 10 −6 K −1 ) across 473–1573 K, extremely low thermal conductivity of 0.8–1.4 W m −1 K −1 from room temperature to 1273 K, and further enhanced CMAS corrosion resistance at 1673 K for 60 h (ultralow corrosion depth of 47 µm). Such superior properties can be attributed to the introduction of the dual‐phase structure and the enhanced stability of the formed apatite structure. Our work provides an alternative way to developing HEREMs with outstanding comprehensive properties.

Moisture-electricity generation is a widely studied green power generation technology in recent years. Aiming at the defects of low output power and unsustainable output signal of moisture-electricity generator (MEG), a new type of MEG is prepared using polypyrrole-modified cleanroom wiper (PPy-CRW) as electrodes. The electrodes exhibit good conductivity and can be infiltrated by sodium alginate (SA)-based functional material, which reduces the contact resistance between electrode and functional material. In addition, graphene oxide (GO) is introduced to enhance the ion conductivity while increasing the amount of active functional groups. Additionally, the addition of hygroscopic salt LiCl and crosslinking with Ca2+ makes MEG adsorb moisture continuously and maintain structural stability. The maximum output voltage of the PPy-CRW-MEG can reach 700 mV, with a stable output duration of up to 27 h in ambient, and the output power density reaches 37 mu w cm-2. This work expands the selection range of electrode materials for MEGs and provides a new view for MEG design.

In this study, BaTiO3 nanopowders were prepared by non-hydrolytic sol-gel (NHSG) method using barium acetate and tetrabutyl titanate (TBT) as precursors and acetylacetone (Hacac) as additive. The effects of acetylacetone modification and calcination temperature on nanoparticle size and crystalline phase were evaluated. The products were analysed by SEM, TEM, DSC/TG, FTIR, XRD, Raman. FTIR analysis showed the formation of Ba-O-Ti bond at the sol stage of the NHSG method. DSC/TG and XRD analyses showed that BaTiO3 was produced at 500 ℃. According to SEM/TEM, the particle size of the powder becomes larger as the temperature increases, meanwhile the addition of acetylacetone can make the final product particle size decrease. Raman analysis showed that BaTiO3 has the presence of tetragonal phase, so the crystalline phases of the product and impurities were analysed by XRD refinement, and the results showed that the relative content of tetragonal phase of BaTiO3 was linearly correlated with the calcination temperature.

Wetlands exhibit a self-purification effect on Cr(VI) owing to the adsorption and reduction capabilities of their humic substance (HS)-Fe(III) coprecipitates. However, the similarities and differences in the adsorption and reduction of Cr(VI) by different types of HS-Fe(III) coprecipitates remains unknown. In this study, fulvic acid (FA)- and humic acid (HA)-Fe(III) coprecipitates were synthesized with initial C/Fe ratios ranging from 0.25 to 15, and a comparative analysis of their adsorption and reduction effects was conducted. The results showed that FA- and HA-Fe(III) coprecipitates exhibit similar abilities to adsorb Cr(VI) by forming inner-sphere complexes with ferrihydrite (Fh), as well as with FA/HA. The association between FA/HA and Fe(III) not only blocked certain FeOH adsorption sites, but also enhanced the electrostatic repulsion towards Cr(VI), resulting in a proportionate decrease in their adsorption ability. For reduction, inductive and intrinsic reduction were involved in both FA- and HA-Fe(III) coprecipitates. However, the synergism/antagonism differed with the inherent sites (e.g., phenolic hydroxyl, ArOH) and activated sites (e.g., alcoholic hydroxyl, AlOH). Based on the size differences between FA and HA, the AlOH contained in FA was more easily activated by Fe(III) than that in HA, owing to the shorter induction path required. Thus, consistent synergism was observed in FA-Fe(III) coprecipitates regardless of Fe(III) species. In contrast, synergism was only observed in HA-Fe(III) coprecipitates containing Fh, because the inductive ability of Fe(III) cations was too weak to activate AlOH through the longer path. Moreover, with irreversible consumption of AlOH, intrinsic reduction became the dominant pathway at concentrations >1 mM Cr(VI). The preferential elimination of ArOH subsequently led to a transition to antagonism. These outcomes deepen our scientifical understanding of the environmental effects of HS-Fe(III) coprecipitates and offer new perspectives for exploring their potential applications in the remediation of Cr-contaminated sites.

To evaluate the mechanisms of Cr(VI) attenuation in a subsurface environment enriched in natural organic matter and iron minerals, fulvic acid (FA)-Fe(III) coprecipitates were synthesized in laboratory. The ability to adsorb and reduce Cr(VI) was compared with that of humic acid (HA)-Fe(III) coprecipitates, which has been investigated in previous study. According to the results, the adsorption of Cr(VI) onto both FA- and HA-Fe(III) coprecipitates may be attributed to the formation of inner- and outer-sphere complexes by Fe(III) and FA/HA. However, the association between FA/HA and Fe(III) not only sheltered certain FeOH adsorption sites but also enhanced the electrostatic repulsion towards Cr(VI). This, subsequently, decreased their adsorption capability. For reduction, two parallel processes, namely inductive and intrinsic reduction, were involved in FA- and HA-Fe(III) coprecipitates, and the final synergism/antagonism depending on the decrease in the number of inherent reduction sites (e.g., phenolic hydroxyl) and the increase in the number of activated sites (e.g., alcoholic hydroxyl). Compared to HA, alcoholic hydroxyls within FA was more easily activated by Fe(III) (hydr)oxides (such as ferrihydrite (Fh)) and even by the weakly inductive Fe(III) cations owing to its smaller molecular size. Thus, consistent synergism was observed in all FA-Fe(III) coprecipitates, but only in HA-Fe(III) coprecipitates containing highly inductive Fh. This synergistic effect surprisingly converted into antagonistic effect as the Cr(VI) concentration increased mainly because the decreased intrinsic reduction caused by FA/HA fractionation became responsible for Cr(VI) reduction instead of inductive reduction, owing to the consumption of activated sites. The outcomes of this study may help explore untapped potential in terms of applications in the remediation of Cr-contaminated sites.

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Humic substance (HS)-ferric iron (Fe(III)) coprecipitates are widespread organo-mineral associations in soils and aquifers and have the capacity to immobilize and detoxify Cr(VI). These coprecipitates undergo transformation owing to their thermodynamic instability; however, the effects of this transformation on their environmental behaviors remain unclear, particularly in aerobic environments. In this study, the aerobic transformation of humic acid (HA)-Fe(III) coprecipitates, a representative of HS-Fe(III) coprecipitates, was simulated. The environmental effect was then evaluated after conducting an adsorption-reduction batch experiment toward Cr(VI). The aerobic transformation characteristics, as well as the adsorption/reduction capacity of HA-Fe(III) coprecipitates, were found to depend strongly on their structures. In ferrihydrite (Fh)-like coprecipitates, amorphous Fh is readily transformed into crystalline hematite and goethite at aerobic environments, leading to a much lower specific surface area and adsorption capacity. However, this increasing degree of crystallization enhanced the inductive reduction ability towards Cr(VI) owing to the more significant shift of electron pairs in the FeOC bond toward the HA direction. In HS-like coprecipitates, Fe(III) always serves as a cation bridge connecting HA molecules, but can be reduced to Fe(II) by the associated HA after aerobic transformation. The produced Fe(II), therefore, drove the reduction of the adsorbed Cr(VI). These findings emphasize the pivotal role of aerobic transformation in enhancing the reduction capacity for Cr(VI), which opens a new avenue for the development of in-situ remediation agents for Cr(VI)-contaminated sites.

Ubiquitous Fe-OM complexes in subsurface environments have substantial retention effects on Cr(VI) migration; however, whether these effects follow the superposition principle remains unclear, particularly for Fe(II)-containing minerals. In this study, Cr(VI) adsorption and reduction by magnetite-humic acid (HA) adsorption complexes (MHAs) were investigated under mildly acidic conditions, and MHAs were found to have antagonistic adsorption and synergistic reduction effects on Cr(VI). Based on the Raman mapping characterization, the MHAs surface was extremely heterogeneous, consisting of two types of sites: (A) magnetite covered by HA and (B) bare magnetite without HA. Owing to the coverage of the magnetite surface by HA, the adsorption and reduction by magnetite was depressed with an antagonistic efficiency of 8 %-70 %, varying with the amount of adsorbed HA. In contrast, the synergistic reduction of Cr(VI) by the HA component at site (A) was observed, resulting in a synergistic factor of up to 44, which could be attributed to the molecular fractionation and functionality activation of HA on the magnetite surface according to the fluorescence excitation-emission matrix combined with parallel factor analysis and density functional theory calculations. Accordingly, a multi-step kinetic model of Cr (VI) adsorption and reduction by MHAs based on antagonistic and synergistic effects was established to quantitatively simulate the Cr(VI) interfacial behavior (R > 0.9). This study is instructive for accurately assessing the effect of Fe-OM complexes on Cr(VI) migration and benefits the development of remediation materials for Cr(VI)-contaminated soils and groundwater.

Widespread landfills represent a significant source of groundwater contamination. Due to the unique and diverse nature of dissolved organic matter (DOM) in landfill leachate, the interaction between DOM and heavy metals, along with its quantitative evaluation, remains unknown. Consequently, we collected ten samples from various landfill types to serve as representatives for a comprehensive investigation of the mechanism involving functional groups and Cr(III) through the establishment of a quantitative structure-activity relationship (QSAR). We employed ESI FT-ICR MS, (MW) 2D-COS, and DFT calculations for this purpose. Our findings indicate that DOM from landfill leachate contains a higher proportion of CHON molecules on intensity compared to those from natural sources. The maximum complexation capacity was determined by the proportion of proteins (69%), normalized carbon average oxidation state (16%), double bond equivalence (8%), and the number of oxygen atoms (7%) in landfill leachate DOM. Besides, N-containing groups such as N = O and C-N in landfill leachate DOM with lower humification, can exhibit stronger affinities than COOH, ArOH, CO, and polysaccharide C-O groups, which are typically identified as dominant sites in natural DOM. A QSAR model incorporating four parameters demonstrated an impressive accuracy rate of 98.8%, underscoring its reliability in predicting the complexation potential of different landfill leachate DOM with Cr(III).