Search Results (537)

The Xujiahe Formation (FM) is a significant source rock layer in the Sichuan Basin. In recent years, a growing number of scholars believe that the shale gas potential of the Xujiahe Formation is equally substantial, with the first member of the formation being the richest resource. The deposition of Member (Mbr) 1 of Xujiahe FM represents the first and most extensive transgression event within the entire Xujiahe Formation. This study investigates the sedimentary environment and organic matter (OM) enrichment mechanisms of the dark mud shales in the Mbr1 of Xujiahe FM on the southeastern margin of the Sichuan Basin, utilizing methods such as elemental geochemistry and organic geochemistry analyses. The results indicate that these dark mud shales possess a relatively high OM abundance, averaging 2.20% and reaching a maximum of 6.22%. The OM is primarily Type II₂ to Type III. Furthermore, the paleoclimate during the Mbr1 period in the study area was warm and humid with lush aquatic vegetation. Intense weathering and ample precipitation transported large amounts of nutrients into the lacustrine/marine basin, promoting the growth and reproduction of algae and terrestrial plants. Correlation analysis between the Total Organic Carbon (TOC) content and various geochemical proxies in the Mbr1 mud shales suggests that OM enrichment in the study area was primarily controlled by the climate and sedimentation rate; substantial OM accumulation occurred only with abundant terrigenous OM input and a relatively high sedimentation rate. Redox conditions, primarily productivity, and terrigenous detrital input acted as secondary factors, collectively modulating OM enrichment. Event-driven transgressions also played an important role in creating conditions favorable for OM preservation. Synthesizing the influence of these multiple factors on OM enrichment, this study proposes two distinct composite models for OM enrichment, dominated by climate and sedimentation rate. Full article

To address the technical challenges in bisphenol A (BPA) pollution control, this research introduced a novel synthetic approach combining co-precipitation with subsequent thermal treatment to engineer layered double hydroxides (LDHs) with a spinel-structured CoMn-LDO catalyst. Systematic material characterizations such as a scanning electron microscope (SEM), an X-ray diffractometer (XRD), a transmission electron microscope (TEM), and X-ray photoelectron spectroscopy (XPS) were employed to analyze the structural and chemical properties of the synthesized CoMn-LDO calcined at 500 °C. The catalytic performance was evaluated under optimized conditions (35 °C, pH 7.0, 2.0 mM PMS, 0.3 g/L catalyst), and mechanistic studies were conducted to identify the dominant reactive oxygen species. The CoMn-LDO exhibited exceptional peroxymonosulfate (PMS) activation performance, achieving 96.75% BPA degradation within 90 min and 58.22% TOC removal. The synergistic redox cycling between Co²⁺/Co³⁺ and Mn³⁺/Mn⁴⁺ promoted the generation of ·OH (72.3% contribution) and SO₄^·−. The catalyst demonstrated superior stability, maintaining 89% degradation efficiency after five cycles. These results provide theoretical and practical insights for developing high-efficiency persulfate-activating catalysts. Full article

Poly(3-thienylboronic acid) (PThBA) has recently been suggested as a conducting polymer with affinity for saccharides. In this study, thin films of this compound were deposited onto gold electrodes. The system obtained was studied as a possible chemical sensor. The measurements were performed by impedance spectroscopy using potassium ferro/ferricyanide as a redox mediator. The thickness of the polymer and the deposition of the adhesive sublayer were optimized to achieve a compromise between the blocking of defects in the polymer layer and the unnecessary increase in the internal resistance of this conductometric sensor. A comparative study of the influence of fructose, glucose, and sorbitol on transversal polymer resistance was conducted. The binding constants for these saccharides were extracted from the concentration dependencies of sensor conductance. Among them, sorbitol showed the highest affinity with a binding constant up to ~15,000 L·mol⁻¹, followed by fructose (~8700 L·mol⁻¹) and glucose (~4500 L·mol⁻¹). In order to exclude the contribution of the analyte tautomers on the obtained binding constants, measurements of ethylene glycol were also performed. The effects of pH and the redox state of PThBA on its affinity properties were studied, revealing higher affinities at alkaline pH and in oxidized state of the chemosensitive polymer. The developed system has the capacity to be applied in chemical sensors and virtual sensor arrays with electrical affinity control. Full article

Photocatalytic technologies based on silicon (Si-based) nanostructures offer a promising solution for water purification, hydrogen generation, and the conversion of CO₂ into useful chemical compounds. This review systematizes the diversity of modern approaches to the synthesis and modification of Si-based photocatalysts, including chemical deposition, metal-associated etching, hydrothermal methods, and atomic layer deposition. Heterostructures, plasmonic effects, and co-catalysts that enhance photocatalytic activity are considered. Particular attention is drawn to the silicon doping of semiconductors, such as TiO₂ and ZnO, to enhance their optical and electronic properties. The formation of heterostructures and the evaluation of their efficiency were discussed. Despite the high biocompatibility and availability of silicon, its photocorrosion and limited stability require the development of protective coatings and morphology optimization. The application of machine learning for predicting redox potentials and optimizing photocatalyst synthesis could offer new opportunities for increasing their efficiency. The review highlights the potential of Si-based materials for sustainable technologies and provides a roadmap for further research. Full article

The regulation of nutrient availability and microbial processes in agroecosystems are strongly mediated by soil physico-chemical factors. Yet, their seasonal dynamics in different crops are not fully understood. This study monitored pH, redox potential (Eh), electrical conductivity (EC), and nitrite (NO₂⁻) in soils grown with clover, maize, and triticale from November to May. Monthly samples were collected in four depth layers (0–20, 20–40, 40–60, 60–80 cm) and analyzed to reveal patterns over time and space. Soil pH remained near neutral, with slight decreases in spring, and it appeared that maize maintained more stable values than clover or triticale. Eh was highest in winter, indicating oxidizing conditions, but decreased in spring, especially at depth under triticale. EC showed moderate variation, with higher surface values under maize. NO₂⁻ was uniformly low in winter but increased in spring, especially in deeper soils with triticale, while clover had lower accumulation. Overall, clover supported greater soil stability, maize increased surface EC, and triticale enhanced nitrite accumulation at depth. These results highlight the need for crop-specific, depth-aware management to maintain soil quality and optimize nitrogen cycling in agricultural systems. Full article

The cycling stability and widespread practical implementation of aqueous zinc ion batteries (AZIBs) are impeded by dendrite growth and the hydrogen evolution reaction (HER). Herein, theaflavins, a low-cost organic bio-compounds and a major component of tea, were innovatively introduced as an electrolyte additive for AZIBs to address these challenges. When added into the electrolyte, theaflavins, with their strong de-solvation capability, facilitated the more uniform and stable diffusion of zinc ions, effectively suppressing dendrite formation and HER. This, in turn, significantly enhanced the coulombic efficiency (>95% in Zn/Cu system) and the stability of the zinc deposition/stripping process in Zn/Zn system. The Zn/Zn symmetric battery system stably cycled for approximately 3000 h at current densities of 1 mA/cm². Compared with H₂O molecules, theaflavins exhibited a narrower LUMO and HOMO gap and higher adsorption energy on zinc surfaces. These properties enabled theaflavins to be preferentially adsorbed onto zinc anode surfaces, forming a protective layer that minimized direct contact between water molecules and the zinc surface. This layer also promoted the electron transfer associated with zinc ions, thereby greatly enhancing interfacial stability and significantly mitigating HER. When 10 mmol/L of theaflavins was present in the electrolyte, the system exhibited lower impedance activation energy, a smoother zinc ion deposition process, reduced corrosion current, and higher HER overpotential. Furthermore, incorporating theaflavins into the electrolyte enhanced the vanadium redox reaction and accelerated zinc ion diffusion, thereby significantly improving battery performance. This work explores the design of a cost-effective electrolyte additive, providing essential insights for the progress of practical AZIBs. Full article

The Lower Submember of the Second Member of the Lianggaoshan Formation (LGS2-LS) in the Fuling area, southeastern Sichuan Basin, represents the deepest lacustrine depositional stage of the formation and constitutes an important target for shale oil and gas exploration. Based on core observations, thin-section petrography, X-ray diffraction, geochemical analyses, and sedimentary facies interpretation from representative wells, this study characterizes the lithofacies types, sedimentary environments, and depositional evolution of the LGS2-LS. Results show that the LGS2-LS is dominated by clay–quartz assemblages, with average clay mineral and quartz contents of 44.6% and 38.8%, respectively, and can be subdivided into shallow and semi-deep lacustrine subfacies comprising eight microfacies. Geochemical proxies indicate alternating warm-humid and hot-arid paleoclimatic phases, predominantly freshwater conditions, variable redox states, and fluctuations in paleoproductivity. Sedimentary evolution reveals multiple transgressive–regressive cycles, with Sub-layer 6 recording the maximum water depth and deposition of thick organic-rich shales under strongly reducing conditions. The proposed sedimentary model outlines a terrigenous clastic lacustrine system controlled by lake-level fluctuations, transitioning from littoral to shallow-lake to semi-deep-lake environments. The distribution of high-quality organic-rich shales interbedded with sandstones highlights the LGS2-LS as a favorable interval for shale oil and gas accumulation, providing a geological basis for further hydrocarbon exploration in the southeastern Sichuan Basin. Full article

Background/Objectives: Rutin (RT), a promising bioflavonoid, faces clinical limitations due to its poor solubility and bioavailability. In this study, we formulated RT-loaded phytosome nanoparticles (RT-PNPs) via thin-layer hydration and characterized their morphology, size distribution, and zeta potential. Methods: We established a mouse model of Ehrlich ascites carcinoma (EAC), randomly allocating ninety female Swiss albino mice into six groups: untreated controls, RT-treated, RT-PNP-treated, EAC, EAC + RT, and EAC + RT-PNPs. Tumor induction and treatment protocols were controlled, with the oral administration of 25 mg/kg/day of RT or RT-PNPs for 20 days. We comprehensively assessed survival, body weight, ascitic fluid/tumor volume, and cell viability and performed detailed hematological, serum biochemical, and tumor marker analyses. Multiorgan (liver and kidney) function and redox homeostasis were evaluated through enzymatic assays for SOD, CAT, GSH-Px, and GSH, as well as lipid peroxidation assessment. Proinflammatory cytokines and tumor markers (AFP, CEA, CA19-9, CA125, and CA15-3) were quantified via ELISA. Results: Gene expression profiling (TP53, Bax, and Bcl-2) and flow cytometry (p53 and Ki-67) elucidated the modulation of apoptosis. Histopathological scoring documented organ protection, while advanced multivariate (heatmap and principal component) analyses revealed distinct treatment clusterings. The RT-PNPs demonstrated potent anti-tumor, antioxidant, anti-inflammatory, and apoptosis-inducing effects, outperforming free RT in restoring physiological markers and tissue integrity. Conclusions: The current results underscore the potential of RT-PNPs as a multifaceted therapeutic approach to EAC, leveraging nanoparticle technology to optimize efficacy and systemic protection. Full article

Corrosion inhibitors can form dense, protective layers on metal surfaces, thereby preventing the penetration of corrosive media and ensuring the long-term safety of industrial equipment and energy facilities. Polyaniline (PANI), renowned for its excellent conductivity and redox activity, not only facilitates the formation of passivation layers on metals but also mitigates pitting corrosion. In this study, a novel doped PANI was synthesized through chemical oxidation using cyclic carboxypropyl oleic acid (CCHOA) as a dopant, and its anti-corrosion properties were evaluated by incorporation into epoxy resin coatings. Scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (FTIR) analyses confirmed that CCHOA-doped PANI produced a more uniform and compact microstructure with reduced agglomeration. The corrosion resistance and toughness of the epoxy coatings initially improved with increasing CCHOA content, but then slightly declined, which allowed us to determine the optimal doping level for PANI. The ideal concentration was found to be 0.5 mol/L in the epoxy resin matrix. Full article

Enargite (Cu₃AsS₄), a copper–arsenic sulfosalt, represents a critical challenge in copper mineral processing due to its high arsenic content, which poses significant environmental, metallurgical, and economic issues. Its flotation behavior closely resembles that of other copper sulfides such as chalcopyrite and chalcocite, complicating selective separation at early beneficiation stages. This review presents a comprehensive examination of enargite’s surface chemistry and electrochemical behavior, focusing on the influence of oxidation, pH, and pulp potential on surface reactivity, charge distribution (zeta potential), and hydrophobicity. Detailed insights into the formation of surface oxidation layers, passivation mechanisms, and contact angle variations are provided to elucidate collector-mineral interactions. Advances in selective flotation techniques are also discussed, including the use of depressant reagents, controlled redox environments, and reagent conditioning strategies. Special attention is given to flotation in seawater, where ionic strength and multivalent ions significantly influence mineral-reagent interactions and flotation outcomes. Galvanic interactions between enargite and other sulfide minerals are identified as critical factors affecting floatability and selectivity. The review consolidates findings from recent experimental and electrochemical studies, highlighting promising approaches to enhance enargite rejection and copper concentrate purity. It concludes with perspectives on future research aimed at optimizing flotation processes and developing sustainable solutions for processing arsenic-bearing copper ores. Full article

We developed dye-sensitized solar cells based on anatase–titanium dioxide (A-TiO₂) nanotubes (TiNTs) and nanocubes (TiNcs) with {001} crystal facets generated using simple and facile electrochemical anodization. We also demonstrated a simple way of developing one-dimensional, two-dimensional, and three-dimensional self-assembled TiO₂ nanostructures via electrochemical anodization, using them as an electron-transporting layer in DSSCs. TiNTs maintain tubular arrays for a limited time before becoming nanocrystals with {001} facets. Using FESEM and TEM, we observed that the TiO₂ nanobundles were transformed into nanocubes with {001} facets and lower fluorine concentrations. Optimizing the reaction approach resulted in better-ordered, crystalline anatase TiNTs/Ncs being formed on the Ti metal foil. The anatase phase of as-grown TiO₂ was confirmed by XRD, with (101) being the predominant intensity and preferred orientation. The nanostructured TiO₂ had lattice values of a = 3.77–3.82 and c = 9.42–9.58. The structure and morphology of these as-grown materials were studied to understand the growth process. The photoconversion efficiency and impedance spectra were explored to analyze the performance of the designed DSSCs, employing N719 dye as a sensitizer and the I⁻/I³⁻ redox pair as electrolytes, sandwiched with a Pt counter-electrode. As a result, we found that self-assembled TiNTs/Ncs presented a more effective photoanode in DSSCs than standard TiO₂ (P25). TiNcs (0.5 and 0.25 NH₄F) and P25 achieved the highest power conversion efficiencies of 3.47, 3.41, and 3.25%, respectively. TiNcs photoanodes have lower charge recombination capability and longer electron lifetimes, leading to higher voltage, photocurrent, and photovoltaic performance. These findings show that electrochemical anodization is an effective method for preparing TiNTs/Ncs and developing low-cost, highly efficient DSSCs by fine-tuning photoanode structures and components. Full article

The excessive emission of cadmium (Cd²⁺) poses a serious threat to the aquatic environment due to its high toxicity and bioaccumulation potential. This study constructed three types of vertical-subsurface-flow constructed wetlands configured with iron–carbon–zeolite composite substrates, including an iron–carbon–zeolite constructed wetland (TF-CW), a zeolite–iron–carbon constructed wetland (FT-CW), and an iron–carbon–zeolite mixed constructed wetland (H-CW), to investigate the purification performance and mechanisms of constructed wetlands for cadmium-containing wastewater (0~6 mg/L). The results demonstrated that iron–carbon–zeolite composite substrates significantly enhanced Cd²⁺ removal efficiency (>99%) through synergistic redox-adsorption mechanisms, where the iron–carbon substrate layer dominated Fe-Cd co-precipitation, while the zeolite layer achieved short-term cadmium retention through ion-exchange adsorption. FT-CW exhibited superior NH₄⁺-N removal efficiency (77.66%~92.23%) compared with TF-CW (71.45%~88.05%), while iron–carbon micro-electrolysis effectively inhibited NO₃⁻-N accumulation (<0.1 mg/L). Under cadmium stress, Typha primarily accumulated cadmium through its root systems (>85%) and alleviated oxidative damage by dynamically regulating antioxidative enzyme activity, with the superoxide dismutase (SOD) peak occurring at 3 mg/L Cd²⁺ treatment. Microbial community analysis revealed that iron–carbon substrates promoted the relative abundance of Bacteroidota and Patescibacteria as well as the enrichment of Saccharimonadales, Thauera, and Rhodocyclaceae (genera), enhancing system stability. This study confirms that iron–carbon–zeolite CWs provide an efficient and sustainable technological pathway for heavy metal-contaminated water remediation through multidimensional mechanisms of “chemical immobilization–plant enrichment–microbial metabolism”. Full article

The development of low-cost and high-efficiency oxygen evolution reaction (OER) catalysts is essential to enhance the practicality of electrochemical water splitting for green hydrogen production. Layered double hydroxides (LDHs), especially those based on nickel and cobalt, have attracted attention due to their tunable composition, abundant redox-active sites, and earth-abundant constituents. However, their application is hindered by their limited conductivity and sluggish reaction kinetics. In this study, rare-earth-element-doped NiCo LDHs were synthesized directly on nickel foam through a one-step hydrothermal approach to improve the OER activity by modulating the electronic structure and optimizing the surface morphology. Among the representative catalysts, the incorporation of Sm significantly influenced the microstructure and electronic configuration of the catalyst, as confirmed by X-ray diffraction (XRD), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). Electrochemical tests showed that the optimized Sm-NiCo LDH achieved a low overpotential of 172 mV at 10 mA cm⁻² and a small Tafel slope of 84 mV dec⁻¹ in 1 M KOH, indicating an expanded electrochemically active surface and improved charge transport. Long-term stability tests further showed its durability. These findings suggest that Sm doping enhances the OER performance by increasing active site exposure and promoting efficient charge transfer, offering a promising strategy for designing rare-earth-modified, non-precious-metal-based OER catalysts. Full article

Cement-based batteries (CBBs) are an emerging category of multifunctional materials that combine structural load-bearing capacity with integrated electrochemical energy storage, enabling the development of self-powered infrastructure. Although previous reviews have explored selected aspects of CBB technology, a comprehensive synthesis encompassing system architectures, material strategies, and performance metrics remains insufficient. In this review, CBB systems are categorized into two representative configurations: probe-type galvanic cells and layered monolithic structures. Their structural characteristics and electrochemical behaviors are critically compared. Strategies to enhance performance include improving ionic conductivity through alkaline pore solutions, facilitating electron transport using carbon-based conductive networks, and incorporating redox-active materials such as zinc–manganese dioxide and nickel–iron couples. Early CBB prototypes demonstrated limited energy densities due to high internal resistance and inefficient utilization of active components. Recent advancements in electrode architecture, including nickel-coated carbon fiber meshes and three-dimensional nickel foam scaffolds, have achieved stable rechargeability across multiple cycles with energy densities surpassing 11 Wh/m². These findings demonstrate the practical potential of CBBs for both energy storage and additional functionalities, such as strain sensing enabled by conductive cement matrices. This review establishes a critical basis for future development of CBBs as multifunctional structural components in infrastructure applications. Full article

Films of a Ni/Al-layered double hydroxide intercalated with reduced graphene oxide were deposited, by means of a simple and rapid electrochemical synthesis, on Pt electrodes previously submitted to a special cleaning procedure. The aim of the research was to determine whether the better electrocatalytic properties of the Ni(III)/Ni(II) couple, due to the presence of the carbon nanomaterial, as compared to the Ni/Al-LDH alone, could allow glucose detection at physiological pHs, as normally LDHs work as redox mediators in basic solutions. Chronoamperometric experiments were carried out by applying a potential of 1.0 V vs. SCE to the electrode soaked in solutions buffered at pHs from 5.0 to 9.0 to which glucose was continuously added. The steady-state currents increased as the pH solution increased, but at pH = 7.0 the modified electrode exhibited a fast and rather sensitive response, which was linear up to 10.0 mM glucose, with a sensitivity of 0.56 A M⁻¹ cm⁻² and a limit of detection of 0.05 mM. Our results suggest the potential application of Ni/Al-LDH(ERGO) composite for the non-enzymatic detection of glucose or other oxidizable analytes under biological conditions. Full article