Migration Channels Research Articles

Multiple Sets of Unconformity Migration Capacity and Their Influence on Hydrocarbon Accumulation in the Bozhong Area of the Bohai Bay Basin

ABSTRACTThe Bohai Bay Basin is one of China's largest basins in terms of discovered hydrocarbon reserves. In this basin, unconformities serve as key pathways for the lateral migration of hydrocarbons, with the T8, T5 and T2 unconformities being the main ones developed here. Studying how these three unconformities differ in migration capacity is therefore essential for understanding hydrocarbon accumulation. By using logging data, along with measurements of porosity, permeability and sedimentary facies distribution, we analysed and compared the structures, physical properties and continuity of these unconformities. Based on this analysis, we linked hydrocarbon reserves per unit area to migration probability and developed a model for migration range. The results show that: (1) Although the T8 unconformity has poorer porosity and permeability compared to T5, it provides better continuity for migration channels, making T8 the main pathway in depressions, while T5 is more discontinuous and thus likely to form lithologic reservoirs in these areas. (2) T8 and T5 overlap gradually along the uplift belts, where both the porosity‐permeability and thickness of these unconformities improve, and T2 has both good continuity and physical properties, facilitating lateral migration on the uplift belts. (3) Compared with other unconformities, T2 is the primary migration pathway above the uplift areas.

Cu3.21Bi4.79S9: Bimetal superionic strategy boosts ultrafast dynamics for Na-ion storage/extraction

Traditional metal sulfides used as anodes for sodium-ion batteries are hindered by sluggish kinetics, which limits their rate performance. Previous attempts to address this issue focused on nanostructured configurations with conductive frameworks. However, these nanomaterials often suffer from low packing density and the tendency for nanoparticles to agglomerate, posing significant challenges for practical applications. To overcome these limitations, this study presents a novel bimetal superionic anode material Cu3.21Bi4.79S9, which effectively resolves the conflict between sluggish kinetics and micrometer-scale particle size. By leveraging the vacancies created by free Cu and Bi atoms, this material forms rapid migration channels during sodium insertion and extraction, significantly reducing the migration barriers for sodium ions. The development of micrometer-scale Cu3.21Bi4.79S9 enables ultrafast charging-discharging capabilities, achieving a reversible capacity of 325.5 mAh g−1 after 4000 cycles at a high rate of 45 C (15 A g−1). This work marks a significant advancement in the field by offering a solution to the inherent trade-off between high capacity and rate performance in coarse-grained materials, reducing the need for reliance on nanostructured configurations for next-generation high-capacity anode materials.

The Role of Ion-Polaron Electrostatic Attraction on Zn2+ Migration in α-V2O5 for Zinc Ion Battery: Insights from First-Principles Calculations.

The migration of Zn2+ ions is significantly more challenging compared to that of Li+ ions within the same crystalline framework, leading to poor rate performance of zinc-ion batteries (ZIBs). Compared to Li+, the slower migration rate of Zn2+ is vaguely attributed to the stronger electrostatic interaction induced by Zn2+. Herein, the rule of how the size of the migration channel and electrostatic interaction affect Zn2+ and Li+ migration in α-V2O5 has been systematically investigated by first-principle calculations. It is found that expanding the layer spacing can facilitate Zn2+ migration. Once the layer spacing surpasses a certain threshold, further expansion does not lead to a continued reduction in the migration barrier. The local structure distortions caused by electron small polarons would lead to a decrease in migration channel size, which should have increased the energy barrier for Li+ and Zn2+ migration. However, interestingly, the electron small polarons decrease the energy barriers, which would be attributed to the ion-polaron electrostatic attraction. The higher activation barriers for the migration of Zn2+ ions compared to those of Li+ ions can be rationalized by the specific ion-polaron electrostatic attraction for Zn2+. Moreover, the comparative strength of the polaron-ion electrostatic attraction for alkali and alkaline earth metal ions is unveiled. Overall, this study provides theoretical insights into the role of ion-polaron electrostatic attraction on ion migration.

Inhibiting ion migration in strontium-lead halide perovskite for pure-blue emission: a first-principle and experimental study.

Bromide-chloride mixed perovskites have garnered significant attention as a direct and efficient material for achieving pure-blue emission. However, the complex problem of halide migration in mixed halide perovskites presents a significant obstacle to achieving stable electroluminescence (EL) spectra. Here, we investigate the mechanism of partially replacing the B-site Pb2+ with the non-toxic Sr2+ to achieve pure-blue emission based on first principles. The ion mobility activation energy of Sr2+ is 1.23 eV, which is an order of magnitude greater than that of halogens. Meanwhile, the incorporation of Sr2+ triples the activation energy for halogen migration. Furthermore, the halide defect formation energy increases from 4.75 eV to 5.62 eV, thereby reducing ion migration channels. Transient absorption spectroscopy demonstrates that suppressing the ion mobility pathway and enhancing ion mobility activation energy promotes the perovskite film to exhibit excellent spectral stability under laser pumping. Our work provides insights for the development of highly stable and eco-friendly perovskite devices.

Identification of gas outburst precursors based on outburst percolation theory

Uniaxial compression experiments were conducted on coal rock utilizing a computed tomography (CT) scanning system for real-time monitoring to explain the issue of gas volume significantly exceeding reservoir capacity during coal and gas outbursts. A percolation factor a which can make a significant contribution to the research on premonitory information of gas outbursts is introduced to determine whether percolation occurs in coal rock, and supports the outburst percolation theory. It was found that percolation probability and correlation length increase with greater porosity, and that the number of pore clusters decreases as porosity increases. All three parameters exhibit explosive increases or decreases before the porosity reaches the percolation threshold. The percolation threshold for the coal varies at different stress levels; as the coal approaches its stress limit, the percolation threshold decreases, making percolation transformation more likely to occur and increasing the risk of a coal and gas outburst. When a > 1, percolation transformation occurs within the coal, and large-scale gas migration channels are formed. This stage completes the latent phase of the outburst, significantly elevating the likelihood of an outburst incident. This approach establishes quantitative relationships between porosity and various percolation parameters at different stress levels. It contributes to the research on precursory information of coal and gas outbursts.

High-Voltage-Resistant Highly Stable Solid Polymer Electrolyte via In Situ Integrated Construction with Fast Ion Migration.

Electric aircraft such as electric aircraft and electric vehicles play a key role in the future electric aviation industry, but they put forward huge requirements for battery energy density. However, the current high-energy-density lithium battery technology still needs to be broken through. Herein, through the molecular structure design of the polymer electrolyte, a strategy of a fast migration channel and wide electrochemical window is proposed to fabricate high-voltage-resistant solid polymer electrolyte (HVPE) via in situ polymerization. Thus, HVPE exhibits an ultrahigh Li+ transfer number (tLi+) of 0.92 and an excellent electrochemical window of 5.1 V to match with a high-voltage lithium cobalt oxide (LCO) cathode. This fast conduction of Li+ allows for stable and uniform lithium plating and stripping deposition for more than 1000 h, which also reveals a well-defined dual interfacial stabilization mechanism. These results endow the assembled LCO|HVPE|Li cell cycles steadily for 500 cycles at 4.5 V and 0.5C with a superior capacity retention of 89.93%. Moreover, the assembled LCO|HVPE|Li pouch cell exhibits a capacity retention rate of up to 94.01% after 50 cycles. More importantly, our proposed HVPE provides new insights into structural design and fabrication strategies for high-energy-density solid-state polymer batteries.

Deep hydrocarbon charging and accumulation in complex fault blocks, the northern part of the eastern Liaohe depression, China

Deep exploration in complex fault-block regions is critical for global oil and gas development. As a representative region characterized by complex fault-block development, the northern part of the eastern Liaohe depression poses challenges in understanding the charging time and migration channels of deep hydrocarbons due to its intricate structural and reservoir conditions. For this purpose, this study utilizes diverse geological data from recent explorations, employing the petrological characteristics of inclusions, homogenization temperatures, and simulations of the thermal burial history to investigate the charging times of deep hydrocarbons. It combines the diagenetic processes of the reservoir with tectonic evolution to reveal the charging pathways and dynamic processes of deep hydrocarbons in the northern part of the eastern Liaohe depression. The results indicate that there are two charging periods in the study area: the late Oligocene (32.9–27.5 Ma) and from the late Neogene to the present (8.7–0 Ma). During these critical periods, faults with high activity intensity and low fault section normal stress were in an open state, which can serve as pathways for the vertical long-distance migration of hydrocarbons. In the first charging period, a substantial volume of hydrocarbon expelled from the source rocks migrates vertically into the deep sandstone reservoir through opening faults, exhibiting characteristics of source–reservoir separation. Subsequently, a brief uplift at the end of the Oligocene halted hydrocarbon generation. In the second charging period, as the source rocks further matured, a substantial volume of natural gas was injected into the deep reservoirs. At this period, the faults approached the seal, preventing hydrocarbons from migrating vertically and allowing them to enter the deep sandstone reservoirs adjacent to the source rocks, reflecting characteristics of source–reservoir proximity.

Understanding the Unique Reactivity of Cu for Electrochemical CO2 Reduction with a 3-Site Model.

Cu-based catalysts for the electrochemical reduction of CO2 and CO exhibit a perplexingly unique reactivity toward multicarbon based products compared to other studied electrocatalysts. Here we use insights gained from a recent phenomenological 3-site microkinetic model and grand-canonical density functional theory calculations to clarify the importance of an underemphasized aspect critical to Cu's unique reactivity: a population of so-called "reservoir" sites. Using model Cu surface motifs, we discuss how these types can be represented by undercoordinated structural defects like step edges and grain boundaries which form a network of highly anisotropic migration channels. These pathways are found to be amenable for feeding *CO over time to reactive sites like Cu adatoms more active toward C-C coupling. These results highlight an often overlooked aspect of catalyst optimization: reservoir site engineering, which exploits surface mobility and presents an equally important avenue for electrocatalyst engineering oversimply maximizing active site densities.

Effect of Stress Aging on Strength, Toughness and Corrosion Resistance of Al-10Zn-3Mg-3Cu Alloy.

The 7000 series aluminum alloy represented by Al-Zn-Mg-Cu has good strength and toughness and is widely used in the aerospace field. However, its high Zn content results in poor corrosion resistance, limiting its application in other fields. In order to achieve the synergistic improvement of both strength and corrosion resistance, this study examines the response of strength, toughness and corrosion resistance of a high-strength aluminum alloy tail frame under aging conditions with external stresses of 135 MPa, 270 MPa and 450 MPa. The results show that with the increase in the external stress level, the strength of the alloy improves, while its corrosion resistance decreases. An optimal balance of strength, toughness and corrosion resistance is achieved at the conditions of 270 MPa-120-24 h. This phenomenon can be attributed to two main factors: first, lattice defects such as vacancy and dislocation are introduced into the stress aging process. The introduction of a vacancy makes it easier for neighboring solute atoms to migrate there. This makes the crystal precipitates more dispersed. Also, the number of precipitates in the matrix increases from 2650 to 3117, and the size is refined from 2.96 nm to 2.64 nm. At the same time, the dislocation entanglement within the crystal structure promotes the dislocation strengthening mechanism and promotes the solute atoms to have enough channels for migration. Since too many dislocations can cause the crystal to become brittle and thus reduce its strength, entangled dislocations hinder the movement of the dislocations, thereby increasing the strength of the alloy. Secondly, under the action of external force, the precipitated phase is discontinuous, which hinders the corrosion expansion at the grain boundary, thus improving the corrosion resistance of the alloy. At low-stress states, the binding force of vacancy is stronger, the precipitation free zone (PFZ) is significantly inhibited, and the intermittent distribution effect of intergranular precipitates is the most obvious. As a result, the self-corrosion current decreases from 1.508 × 10-4 A∙cm-2 in the non-stress state to 1.999 × 10-5 A∙cm-2, representing an order of magnitude improvement. Additionally, the maximum depth of intergranular corrosion is reduced from 274.9 μm in the non-stress state to 237.7 μm.

A surface engineering strategy for the stabilization of zinc metal anodes with montmorillonite layers toward long-life rechargeable aqueous zinc ion batteries

Rechargeable aqueous zinc-ion batteries (AZIBs) exhibit appreciable potential in the domain of electrochemical energy storage. However, there are serious challenges for AZIBs, for instance zinc dendrite growth, hydrogen evolution reaction (HER), and corrosion side reactions. Herein, we propose a surface engineering modification strategy for coating the montmorillonite (MMT) layer onto the surface of the Zn anode to tackle these issues, thereby achieving high cycling stability for rechargeable AZIBs. The results reveal that the MMT layer on the surface of the Zn anode is able to provide ordered zincophilic channels for zinc ions migration, facilitating the reaction kinetics of zinc ions. Density functional theory (DFT) calculations and water contact angle (CA) tests prove that MMT@Zn anode exhibits superior adsorption capacity for Zn2+ and better hydrophobicity than the bare Zn anode, thereby achieving excellent cycling stability. Moreover, the MMT@Zn||MMT@Zn symmetric cell holds the stable cycling over 5600 h at 0.5 mA cm−2 and 0.125 mA h cm−2, even exceeding 1800 h long cycling under harsh conditions of 5 mA cm−2 and 1.25 mA h cm−2. The MMT@Zn||V2O5 full cell reaches over 3000 cycles at 2 A g−1 with excellent rate capability. Therefore, this surface engineering modification strategy for enhancing the electrochemical performance of AZIBs represents a promising application.

Cationic chitosan enables eutectogels with high ionic conductivity for multifunctional applications in energy harvesting and storage

Eutectogels are popular as an emerging material in the field of flexible electronics. However, limited mechanical properties and ionic conductivity restrict their multifunctional application expansion. Herein, cationic chitosan quaternary ammonium salt (CQS) was evenly embedded into the three-dimensional porous framework of eutectogel to build ion migration channels. And a simple solvent replacement process enhanced the crystallization of polyvinyl alcohol matrix and hydrogen bonding, preparing composite eutectogels with high toughness, environmental tolerance and conductivity. The prepared gel exhibites excellent mechanical properties (1.72 MPa, 413 %) and conductivity (0.40 S·m−1). Under external force, three-dimensional porous network with cationic polysaccharide distribution can achieve effective piezoionic effect. Moderate CQS significantly enhances the piezoionic voltage output to 270 mV, which is 4.5 times that of the pure eutectogel. Further, the prepared composite eutectogels was used for capacitor energy storage and wearable sensing devices, and has good charge/discharge stability (94 % capacitance retention) and fast response time (292 ms). This design is typically suitable for preparing advanced multifunctional ion conductors using various natural polysaccharides with sustainable application potential.

EU‒Africa Relations: Migration Diplomacy Approach

The article offers a fresh insight into the relations between the European Union and Africa from “migration diplomacy” perspective which is being introduced in migration and international relations research in Russia. The author notes the explanatory and predictive potential of the “migration diplomacy” concept for considering the complex relations between states within different migration systems. The analysis of interactions and cooperation of the EU, as a receiving side, with the states of origin and transit of international migrants in Africa allowed to highlight the specifics of the EU approach. The latter consists in using various diplomatic means and formats to address the problem of illegal immigration and reducing the number of asylum seekers in the EU. The increasing dependence of the European Union on cooperation with third countries results in the use of migration as a tool of political pressure by partner states. Intracontinental migration processes are at the centre of the migration diplomacy of the African continent, including those related to freedom of movement. Despite the differences in the approaches of the parties, the potential for cooperation lies in the development of channels for legal labour migration.

Новые направления трудовой миграции из Таджикистана: на примере Великобритании

Introduction. Tajikistan is one of the few countries in the world whose state budget is largely based on tax revenues from remittances from citizens working abroad. The deterioration of the economic situation in Russia has forced migrants to look for a new direction of labor migration. In particular, the Government of Tajikistan itself is interested in reorienting migrants to a new direction. In 2021, Tajikistan signed an employment agreement with the United Kingdom (UK) and the Republic of Korea to send seasonal migrants. Goals. The article aims to identify the prospects and trends in the development of labor emigration from Tajikistan to the UK, as well as the features and channels of seasonal migration from Tajikistan to the UK. Materials and methods. In this study, statistical and sociological research methods are used. The statistics includes numbers of seasonal migrants from Tajikistan for a variety of years. A content analysis of interviews with labor migrants to the UK has been conducted. The analytical method includes systematization of the materials of recruitment agencies’ websites and bilateral agreements of the Republic of Tajikistan with foreign countries. The data are provided by the Agency on Statistics under the President of the Republic of Tajikistan, the National Statistical Service of Great Britain, World Bank, International Organization for Migration (IOM). Currently, the Agency on Statistics under the President of the Republic of Tajikistan has information on the unemployment rate in the country, the economically active population, as well as the number of Tajik migrants until 2021, the World Bank provides data until 2021. Data on the number of seasonal migrants and the structure of labor migration from Tajikistan at the end of 2022 are published in annual or quarterly sections and posted on the official website of the National Statistical Service of the UK. Results. The UK, which needs cheap labor for agriculture, after BREXIT was forced to expand the geography of attracting labor. In addition to the traditional region of hiring seasonal workers — Eastern European countries (Poland, Baltic states, Bulgaria), labor resources began to be actively attracted from Central Asian countries, including Tajikistan. The main factor in attracting migrants from Tajikistan to the UK is the shortage of labor in the country’s labor market after leaving the EU. The main reasons for the reorientation of Tajik migrants from the Russian labor market to the UK are as follows: economic crises in Russia; tightening of migration policy towards Tajik migrants; the spread of English among the youth of Tajikistan, etc. Migration of low-skilled citizens of Tajikistan began in the second quarter of 2021. The main type of migration from Tajikistan to the UK are seasonal migration. The main channel of emigration from Tajikistan to the UK are public and private recruitment agencies. The main one from the bottom is the state institution — Center for Counseling and Pre-Departure Training of Migrant Workers.

Ion Migration at Metal Halide Perovskite Grain Boundaries Elucidated with a Machine Learning Force Field.

Metal halide perovskites are promising optoelectronic materials with excellent defect tolerance in carrier recombination, believed to arise largely from their unique soft lattices. However, weak lattice interactions also promote ion migration, leading to serious stability issues. Grain boundaries (GBs) have been experimentally identified as the primary migration channels, but the relevant mechanism remains elusive. Using molecular dynamics with a machine learning force field, we directly model ion migration at a common CsPbBr3 GB. We demonstrate that the as-built GB model, containing 6400 atoms, experiences structural reconstruction over several nanoseconds, and only Br atoms diffuse after that. A fraction of Br atoms near the GB either migrate toward the GB center or along the GB through different migration channels. Increasing the temperature not only accelerates the ion migration via the Arrhenius activation but also allows more Br atoms to migrate. The activation energies are much lower at the GB than in the bulk due to large-scale structural distortions and favorable non-stoichiometric local environments available at GBs. Making the local GB composition more stoichiometric by doping or annealing can suppress the ion migration. The reported results provide valuable atomistic insights into the GB properties and ion migration in metal halide perovskites.

VN Quantum Dots Anchored onto Carbon Nanofibers as a Superior Anode for Sodium Ion Storage.

Vanadium-based compounds exhibit a high theoretical capacity to be used as anode materials in sodium-ion batteries, but the volume change in the active ions during the process of release leads to structural instability during the cycle. The structure of carbon nanofibers is stable, while it is difficult to deform. At the same time, the huge specific surface area energy of quantum dot materials can speed up the electrochemical reaction rate. Here, we coupled quantum-grade VN nanodots with carbon nanofibers. The strong coupling of VN quantum dots and carbon nanofibers makes the material have a network structure of interwoven nanofibers. Secondly, the carbon skeleton provides a three-dimensional channel for the rapid migration of sodium ions, and the material has low charge transfer resistance, which promotes the diffusion, intercalation and release of sodium ions, and significantly improves the electrochemical activity of sodium storage. When the material is used as the anode material in sodium ion batteries, the specific capacity is stable at 230.3 mAh g-1 after 500 cycles at 0.5 A g-1, and the specific capacity is still maintained at 154.7 mAh g-1 after 1000 cycles at 2 A g-1.

A Study on the Accurate Equation Inversion Method for Uncoupled Interface Parameters of OA Media Considering Initial Stress

Underground media are generally affected by the initial stress of the overlying strata. At the same time, the uncoupled interface is an important influencing factor of seismic response, as well as an essential reservoir environment, reservoir space, and migration channel. It is significant to explore the parameters of the uncoupled interface under stress for identifying oil and gas reservoirs. As an effective means of predicting reservoir physical parameters, pre-stack seismic inversion uses information on uncoupled interface fractures under stress to improve the accuracy of reservoir parameter prediction, overcome the problem of insufficient interface parameter prediction methods, and promote oil and gas reservoir exploration and development. Based on the precise equations for directly characterizing uncoupled interface fracture weakness parameters, this paper uses the ANNI inversion method to realize the nonlinear inversion method of uncoupled interface fracture parameters. The feasibility and practicability of predicting underground medium parameters from seismic response characteristics have been verified through model testing and actual work area application.

Hydrogeochemical characteristics and evolution of formation water in the continental sedimentary basin: A case study in the Qaidam Basin, China.

In deep formations, oil or gas reservoir rocks are generally accompanied by groundwater with high total dissolved solids (TDS), commonly referred to as "formation water". The enrichment of trace and/or metallic elements such as K, B, Li, Br, Sr in this type of groundwater holds significant industrial values and socioeconomic benefits. However, the processes involved in the burial and generation of formation water remain not fully understood. In this study, totally 468 sets of major ions and trace elements were collected from current study and literatures to investigate the hydrogeochemical characteristics and evolution mechanisms of formation water from different regional geological structure units in Qaidam Basin, China. The results indicated that TDS of formation water in Western (QW), Central (QC) and Northern (QN) units of Qaidam basin ranged from 173 to 290g/L, 101 to 152g/L and 32 to 73g/L, respectively, which were several to dozens of times higher than those of seawater, but lower than those of intercrystalline brine and salt lake water. The enrichment of Ca, Li, B, Br and depletion of Mg and SO42- were observed in the formation water in comparison to seawater and salt lake water. Formation water especially in QC and QW was identified as typical dissolved brine of terrestrial rock origin, experiencing prolonged water-rock interactions. However, the time and degree of water-rock interaction and metamorphism differed regionally due to the sedimentary history and patterns of Qaidam Paleolake. Overall, the large paleolake deposits under the control of multiple tectonic movements laid the material foundation for the burial and generation of the formation water, and a variety of fluids and deep faults became the sources and migration channels for formation water. It mainly experienced two stages, including the sedimentary process of saline strata and the transformation in the later period.

Tackling Modern Slavery or Worsening Vulnerability? UK’s Modern Slavery Agenda in Nigeria

Nigeria is said to be one of the largest source countries for victims of modern slavery in the UK (Throughout this paper, I use the terms ‘modern slavery’, ‘slavery’ and ‘human trafficking’ loosely and interchangeably to refer to extreme exploitation as often described in many international documents as well as in the UK’s MSA which is the focus of this paper). Thus, the UK government has often lauded its partnership with the Nigerian government in tackling the problem of modern slavery, often presented as a problem of irregular migration. At the same time, legal migration channels into the UK are increasingly being tightened, and Nigerians are among those who suffer the consequences of such. This paper reviews the UK government policies, partnerships and activities in Nigeria in the light of the Modern Slavery Act. It argues that the emphasis on deterring migration and sex trafficking has meant that the UK government agenda is being promoted to the detriment of key structural factors contributing to other dimensions of vulnerability and exploitation in Nigeria.

Evaluation of innovative drying technologies in Gardenia jasminoides Ellis drying considering product quality and drying efficiency

Gardenia jasminoides Ellis is widely used as healthy food and herbal medicine for its anti-inflammatory, analgesic, antihypertensive, and antiviral functions. The drying behavior and physicochemical quality of Gardenia jasminoides Ellis were studied to evaluate its adaptability under four drying techniques: hot air drying (HAD), medium-and short-wave infrared drying (MSWID), pulsed vacuum drying (PVD), and radio frequency-HAD (RF-HAD). Compared with HAD and MSWID, PVD and RF-HAD can form beneficial microporous channels for moisture migration inside Gardenia jasminoides Ellis, thus shortening drying time by 32.56–42.51 % and increasing geniposide content by 3.31–13.77 %, while better preserving the brightness and redness. In addition, Pearson correlation analysis confirmed the RF-HAD dried samples showed the best antioxidant activity with the highest content of active ingredients (chlorogenic acid, geniposide), and there was a significant positive correlation between sample color and yellow pigment content. After comprehensive comparison, RF-HAD is proposed to be the most suitable method for Gardenia jasminoides Ellis drying. This research could provide scientific basis and technical support for promoting the high quality development of industrial processing of Gardenia jasminoides Ellis.

Revealing multi-level shortrange migration of electrons on full-spectrum response e-LDH/t-BiOCl/Bi2S3 and their essential role in the detoxification of Cr(VI) and refractory organic pollutants

The toxic dyeing wastewater containing both carcinogenic Cr(VI) and refractory dyes poses serious threats to ecological safety and human health. Herein, a novel composite photocatalytic material e-LDH/t-BiOCl/Bi2S3 with an ultrathin sandwich structure constructed achieves removal rate constants of 0.044 and 0.019 min−1 for Cr(VI) and reactive red 2 by adsorption-photocatalysis synergistic mechanism in full-spectrum illumination. This structure employs the interface conditions and built-in electric field to form multilevel short-range charge migration channel, achieving the targeted reduction and oxidation of Cr(VI) and azoxy dyes by electrons (e−) and holes (h+). Besides facilitating the reduction of Cr(VI), e− can also enhance the effective utilization of h+ and mediate the formation of other reactive oxygen species that target RR2 degradation. The degradation mechanism, pathway, and biological toxicity of RR2 single and Cr(VI)/RR2 coexistence reaction system were discussed by DFT calculation, LC-MS characterization, and T.E.S.T. evaluation. Moreover, we further investigated the photocatalytic activity and cost-effectiveness of the e-LDH/t-BiOCl/Bi2S3 system under continuous flow and real water settings, and determined the primary water quality parameters that influence photocatalytic performance. This work establishes a new concept for the rational design of robust ternary heterostructure photocatalysts with desirable morphology and competitive performance for photocatalytic applications.