Production Rate Research Articles

Unbiased photoelectrochemical H2O2 coupled to H2 production via dual Sb2S3-based photoelectrodes with ultralow onset potential.

The productions of hydrogen peroxide (H2O2) and hydrogen (H2) in a photoelectrochemical (PEC) water splitting cell suffer from an onset potential that limits solar conversion efficiencies. The formation of H2O2 through two-electron PEC water oxidation reaction competes with four-electron oxidation evolution reaction. Herein, we developed the surface selenium doped antimony trisulfide photoelectrode with the integrated ruthenium cocatalyst (Ru/Sb2(S,Se)3) to achieve the low onset potential and high Faraday efficiency (FE) for selective H2O2 production. The photoanode exhibits an average FE of 85% in the potential range of 0.4-1.6 VRHE and the H2O2 yield of 1.01 μmol cm-2 min-1 at 1.6 VRHE, especially at low potentials of 0.1-0.55 VRHE with 80.4% FE. Impressively, an unassisted PEC system that employs light and electrolyte was constructed to simultaneously produce H2O2 and H2 production on bothRu/Sb2(S,Se)3photoanode and the Pt/TiO2/Sb2S3photocathode. The integrated system enables the average PEC H2O2 production rate of 0.637 μmol cm-2 min-1 without applying any addition bias. This is the first demonstration that Sb2S3-based photoelectrodes exhibit H2O2/H2 two-side production with a strict key factor of the system, which represents its powerful platform to achieve high efficiency and productivity and the feasibility to facilitate value-added products in neutral conditions.

Scaling the polymerization of polyaldehydes through continuous flow synthesis

AbstractA plug flow reactor was constructed to scale the synthesis of metastable, phthalaldehyde-based polymers to achieve production rates of 1–2 kg per day. The flow-induced mixing and in-line polymerization quench and precipitation sequences resulted in improved polymer purity and long-term stability compared to the same materials made from a conventional batch process. Cryogenic rheology was used to probe the complex fluid dynamics encountered during the polymerization of PPA homopolymers. It is envisioned that this continuous flow manufacturing approach could be extended to other low ceiling temperature or aldehyde monomer systems to help implement and support a plastic circular economy. Graphical abstract

Stable production of hydrogen peroxide over zinc oxide @ zeolitic imidazolate Framework-8 composite catalysts

A promising method of producing hydrogen peroxide (H2O2) is the electrochemical two-electron water oxidation reaction (2e− WOR). In this process, it is important to design electrocatalysts that are both earth abundant and environmentally friendly, as well as offering high stability and production rates. The research of WOR catalysts, such as the extensively used transition metal oxides, is mainly focused on the modification of transition metal elements. Few studies pay attention to the protective heterostructure of metal oxides. Here, we demonstrate for the first time an organometallic skeleton protection strategy to develop highly stable WOR catalysts for H2O2 generation. Unlike the pure ZnO and zeolite imidazole framework-8 (ZIF-8) catalysts, ZnO@ZIF-8 enabled the production of hydrogen peroxide at high voltages. The experimental results demonstrate that the ZnO@ZIF-8 catalyst stably generates H2O2 even under a high voltage of 3.0 V vs. RHE, with a yield reaching 2845.819 μmolmin−1 g−1. ZnO@ZIF-8 shows a relatively low overpotential, with a current density of 10 mA cm−2 and an overpotential of 110 mV. The ZnO@ZIF-8 catalyst’s maximal FE value was 4.72 %. Moreover, the ZnO@ZIF-8 catalyst exhibits remarkable durability even after an extended 60-hour stability test. Operando Raman and theoretic calculation analyses reveal that the metal–organic skeleton being encapsulated on the metal oxide surface synergizes with each other, not only expanding the electrochemical surface area, but also adjusting the catalyst metal sites’ adsorption capacity. A novel approach to the modification of 2e− WOR metal oxide catalyst is presented in this work.

Life-cycle production optimization with nonlinear constraints using a least-squares support-vector regression proxy

When nonlinear constraints such as field liquid or water production rate, injection pressures, etc., as functions of time need to be honored in addition to linear ones, the life-cycle production optimization problem, a component of a closed loop reservoir management, becomes challenging and computationally expensive to perform using a high-fidelity reservoir simulator with the existing gradient-based methods using the adjoint or stochastic approximate gradient methods. Therefore, the objective of this study is to present computationally efficient methods for deterministic production optimization under nonlinear constraints using a kernel-based machine learning method where the cost function is the net present value (NPV). We use the least-squares support-vector regression (LSSVR) to approximate the NPV function. To achieve computational efficiency, we generate a set of output values of the NPV and nonlinear constraint functions, which are field liquid production rate (FLPR) and water production rate (FWPR) in this study, by running the high-fidelity simulator for a broad set of input design variables (well controls) and then using the collection of input/output data to train LSSVR proxy models to replace the high-fidelity simulator to compute NPV and nonlinear state constraint functions during iterations of sequential quadratic programming (SQP). To obtain improved (higher) estimated optimal NPV values, we use the existing so-called iterative sampling refinement (ISR) method to update the LSSVR proxy so that the updated proxy remains predictive toward promising regions of search space during the optimization. Direct and indirect ways of constructing LSSVR-based NPVs as well as different combinations of input data, including nonlinear state constraints and/or the bottomhole pressures (BHPs) and water injection rates, are tested as alternative feature spaces. The results obtained from our proposed LSSVR-based optimization methods are compared with those obtained from our in-house stochastic simplex approximate gradient (StoSAG)-based line-search SQP programming (LS-SQP-StoSAG) algorithm that uses directly a high-fidelity simulator to compute the gradients of the objective function and the nonlinear state functions with StoSAG for the Brugge reservoir model. The results show that nonlinear constrained optimization with the LSSVR ISR with SQP is computationally 3.25 fold more efficient than LS-SQP-StoSAG. In addition, the results show that constructing NPV indirectly using the field liquid and water rates for a waterflooding problem where inputs come from LSSVR proxies of the nonlinear state constraints requires significantly fewer training samples than the method constructing NPV directly from the NPVs computed from a high-fidelity simulator. LSSVR has advantages for its computational efficiency which is the main goal in our research, and robustness against overfitting especially for the cases where we have limited data. However, DNNs and random forest require large training size and require much more computational resources and longer training times. Also, Random Forests and Gradient Boosting Machines can be prone to overfitting and become computationally intensive.

Integrated study on CO2 enhanced oil recovery and geological storage in tight oil reservoirs

Carbon utilization, and sequestration (CUS) in tight oil reservoirs stands as a pivotal strategy for enhancing oil recovery and mitigating CO2 emissions. Research on CUS mainly focuses on the calculation of overall displacement efficiency and the total sequestration amount. However, the primary control and sequestration mechanisms throughout the life cycle of CUS, as well as the contribution of each mechanism at different development stages and under various injection and production parameters, are not clear, which limits effective guidance for oilfield development. Therefore, this paper studies the entire life cycle of tight oil reservoirs, from water flooding to CO2 flooding and CO2 sequestration after reservoir abandonment. The contribution degree changes of dissolution, structural, residual gas and mineralized sequestration mechanisms during the whole life cycle are analyzed. The results show that the main sequestration mechanism during CO2 flooding stage and injection sequestration stage after shutting down production wells is structural sequestration, which accounts for 84.75%. In the 2000 years following the cessation of CO2 injection, the proportion of structural sequestration gradually decreases, with a cumulative decrease of 12.41%, and it is mainly converted to the other three sequestration modes, with the largest increase in mineralization sequestration, reaching 8.81%, mainly due to the reaction of dicalcium silicate with CO2 to produce more stable calcite. When the injection pressure was increased from 23 MPa to 44 MPa, the sequestration efficiency increased by 18.45%. An interesting finding is that the solubility of CO2 in water in the target reservoir reaches its lowest point at 80 °C, and both warming and cooling at this point are conducive to the dissolution and sequestration of CO2. The initial pH value of formation water mainly affects mineralization and sequestration. The rate of calcite production and the contribution of CO2 dissolution and sequestration are positively correlated with water saturation. The findings underscore the importance of understanding dynamic contributions of various sequestration mechanisms and optimizing conditions to enhance CO2 sequestration efficiency.

Thienyl-fused dibenzothiophene-S,S-dioxide based conjugated polymer toward highly efficient photocatalytic hydrogen production

Dibenzothiophene-S,S-dioxide (BTDO) is one of the cutting-edge electron-acceptor monomers for designing conjugated polymer based organic materials toward photocatalytic H2 production from water. Normally, structure design of BTDO containing donor-acceptor (D-A) polymer photocatalyst mainly focuses on screening electron-donor motifs, the importance of modification on BTDO molecular toward improving charge carrier separation and photocatalytic performance is always ignored. Herein, a novel thienyl-fused BTDO building block (BTDO-DT) is prepared and utilized to synthesize B-BTDO-DT polymer photocatalyst by Sonogashira-Hagihara cross-coupling polycondensation using 1,4-Diethynylbenzene (B) and BTDO-DT as monomers. Experimental and density functional theory (DFT) calculation results demonstrate that modification of BTDO by thiophene not only enlarges light absorption region and promotes photogenerated e−/h+ separation, but also decreases H atom adsorption free energy (ΔGH*) on oxygen atom in the OSO group. As a result, B-BTDO-DT exhibits an outstanding visible light induced photocatalytic H2 production rate of 156.6 μmol h−1 using 30 mg catalyst without Pt cocatalyst, which is 4.5 times higher than that of B-BTDO. And the H2 production rate of B-BTDO-DT is further improved to be 259.8 μmol h−1 with 2.0 wt% Pt as co-catalyst. The present work may open a new direction for the design of conjugated polymer based photocatalysts with high photocatalytic activities.

Fluence measurement of monoenergetic neutrons from D(d,n) and T(d,n) reactions at the KRISS

A Cockcroft–Walton accelerator from High Voltage Engineering Europa BV was installed at the Korea Research Institute of Standards and Science in June 2022 to generate monoenergetic neutron fields. In this study, the fluences of monoenergetic neutron fields with energy peaks at 2.5, 2.8, and 3.2 MeV from the D(d,n) reaction and at 14.8 MeV from the T(d,n) reaction were measured. To measure neutron fluence, Bonner spheres with diameters of 17.78, 20.32, and 25.40 cm were placed at a distance of 1.50 m from the target. Additionally, a small size long counter was used separately as a neutron reference detector to monitor the stability of neutron production rate. For a deuteron beam current of 1 μA, the neutron fluences of monoenergetic neutron fields with energy peak at 2.5, 2.8, 3.2, and 14.8 MeV were determined to be 0.71 ± 0.03, 1.10 ± 0.04, 13.9 ± 0.5, and 258.0 ± 8.1 cm−2s−1μA−1, respectively.

Numerical investigation of soot formation in methane/n-heptane laminar diffusion flame doped with hydrogen at elevated pressure

The addition of hydrogen in a dual-fuel mode based on natural gas and diesel offers great potential for improving engine efficiency and reducing emissions. Therefore, detailed numerical simulations have been used to explore the effects of soot formation characteristics of natural gas-diesel dual-fuel engines doped by hydrogen at elevated pressure. Numerical simulations are compared with available experimental data, the effects of H2 addition on soot formation in laminar CH4 + n-heptane, H2 + CH4 + n-heptane, FH2 + CH4 + n-heptane diffusion flames at 2, 4, 6 and 8 atm are simulated, FH2 is added to separate the H2 chemical effects. The results show that the dilution and thermal effects of H2 inhibit soot formation, while the chemical effects of H2 promote soot formation under different pressures. The addition of H2 increases the concentration of H and OH radicals, which promotes the formation of C2H2 and benzene (A1). By simplifying the reaction path and analyzing the production rate of A1, the mechanism of H2 addition to promote A1 formation is illustrated. The concentrations of polycyclic aromatic hydrocarbon (PAH) pyrene (A4), benzo(ghi)fluoranthene (BGHIF) and benzo(a)pyrene (BAPYR) are inhibited at higher pressures that result in lower inception and condensation rates. Therefore, the increase of hydrogen abstraction acetylene addition (HACA) rate is the main reason for the increase of soot formation under chemical effects. While the O2 oxidation rate decreases and the OH oxidation rate increases, that is due to the decrease of O2 concentration and the increase of OH concentration in the soot formation area under chemical effects.

Oxygen-bridged Schottky junction in ZnO–Ni3ZnC0.7 promotes photocatalytic reduction of CO2 to CO: Steering charge flow and modulating electron density of active sites

Developing carbon dioxide (CO2) photocatalysts from transition metal carbides (TMCs) with abundant active sites, modulable electron cloud density, as well as low cost and high stability is of great significance for artificial photosynthesis. Building an efficient electron transfer channel between the photo-excitation site and the reaction-active site to extract and steer photo-induced electron flow is necessary but challenging for the highly selective conversion of CO2. In this study, we achieved an oxygen-bridged Schottky junction between ZnO and Ni3ZnC0.7 (denoted as Znoxide–O–ZnTMC) through a ligand-vacancy strategy of MOF. The ZnO–Ni3ZnC0.7 heterostructure integrates the photo-exciter (ZnO), high-speed electron transport channel (Znoxide–O–ZnTMC), and reaction-active species (Ni3ZnC0.7), where Znoxide–O–ZnTMC facilitates the transfer of excited electrons in ZnO to Ni3ZnC0.7. The Zn atoms in Ni3ZnC0.7 serve as electron-rich active sites, regulating the CO2 adsorption energy, promoting the transformation of *COOH to CO, and inhibiting H2 production. The ZnO–Ni3ZnC0.7 shows a high CO yield of 2674.80 μmol g–1h–1 with a selectivity of 93.40 % and an apparent quantum yield of 18.30 % (λ = 420 nm) with triethanolamine as a sacrificial agent. The CO production rate remains at 96.40 % after 18 h. Notably, ZnO–Ni3ZnC0.7 exhibits a high CO yield of 873.60 μmol g–1h–1 with a selectivity of 90.20 % in seawater.

Optimizing Light Dynamics: Designing ANi-MOF Functionalized g-C3N4Type II Heterostructure and a Ti3C2 MXene Schottky Junction for Efficient Photocatalytic H2 Production.

The photocatalytic production of hydrogen (H2) from water is a vital avenue towards sustainable energy and addressing global environmental challenges. To maximize efficiency, harnessing the synergistic effects of multiple co-catalysts is essential, as these interactions can significantly enhance performance. In this study, we introduce a ternary heterojunction composed of a nickel-imidazole framework (Ni-MOF), graphitic carbon nitride (CN), and Ti3C2 MXene (TC), employing solvothermal and wet impregnation methods, featuring a well-designed Type II heterojunction and a noble metal-free Schottky junction for efficient hydrogen evolution. The Type II heterojunction between Ni-MOF and CN minimizes charge carrier recombination and promotes photogenerated electron generation, while TC as an electron acceptor enhances electron capture, increases participation in surface reactions, and augments active sites. Consequently, the Ni-MOF/CN/TC hybrid catalyst achieves outstanding photocatalytic hydrogen evolution under visible light, with a peak production rate of 1044.46 μmol/g over 3 hours, surpassing CN by 13 fold and Ni-MOF/CN by 50%. This work provides insights into MXene-based ternary systems, emphasizing the potential for enhanced light absorption and efficient charge separation, making it a promising platform for photocatalytic applications.

Magnetic-guided nanocarriers for ionizing/non-ionizing radiation synergistic treatment against triple-negative breast cancer

BackgroundTriple-negative breast cancer (TNBC) is a subtype of breast cancer with the worst prognosis. Radiotherapy (RT) is one of the core modalities for the disease; however, the ionizing radiation of RT has severe side effects. The consistent development direction of RT is to achieve better therapeutic effect with lower radiation dose. Studies have demonstrated that synergistic effects can be achieved by combining RT with non-ionizing radiation therapies such as light and magnetic therapy, thereby achieving the goal of dose reduction and efficacy enhancement.MethodsIn this study, we applied FeCo NPs with magneto thermal function and phototherapeutic agent IR-780 to construct an ionizing and non-ionizing radiation synergistic nanoparticle (INS NPs). INS NPs are first subjected to morphology, size, colloidal stability, loading capacity, and photothermal conversion tests. Subsequently, the cell inhibitory and cellular internalization were evaluated using cell lines in vitro. Following comprehensive assessment of the NPs’ in vivo biocompatibility, tumor-bearing mouse model was established to evaluate their distribution, targeted delivery, and anti-tumor effects in vivo.ResultsINS NPs have a saturation magnetization exceeding 72 emu/g, a hydrodynamic particle size of approximately 40 nm, a negatively charged surface, and good colloidal stability and encapsulation properties. INS NPs maintain the spectral characteristics of IR-780 at 808 nm. Under laser irradiation, the maximum temperature was 92 °C, INS NPs also achieved the effective heat temperature in vivo. Both in vivo and in vitro tests have proven that INS NPs have good biocompatibility. INS NPs remained effective for more than a week after one injection in vivo, and can also be guided and accumulated in tumors through permanent magnets. Later, the results exhibited that under low-dose RT and laser irradiation, the combined intervention group showed significant synergetic effects, and the ROS production rate was much higher than that of the RT and phototherapy-treated groups. In the mice model, 60% of the tumors were completely eradicated.ConclusionsINS NPs effectively overcome many shortcomings of RT for TNBC and provide experimental basis for the development of novel clinical treatment methods for TNBC.

Dietary silymarin improves performance by altering hepatic lipid metabolism and cecal microbiota function and its metabolites in late laying hens

BackgroundLiver lipid dysregulation is one of the major factors in the decline of production performance in late-stage laying hens. Silymarin (SIL), a natural flavonolignan extracted from milk thistle, is known for its hepatoprotective and lipid-lowering properties in humans. This study evaluates whether SIL can provide similar benefits to late-stage laying hens. A total of 480 68-week-old Lohmann Pink laying hens were randomly assigned into 5 groups, each group consisting of 6 replicates with 16 hens each. The birds received a basal diet either without silymarin (control) or supplemented with silymarin at concentrations of 250, 500, 750, or 1,000 mg/kg (SIL250, SIL500, SIL750, SIL1000) over a 12-week period.ResultsThe CON group exhibited a significant decline in laying rates from weeks 9 to 12 compared to the initial 4 weeks (P = 0.042), while SIL supplementation maintained consistent laying rates throughout the study (P > 0.05). Notably, the SIL500 and SIL750 groups showed higher average egg weight than the CON group during weeks 5 to 8 (P = 0.049). The SIL750 group had a significantly higher average daily feed intake across the study period (P < 0.05), and the SIL500 group saw a marked decrease in the feed-to-egg ratio from weeks 5 to 8 (P = 0.003). Furthermore, the SIL500 group demonstrated significant reductions in serum ALT and AST levels (P < 0.05) and a significant decrease in serum triglycerides and total cholesterol at week 12 with increasing doses of SIL (P < 0.05). SIL also positively influenced liver enzyme expression (FASN, ACC, Apo-VLDL II, FXR, and CYP7A1; P < 0.05) and altered the cecal microbiota composition, enhancing species linked to secondary bile acid synthesis. Targeted metabolomics identified 9 metabolites predominantly involved in thiamin metabolism that were significantly different in the SIL groups (P < 0.05).ConclusionsOur study demonstrated that dietary SIL supplementation could ameliorate egg production rate in late stage laying hens, mechanistically, this effect was via improving hepatic lipid metabolism and cecal microbiota function to achieve. Revealed the potentially of SIL as a feed supplementation to regulate hepatic lipid metabolism dysregulation. Overall, dietary 500 mg/kg SIL had the best effects.Graphical

In vivo turnover and biodistribution of soluble AXL: implications for biomarker development

Soluble biomarkers are paramount to personalized medicine. However, the in vivo turnover and biodistribution of soluble proteins is seldom characterized. The cleaved extracellular domain of the AXL receptor (sAXL) is a prognostic biomarker in several diseases and a predictive marker of AXL targeting agents. Plasma sAXL reflects a balance between production in tissues with lymphatic transport into the circulation and removal from blood by degradation or excretion. It is unclear how this transport cycle affects plasma sAXL levels that are the metric for biomarker development. Radiolabeled mouse sAxl was monitored after intravenous injection to measure degradation and urinary excretion of sAxl, and after intradermal injection to mimic tissue or tumor production. sAxl was rapidly taken-up and degraded by the liver and kidney cortex. Surprisingly, intact sAxl was detectable in urine, indicating passage through the glomerular filter and a unique sampling opportunity. The structure of sAxl showed an elongated, flexible molecule with a length of 18 nm and a thickness of only 3 nm, allowing passage through the glomerulus and excretion into the urine. Intradermally injected sAxl passed through local and distant lymph nodes, followed by uptake in liver and kidney cortex. Low levels of sAxl were seen in the plasma, consistent with an extended transit time from local tissue to circulation. The rapid plasma clearance of sAxl suggests that steady-state levels in blood will sensitively and dynamically reflect the rate of production of sAxl in the tissues but will be influenced by perturbations of liver and kidney function.

Upscaled Production of Satellite-Free Droplets: Step Emulsification with Deterministic Lateral Displacement.

Step emulsification is a key technique for achieving scalable production of monodisperse emulsion droplets owing to its resilience to flow fluctuations. However, the persistent issue of satellite droplets, an inherent byproduct of main droplets, poses challenges for achieving truly uniform product sizes. In a previous study, we introduced a module with step-emulsifier nozzles upstream and deterministic lateral displacement (DLD) micropillar arrays downstream to generate satellite-free droplets at a low throughput. In this study, we demonstrate an upscaled parallelized setup with ten modules that were designed to produce satellite-free droplets. Each module integrated 100 step-emulsification nozzles in the upstream region with DLD micropillar arrays downstream. We conducted 3D flow simulations to ensure homogeneous distribution of the input fluids. Uniformly supplying an aqueous polyvinyl alcohol solution and an acrylate monomer as continuous and dispersed phases into the ten modules, the nozzles in each module exhibited a production rate of 539.5 ± 28.6 drop/s (n = 10). We successfully isolated the main droplets with a mean diameter of 66 μm and a coefficient of variation of 3.1% from satellite droplets with a mean diameter of 3 μm. The total throughput was 3.0 mL/h. The high yield and contamination-free features of our approach are promising for diverse industrial applications.

Hydrothermal performance and irreversibility production of distilled H2O flowing in outwardly-corrugated converging pipes

The study of performance parameters that characterize the convective heat transfer performance (CHTP) and entropy production rates (EPR) of fluids is of great importance in science and engineering due to its widespread applications in the design of new thermal devices. This study considers the turbulent CHTP and EPR of distilled H 2 O flowing in outwardly-corrugated converging pipes (OCCPs) and investigates the influence of the diameter ratio DR ( 1 ≤ DR ≤ 2 ) on the behavior of performance parameters against the Reynolds numbers (Re) within the range ( 5.0 × 10 3 ≤ Re ≤ 5.0 × 10 4 ). The governing equations and boundary conditions are solved with the use of SST k − ω turbulence model. The considered OCCP is designed such that its average diameter is 0.03m while its normalized length is 26.6. It is obtained that increasing DR enhances the average Nusselt number (Nu), Poiseuille number (fRe), and EPR whereas the reverse is the case for thermal effective number ( I G ), Bejan number (Be), and performance evaluation criterion (PEC). At Re = 2.0 × 10 4 in OCCPs of DR = 1.00, 1.25, 1.50, 1.75, and 2.00, EPR is increased by factors 0.88, 1.42, 2.64, 4.84, and 9.61; fRe is improved by factors 3.39, 8.54, 16.27, 27.74, and 49.22; and Nu is enhanced by factors 1.28, 1.31, 1.34, 1.37, and 1.43, respectively. The enhancement is attributed to the flow acceleration, vortices production, and high mixing rate of the hot fluid near the wall with the cold fluid at the core fluid zone. Finally, and among other things it is revealed that the OCCPs of DR = 1.00, 1.25, and 1.50 are advantageous ( I G > 1 ) over the straight tube within the range 5 × 10 3 ≤ Re < 2.25 × 10 4 .

Heterojunction composites of covalent organic frameworks grown on the surface of persistent luminescent nanoparticles for photocatalytic hydrogen evolution and degradation of organic pollutants

Covalent organic frameworks (COFs) have shown great promise for photocatalytic hydrogen evolution from water and photocatalytic degradation of organic pollutants. However, a single COFs suffers from poor photogenerated charge separation efficiency. In this study, we synthesized persistent luminescent nanoparticles (PLNPs)@COFs composites with core–shell heterostructures by the in situ growth of COFs on the surface of PLNPs. The PLNPs@COFs composites demonstrated better photocatalytic performance than pure PLNPs and COFs. The hydrogen production rate of PLNPs@COFs (1:6) was about 35 mmol h−1 g−1, and the photodegradation efficiency of Rhodamine B by PLNPs@COFs (3:1) reached 100 % in 50 min. Evidently, the combination of COFs with PLNPs to form a core–shell heterostructure with a tight contact interface can effectively improve the photogenerated charge separation efficiency. Our covalent bonding and in situ growth approach is more conducive to the formation of stable core-shell heterostructures. A good match between the persistent luminescence emission spectrum of the PLNPs and the absorption range of the COFs improves the potential of PLNPs@COFs to function as a round-the-clock photocatalyst. This strategy holds excellent promise in the efficient use of solar photocatalytic hydrogen evolution and in environmental purification in the future.

Highly Dispersed Pd-CeOx Nanoparticles in Zeolite Nanosheets for Efficient CO2-Mediated Hydrogen Storage and Release.

Formic acid (FA) dehydrogenation and CO2 hydrogenation to FA/formate represent promising methodologies for the efficient and clean storage and release of hydrogen, forming a CO2-neutral energy cycle. Here, we report the synthesis of highly dispersed and stable bimetallic Pd-based nanoparticles, immobilized on self-pillared silicalite-1 (SP-S-1) zeolite nanosheets using an incipient wetness co-impregnation technique. Owing to the highly accessible active sites, effective mass transfer, exceptional hydrophilicity, and the synergistic effect of the bimetallic species, the optimized PdCe0.2/SP-S-1 catalyst demonstrated unparalleled catalytic performance in both FA dehydrogenation and CO2 hydrogenation to formate. Remarkably, it achieved a hydrogen generation rate of 5974 molH2 molPd-1 h-1 and a formate production rate of 536 molformate molPd-1 h-1 at 50 °C, surpassing most previously reported heterogeneous catalysts under similar conditions. Density functional theory calculations reveal that the interfacial effect between Pd and cerium oxide clusters substantially reduces the activation barriers for both reactions, thereby increasing the catalytic performance. Our research not only showcases a compelling application of zeolite nanosheet-supported bimetallic nanocatalysts in CO2-mediated hydrogen storage and release but also contributes valuable insights towards the development of safe, efficient, and sustainable hydrogen technologies.

Pyrolytic hydrocarbon generation characteristics of the Chang 7 shale based on different experimental methods: Implications for shale oil and gas in the Ordos Basin

Shale oil and gas resources are abundant in the Chang 7 shale of the Yanchang Formation in Ordos Basin. To determine the characteristics and influencing factors of hydrocarbon generation evolution of the Chang 7 shale, a series of thermal simulation experiments were conducted on low‐maturity shale and kerogen samples. The results indicate that the maximum yield of shale oil are 294.5 and 304.3 mg/g TOC for kerogen sample at heating rates of 20 and 2°C/h, and the corresponding experimental temperatures are 360.2°C and 408.0°C, respectively. The utilization of lower heating rates is favourable for shale oil generation and it is recommended to employ a lower heating rate during in situ heating processes to maximize the economic benefits. The formation of crude oil cracking gas begins when simulating temperature exceeds 528.0°C (Easy Ro 2.6%) at a heating rate of 20°C/h and 480.0°C (Easy Ro 2.5%) at a heating rate of 2°C/h, as indicated by the carbon isotopic composition of gaseous hydrocarbons. The maximum oil production rate of the rock powder sample is 159.8 mg/g TOC, which is lower than that of the kerogen sample. It suggests that certain minerals in the Chang 7 shale may impede hydrocarbon generation. After the addition of pyrite, the highest yield of shale oil is 213.96 mg/g TOC, 33.9% higher than the yield of the original rock powder sample, reflecting the positive catalytic effect of pyrite on hydrocarbon generation of Chang 7 shale. Under geologic conditions, pyrite catalytic hydrocarbon generation may act primarily on the migration of organic matter by macromolecules, which considerably increases the probability of direct contact between pyrite and organic matter. Therefore, the organic‐rich shale with high pyrite content in Chang 7 member is the preferred target for in situ conversion of shale oil and gas in the Ordos Basin.

Variability in n-caprylate and n-caproate producing microbiomes in reactors with in-line product extraction.

Medium-chain carboxylates (MCCs) are used in various industrial applications. These chemicals are typically extracted from palm oil, which is deemed not sustainable. Recent research has focused on microbial chain elongation using reactors to produce MCCs, such as n-caproate (C6) and n-caprylate (C8), from organic substrates such as wastes. Even though the production of n-caproate is relatively well-characterized, bacteria and metabolic pathways that are responsible for n-caprylate production are not. Here, three 5 L reactors with continuous membrane-based liquid-liquid extraction (i.e., pertraction) were fed ethanol and acetate and operated for an operating period of 234 days with different operating conditions. Metagenomic and metaproteomic analyses were employed. n-Caprylate production rates and reactor microbiomes differed between reactors even when operated similarly due to differences in H2 and O2 between the reactors. The complete reverse β-oxidation (RBOX) pathway was present and expressed by several bacterial species in the Clostridia class. Several Oscillibacter spp., including Oscillibacter valericigenes, were positively correlated with n-caprylate production rates, while Clostridium kluyveri was positively correlated with n-caproate production. Pseudoclavibacter caeni, which is a strictly aerobic bacterium, was abundant across all the operating periods, regardless of n-caprylate production rates. This study provides insight into microbiota that are associated with n-caprylate production in open-culture reactors and provides ideas for further work.IMPORTANCEMicrobial chain elongation pathways in open-culture biotechnology systems can be utilized to convert organic waste and industrial side streams into valuable industrial chemicals. Here, we investigated the microbiota and metabolic pathways that produce medium-chain carboxylates (MCCs), including n-caproate (C6) and n-caprylate (C8), in reactors with in-line product extraction. Although the reactors in this study were operated similarly, different microbial communities dominated and were responsible for chain elongation. We found that different microbiota were responsible for n-caproate or n-caprylate production, and this can inform engineers on how to operate the systems better. We also observed which changes in operating conditions steered the production toward and away from n-caprylate, but more work is necessary to ascertain a mechanistic understanding that could be predictive. This study provides pertinent research questions for future work.

Enhancing the pure water splitting using carbon-iron oxide–carbon nitride (Fe2O3-C/CN) heterostructure

Highly efficient pure photocatalysts for water-splitting applications have long been plagued by structure imperfectness, narrowband light absorption, rapid charge recombination, and sluggish surface reaction kinetics. Herein we report a Z-scheme heterojunction photocatalyst made of Fe2O3, CN, and a conductive carbon layer (C) at the interface of the two materials (Fe2O3-C/CN). The structure has been characterized using a range of physicochemical and photo-electrochemical techniques. Compared to pristine Fe2O3, the Fe2O3-C/CN photocatalyst revealed superior photogenerated charge carriers, transport efficiency, and suppressed recombination process along with the conductive carbon layer acting as a mediator. The optimum composite of (5 wt% Fe2O3-C/CN) shows excellent activity towards pure water splitting, which reached 408 and 199 μmol/g.h for H2 and O2 evolution respectively, and a solar-to-hydrogen conversion efficiency of approximately 0.29 % when used for the pure water splitting process. Such a superior efficiency and production rate offer great potential for pure water splitting, and provide an alternative solution to future green energy production processes.