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By employing metal oxides as oxygen carriers, chemical looping demonstrates its effectiveness in transferring oxygen between reduction and oxidation environments to partially oxidize fuels into syngas and convert CO2 into CO. Generally, NiFe2O4 oxygen carriers have demonstrated remarkable efficiency in chemical looping CO2 conversion. Nevertheless, the intricate process of atomic migration and evolution within the internal structure of bimetallic oxygen carriers during continuous high‐temperature redox cycling remains unclear. Consequently, the lack of a fundamental understanding of the complex ionic migration and oxygen transfer associated with energy conversion processes hampers the design of high‐performance oxygen carriers. Thus, in this study, we employed in situ characterization techniques and theoretical calculations to investigate the ion migration behavior and structural evolution in the bulk of NiFe2O4 oxygen carriers during H2 reduction and CO2/lab air oxidation cycles. We discovered that during the H2 reduction step, lattice oxygen rapidly migrates to vacancy layers to replenish consumed active oxygen species, while Ni leaches from the material and migrates to the surface. During the CO2 splitting step, Ni migrates toward the core of the bimetallic oxygen carrier, forming Fe–Ni alloys. During the air oxidation step, Fe–Ni migrates outward, creating a hollow structure owing to the Kirkendall effect triggered by the swift transfer of lattice oxygen. The metal atom migration paths depend on the oxygen transfer rates. These discoveries highlight the significance of regulating the release–recovery rate of lattice oxygen to uphold the structures and reactivity of oxygen carriers. This work offers a comprehensive understanding of the oxidation/reduction‐driven atomic interdiffusion behavior of bimetallic oxygen carriers. During chemical looping CO2 conversion, in situ environmental transmission electron microscopy–electron energy loss spectroscopy combined with quasi in situ X‐ray photoelectron spectroscopy, and theoretical calculations have been utilized to reveal the migration and diffusion processes of lattice oxygen and metal atoms inside oxygen carriers. It is highlighted that the structure of the oxygen carrier depends on the migration rate of lattice oxygen.

Traditional fossil energy sources still dominate the world energy structure. And fully utilizing biomass is a viable approach for energy transition. A bubbling fluidized bed has better heat and mass transfer, while particle agglomeration limits the development of its industrial application. In this paper, two-phase flow characteristics of a bubbling fluidized bed are investigated by combining numerical simulations and fluidized bed gasification experiments. Numerical simulations found that the bed fluidization height reached twice the initial fluidization height at the 0.054 m initial fluidization height with uniform particle distribution. Fluidized bed gasification experiments found that syngas yield increased with increasing temperature. The carbon conversion efficiency reached 79.3% and the effective gas production was 0.64 m3/kg at 850 °C. In addition, when the water vapor concentration reached 15%, the carbon conversion efficiency and effective gas production reached the maximum values of 86.01% and 0.81 m3/kg, respectively.

Currently, the production of sludge in China is on the rise annually, and the co-combustion of sludge with biomass for power and heat generation represents a viable method for the bulk treatment of sludge. In this study, we examined the combustion characteristics of municipal sludge (MS), bagasse (BA), and their blends using thermogravimetric analysis. Orthogonal experiments were conducted to assess the impact of ultrasonic pretreatment on the co-combustion properties of MS and BA. Prior to ultrasonic pretreatment, the combustion of BA was characterized by three distinct stages, while MS exhibited two stages. At a 30% MS ratio, the promotional interaction between BA and MS was most pronounced. Following ultrasonic pretreatment, the combustion of BA was simplified to two stages. With a 10% MS mass ratio, ultrasonic pretreatment enhanced the comprehensive combustion characteristic index, thereby improving the combustion performance of the mixture. The activation energy increased post-pretreatment, particularly when the MS content was 50%. Under the conditions of 45 kHz frequency, 500 W power, 3 h duration, and a 10% MS blending ratio, the mixture displayed reduced mass residue, elevated reaction rates, and superior combustion efficiency. This research aims to introduce a novel approach to the harmless disposal, volume reduction, and resourceful utilization of sludge.

By employing metal oxides as oxygen carriers, chemical looping demonstrates its effectiveness in transferring oxygen between reduction and oxidation environments to partially oxidize fuels into syngas and convert CO 2 into CO. Generally, NiFe 2 O 4 oxygen carriers have demonstrated remarkable efficiency in chemical looping CO 2 conversion. Nevertheless, the intricate process of atomic migration and evolution within the internal structure of bimetallic oxygen carriers during continuous high‐temperature redox cycling remains unclear. Consequently, the lack of a fundamental understanding of the complex ionic migration and oxygen transfer associated with energy conversion processes hampers the design of high‐performance oxygen carriers. Thus, in this study, we employed in situ characterization techniques and theoretical calculations to investigate the ion migration behavior and structural evolution in the bulk of NiFe 2 O 4 oxygen carriers during H 2 reduction and CO 2 /lab air oxidation cycles. We discovered that during the H 2 reduction step, lattice oxygen rapidly migrates to vacancy layers to replenish consumed active oxygen species, while Ni leaches from the material and migrates to the surface. During the CO 2 splitting step, Ni migrates toward the core of the bimetallic oxygen carrier, forming Fe–Ni alloys. During the air oxidation step, Fe–Ni migrates outward, creating a hollow structure owing to the Kirkendall effect triggered by the swift transfer of lattice oxygen. The metal atom migration paths depend on the oxygen transfer rates. These discoveries highlight the significance of regulating the release–recovery rate of lattice oxygen to uphold the structures and reactivity of oxygen carriers. This work offers a comprehensive understanding of the oxidation/reduction‐driven atomic interdiffusion behavior of bimetallic oxygen carriers.

Selective growth of cocatalyst on the surface of photocatalyst has been attracted considerable attention due to their efficient charges transfer property. In this study, the robust NiS modified graphitic carbon nitride (g-C 3 N 4 ) hybrids were successfully synthesized by a facile surface photochemical deposition process. The structure and composition characterization results revealed that the NiS is highly dispersed loading on the surface of g-C 3 N 4 nanosheets, and the NiS/g-C 3 N 4 hybrids possess large surface areas and excellent optical properties. Under the visible light illumination, the NiS/g-C 3 N 4 hybrids with 1.0% weight content of NiS cocatalyst exhibits the highest hydrogen evolution rate of 1346.1 μmol h −1  g −1 with an apparent quantum efficiency (AQE) of 7.67%. On the basis of photoluminescence (PL) spectra and photoelectrochemical methodology, the photocatalytic hydrogen evolution mechanism was proposed. The results demonstrated that the excellent activity arises from the strong electronic coupling, highly efficient charges separation and migration. This work demonstrates a facile photochemical deposition method to consciously construct the robust two-dimensional (2D) hybrids, so as to realize accurate deposition of cocatalyst and efficient migration of photo-generated carriers. Graphic Abstract

Background Soybean ( Glycine max [L.] Merr.) is one of the most important oil and protein crops. Ever-increasing soybean consumption necessitates the improvement of varieties for more efficient production. However, both correlations among different traits and genetic interactions among genes that affect a single trait pose a challenge to soybean breeding. Results To understand the genetic networks underlying phenotypic correlations, we collected 809 soybean accessions worldwide and phenotyped them for two years at three locations for 84 agronomic traits. Genome-wide association studies identified 245 significant genetic loci, among which 95 genetically interacted with other loci. We determined that 14 oil synthesis-related genes are responsible for fatty acid accumulation in soybean and function in line with an additive model. Network analyses demonstrated that 51 traits could be linked through the linkage disequilibrium of 115 associated loci and these links reflect phenotypic correlations. We revealed that 23 loci, including the known Dt1 , E2 , E1 , Ln , Dt2 , Fan , and Fap loci, as well as 16 undefined associated loci, have pleiotropic effects on different traits. Conclusions This study provides insights into the genetic correlation among complex traits and will facilitate future soybean functional studies and breeding through molecular design.

Background The inherent brittleness of calcium phosphate cement has limited its clinical application. Polyvinyl alcohol fibers have been demonstrated to enhance the tensile toughness of concrete matrices. However, only a few international studies have investigated the modification of calcium phosphate cement using polyvinyl alcohol fibers. These studies have predominantly focused on the macroscopic and microscopic mechanical properties, often neglecting comprehensive evaluations of the composites’ osteoconductivity, degradation rate, and osteogenic properties. Objective To evaluate the cellular biocompatibility, bending strength, elastic modulus, and fracture toughness of polyvinyl alcohol/calcium phosphate cement composites, as well as to assess their degradability and osteoconductivity, providing a theoretical basis for their potential clinical application. Method Polyvinyl alcohol/calcium phosphate cement composite cement was prepared by incorporating polyvinyl alcohol fibers into the calcium phosphate cement solid phase. The degradability of the composite material was assessed via in vitro immersion experiments. Biocompatibility was evaluated by observing cell morphology and growth, using the cell counting kit-8 for assessing the cell viability and performing live/dead fluorescent staining. The impact of the composite on cellular alkaline phosphatase activity was determined using alkaline phosphatase assays. Finally, the composite material’s bending strength, elastic modulus, and fracture toughness were measured through three-point bending tests. Results and conclusions: Incorporation of polyvinyl alcohol fibers significantly enhances the fracture toughness of calcium phosphate cement. Additionally, the bending strength and Young’s modulus of the composite material are improved, addressing the high brittleness of calcium phosphate cement. The composite material maintains the excellent biocompatibility and osteoconductivity of the calcium phosphate cement. Furthermore, the osteogenesis and degradation rate of the composite do not significantly differ from those of calcium phosphate cement.

In this paper, we report the synthesis of ligand-free Au nanoclusters (NCs)/g-C3N4 ultra-thin nanosheets (NSs) composite via a facile wet-impregnation method with post-annealing. On the one hand, post-annealing was used for the exfoliation of multi-layered g-C3N4 to obtain ultra-thin NSs; on the other hand, after Au25(Cys)18 NCs were loaded, post-annealing was further adopted to remove the ligands to obtain clean surface on Au NCs. It is demonstrated that the loaded Au NCs were aggregating resistant by post-annealing. Constructing heterojunctions with appropriate inter-band structures between the ligand-free Au NCs and the ultra-thin g-C3N4 NSs, along with the mono-distribution of the Au NCs and their intimate contact with g-C3N4 NSs ensured the smooth interfacial charge transfer. As a result, the composite photocatalysts exhibited efficient visible-light-induced photocatalytic H2 generation, mainly due to the local electric field enhancement induced by excitation of Au NCs under visible light and the improved charge separation in g-C3N4. This work provides a general strategy for the synthesis of noble metal NCs based composites with clean surface as the efficient photocatalysts for solar energy conversion. A stepwise post-annealing strategy is exploited to prepare g-C3N4 ultra-thin nanosheets modified with highly dispersed ligand-free Au nanoclusters for efficient photocatalytic hydrogen production.

Chemical doping is a powerful method to intrinsically tailor the electrochemical properties of electrode materials. Here, an interstitial boron‐doped tunnel‐type VO2(B) is constructed via a facile hydrothermal method. Various analysis techniques demonstrate that boron resides in the interstitial site of VO2(B) and such interstitial doping can boost the zinc storage kinetics and structural stability of VO2(B) cathode during cycling. Interestingly, we found that the boron doping level has a saturation limit peculiarity as proved by the quantitative analysis. Notably, the 2 at.% boron‐doped VO2(B) shows enhanced zinc ion storage performance with a high storage capacity of 281.7 mAh g−1 at 0.1 A g−1, excellent rate performance of 142.2 mAh g−1 at 20 A g−1, and long cycle stability up to 1000 cycles with the capacity retention of 133.3 mAh g−1 at 5 A g−1. Additionally, the successful preparation of the boron‐doped tunnel‐type α‐MnO2 further indicates that the interstitial boron doping approach is a general strategy, which supplies a new chance to design other types of functional electrode materials for multivalence batteries. An interstitial boron‐doped tunnel‐type VO2(B) is constructed via a facile hydrothermal method. Such interstitial doping can boost the zinc storage kinetics and structural stability of VO2(B) cathode during cycling. Interestingly, the saturation limit peculiarity of the boron doping level has been determined by the quantitative analysis.

Cycloadditions of epoxides and carbon dioxide into corresponding cyclic carbonates were performed over mesoporous Ta–W composite oxides prepared by a modified hydrolytic method. The best yields of styrene carbonate were obtained when the Ta/W mole ratio was 2:1 (labeled as Ta0.67W0.33Os). Under optimal reaction conditions, the conversion of styrene oxide and selectivity of styrene carbonate reached 95 and 97%, respectively. These Ta–W composite oxides have been extensively characterized by several techniques. X-ray diffraction (XRD) patterns and Transmission Electron Microscope (TEM) revealed that Ta2O5 was completely dispersed in WOx. Scanning electron microscopy (SEM) exhibited that the particle size distributions become more and more uniform with increment of tungsten content. CO2 and NH3 temperature-programmed desorption (CO2 and NH3-TPD) revealed that Ta0.67W0.33Os catalyst had the strongest acid and base strength. X-ray photoelectron spectroscopy (XPS) shows that the strongest acid–base sites of Ta0.67W0.33Os catalyst origin from its highest lattice oxygen concentration and W 4f5/2 species with Bronsted acidity. We discussed the reaction kinetics and proposed a possible mechanism, indicating the excellent catalytic activity is attributed to the cooperative action of acidic and neighboring basic sites on the catalyst surface.Graphic AbstractCycloaddition reactions of carbon dioxide with epoxides into corresponding cyclic carbonates were performed over mesoporous Ta–W composite oxides prepared by a modified hydrolytic method. The best yields for cyclic carbonates were obtained when the Ta/W mole ratio was 2:1 (denoted as Ta0.67W0.33Os). Acid-base synergy, specific surface area and mesoporous structure could be ascribed to the main reasons for the highest catalytic activity of Ta0.67W0.33Os catalyst. Meanwhile, reaction kinetics was discussed and a possible reaction pathway was proposed.