BACKGROUND Simulated microgravity environment can lead to gastrointestinal motility disturbance.The pathogenesis of gastrointestinal motility disorders is closely related to the stem cell factor(SCF)/c-kit signaling p...BACKGROUND Simulated microgravity environment can lead to gastrointestinal motility disturbance.The pathogenesis of gastrointestinal motility disorders is closely related to the stem cell factor(SCF)/c-kit signaling pathway associated with intestinal flora and Cajal stromal cells.Moreover,intestinal flora can also affect the regulation of SCF/c-kit signaling pathway,thus affecting the expression of Cajal stromal cells.Cajal cells are the pacemakers of gastrointestinal motility.AIM To investigate the effects of Bifidobacterium lactis(B.lactis)BLa80 on the intestinal flora of rats in simulated microgravity and on the gastrointestinal motility-related SCF/c-kit pathway.METHODS The internationally recognized tail suspension animal model was used to simulate the microgravity environment,and 30 rats were randomly divided into control group,tail suspension group and drug administration tail suspension group with 10 rats in each group for a total of 28 days.The tail group was given B.lactis BLa80 by intragastric administration,and the other two groups were given water intragastric administration,the concentration of intragastric administration was 0.1 g/mL,and each rat was 1 mL/day.Hematoxylin&eosin staining was used to observe the histopathological changes in each segment of the intestine of each group,and the expression levels of SCF,c-kit,extracellular signal-regulated kinase(ERK)and p-ERK in the gastric antrum of each group were detected by Western blotting and PCR.The fecal flora and mucosal flora of rats in each group were detected by 16S rRNA.RESULTS Simulated microgravity resulted in severe exfoliation of villi of duodenum,jejunum and ileum in rats,marked damage,increased space between villi,loose arrangement,shortened columnar epithelium of colon,less folds,narrower mucosal thickness,reduced goblet cell number and crypts,and significant improvement after probiotic intervention.Simulated microgravity reduced the expressions of SCF and c-kit,and increased the expressions of ERK and P-ERK in the gastric antrum of rats.However,after probiotic intervention,the expressions of SCF and ckit were increased,while the expressions of ERK and P-ERK were decreased,with statistical significance(P<0.05).In addition,simulated microgravity can reduce the operational taxonomic unit(OTU)of the overall intestinal flora of rats,B.lactis BLa80 can increase the OTU of rats,simulated microgravity can reduce the overall richness and diversity of stool flora of rats,increase the abundance of firmicutes in stool flora of rats,and reduce the abundance of Bacteroides in stool flora of rats,most of which are mainly beneficial bacteria.Simulated microgravity can increase the overall richness and diversity of mucosal flora,increase the abundance of Bacteroides and Desulphurides in the rat mucosal flora,and decrease the abundance of firmicutes,most of which are proteobacteria.After probiotics intervention,the overall Bacteroidetes trend in simulated microgravity rats was increased.CONCLUSION B.lactis BLa80 can ameliorate intestinal mucosal injury,regulate intestinal flora,inhibit ERK expression,and activate the SCF/c-kit signaling pathway,which may have a facilitating effect on gastrointestinal motility in simulated microgravity rats.展开更多
Objective:Based on multistage metabolomic profiling and Mendelian randomization analyses,the current study identified plasma metabolites that predicted the risk of developing gastric cancer(GC)and determined whether k...Objective:Based on multistage metabolomic profiling and Mendelian randomization analyses,the current study identified plasma metabolites that predicted the risk of developing gastric cancer(GC)and determined whether key metabolite levels modified the GC primary prevention effects.Methods:Plasma metabolites associated with GC risk were identified through a case-control study.Bi-directional two-sample Mendelian randomization analyses were performed to determine potential causal relationships utilizing the Shandong Intervention Trial(SIT),a nested case-control study of the Mass Intervention Trial in Linqu,Shandong province(MITS),China,the UK Biobank,and the Finn Gen project.Results:A higher genetic risk score for plasma L-aspartic acid was significantly associated with an increased GC risk in the northern Chinese population(SIT:HR=1.26 per 1 SD change,95%CI:1.07±1.49;MITS:HR=1.07,95%CI:1.00±1.14)and an increased gastric adenocarcinoma risk in Finn Gen(OR=1.68,95%CI:1.16±2.45).Genetically predicted plasma L-aspartic acid levels also modified the GC primary prevention effects with the beneficial effect of Helicobacter pylori eradication notably observed among individuals within the top quartile of L-aspartic acid level(P-interaction=0.098)and the beneficial effect of garlic supplementation only for those within the lowest quartile of L-aspartic acid level(P-interaction=0.02).Conclusions:Elevated plasma L-aspartic acid levels significantly increased the risk of developing GC and modified the effects of GC primary prevention.Further studies from other populations are warranted to validate the modification effect of plasma L-aspartic acid levels on GC prevention and to elucidate the underlying mechanisms.展开更多
L-arabinose isomerase (L-AI) is the key enzyme for D-galactose isomerization of D-tagatose by biological method. In this research, Lactobacillus plantarum WU14 with high D-tagatose yield was identified as Lactobacillu...L-arabinose isomerase (L-AI) is the key enzyme for D-galactose isomerization of D-tagatose by biological method. In this research, Lactobacillus plantarum WU14 with high D-tagatose yield was identified as Lactobacillus plantarum was isolated from the number of lactic acid bacteria from pickled vegetables. The crude L-arabinose isomerase activity of Lactobacillus plantarum WU14 with high D-tagatose yield was 13.95 U/mL under the optimal temperature 60°C, pH 7.17 and substrate concentration 0.8 mol/L, and the conversion rate of 56.12% could be gained after 28 hours. Protein structure and specific of L-Arabinose Isomerase of Lactobacillus plantarum WU14 were researched. The results showed that L-arabinose isomerase is mainly composed of alpha helix and random coil. Then the recombinant L-AI gene was inserted into the food-grade expression vector pRNA48 and expressed in L. lactis NZ9000 successfully. The target protein expression reached the maximum amount when the induced concentration of nisin reaches 30 ng/mL after 12 h. And the crude enzyme activity of recombinant bacteria reached 6.21 U/mL under 60°C. Otherwise the optimal conversion rate recombinant of L. lactis NZ9000/pRNA48-L-AI can reach 39.21% under the temperature of 50°C, pH 7.17 and D-galactose concentration was 0.6 mol/L.展开更多
Hydrogen evolution reaction (HER) from water electrolysis is an ideal alternative solution to address the energy crisis and develop clean energy. However, the construction of an efficient electrocatalyst with multiple...Hydrogen evolution reaction (HER) from water electrolysis is an ideal alternative solution to address the energy crisis and develop clean energy. However, the construction of an efficient electrocatalyst with multiple active sites that can ensure high metal utilization and promote reaction kinetics simultaneously still leaves a major challenge. Herein, we present a facile strategy to synthesize a HER catalyst comprising Pt single atoms (PtSA) anchored in Fe vacancies and Pt quantum dots (Pt_(QD)) on the surface of NiFe LDH. Benefitting from the hierarchical and ultrathin nanosheet arrays and strong electronic interaction between PtSA/Pt_(QD) and NiFe LDH matrix, the optimized sample (Pt_(SA/QD)-NiFe_(V9) LDH) exhibits outstanding HER performance in 1 M KOH with ultra-low overpotentials of 20 and 67 mV at 10 and 100 mA cm^(−2), respectively, outperforming the benchmark Pt/C electrocatalyst. In addition, the electrolyzer using Pt_(SA/QD)-NiFe_(V9) LDH as a cathode requires voltages of only 1.48 and 1.73 V to yield current densities of 10 and 1000 mA cm^(−2), respectively. The combination of in situ tests and density functional theory (DFT) calculations reveal that the synergy of PtSA and Pt_(QD) can optimize the kinetics of water dissociation and hydrogen desorption, thus the Volmer-Tafel pathway prevailing the HER process. This work provides a promising surface engineering strategy to develop catalysts for efficient and robust hydrogen evolution.展开更多
Metal-support interaction(MSI)is regarded as an indispensable manner to stabilize active metals and modulate catalytic activity,which shows great potentials in developing of efficient hydrogen evolution reaction(HER)e...Metal-support interaction(MSI)is regarded as an indispensable manner to stabilize active metals and modulate catalytic activity,which shows great potentials in developing of efficient hydrogen evolution reaction(HER)electrode with high activity and strong robustness.Herein,this work presents a novel heterostructure with ultrafine platinum quantum dots(Pt QDs)on defective catalytic supports derived from metal-organic frameworks(MOFs).It is indicated substantial oxygen vacancies can be generated and Pt–Pt bonds can be optimized through topological transformation.The resulting Pt/T-NiFe-BDC(BDC:C8H6O4)exhibits competitive HER activity in alkaline seawater,attaining ultralow overpotentials of 158 and 266 mV at 500 and 1000 mA cm^(-2)with fast kinetics and outstanding stability.An asymmetric water electrolyzer using Pt/T-NiFe-BDC as a cathode only requires a voltage of 1.89 V to generate an industrial density of 1000 mA cm^(-2)and shows no attenuation in 500-h continuous test at 500 mA cm^(-2).Theoretical calculations and in-situ spectroscopic analysis reveal the reversible hydrogen spillover mechanism,in which oxygen vacancies facilitate the sluggish water dissociation and Pt QDs promote the H^(*)combination.This study provides a new paradigm to engineer metal-supported catalysts for efficient and robust seawater splitting.展开更多
Energy storage plays a critical role in sustainable development,with secondary batteries serving as vital technologies for efficient energy conversion and utilization.This review provides a comprehensive summary of re...Energy storage plays a critical role in sustainable development,with secondary batteries serving as vital technologies for efficient energy conversion and utilization.This review provides a comprehensive summary of recent advancements across various battery systems,including lithium-ion,sodium-ion,potassium-ion,and multivalent metal-ion batteries such as magnesium,zinc,calcium,and aluminum.Emerging technologies,including dual-ion,redox flow,and anion batteries,are also discussed.Particular attention is given to alkali metal rechargeable systems,such as lithium-sulfur,lithium-air,sodium-sulfur,sodium-selenium,potassium-sulfur,potassium-selenium,potassium-air,and zinc-air batteries,which have shown significant promise for high-energy applications.The optimization of key components—cathodes,anodes,electrolytes,and interfaces—is extensively analyzed,supported by advanced characterization techniques like time-of-flight secondary ion mass spectrometry(TOF-SIMS),synchrotron radiation,nuclear magnetic resonance(NMR),and in-situ spectroscopy.Moreover,sustainable strategies for recycling spent batteries,including pyrometallurgy,hydrometallurgy,and direct recycling,are critically evaluated to mitigate environmental impacts and resource scarcity.This review not only highlights the latest technological breakthroughs but also identifies key challenges in reaction mechanisms,material design,system integration,and waste battery recycling,and presents a roadmap for advancing high-performance and sustainable battery technologies.展开更多
Solar-driven water splitting has emerged as a promising route for sustainable hydrogen generation,however,developing broad-spectrum responsive photocatalysts remains a challenge for achieving efficient solar-to-hydrog...Solar-driven water splitting has emerged as a promising route for sustainable hydrogen generation,however,developing broad-spectrum responsive photocatalysts remains a challenge for achieving efficient solar-to-hydrogen conversion.Here,we demonstrate a g-C_(3)N_(4)-based(UCN)catalyst with dispersed Ag single atoms(Ag SAs)and Ag nanoparticles(Ag NPs)for synergistically broad-spectrum photocatalytic hydrogen evolution.Experimental and theoretical results reveal that both Ag SAs and Ag NPs serve as active sites,with the Schottky junction between Ag NPs and g-C_(3)N_(4)effectively promoting charge separation,while Ag NPs induce localized surface plasmon resonance,extending the light response range from visible to near-infrared regions.The optimized catalyst Ag-UCN-3 exhibits a hydrogen evolution rate as high as 22.11 mmol/g/h and an apparent quantum efficiency(AQE)of 10.16%under 420 nm light illumination.Notably,it still had a high hydrogen evolution rate of 633.57μmol/g/h under 700 nm irradiation.This work unveils dual active sites engineering strategy that couples Ag SAs and Ag NPs with plasma and hot electrons,offering a new strategy for designing high-performance solar-driven energy systems.展开更多
As an innovative approach to addressing climate change,significant efforts have been dedicated to the development of amine sorbents for CO_(2)capture.However,the high energy requirements and limited lifespan of these ...As an innovative approach to addressing climate change,significant efforts have been dedicated to the development of amine sorbents for CO_(2)capture.However,the high energy requirements and limited lifespan of these sorbents,such as oxidative and water stability,pose significant challenges to their widespread commercial adoption.Moreover,the understanding of the relationship between adsorption energy and adsorption sites is not known.In this work,a dual-bond strategy was used to create novel secondary amine structures by a polyethyleneimine(PEI)network with electron-extracted(EE)amine sites at adjacent sites,thereby weakening the CO_(2)binding energy while maintaining the binding ability.Insitu FT-IR and DFT demonstrated the oxygen-containing functional groups adjacent to the amino group withdraw electrons from the N atom thereby reducing the CO_(2)adsorption capacity of the secondary amine,resulting in lower regeneration energy consumption of 1.39 GJ t^(-1)-CO_(2)In addition,the EE sorbents demonstrated remarkable performance with retention of over 90%of their working capacity after 100 cycles,even under harsh conditions containing 10%O_(2)and 20%H_(2)O.DFT calculations were employed to clarify for the first time the mechanism that the oxygen functional group at the a-site hinders the formation of the urea structure,thereby being an antioxidant.These findings highlight the promising potential of such sorbents for deployment in various CO_(2)emission scenarios,irrespective of environmental conditions.展开更多
The reasonable development and design of high-efficiency and low-cost electrocatalysts for hydrogen evolution reaction(HER)under industrial current densities are imperative for achieving carbon neutrality,while also p...The reasonable development and design of high-efficiency and low-cost electrocatalysts for hydrogen evolution reaction(HER)under industrial current densities are imperative for achieving carbon neutrality,while also posing challenges.In this study,an efficient electrocatalyst is successfully constructed through electrodeposition methods,which consists of monodispersed Pt loaded on amorphous/crystalline nickel–iron layered double hydroxide(Pt-SAs/ac-NiFe LDH).The Pt-SAs/ac-NiFe LDH demonstrates an elevated mass activity of 17.66 A mg_(Pt)^(−1)and a significant turnover frequency of 17.90 s^(−1)for HER in alkaline conditions under the overpotential of 100 mV.Meanwhile,for alkaline freshwater and seawater,Pt-SAs/ac-NiFe LDH exhibits ultra-low overpotentials of 141 and 138 mV to reach 1000 mA cm^(−2),respectively.Remarkably,it maintains stable operation for 100 h at 500 mA cm^(−2),showcasing its robustness and reliability.In situ Raman spectra reveal that Pt single atoms(Pt-SAs)accelerate interfacial water dissociation,thereby enhancing the HER kinetics in Pt-SAs/ac-NiFe LDH.Furthermore,theoretical calculation results show significant electronic interaction between the Pt-SAs and the ac-NiFe LDH support.The interaction significantly enhances water adsorption and dissociation,and balances the adsorption/desorption of hydrogen intermediates,ultimately improving HER performance.This research provides a viable method for designing efficient HER catalysts for water electrolysis in alkaline freshwater and seawater under industrial current densities.展开更多
The development of geological lamination in shale reservoirs influences fracture propagation during hydraulic stimulation,and the fracture generation mechanism as it propagates through the laminated interface is close...The development of geological lamination in shale reservoirs influences fracture propagation during hydraulic stimulation,and the fracture generation mechanism as it propagates through the laminated interface is closely related to fracturing effects.In this paper,the laminated shale was selected to conduct three-point bending experiments using digital image correlation(DIC)and acoustic emission(AE)techniques,which revealed that the propagation path of cross-layer fractures exhibits dislocation features.The cohesive fracture mechanism of cross-layer fractures is investigated from the viewpoint of the fracture process zone(FPZ),which displays the characteristics of intermittence and dislocation during fracture development.A computational criterion for predicting the dislocation of cross-layer fracture at the interface is proposed,which shows that the maximum dislocation range does not exceed 72%of the FPZ length.Considering the mechanical differences between adjacent layers of laminated shale,the cohesive zone model of cross-layer fracture is discussed,from which the constitutive relationship and fracture energy during FPZ development are characterized,and the discontinuous nature of the constitutive relationship is found.This study improves the understanding of the geometry and cohesive fracture mechanism of the cross-layer fracture and provides valuable insights for field fracturing in shale reservoirs.展开更多
文摘BACKGROUND Simulated microgravity environment can lead to gastrointestinal motility disturbance.The pathogenesis of gastrointestinal motility disorders is closely related to the stem cell factor(SCF)/c-kit signaling pathway associated with intestinal flora and Cajal stromal cells.Moreover,intestinal flora can also affect the regulation of SCF/c-kit signaling pathway,thus affecting the expression of Cajal stromal cells.Cajal cells are the pacemakers of gastrointestinal motility.AIM To investigate the effects of Bifidobacterium lactis(B.lactis)BLa80 on the intestinal flora of rats in simulated microgravity and on the gastrointestinal motility-related SCF/c-kit pathway.METHODS The internationally recognized tail suspension animal model was used to simulate the microgravity environment,and 30 rats were randomly divided into control group,tail suspension group and drug administration tail suspension group with 10 rats in each group for a total of 28 days.The tail group was given B.lactis BLa80 by intragastric administration,and the other two groups were given water intragastric administration,the concentration of intragastric administration was 0.1 g/mL,and each rat was 1 mL/day.Hematoxylin&eosin staining was used to observe the histopathological changes in each segment of the intestine of each group,and the expression levels of SCF,c-kit,extracellular signal-regulated kinase(ERK)and p-ERK in the gastric antrum of each group were detected by Western blotting and PCR.The fecal flora and mucosal flora of rats in each group were detected by 16S rRNA.RESULTS Simulated microgravity resulted in severe exfoliation of villi of duodenum,jejunum and ileum in rats,marked damage,increased space between villi,loose arrangement,shortened columnar epithelium of colon,less folds,narrower mucosal thickness,reduced goblet cell number and crypts,and significant improvement after probiotic intervention.Simulated microgravity reduced the expressions of SCF and c-kit,and increased the expressions of ERK and P-ERK in the gastric antrum of rats.However,after probiotic intervention,the expressions of SCF and ckit were increased,while the expressions of ERK and P-ERK were decreased,with statistical significance(P<0.05).In addition,simulated microgravity can reduce the operational taxonomic unit(OTU)of the overall intestinal flora of rats,B.lactis BLa80 can increase the OTU of rats,simulated microgravity can reduce the overall richness and diversity of stool flora of rats,increase the abundance of firmicutes in stool flora of rats,and reduce the abundance of Bacteroides in stool flora of rats,most of which are mainly beneficial bacteria.Simulated microgravity can increase the overall richness and diversity of mucosal flora,increase the abundance of Bacteroides and Desulphurides in the rat mucosal flora,and decrease the abundance of firmicutes,most of which are proteobacteria.After probiotics intervention,the overall Bacteroidetes trend in simulated microgravity rats was increased.CONCLUSION B.lactis BLa80 can ameliorate intestinal mucosal injury,regulate intestinal flora,inhibit ERK expression,and activate the SCF/c-kit signaling pathway,which may have a facilitating effect on gastrointestinal motility in simulated microgravity rats.
基金funded by the National Natural Science Foundation of China(No.82273704)Noncommunicable Chronic Diseases-National Science and Technology Major Project(No.2023ZD0501400-2023ZD0501402)+4 种基金Beijing Hospitals Authority’s Ascent Plan(DFL20241102)Beijing Hospitals Authority Clinical Medicine Development of Special Funding Support(No.ZLRK202325)China Postdoctoral Science Foundation(2024M760152)Peking University Medicine Fund for World’s Leading Discipline or Discipline Cluster Development(No.BMU2022XKQ004)Science Foundation of Peking University Cancer Hospital(Nos.BJCH2024BJ02,XKFZ2410,BJCH2025CZ04,and 2022-27)。
文摘Objective:Based on multistage metabolomic profiling and Mendelian randomization analyses,the current study identified plasma metabolites that predicted the risk of developing gastric cancer(GC)and determined whether key metabolite levels modified the GC primary prevention effects.Methods:Plasma metabolites associated with GC risk were identified through a case-control study.Bi-directional two-sample Mendelian randomization analyses were performed to determine potential causal relationships utilizing the Shandong Intervention Trial(SIT),a nested case-control study of the Mass Intervention Trial in Linqu,Shandong province(MITS),China,the UK Biobank,and the Finn Gen project.Results:A higher genetic risk score for plasma L-aspartic acid was significantly associated with an increased GC risk in the northern Chinese population(SIT:HR=1.26 per 1 SD change,95%CI:1.07±1.49;MITS:HR=1.07,95%CI:1.00±1.14)and an increased gastric adenocarcinoma risk in Finn Gen(OR=1.68,95%CI:1.16±2.45).Genetically predicted plasma L-aspartic acid levels also modified the GC primary prevention effects with the beneficial effect of Helicobacter pylori eradication notably observed among individuals within the top quartile of L-aspartic acid level(P-interaction=0.098)and the beneficial effect of garlic supplementation only for those within the lowest quartile of L-aspartic acid level(P-interaction=0.02).Conclusions:Elevated plasma L-aspartic acid levels significantly increased the risk of developing GC and modified the effects of GC primary prevention.Further studies from other populations are warranted to validate the modification effect of plasma L-aspartic acid levels on GC prevention and to elucidate the underlying mechanisms.
文摘L-arabinose isomerase (L-AI) is the key enzyme for D-galactose isomerization of D-tagatose by biological method. In this research, Lactobacillus plantarum WU14 with high D-tagatose yield was identified as Lactobacillus plantarum was isolated from the number of lactic acid bacteria from pickled vegetables. The crude L-arabinose isomerase activity of Lactobacillus plantarum WU14 with high D-tagatose yield was 13.95 U/mL under the optimal temperature 60°C, pH 7.17 and substrate concentration 0.8 mol/L, and the conversion rate of 56.12% could be gained after 28 hours. Protein structure and specific of L-Arabinose Isomerase of Lactobacillus plantarum WU14 were researched. The results showed that L-arabinose isomerase is mainly composed of alpha helix and random coil. Then the recombinant L-AI gene was inserted into the food-grade expression vector pRNA48 and expressed in L. lactis NZ9000 successfully. The target protein expression reached the maximum amount when the induced concentration of nisin reaches 30 ng/mL after 12 h. And the crude enzyme activity of recombinant bacteria reached 6.21 U/mL under 60°C. Otherwise the optimal conversion rate recombinant of L. lactis NZ9000/pRNA48-L-AI can reach 39.21% under the temperature of 50°C, pH 7.17 and D-galactose concentration was 0.6 mol/L.
基金funded by the National Key Research and Development Program of China(No.2022YFB3803600)the National Natural Science Foundation of China(Nos.22368050,22378346)+4 种基金the Key Research and Development Program of Yunnan Province(No.202302AF080002)the Yunnan Basic Applied Research Project(Nos.202401AU070229,202401AT070460)the Scientific Research Fund Project of Yunnan Education Department(Nos.2024J0013,2024J0014)the Open Project of Yunnan Precious Metals Labo-ratory Co.,Ltd(Nos.YPML-2023050259,YPML-2023050260).Au-thors thank the Shiyanjia Lab(www.shiyanjia.com)the Electron Microscopy Center,the Advanced Computing Center,and the Ad-vanced Analysis and Measurement Center of Yunnan University for the sample testing and computational services.
文摘Hydrogen evolution reaction (HER) from water electrolysis is an ideal alternative solution to address the energy crisis and develop clean energy. However, the construction of an efficient electrocatalyst with multiple active sites that can ensure high metal utilization and promote reaction kinetics simultaneously still leaves a major challenge. Herein, we present a facile strategy to synthesize a HER catalyst comprising Pt single atoms (PtSA) anchored in Fe vacancies and Pt quantum dots (Pt_(QD)) on the surface of NiFe LDH. Benefitting from the hierarchical and ultrathin nanosheet arrays and strong electronic interaction between PtSA/Pt_(QD) and NiFe LDH matrix, the optimized sample (Pt_(SA/QD)-NiFe_(V9) LDH) exhibits outstanding HER performance in 1 M KOH with ultra-low overpotentials of 20 and 67 mV at 10 and 100 mA cm^(−2), respectively, outperforming the benchmark Pt/C electrocatalyst. In addition, the electrolyzer using Pt_(SA/QD)-NiFe_(V9) LDH as a cathode requires voltages of only 1.48 and 1.73 V to yield current densities of 10 and 1000 mA cm^(−2), respectively. The combination of in situ tests and density functional theory (DFT) calculations reveal that the synergy of PtSA and Pt_(QD) can optimize the kinetics of water dissociation and hydrogen desorption, thus the Volmer-Tafel pathway prevailing the HER process. This work provides a promising surface engineering strategy to develop catalysts for efficient and robust hydrogen evolution.
文摘Metal-support interaction(MSI)is regarded as an indispensable manner to stabilize active metals and modulate catalytic activity,which shows great potentials in developing of efficient hydrogen evolution reaction(HER)electrode with high activity and strong robustness.Herein,this work presents a novel heterostructure with ultrafine platinum quantum dots(Pt QDs)on defective catalytic supports derived from metal-organic frameworks(MOFs).It is indicated substantial oxygen vacancies can be generated and Pt–Pt bonds can be optimized through topological transformation.The resulting Pt/T-NiFe-BDC(BDC:C8H6O4)exhibits competitive HER activity in alkaline seawater,attaining ultralow overpotentials of 158 and 266 mV at 500 and 1000 mA cm^(-2)with fast kinetics and outstanding stability.An asymmetric water electrolyzer using Pt/T-NiFe-BDC as a cathode only requires a voltage of 1.89 V to generate an industrial density of 1000 mA cm^(-2)and shows no attenuation in 500-h continuous test at 500 mA cm^(-2).Theoretical calculations and in-situ spectroscopic analysis reveal the reversible hydrogen spillover mechanism,in which oxygen vacancies facilitate the sluggish water dissociation and Pt QDs promote the H^(*)combination.This study provides a new paradigm to engineer metal-supported catalysts for efficient and robust seawater splitting.
基金supported by the National Natural Science Foundation of China(Nos.U21A20311 and 22409147)。
文摘Energy storage plays a critical role in sustainable development,with secondary batteries serving as vital technologies for efficient energy conversion and utilization.This review provides a comprehensive summary of recent advancements across various battery systems,including lithium-ion,sodium-ion,potassium-ion,and multivalent metal-ion batteries such as magnesium,zinc,calcium,and aluminum.Emerging technologies,including dual-ion,redox flow,and anion batteries,are also discussed.Particular attention is given to alkali metal rechargeable systems,such as lithium-sulfur,lithium-air,sodium-sulfur,sodium-selenium,potassium-sulfur,potassium-selenium,potassium-air,and zinc-air batteries,which have shown significant promise for high-energy applications.The optimization of key components—cathodes,anodes,electrolytes,and interfaces—is extensively analyzed,supported by advanced characterization techniques like time-of-flight secondary ion mass spectrometry(TOF-SIMS),synchrotron radiation,nuclear magnetic resonance(NMR),and in-situ spectroscopy.Moreover,sustainable strategies for recycling spent batteries,including pyrometallurgy,hydrometallurgy,and direct recycling,are critically evaluated to mitigate environmental impacts and resource scarcity.This review not only highlights the latest technological breakthroughs but also identifies key challenges in reaction mechanisms,material design,system integration,and waste battery recycling,and presents a roadmap for advancing high-performance and sustainable battery technologies.
文摘Solar-driven water splitting has emerged as a promising route for sustainable hydrogen generation,however,developing broad-spectrum responsive photocatalysts remains a challenge for achieving efficient solar-to-hydrogen conversion.Here,we demonstrate a g-C_(3)N_(4)-based(UCN)catalyst with dispersed Ag single atoms(Ag SAs)and Ag nanoparticles(Ag NPs)for synergistically broad-spectrum photocatalytic hydrogen evolution.Experimental and theoretical results reveal that both Ag SAs and Ag NPs serve as active sites,with the Schottky junction between Ag NPs and g-C_(3)N_(4)effectively promoting charge separation,while Ag NPs induce localized surface plasmon resonance,extending the light response range from visible to near-infrared regions.The optimized catalyst Ag-UCN-3 exhibits a hydrogen evolution rate as high as 22.11 mmol/g/h and an apparent quantum efficiency(AQE)of 10.16%under 420 nm light illumination.Notably,it still had a high hydrogen evolution rate of 633.57μmol/g/h under 700 nm irradiation.This work unveils dual active sites engineering strategy that couples Ag SAs and Ag NPs with plasma and hot electrons,offering a new strategy for designing high-performance solar-driven energy systems.
基金support from the National Natural Science Foundation of China(22378184,22378183)。
文摘As an innovative approach to addressing climate change,significant efforts have been dedicated to the development of amine sorbents for CO_(2)capture.However,the high energy requirements and limited lifespan of these sorbents,such as oxidative and water stability,pose significant challenges to their widespread commercial adoption.Moreover,the understanding of the relationship between adsorption energy and adsorption sites is not known.In this work,a dual-bond strategy was used to create novel secondary amine structures by a polyethyleneimine(PEI)network with electron-extracted(EE)amine sites at adjacent sites,thereby weakening the CO_(2)binding energy while maintaining the binding ability.Insitu FT-IR and DFT demonstrated the oxygen-containing functional groups adjacent to the amino group withdraw electrons from the N atom thereby reducing the CO_(2)adsorption capacity of the secondary amine,resulting in lower regeneration energy consumption of 1.39 GJ t^(-1)-CO_(2)In addition,the EE sorbents demonstrated remarkable performance with retention of over 90%of their working capacity after 100 cycles,even under harsh conditions containing 10%O_(2)and 20%H_(2)O.DFT calculations were employed to clarify for the first time the mechanism that the oxygen functional group at the a-site hinders the formation of the urea structure,thereby being an antioxidant.These findings highlight the promising potential of such sorbents for deployment in various CO_(2)emission scenarios,irrespective of environmental conditions.
基金funded by the National Key Research and Development Program of China(2022YFB3803600)the National Natural Science Foundation of China(22368050,22378346)+4 种基金the Key Research and Development Program of Yunnan Province(202302AF080002)Yunnan Basic Applied Research Project(202401AT070460,202401AU070229)Xingdian Talent Support Program Project in Yunnan Province,the Scientific Research Fund Project of Yunnan Education Department(2024J0014,2024J0013)the Open Project of Yunnan Precious Metals Laboratory Co.,Ltd(YPML-2023050259,YPML-2023050260,YPML-20240502008)the Scientific Research and Innovation Project of Postgraduate Students in the Academic Degree of Yunnan University.
文摘The reasonable development and design of high-efficiency and low-cost electrocatalysts for hydrogen evolution reaction(HER)under industrial current densities are imperative for achieving carbon neutrality,while also posing challenges.In this study,an efficient electrocatalyst is successfully constructed through electrodeposition methods,which consists of monodispersed Pt loaded on amorphous/crystalline nickel–iron layered double hydroxide(Pt-SAs/ac-NiFe LDH).The Pt-SAs/ac-NiFe LDH demonstrates an elevated mass activity of 17.66 A mg_(Pt)^(−1)and a significant turnover frequency of 17.90 s^(−1)for HER in alkaline conditions under the overpotential of 100 mV.Meanwhile,for alkaline freshwater and seawater,Pt-SAs/ac-NiFe LDH exhibits ultra-low overpotentials of 141 and 138 mV to reach 1000 mA cm^(−2),respectively.Remarkably,it maintains stable operation for 100 h at 500 mA cm^(−2),showcasing its robustness and reliability.In situ Raman spectra reveal that Pt single atoms(Pt-SAs)accelerate interfacial water dissociation,thereby enhancing the HER kinetics in Pt-SAs/ac-NiFe LDH.Furthermore,theoretical calculation results show significant electronic interaction between the Pt-SAs and the ac-NiFe LDH support.The interaction significantly enhances water adsorption and dissociation,and balances the adsorption/desorption of hydrogen intermediates,ultimately improving HER performance.This research provides a viable method for designing efficient HER catalysts for water electrolysis in alkaline freshwater and seawater under industrial current densities.
基金financiallysupported by the Excellent Young Fund of Sinopec Petroleum Exploration and Production Research Institute(Grant No.YK2024009)the National Natural Science Foundation of China(Grant Nos.U23B6004 and 51925405).
文摘The development of geological lamination in shale reservoirs influences fracture propagation during hydraulic stimulation,and the fracture generation mechanism as it propagates through the laminated interface is closely related to fracturing effects.In this paper,the laminated shale was selected to conduct three-point bending experiments using digital image correlation(DIC)and acoustic emission(AE)techniques,which revealed that the propagation path of cross-layer fractures exhibits dislocation features.The cohesive fracture mechanism of cross-layer fractures is investigated from the viewpoint of the fracture process zone(FPZ),which displays the characteristics of intermittence and dislocation during fracture development.A computational criterion for predicting the dislocation of cross-layer fracture at the interface is proposed,which shows that the maximum dislocation range does not exceed 72%of the FPZ length.Considering the mechanical differences between adjacent layers of laminated shale,the cohesive zone model of cross-layer fracture is discussed,from which the constitutive relationship and fracture energy during FPZ development are characterized,and the discontinuous nature of the constitutive relationship is found.This study improves the understanding of the geometry and cohesive fracture mechanism of the cross-layer fracture and provides valuable insights for field fracturing in shale reservoirs.
