Oxygen evolution reaction(OER),a critical half-reaction in photocatalytic overall water splitting for producing hydrogen,is a key step toward sustainable energy conversion.Conventional photocatalysts often suffer from...Oxygen evolution reaction(OER),a critical half-reaction in photocatalytic overall water splitting for producing hydrogen,is a key step toward sustainable energy conversion.Conventional photocatalysts often suffer from limited light absorption and rapid charge recombination,hindering their further applications.To address these challenges,we have designed and synthesized a novel series of self-sensitized metal-organic frameworks(MOFs),Fe_(2)MCDDB(M=Ni,Mn,or Co).By incorporating photosensitive ligands,we have achieved efficient charge separation and promoted the transfer of photogenerated electrons to the active metal sites for water oxidation.Among the series,Fe_(2)NiCDDB exhibits exceptional OER activity,achieving an oxygen evolution rate of 125.3μmol g^(−1)h^(−1)under visible light irradiation.Experimental and theoretical results reveal that the optimized electronic structure and prolonged excited-state lifetime of Fe_(2)NiCDDB contribute to its enhanced catalytic performance.This work provides a promising strategy for designing two-in-one MOF photocatalysts for water oxidation.展开更多
Three sets of MXene(Ti_(3)C_(2)T_(x))@nano-Fe_(1)Co_(0.8)Ni_(1)composites with 15,45,and 90 mg MXene were prepared by in-situ liquid-phase deposition to effectively investigate the impact of the relationship between M...Three sets of MXene(Ti_(3)C_(2)T_(x))@nano-Fe_(1)Co_(0.8)Ni_(1)composites with 15,45,and 90 mg MXene were prepared by in-situ liquid-phase deposition to effectively investigate the impact of the relationship between MXene(Ti_(3)C_(2)T_(x))and nano-Fe_(1)Co_(0.8)Ni_(1)magnetic particles on the electromagnetic absorption properties of the composites.The microstructure,static magnetic properties,and electromag-netic absorption performance of these composites were studied.Results indicate that the MXene@nano-Fe_(1)Co_(0.8)Ni_(1)composites were primarily composed of face-centered cubic crystal structure particles and MXene,with spherical Fe_(1)Co_(0.8)Ni_(1)particles uniformly distrib-uted on the surface of the multilayered MXene.The alloy particles had an average particle size of approximately 100 nm and exhibited good dispersion without noticeable particle aggregation.With the increase in MXene content,the specific saturation magnetic and coer-civity of the composite initially decreased and then increased,displaying typical soft magnetic properties.Compared with those of the Fe_(1)Co_(0.8)Ni_(1)magnetic alloy particles alone,MXene addition caused an increasing trend in the real and imaginary parts of the dielectric constant of the composite.Meanwhile,the real and imaginary parts of the magnetic permeability exhibit decreasing trend.With the in-crease in MXene addition,the material attenuation constant increased and the impedance matching decreased.The minimum reflection loss increased,and the maximum effective absorption bandwidth decreased.When the MXene addition was 90 mg,the composite exhib-ited a minimum reflection loss of-46.9 dB with a sample thickness of 1.1 mm and a maximum effective absorption bandwidth of 3.60 GHz with a sample thickness of 1.0 mm.The effective absorption bandwidth of the composites and their corresponding thicknesses showed a decreasing trend with the increase in MXene addition,reducing by 50%from 1.5 mm without MXene addition to 1 mm with 90 mg of MXene addition.展开更多
The lower Cambrian Qiongzhusi(Є1 q)shale in the Sichuan Basin,formerly considered a source rock,recently achieved high gas production(7.388×105 m^(3)·d^(-1))from well Z201 in the Deyang-Anyue rift trough(DAR...The lower Cambrian Qiongzhusi(Є1 q)shale in the Sichuan Basin,formerly considered a source rock,recently achieved high gas production(7.388×105 m^(3)·d^(-1))from well Z201 in the Deyang-Anyue rift trough(DART),marking an exploration breakthrough of the world’s oldest industrial shale gas reser-voir.However,the shale gas enrichment mechanism within the DART is not fully understood.This study reviews the formation of the Qiongzhusi shale gas reservoirs within the DART by comparing them with cotemporaneous deposits outside the DART,and several findings are presented.The gas production interval was correlated with the main phase of the Cambrian explosion(lower Cambrian stage 3).In the early Cambrian ecosystem,dominant animals likely accelerated the settling rates of organic matter(OM)in the upper 1st member ofЄ_(1) q(Є_(1) q_(12))by feeding on small planktonic organisms and producing larger organic fragments and fecal pellets.High primary productivity and euxinic con-ditions contributed to OM enrichment in the lower 1st member ofЄ1 q(Є_(1) q_(11)).Additionally,shale reservoirs inside the DART demonstrated better properties than those outside in terms of thickness,brittle minerals,gas content,and porosity.In particular,the abundant OM pores inside the DART facil-itated shale gas enrichment,whereas the higher thermal maturity of the shales outside the DART pos-sibly led to the graphitization and collapse of some OM pores.Meanwhile,the overpressure of high-production wells inside the DART generally reflects better shale gas preservation,benefiting from the shale’s self-sealing nature,"upper capping and lower plugging"configuration,and limited faults and microfractures.Considering these insights,we introduced a"ternary enrichment"model for the Qiongzhusi shale gas.Although the current high gas production of Z201 was found at the reservoir 3,two additional reservoirs were identified with significant potential,thus suggesting a"multilayer stereoscopic development"strategy in future shale gas exploration within the DART.展开更多
The complex evolutionary history of the Qinghai-Tibetan Plateau and its surrounding areas,including the continental blocks(Indian,Lhasa,South Qiangtang,Tarim,Olongbuluk,Central Qilian,Alxa,North China,Yangtze,Central ...The complex evolutionary history of the Qinghai-Tibetan Plateau and its surrounding areas,including the continental blocks(Indian,Lhasa,South Qiangtang,Tarim,Olongbuluk,Central Qilian,Alxa,North China,Yangtze,Central Iran and Oman)and the orogenic belts between them,has long been the frontier in Earth science research.The Cryogenian and Ediacaran strata are extensively distributed in these blocks.Specifically,relatively complete Cryogenian and Ediacaran successions have been discovered in Oman,Indian,Yangtze,and Tarim blocks,while only the Ediacaran successions have been reported in Iran,the South Qiangtang,Central Qilian,Alxa,and North China blocks.Based on previous studies together with the integration of new materials and advancement obtained through the Second Tibetan Plateau Scientific Expedition and Research,this review aims to synthesize a correlative stratigraphic framework of the representative Cryogenian and Ediacaran sequences from the Qinghai-Tibetan Plateau and its surrounding areas.Furthermore,the Cryogenian and Ediacaran biotas and major geological events in these areas are comprehensively discussed in aspects of current research status.The results indicate that,in general,Ediacaran fossils of each area exhibit distinct features in preservation and assemblage composition,but the typical late Ediacaran fossils Cloudina and Shaanxilithes have been reported from most of these areas.In addition to the two global Cryogenian glaciations,late Ediacaran glaciogenic deposits are extensively recorded in the areas within and around the northern Qinghai-Tibetan Plateau(including the North China,Alxa,Central Qilian,Olongbuluk,and Tarim blocks,and the North Qilian Accretionary Belt),as well as central and southern Iran.However,further research is required to determine the age,distribution,and origin of these late Ediacaran glaciogenic deposits.Meanwhile,the middle Ediacaran DOUNCE/Shuram Excursion is widely documented in the Qinghai-Tibetan Plateau and its surrounding areas.The available data show that,after the break-up of the Rodinia supercontinent,most of the continental blocks in the areas were located along the northern margin of East Gondwana and a few(such as North China)were located between the Gondwana and Laurentia.In general,the paleogeographic evolution of most of these blocks during the Cryogenian and Ediacaran remains disputatious,necessitating further research to resolve the controversies surrounding their paleogeographic reconstruction models during this critical time interval.展开更多
基金funded by the National Natural Science Foundation of China(22271063 and 22371054)the Foundation of Basic and Applied Basic Research of Guangdong Province(2024A1515010423)+1 种基金Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program(2017BT01Z032)Science and Technology Planning Project of Guangdong Province(2021A0505030066).
文摘Oxygen evolution reaction(OER),a critical half-reaction in photocatalytic overall water splitting for producing hydrogen,is a key step toward sustainable energy conversion.Conventional photocatalysts often suffer from limited light absorption and rapid charge recombination,hindering their further applications.To address these challenges,we have designed and synthesized a novel series of self-sensitized metal-organic frameworks(MOFs),Fe_(2)MCDDB(M=Ni,Mn,or Co).By incorporating photosensitive ligands,we have achieved efficient charge separation and promoted the transfer of photogenerated electrons to the active metal sites for water oxidation.Among the series,Fe_(2)NiCDDB exhibits exceptional OER activity,achieving an oxygen evolution rate of 125.3μmol g^(−1)h^(−1)under visible light irradiation.Experimental and theoretical results reveal that the optimized electronic structure and prolonged excited-state lifetime of Fe_(2)NiCDDB contribute to its enhanced catalytic performance.This work provides a promising strategy for designing two-in-one MOF photocatalysts for water oxidation.
文摘Three sets of MXene(Ti_(3)C_(2)T_(x))@nano-Fe_(1)Co_(0.8)Ni_(1)composites with 15,45,and 90 mg MXene were prepared by in-situ liquid-phase deposition to effectively investigate the impact of the relationship between MXene(Ti_(3)C_(2)T_(x))and nano-Fe_(1)Co_(0.8)Ni_(1)magnetic particles on the electromagnetic absorption properties of the composites.The microstructure,static magnetic properties,and electromag-netic absorption performance of these composites were studied.Results indicate that the MXene@nano-Fe_(1)Co_(0.8)Ni_(1)composites were primarily composed of face-centered cubic crystal structure particles and MXene,with spherical Fe_(1)Co_(0.8)Ni_(1)particles uniformly distrib-uted on the surface of the multilayered MXene.The alloy particles had an average particle size of approximately 100 nm and exhibited good dispersion without noticeable particle aggregation.With the increase in MXene content,the specific saturation magnetic and coer-civity of the composite initially decreased and then increased,displaying typical soft magnetic properties.Compared with those of the Fe_(1)Co_(0.8)Ni_(1)magnetic alloy particles alone,MXene addition caused an increasing trend in the real and imaginary parts of the dielectric constant of the composite.Meanwhile,the real and imaginary parts of the magnetic permeability exhibit decreasing trend.With the in-crease in MXene addition,the material attenuation constant increased and the impedance matching decreased.The minimum reflection loss increased,and the maximum effective absorption bandwidth decreased.When the MXene addition was 90 mg,the composite exhib-ited a minimum reflection loss of-46.9 dB with a sample thickness of 1.1 mm and a maximum effective absorption bandwidth of 3.60 GHz with a sample thickness of 1.0 mm.The effective absorption bandwidth of the composites and their corresponding thicknesses showed a decreasing trend with the increase in MXene addition,reducing by 50%from 1.5 mm without MXene addition to 1 mm with 90 mg of MXene addition.
基金supported by the National Natural Science Foundation of China(U23B20155 and 42303004)China Postdoctoral Science Foundation(2023M730038)+1 种基金the Science and Technology Research Project for the China National Petroleum Corporation(2021DJ1802 and 2021YJCQ03)the National Postdoctoral Researcher Program of China(GZC20233111).
文摘The lower Cambrian Qiongzhusi(Є1 q)shale in the Sichuan Basin,formerly considered a source rock,recently achieved high gas production(7.388×105 m^(3)·d^(-1))from well Z201 in the Deyang-Anyue rift trough(DART),marking an exploration breakthrough of the world’s oldest industrial shale gas reser-voir.However,the shale gas enrichment mechanism within the DART is not fully understood.This study reviews the formation of the Qiongzhusi shale gas reservoirs within the DART by comparing them with cotemporaneous deposits outside the DART,and several findings are presented.The gas production interval was correlated with the main phase of the Cambrian explosion(lower Cambrian stage 3).In the early Cambrian ecosystem,dominant animals likely accelerated the settling rates of organic matter(OM)in the upper 1st member ofЄ_(1) q(Є_(1) q_(12))by feeding on small planktonic organisms and producing larger organic fragments and fecal pellets.High primary productivity and euxinic con-ditions contributed to OM enrichment in the lower 1st member ofЄ1 q(Є_(1) q_(11)).Additionally,shale reservoirs inside the DART demonstrated better properties than those outside in terms of thickness,brittle minerals,gas content,and porosity.In particular,the abundant OM pores inside the DART facil-itated shale gas enrichment,whereas the higher thermal maturity of the shales outside the DART pos-sibly led to the graphitization and collapse of some OM pores.Meanwhile,the overpressure of high-production wells inside the DART generally reflects better shale gas preservation,benefiting from the shale’s self-sealing nature,"upper capping and lower plugging"configuration,and limited faults and microfractures.Considering these insights,we introduced a"ternary enrichment"model for the Qiongzhusi shale gas.Although the current high gas production of Z201 was found at the reservoir 3,two additional reservoirs were identified with significant potential,thus suggesting a"multilayer stereoscopic development"strategy in future shale gas exploration within the DART.
基金supported by the Second Tibetan Plateau Scientific Expedition and Research Program(Grant No.2019QZKK0706)the National Natural Science Foundation of China(Grant No.41921002)。
文摘The complex evolutionary history of the Qinghai-Tibetan Plateau and its surrounding areas,including the continental blocks(Indian,Lhasa,South Qiangtang,Tarim,Olongbuluk,Central Qilian,Alxa,North China,Yangtze,Central Iran and Oman)and the orogenic belts between them,has long been the frontier in Earth science research.The Cryogenian and Ediacaran strata are extensively distributed in these blocks.Specifically,relatively complete Cryogenian and Ediacaran successions have been discovered in Oman,Indian,Yangtze,and Tarim blocks,while only the Ediacaran successions have been reported in Iran,the South Qiangtang,Central Qilian,Alxa,and North China blocks.Based on previous studies together with the integration of new materials and advancement obtained through the Second Tibetan Plateau Scientific Expedition and Research,this review aims to synthesize a correlative stratigraphic framework of the representative Cryogenian and Ediacaran sequences from the Qinghai-Tibetan Plateau and its surrounding areas.Furthermore,the Cryogenian and Ediacaran biotas and major geological events in these areas are comprehensively discussed in aspects of current research status.The results indicate that,in general,Ediacaran fossils of each area exhibit distinct features in preservation and assemblage composition,but the typical late Ediacaran fossils Cloudina and Shaanxilithes have been reported from most of these areas.In addition to the two global Cryogenian glaciations,late Ediacaran glaciogenic deposits are extensively recorded in the areas within and around the northern Qinghai-Tibetan Plateau(including the North China,Alxa,Central Qilian,Olongbuluk,and Tarim blocks,and the North Qilian Accretionary Belt),as well as central and southern Iran.However,further research is required to determine the age,distribution,and origin of these late Ediacaran glaciogenic deposits.Meanwhile,the middle Ediacaran DOUNCE/Shuram Excursion is widely documented in the Qinghai-Tibetan Plateau and its surrounding areas.The available data show that,after the break-up of the Rodinia supercontinent,most of the continental blocks in the areas were located along the northern margin of East Gondwana and a few(such as North China)were located between the Gondwana and Laurentia.In general,the paleogeographic evolution of most of these blocks during the Cryogenian and Ediacaran remains disputatious,necessitating further research to resolve the controversies surrounding their paleogeographic reconstruction models during this critical time interval.
