Extensive use of thermal energy in daily life is ideal for reducing carbon emissions to achieve carbon neutrality;however,the effective collection of thermal energy is a major hurdle.Thermoelectric(TE)conversion techn...Extensive use of thermal energy in daily life is ideal for reducing carbon emissions to achieve carbon neutrality;however,the effective collection of thermal energy is a major hurdle.Thermoelectric(TE)conversion technology based on the Seebeck effect and thermal energy storage technology based on phase change materials(PCMs)represent smart,feasible,and research-worthy approaches to overcome this hurdle.However,the integration of multiple thermal energy sources freely existing in the environment for storage and output of thermal and electrical energy simultaneously still remains a huge challenge.Herein,three-dimensional(3D)nanostructured metal-organic frameworks(MOFs)are in situ nucleated and grown onto carbon nanotubes(CNTs)via coordination bonding.After calcination,the prepared core-shell structural CNTs@MOFs are transformed into tightened 1D/3D carbon heterostructure loading Co nanoparticles for efficient solar-thermoelectric energy harvesting.Surprisingly,the corresponding composite PCMs show a record-breaking solar-thermal conversion efficiency of 98.1%due to the tightened carbon heterostructure and the local surface plasmon resonance effect of Co nanoparticles.Moreover,our designed all-in-one composite PCMs are also capable of creating an electrical potential of 0.5 mV based on the Seebeck effect without a TE generator.This promising approach can store thermal and electrical energy simultaneously,providing a new direction in the design of advanced all-in-one multifunctional PCMs for thermal energy storage and utilization.展开更多
Developing advanced nanocomposite integrating solar-driven thermal energy storage and thermal management functional microwave absorption can facilitate the cutting-edge application of phase change materials(PCMs).To c...Developing advanced nanocomposite integrating solar-driven thermal energy storage and thermal management functional microwave absorption can facilitate the cutting-edge application of phase change materials(PCMs).To conquer this goal,herein,two-dimensional MoS_(2) nanosheets are grown in situ on the surface of one-dimensional CNTs to prepare core-sheath MoS_(2)@CNTs for the encapsulation of paraffin wax(PW).Benefiting from the synergistic enhancement photothermal effect of MoS_(2) and CNTs,MoS_(2)@CNTs is capable of efficiently trapping photons and quickly transporting phonons,thus yielding a high solar-thermal energy conversion and storage efficiency of 94.97%.Meanwhile,PW/MoS_(2)@CNTs composite PCMs exhibit a high phase change enthalpy of 101.60 J/g and excellent lo ng-term thermal storage durability after undergoing multiple heating-cooling cycles.More attractively,PW/MoS_(2)@CNTs composite PCMs realize thermal management functional microwave absorption in heat-related electronic application scenarios,which is superior to the single microwave absorption of traditional materials.The minimum reflection loss(RL) for PW/MoS_(2)@CNTs is-28 dB at 12.91 GHz with a 2.0 mm thickness.This functional integration design provides some insightful references on developing advanced microwave absorbing composite PCMs,holding great potential towards high-efficiency solar energy utilization and thermally managed microwave absorption fields.展开更多
The purpose of the learner-centered approaches is to develop students' communicative ability. Unfortunately, for decades the English teacher is regarded as an authority who dominates the whole class. In this paper, t...The purpose of the learner-centered approaches is to develop students' communicative ability. Unfortunately, for decades the English teacher is regarded as an authority who dominates the whole class. In this paper, the author introduces some effective ways on how to shift successfully from a teacher-dominated to a learner-centered English classroom.展开更多
The liquid leakage and weak solar absorption capacity of organic phase change materials(PCMs)seriously hinder the efficient utilization of solar energy and thermal energy storage.To address these issues,we prepared na...The liquid leakage and weak solar absorption capacity of organic phase change materials(PCMs)seriously hinder the efficient utilization of solar energy and thermal energy storage.To address these issues,we prepared nanoporous metal organic framework(Ni-MOF)for the vacuum infiltration of paraffin wax(PW),followed by the coating of solar-absorbing functional polydopamine(PDA)on the surface of PW@MOF for photothermal conversion and storage.As an efficient photon harvester,PDA coating endows PW@MOF/PDA composite PCMs with excellent photothermal conversion and storage properties due to the robust broadband solar absorption capability in the UV–vis region.Resultantly,our prepared PW@MOF/PDA composite PCMs exhibit a high photothermal conversion and storage efficiency of 91.2%,while that of PW@MOF composite PCMs is only zero.In addition,PW@MOF/PDA composite PCMs also exhibit excellent thermal stability,shape stability,energy storage stability,and photothermal conversion stability.More importantly,this coating strategy is universal by integrating different MOFs and solar absorbers,showing the potential to accelerate the major breakthroughs of high-efficiency MOF-based photothermal composite PCMs in solar energy utilization.展开更多
Inherent weak photon-capturing ability is a long-standing bottleneck for pristine phase change materials(PCMs)in photothermal conversion application.To conquer this difficulty,herein,magnetic Fe_(3)O_(4) nanoparticles...Inherent weak photon-capturing ability is a long-standing bottleneck for pristine phase change materials(PCMs)in photothermal conversion application.To conquer this difficulty,herein,magnetic Fe_(3)O_(4) nanoparticles were in situ anchored between the layers and the surface of two-dimensional MXene for the infiltration of myristic acid(MA)by an in situ chemical anchoring strategy.Benefiting from the synergistic localized surface plasmon resonance effect of MXene and Fe_(3)O_(4) nanoparticles,our designed MXene@Fe_(3)O_(4)-MA composite PCMs harvested an ultrahigh photothermal conversion efficiency of 97.7%.During the photothermal conversion process,MXene can capture photons and convert solar energy into heat energy efficiently,and the in situ anchored Fe_(3)O_(4) nanoparticles further enhanced the photothermal conversion efficiency.Moreover,the introduction of Fe_(3)O_(4) nanoparticles improved the thermal energy storage density(144.17 J/g)of MXene-MA composite PCMs since Fe_(3)O_(4) nanoparticles provided more heterogeneous nucleation sites for MA.Simultaneously,MXene@Fe_(3)O_(4)-MA composite PCMs were endowed with excellent paramagnetism,and realized efficient magnetic-thermal conversion.Additionally,MXene@Fe_(3)O_(4)-MA composite PCMs exhibited excellent energy conversion stability,thermal stability,and reliability after undergoing multiple thermal cycles.Therefore,high-performance MXene@Fe_(3)O_(4)-based energy conversion composite PCMs are promising candidates to accelerate efficient utilization of the practical solar energy and magnetic energy.展开更多
基金National Natural Science Foundation of China,Grant/Award Number:51902025Fundamental Research Funds for the Central Universities,Grant/Award Numbers:2019NTST29,FRF-BD-20-07A+1 种基金China Postdoctoral Science Foundation,Grant/Award Numbers:2019M660520,2020T130060Scientific and Technological Innovation Foundation of Shunde Graduate School,University of Science and Technology Beijing,Grant/Award Number:BK20AE003。
文摘Extensive use of thermal energy in daily life is ideal for reducing carbon emissions to achieve carbon neutrality;however,the effective collection of thermal energy is a major hurdle.Thermoelectric(TE)conversion technology based on the Seebeck effect and thermal energy storage technology based on phase change materials(PCMs)represent smart,feasible,and research-worthy approaches to overcome this hurdle.However,the integration of multiple thermal energy sources freely existing in the environment for storage and output of thermal and electrical energy simultaneously still remains a huge challenge.Herein,three-dimensional(3D)nanostructured metal-organic frameworks(MOFs)are in situ nucleated and grown onto carbon nanotubes(CNTs)via coordination bonding.After calcination,the prepared core-shell structural CNTs@MOFs are transformed into tightened 1D/3D carbon heterostructure loading Co nanoparticles for efficient solar-thermoelectric energy harvesting.Surprisingly,the corresponding composite PCMs show a record-breaking solar-thermal conversion efficiency of 98.1%due to the tightened carbon heterostructure and the local surface plasmon resonance effect of Co nanoparticles.Moreover,our designed all-in-one composite PCMs are also capable of creating an electrical potential of 0.5 mV based on the Seebeck effect without a TE generator.This promising approach can store thermal and electrical energy simultaneously,providing a new direction in the design of advanced all-in-one multifunctional PCMs for thermal energy storage and utilization.
基金supported by the National Natural Science Foundation of China (51902025)China Postdoctoral Science Foundation (2020T130060 and 2019M660520)。
文摘Developing advanced nanocomposite integrating solar-driven thermal energy storage and thermal management functional microwave absorption can facilitate the cutting-edge application of phase change materials(PCMs).To conquer this goal,herein,two-dimensional MoS_(2) nanosheets are grown in situ on the surface of one-dimensional CNTs to prepare core-sheath MoS_(2)@CNTs for the encapsulation of paraffin wax(PW).Benefiting from the synergistic enhancement photothermal effect of MoS_(2) and CNTs,MoS_(2)@CNTs is capable of efficiently trapping photons and quickly transporting phonons,thus yielding a high solar-thermal energy conversion and storage efficiency of 94.97%.Meanwhile,PW/MoS_(2)@CNTs composite PCMs exhibit a high phase change enthalpy of 101.60 J/g and excellent lo ng-term thermal storage durability after undergoing multiple heating-cooling cycles.More attractively,PW/MoS_(2)@CNTs composite PCMs realize thermal management functional microwave absorption in heat-related electronic application scenarios,which is superior to the single microwave absorption of traditional materials.The minimum reflection loss(RL) for PW/MoS_(2)@CNTs is-28 dB at 12.91 GHz with a 2.0 mm thickness.This functional integration design provides some insightful references on developing advanced microwave absorbing composite PCMs,holding great potential towards high-efficiency solar energy utilization and thermally managed microwave absorption fields.
文摘The purpose of the learner-centered approaches is to develop students' communicative ability. Unfortunately, for decades the English teacher is regarded as an authority who dominates the whole class. In this paper, the author introduces some effective ways on how to shift successfully from a teacher-dominated to a learner-centered English classroom.
基金This work was financially supported by the National Natural Science Foundation of China(No.51902025)Key Laboratory of Low-grade Energy Utilization Technologies and Systems(Chongqing University),Ministry of Education of China,Chongqing University(No.LLEUTS-202232)+4 种基金Fundamental Research Funds for the Jiangsu Province Universities(No.20KJB430037)Natural Science Foundation of Jiangsu Province(No.BK20220637)Fundamental Research Funds for the Central Universities(Nos.2019NTST29 and FRF-BD-20-07A)China Postdoctoral Science Foundation(Nos.2020T130060 and 2019M660520)Scientific and Technological Innovation Foundation of Shunde Graduate School,University of Science and Technology Beijing(No.BK20AE003).
文摘The liquid leakage and weak solar absorption capacity of organic phase change materials(PCMs)seriously hinder the efficient utilization of solar energy and thermal energy storage.To address these issues,we prepared nanoporous metal organic framework(Ni-MOF)for the vacuum infiltration of paraffin wax(PW),followed by the coating of solar-absorbing functional polydopamine(PDA)on the surface of PW@MOF for photothermal conversion and storage.As an efficient photon harvester,PDA coating endows PW@MOF/PDA composite PCMs with excellent photothermal conversion and storage properties due to the robust broadband solar absorption capability in the UV–vis region.Resultantly,our prepared PW@MOF/PDA composite PCMs exhibit a high photothermal conversion and storage efficiency of 91.2%,while that of PW@MOF composite PCMs is only zero.In addition,PW@MOF/PDA composite PCMs also exhibit excellent thermal stability,shape stability,energy storage stability,and photothermal conversion stability.More importantly,this coating strategy is universal by integrating different MOFs and solar absorbers,showing the potential to accelerate the major breakthroughs of high-efficiency MOF-based photothermal composite PCMs in solar energy utilization.
基金National Natural Science Foundation of China,Grant/Award Number:51902025Fundamental Research Funds for the Central Universities,Grant/Award Numbers:2019NTST29,FRF-BD-20-07A+1 种基金China Postdoctoral Science Foundation,Grant/Award Numbers:2020T130060,2019M660520Scientific and Technological Innovation Foundation of Shunde Graduate School,University of Science and Technology Beijing,Grant/Award Number:BK20AE003。
文摘Inherent weak photon-capturing ability is a long-standing bottleneck for pristine phase change materials(PCMs)in photothermal conversion application.To conquer this difficulty,herein,magnetic Fe_(3)O_(4) nanoparticles were in situ anchored between the layers and the surface of two-dimensional MXene for the infiltration of myristic acid(MA)by an in situ chemical anchoring strategy.Benefiting from the synergistic localized surface plasmon resonance effect of MXene and Fe_(3)O_(4) nanoparticles,our designed MXene@Fe_(3)O_(4)-MA composite PCMs harvested an ultrahigh photothermal conversion efficiency of 97.7%.During the photothermal conversion process,MXene can capture photons and convert solar energy into heat energy efficiently,and the in situ anchored Fe_(3)O_(4) nanoparticles further enhanced the photothermal conversion efficiency.Moreover,the introduction of Fe_(3)O_(4) nanoparticles improved the thermal energy storage density(144.17 J/g)of MXene-MA composite PCMs since Fe_(3)O_(4) nanoparticles provided more heterogeneous nucleation sites for MA.Simultaneously,MXene@Fe_(3)O_(4)-MA composite PCMs were endowed with excellent paramagnetism,and realized efficient magnetic-thermal conversion.Additionally,MXene@Fe_(3)O_(4)-MA composite PCMs exhibited excellent energy conversion stability,thermal stability,and reliability after undergoing multiple thermal cycles.Therefore,high-performance MXene@Fe_(3)O_(4)-based energy conversion composite PCMs are promising candidates to accelerate efficient utilization of the practical solar energy and magnetic energy.