电化学硝酸根还原制氨(Nitrate reduction to ammonia, NRA)是以硝酸根和水分别作为氮和氢的来源,采用电化学的途径实现室温下氨的绿色合成兼去除水中硝酸盐污染物,对缓解能源危机和环境问题具有重要的研究意义。然而,硝酸根到氨是一个...电化学硝酸根还原制氨(Nitrate reduction to ammonia, NRA)是以硝酸根和水分别作为氮和氢的来源,采用电化学的途径实现室温下氨的绿色合成兼去除水中硝酸盐污染物,对缓解能源危机和环境问题具有重要的研究意义。然而,硝酸根到氨是一个复杂的8e-转移过程且伴随着激烈的析氢副反应,这严重制约了合成氨的选择性和法拉第效率。为此,采用水热合成法及后续的热处理设计制备了泡沫镍负载氧化铜纳米花催化剂并探究其电化学硝酸根还原制氨性能。通过调控硝酸铜与尿素比例、热解温度等合成条件,达到泡沫镍(Ni foam, NF)均匀负载CuO纳米花的目的。结果表明,当Cu(NO3)2、CO(NH2)2的物质的量比为1∶6时,所得到的目标催化剂(CuO-6@NF)在法拉第效率、NH3产率、选择性和硝酸盐转换率方面表现出最佳性能。在-0.23 V vs.RHE情况下,CuO-6@NF NH3的产率达到1.15 mmol·h-1·cm-2,选择性为89.36%,总氮的去除率高达96.71%。此外,该催化剂还表现出良好的再现性、高稳定性以及较宽泛浓度下的适用性。展开更多
Self-destructing chips have promising applications for securing data.This paper proposes a new concept of energetic diodes for the first time,which can be used for self-destructive chips.A simple two-step electrochemi...Self-destructing chips have promising applications for securing data.This paper proposes a new concept of energetic diodes for the first time,which can be used for self-destructive chips.A simple two-step electrochemical deposition method is used to prepare ZnO/CuO/Al energetic diode,in which N-type ZnO and P-type CuO are constricted to a PN junction.This paper comprehensively discusses the material properties,morphology,semiconductor characteristics,and exploding performances of the energetic diode.Experimental results show that the energetic diode has typical rectification with a turn-on voltage of about 1.78 V and a reverse leakage current of about 3×10^(-4)A.When a constant voltage of 70 V loads to the energetic diode in the forward direction for about 0.14 s or 55 V loads in the reverse direction for about 0.17 s,the loaded power can excite the energetic diode exploding and the current rises to about100 A.Due to the unique performance of the energetic diode,it has a double function of rectification and explosion.The energetic diode can be used as a logic element in the normal chip to complete the regular operation,and it can release energy to destroy the chip accurately.展开更多
The safety and reliability of weapon systems would be significantly affected by changes in the performance of energetic materials due to ambient temperature and humidity.Nanothermites have promising applications due t...The safety and reliability of weapon systems would be significantly affected by changes in the performance of energetic materials due to ambient temperature and humidity.Nanothermites have promising applications due to their excellent reactivity.Therefore it becomes extremely important to understand their aging and failure process in the environment before using them.Here,the aging and failure process of Al/CuO in 71°C/60%RH were investigated,and showed that CuO nanoparticles negatively catalyze Al nanopowders,resulting in rapid hydration.The anti-aging effect of FAS-17-coated Al nanopowder was also examined.The aging process of Al,Al/CuO,and Al@FAS-17/CuO in high humidity and heat environment were revealed by quasi-in situ SEM and TEM methods.Compared with the aging of pure Al,the Al nanopowder in the nanothermites strongly agglomerated with the CuO nanopowder and hydrated earlier.This may be caused by CuO catalyzed hydration of Al nanopowder.The energy release experiments showed that the performance of Al/CuO decreased rapidly and failed to ignite after 4 h of aging.In contrast,the Al@FAS-17/CuO thermite can achieve long-term stability of up to 60 h in the same environment by simple cladding of FAS-17.It is found that FAS-17 coated Al nanopowder can prevent both particle agglomeration and water erosion,which is an effective means to make nanothermites application in high humidity and heat environment.展开更多
基金Projects(22068021,52064030)supported by the National Natural Science Foundation of ChinaProject(202305AC160064)supported by the Yunnan Young and Middle-aged Academic and Technical Leaders Reserve Talent Program,ChinaProjects(202202AG050011,202202AG050007)supported by Yunnan Major Scientific and Technological Program,China。
基金supported by the National Natural Science Foundation of China (Nos.52274295,52104291,51874079)the Natural Science Foundation of Hebei Province,China (Nos.E2022501028,E2022501029,E2021501029,A2021501007,E2018501091,E2020501001,E2022501030)+4 种基金the Hebei Province Key Research and Development Plan Project,China (No.19211302D)Performance Subsidy Fund for Key Laboratory of Dielectric and Electrolyte Functional Material Hebei Province,China (No.22567627H)the Fundamental Research Funds for the Central Universities,China (Nos.N2223009,N2223010,N2123035,N2023040)the Science and Technology Project of Hebei Education Department,China (No.ZD2022158)the Central Guided Local Science and Technology Development Fund Project of Hebei Province,China (No.226Z4401G).
基金the National Natural Science Foundation of China(Grant Nos.22275092,52372084)the Fundamental Research Funds for the Central Universities(Grant No.30923010920)。
文摘Self-destructing chips have promising applications for securing data.This paper proposes a new concept of energetic diodes for the first time,which can be used for self-destructive chips.A simple two-step electrochemical deposition method is used to prepare ZnO/CuO/Al energetic diode,in which N-type ZnO and P-type CuO are constricted to a PN junction.This paper comprehensively discusses the material properties,morphology,semiconductor characteristics,and exploding performances of the energetic diode.Experimental results show that the energetic diode has typical rectification with a turn-on voltage of about 1.78 V and a reverse leakage current of about 3×10^(-4)A.When a constant voltage of 70 V loads to the energetic diode in the forward direction for about 0.14 s or 55 V loads in the reverse direction for about 0.17 s,the loaded power can excite the energetic diode exploding and the current rises to about100 A.Due to the unique performance of the energetic diode,it has a double function of rectification and explosion.The energetic diode can be used as a logic element in the normal chip to complete the regular operation,and it can release energy to destroy the chip accurately.
基金supported by the National Natural Science Foundation of China(Grant No.22275092)。
文摘The safety and reliability of weapon systems would be significantly affected by changes in the performance of energetic materials due to ambient temperature and humidity.Nanothermites have promising applications due to their excellent reactivity.Therefore it becomes extremely important to understand their aging and failure process in the environment before using them.Here,the aging and failure process of Al/CuO in 71°C/60%RH were investigated,and showed that CuO nanoparticles negatively catalyze Al nanopowders,resulting in rapid hydration.The anti-aging effect of FAS-17-coated Al nanopowder was also examined.The aging process of Al,Al/CuO,and Al@FAS-17/CuO in high humidity and heat environment were revealed by quasi-in situ SEM and TEM methods.Compared with the aging of pure Al,the Al nanopowder in the nanothermites strongly agglomerated with the CuO nanopowder and hydrated earlier.This may be caused by CuO catalyzed hydration of Al nanopowder.The energy release experiments showed that the performance of Al/CuO decreased rapidly and failed to ignite after 4 h of aging.In contrast,the Al@FAS-17/CuO thermite can achieve long-term stability of up to 60 h in the same environment by simple cladding of FAS-17.It is found that FAS-17 coated Al nanopowder can prevent both particle agglomeration and water erosion,which is an effective means to make nanothermites application in high humidity and heat environment.
