Electrocatalytic synthesis under mild conditions has become increasingly important as one of the practical alternatives for industrial applications,especially for the green ammonia(NH_(3))industry.A properly engineere...Electrocatalytic synthesis under mild conditions has become increasingly important as one of the practical alternatives for industrial applications,especially for the green ammonia(NH_(3))industry.A properly engineered electrocatalyst plays a vital role in the realization of superior catalytic performance.Among various types of promising nanomaterials,metal–organic frameworks(MOFs)are competitive candidates for developing efficient electrocatalytic NH_(3) synthesis from simple nitrogen-containing molecules or ions,such as N_(2) and NO_(3)^(−).In this review,recent advances in the development of electrocatalysts derived from MOFs for the electrosynthesis of NH_(3) are collected,categorized,and discussed,including their application in the N_(2) reduction reaction(NRR)and the NO_(3)^(−)reduction reaction(NO3RR).Firstly,the fundamental principles are illustrated,such as plausible mechanisms of NH_(3) generation from N_(2) and NO_(3)^(−),the apparatus of corresponding electrocatalysis,parameters for evaluation of reaction efficiency,and detection methods of yielding NH_(3).Then,the electrocatalysts for NRR processes are discussed in detail,including pristine MOFs,MOF-hybrids,MOF-derived N-doped porous carbons,single atomic catalysts from pyrolysis of MOFs,and other MOF-related materials.Subsequently,MOF-related NO3RR processes are also listed and discussed.Finally,the existing challenges and prospects for the rational design and fabrication of electrocatalysts from MOFs for electrochemical NH_(3) synthesis are presented,such as the evolution of investigation methods with artificial intelligence,innovation in synthetic methods of MOF-related catalysts,advancement of characterization techniques,and extended electrocatalytic reactions.展开更多
A thin film TiO2 in hierarchical nano-structure with high photocatalytic activities was synthesized in simple steps with ultrasonication. The crystal structure and morphology of the photocatalyst were investigated by ...A thin film TiO2 in hierarchical nano-structure with high photocatalytic activities was synthesized in simple steps with ultrasonication. The crystal structure and morphology of the photocatalyst were investigated by X-ray diffraction (XRD) and high-resolution field emission scanning electron microscope (FE-SEM). In the present work, nanostructured TiO2 was directly formed onto a Ti substrate via a solution approach. This nanostructured TiO2 photocatalyst can be reused and will not generate secondary contamination to treated water. The photocatalytic activity of the synthesized TiO2 photocatalyst was evaluated by the degradation of phenol under UVC irradiation in water and was compared with the general sol-gel derived TiO2 films as well as a commercial DP-25 TiO2 coating. It was found that the synthesized nanostructured TiO2has significantly high and stable photocatalytic activity.展开更多
Under the current economic situation,companies should fully realize the importance of relationship marketing,establish good and stable relationships with all related parties,strengthen exchanges and cooperation with e...Under the current economic situation,companies should fully realize the importance of relationship marketing,establish good and stable relationships with all related parties,strengthen exchanges and cooperation with each other,achieve win-win benefits,and promote corporate marketing activities.For the success of the company,we will conduct in-depth investigations in the economic market,improve the products in time,and make plans based on the current development situation.展开更多
Transparent and flexible thermoelectrics has been highly sought after for future wearable devices.However,the main stumbling block to prevent its widespread adoption is the lack of p-type transparent thermoelectrics a...Transparent and flexible thermoelectrics has been highly sought after for future wearable devices.However,the main stumbling block to prevent its widespread adoption is the lack of p-type transparent thermoelectrics and the stringent criteria of electrical and thermal properties matching appropriately between p-legs and n-legs.This work demonstrates the fabrication of p-type PEDOT:PSS films whose optical properties,electrical conductivity,thermal conductivity,and Seebeck coefficient were engineered to perfectly match the n-type indium tin oxide(ITO)counterparts.The dense p-type PEDOT:PSS and n-type ITO thin films show a thermoelectric figure of merit of zT=0.30 and 0.29 at 450 K,and a thermal conductivity of 0.22 and 0.32 W m^(−1) K^(−1),respectively.A flexible thermoelectric generator(TEG)module with a high transmittance of>81%in the visible wavelength range of 400-800 nm is fabricated using 10 pairs of p-type PEDOT:PSS and n-type ITO thin film legs.An ultra-high power density of 22.2 W m^(−2) at a temperature gradient of 80 K was observed,which is the highest power density reported for organic/hybrid-based flexible TEGs so far.Our transparent flexible thin-film p-n junction thermoelectric module with exceptionally high power generation may take a tremendous step forward towards multi-functional wearable devices.展开更多
基金support from the Natural Science Foundation of Liaoning Province(general program)(2020-MS-137)T.J.White would like to thank the MOE2019-T2-2-032 grant and Monetary Academic Resources for Research Grant 001561-00001 in Nanyang Technological University,Singapore+9 种基金T.Ma would like to thank the National Natural Science Foundation of China(Nos.52071171,52202248)Liaoning BaiQianWan Talents Program(LNBQW2018B0048)Shenyang Science and Technology Project(21-108-9-04)Australian Research Council(ARC)through Future Fellowship(FT210100298,FT210100806)Discovery Project(DP220100603)Linkage Project(LP210100467,LP210200504,LP210200345,LP220100088)Industrial Transformation Training Centre(IC180100005)schemesthe Australian Government through the Cooperative Research Centres Projects(CRCPXIII000077)F.Wei would like to thank the A^(*)STAR career development fund C210112054Singapore structural metal alloy program grant No.A18b1B0061.A.K.Cheetham would like to thank the Ras al Khaimah Centre for Advanced Materials.
文摘Electrocatalytic synthesis under mild conditions has become increasingly important as one of the practical alternatives for industrial applications,especially for the green ammonia(NH_(3))industry.A properly engineered electrocatalyst plays a vital role in the realization of superior catalytic performance.Among various types of promising nanomaterials,metal–organic frameworks(MOFs)are competitive candidates for developing efficient electrocatalytic NH_(3) synthesis from simple nitrogen-containing molecules or ions,such as N_(2) and NO_(3)^(−).In this review,recent advances in the development of electrocatalysts derived from MOFs for the electrosynthesis of NH_(3) are collected,categorized,and discussed,including their application in the N_(2) reduction reaction(NRR)and the NO_(3)^(−)reduction reaction(NO3RR).Firstly,the fundamental principles are illustrated,such as plausible mechanisms of NH_(3) generation from N_(2) and NO_(3)^(−),the apparatus of corresponding electrocatalysis,parameters for evaluation of reaction efficiency,and detection methods of yielding NH_(3).Then,the electrocatalysts for NRR processes are discussed in detail,including pristine MOFs,MOF-hybrids,MOF-derived N-doped porous carbons,single atomic catalysts from pyrolysis of MOFs,and other MOF-related materials.Subsequently,MOF-related NO3RR processes are also listed and discussed.Finally,the existing challenges and prospects for the rational design and fabrication of electrocatalysts from MOFs for electrochemical NH_(3) synthesis are presented,such as the evolution of investigation methods with artificial intelligence,innovation in synthetic methods of MOF-related catalysts,advancement of characterization techniques,and extended electrocatalytic reactions.
文摘A thin film TiO2 in hierarchical nano-structure with high photocatalytic activities was synthesized in simple steps with ultrasonication. The crystal structure and morphology of the photocatalyst were investigated by X-ray diffraction (XRD) and high-resolution field emission scanning electron microscope (FE-SEM). In the present work, nanostructured TiO2 was directly formed onto a Ti substrate via a solution approach. This nanostructured TiO2 photocatalyst can be reused and will not generate secondary contamination to treated water. The photocatalytic activity of the synthesized TiO2 photocatalyst was evaluated by the degradation of phenol under UVC irradiation in water and was compared with the general sol-gel derived TiO2 films as well as a commercial DP-25 TiO2 coating. It was found that the synthesized nanostructured TiO2has significantly high and stable photocatalytic activity.
文摘Under the current economic situation,companies should fully realize the importance of relationship marketing,establish good and stable relationships with all related parties,strengthen exchanges and cooperation with each other,achieve win-win benefits,and promote corporate marketing activities.For the success of the company,we will conduct in-depth investigations in the economic market,improve the products in time,and make plans based on the current development situation.
基金The authors acknowledge support from the A*STAR,Industry Alignment Fund,Pharos“Hybrid thermoelectric materials for ambient applications”Program(Grant nos.1527200019 and 1527200021).
文摘Transparent and flexible thermoelectrics has been highly sought after for future wearable devices.However,the main stumbling block to prevent its widespread adoption is the lack of p-type transparent thermoelectrics and the stringent criteria of electrical and thermal properties matching appropriately between p-legs and n-legs.This work demonstrates the fabrication of p-type PEDOT:PSS films whose optical properties,electrical conductivity,thermal conductivity,and Seebeck coefficient were engineered to perfectly match the n-type indium tin oxide(ITO)counterparts.The dense p-type PEDOT:PSS and n-type ITO thin films show a thermoelectric figure of merit of zT=0.30 and 0.29 at 450 K,and a thermal conductivity of 0.22 and 0.32 W m^(−1) K^(−1),respectively.A flexible thermoelectric generator(TEG)module with a high transmittance of>81%in the visible wavelength range of 400-800 nm is fabricated using 10 pairs of p-type PEDOT:PSS and n-type ITO thin film legs.An ultra-high power density of 22.2 W m^(−2) at a temperature gradient of 80 K was observed,which is the highest power density reported for organic/hybrid-based flexible TEGs so far.Our transparent flexible thin-film p-n junction thermoelectric module with exceptionally high power generation may take a tremendous step forward towards multi-functional wearable devices.
