Renewable energy driven N_(2) electroreduction with air as nitrogen source holds great promise for realizing scalable green ammonia production.However,relevant out-lab research is still in its infancy.Herein,a novel S...Renewable energy driven N_(2) electroreduction with air as nitrogen source holds great promise for realizing scalable green ammonia production.However,relevant out-lab research is still in its infancy.Herein,a novel Sn-based MXene/MAX hybrid with abundant Sn vacancies,Sn@Ti_(2)CTX/Ti_(2)SnC–V,was synthesized by controlled etching Sn@Ti_(2)SnC MAX phase and demonstrated as an efficient electrocatalyst for electrocatalytic N2 reduction.Due to the synergistic effect of MXene/MAX heterostructure,the existence of Sn vacancies and the highly dispersed Sn active sites,the obtained Sn@Ti2CTX/Ti_(2)SnC–V exhibits an optimal NH_(3) yield of 28.4μg h^(−1) mg_(cat)^(−1) with an excellent FE of 15.57% at−0.4 V versus reversible hydrogen electrode in 0.1 M Na_(2)SO_(4),as well as an ultra-long durability.Noticeably,this catalyst represents a satisfactory NH3 yield rate of 10.53μg h^(−1) mg^(−1) in the home-made simulation device,where commercial electrochemical photovoltaic cell was employed as power source,air and ultrapure water as feed stock.The as-proposed strategy represents great potential toward ammonia production in terms of financial cost according to the systematic technical economic analysis.This work is of significance for large-scale green ammonia production.展开更多
MAX phases and corresponding 2 D derivative MXenes have attracted considerable interests due to not only their fascinating mechanical,physical and chemical properties but also their unique atomically laminated structu...MAX phases and corresponding 2 D derivative MXenes have attracted considerable interests due to not only their fascinating mechanical,physical and chemical properties but also their unique atomically laminated structures.As the most important way to tailor the materials properties,the structural defects in MAX phases and MXenes have been extensively investigated but lack of systematic survey although six reviews and two books in this field have been published.To make the defect-engineering based materials design and exploration more efficient and targeted,this paper provides a review of the recent progress on the nature of different-dimensional structural defects and their influence on the properties,in the hope of facilitating the conversion of established experiment and simulation results into practical guideline for optimizing defects in a broad range of demand-oriented materials development in the future.Also,unsolved issues on the structural defects of these scientifically and technologically important materials are also highlighted for the future study.展开更多
以氢化钛(TiH2)粉代替钛粉,与氮化铝(AlN)粉体混合,合成高纯的三元氮化物Ti2AlN陶瓷粉体。氢化钛与氮化铝按照摩尔比2∶1的配比,在混料机中混合12 h,然后放入流动氩气气氛保护的管式炉中高温处理。通过对在不同温度以及不同时间下进行...以氢化钛(TiH2)粉代替钛粉,与氮化铝(AlN)粉体混合,合成高纯的三元氮化物Ti2AlN陶瓷粉体。氢化钛与氮化铝按照摩尔比2∶1的配比,在混料机中混合12 h,然后放入流动氩气气氛保护的管式炉中高温处理。通过对在不同温度以及不同时间下进行热处理得到的产物进行物相分析,探究Ti2AlN的形成机理,发现在1400℃下保温2 h得到的Ti2AlN粉体纯度最高,约为96.2%(质量分数)。在同样条件下,以钛粉为钛源合成Ti2AlN粉体的纯度只有80.2%(质量分数)。因为氢化钛粉体价格低于钛粉,并且合成的样品纯度显著提高。所以,以氢化钛粉代替钛粉为钛源,合成Ti2AlN具有显著优势。同时研究了所合成Ti2AlN粉体在不同酸溶液(KF-HCl、NaF-HCl和NH4F-HCl)腐蚀行为。结果发现:将Ti2AlN(~2 g)浸入由2 g KF溶解在40 mL 6 M HCl的KF-HCl混合液中,在50℃下搅拌48 h得到碎片团簇型TiN。但是二维碳化物Ti2N MXene不能通过选择性刻蚀Ti2AlN的方法得到。展开更多
基金This work was supported by the National Natural Science Foundation of China(Nos.22308139,52071171,52202248)Natural Science Foundation of Liaoning Province(2023-MS-140)+11 种基金Liaoning BaiQianWan Talents Program(LNBQW2018B0048)Shenyang Science and Technology Project(21-108-9-04)Young Scientific and Technological Talents Project of the Department of Education of Liaoning Province(LQN202008)Key Research Project of Department of Education of Liaoning Province(LJKZZ20220015)Foundation of State Key Laboratory of Clean and Efficient Coal Utilization,Taiyuan University of Technology(MJNYSKL202301)Foundation of State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering(KF2023006)Anhui Province Key Laboratory of Coal Clean Conversion and High Valued Utilization,Anhui University of Technology(CHV22-05)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).
文摘Renewable energy driven N_(2) electroreduction with air as nitrogen source holds great promise for realizing scalable green ammonia production.However,relevant out-lab research is still in its infancy.Herein,a novel Sn-based MXene/MAX hybrid with abundant Sn vacancies,Sn@Ti_(2)CTX/Ti_(2)SnC–V,was synthesized by controlled etching Sn@Ti_(2)SnC MAX phase and demonstrated as an efficient electrocatalyst for electrocatalytic N2 reduction.Due to the synergistic effect of MXene/MAX heterostructure,the existence of Sn vacancies and the highly dispersed Sn active sites,the obtained Sn@Ti2CTX/Ti_(2)SnC–V exhibits an optimal NH_(3) yield of 28.4μg h^(−1) mg_(cat)^(−1) with an excellent FE of 15.57% at−0.4 V versus reversible hydrogen electrode in 0.1 M Na_(2)SO_(4),as well as an ultra-long durability.Noticeably,this catalyst represents a satisfactory NH3 yield rate of 10.53μg h^(−1) mg^(−1) in the home-made simulation device,where commercial electrochemical photovoltaic cell was employed as power source,air and ultrapure water as feed stock.The as-proposed strategy represents great potential toward ammonia production in terms of financial cost according to the systematic technical economic analysis.This work is of significance for large-scale green ammonia production.
文摘MAX phases and corresponding 2 D derivative MXenes have attracted considerable interests due to not only their fascinating mechanical,physical and chemical properties but also their unique atomically laminated structures.As the most important way to tailor the materials properties,the structural defects in MAX phases and MXenes have been extensively investigated but lack of systematic survey although six reviews and two books in this field have been published.To make the defect-engineering based materials design and exploration more efficient and targeted,this paper provides a review of the recent progress on the nature of different-dimensional structural defects and their influence on the properties,in the hope of facilitating the conversion of established experiment and simulation results into practical guideline for optimizing defects in a broad range of demand-oriented materials development in the future.Also,unsolved issues on the structural defects of these scientifically and technologically important materials are also highlighted for the future study.
基金National Natural Science Foundation of China(51731004,52101064,52072003)Anhui Provincial Natural Science Foundation(2008085QE195)+2 种基金National Key Research and Development Program of China(2017YFE0301403)Jiangsu Planned Projects for Postdoctoral Research Funds(2020Z158)Natural Science Foundation of Jiangsu Province(BK20201283)。
文摘以氢化钛(TiH2)粉代替钛粉,与氮化铝(AlN)粉体混合,合成高纯的三元氮化物Ti2AlN陶瓷粉体。氢化钛与氮化铝按照摩尔比2∶1的配比,在混料机中混合12 h,然后放入流动氩气气氛保护的管式炉中高温处理。通过对在不同温度以及不同时间下进行热处理得到的产物进行物相分析,探究Ti2AlN的形成机理,发现在1400℃下保温2 h得到的Ti2AlN粉体纯度最高,约为96.2%(质量分数)。在同样条件下,以钛粉为钛源合成Ti2AlN粉体的纯度只有80.2%(质量分数)。因为氢化钛粉体价格低于钛粉,并且合成的样品纯度显著提高。所以,以氢化钛粉代替钛粉为钛源,合成Ti2AlN具有显著优势。同时研究了所合成Ti2AlN粉体在不同酸溶液(KF-HCl、NaF-HCl和NH4F-HCl)腐蚀行为。结果发现:将Ti2AlN(~2 g)浸入由2 g KF溶解在40 mL 6 M HCl的KF-HCl混合液中,在50℃下搅拌48 h得到碎片团簇型TiN。但是二维碳化物Ti2N MXene不能通过选择性刻蚀Ti2AlN的方法得到。
