Conversion-type reaction anode materials with high specific capacity are attractive candidates to improve lithium ion batteries(LIBs), yet the rapid capacity fading and poor rate capability caused by drastic volume ch...Conversion-type reaction anode materials with high specific capacity are attractive candidates to improve lithium ion batteries(LIBs), yet the rapid capacity fading and poor rate capability caused by drastic volume change and low electronic conductivity greatly hinder their practical applications. To circumvent these issues, the successful design of yolk@shell Fe2 O3@C hybrid composed of a columnar-like Fe2O3 core within a hollow cavity completely surrounded by a thin, self-supported carbon(C) shell is presented as an anode for high-performance LIBs. This yolk@shell structure allows each Fe2O3 core to swell upon lithiation without deforming the carbon shell. This preserves the structural and electrical integrity against pulverization, as revealed by in situ transmission electron microscopy(TEM) measurement. Benefiting from these structural advantages, the resulting electrode exhibits a high reversible capacity(1013 m Ah g-1 after80 cycles at 0.2 A g-1), outstanding rate capability(710 m Ah g-1 at 8 A g-1) and superior cycling stability(800 m Ah g-1 after 300 cycles at 4 A g-1). A Li-ion full cell using prelithiated yolk@shell Fe2 O3@C hybrid as the anode and commercial Li CoO2(LCO) as the cathode demonstrates impressive cycling stability with a capacity retention of 84.5% after 100 cycles at 1 C rate, holding great promise for future practical applications.展开更多
The development of catalytic materials for the recycling CO_(2) through a myriad of available processes is an attractive field,especially given the current climate change.While there is increasing publication in this ...The development of catalytic materials for the recycling CO_(2) through a myriad of available processes is an attractive field,especially given the current climate change.While there is increasing publication in this field,the reported catalysts rarely deviate from the traditionally supported metal nanoparticle morphology,with the most simplistic method of enhancement being the addition of more metals to an already complex composition.Encapsulated catalysts,especially yolk@shell catalysts with hollow voids,offer answers to the most prominent issues faced by this field,coking and sintering,and further potential for more advanced phenomena,for example,the confinement effect,to promote selectivity or offer greater protection against coking and sintering.This work serves to demonstrate the current position of catalyst development in the fields of thermal CO_(2) reforming and hydrogenation,summarizing the most recent work available and most common metals used for these reactions,and how yolk@shell catalysts can offer superior performance and survivability in thermal CO_(2) reforming and hydrogenation to the more traditional structure.Furthermore,this work will briefly demonstrate the bespoke nature and highly variable yolk@shell structure.Moreover,this review aims to illuminate the spatial confinement effect and how it enhances yolk@shell structured nanoreactors is presented.展开更多
采用阳离子表面活性剂协助的自模板法合成了中空介孔Si O_2微球(HMSS),然后向含HMSS的悬浮液中加入醋酸钴溶液和氨水,让两种溶液经HMSS表面介孔进入空腔中反应生成Co_3O_4内核,合成了多核yolk-shell型Co_3O_4@m Si O_2(介孔Si O_2)纳米...采用阳离子表面活性剂协助的自模板法合成了中空介孔Si O_2微球(HMSS),然后向含HMSS的悬浮液中加入醋酸钴溶液和氨水,让两种溶液经HMSS表面介孔进入空腔中反应生成Co_3O_4内核,合成了多核yolk-shell型Co_3O_4@m Si O_2(介孔Si O_2)纳米反应器.结合XRD、XPS、SEM、STEM、BET等手段,分析了纳米反应器的形貌、结构、元素形态和比表面积.结果显示纳米反应器均匀分散,粒径约为300nm,表面布满介孔,内部分布大量Co_3O_4纳米粒子,拥有极大的比表面积161m^2/g,远大于Co_3O_4纳米粒子的比表面积35m^2/g,能有效吸附双酚A(BPA),1h吸附容量达12.7mg/g.多核yolk-shell型Co_3O_4@m Si O_2纳米反应器能高效催化过一硫酸氢盐(PMS)降解BPA,2h降解率达81.8%,远高于Co_3O_4纳米粒子的降解率51.3%,同时能节省PMS的投加量,避免水中盐度过高.此外,合成的纳米反应器具有很好的再利用性,在p H值3~9范围内表现出稳定而高效的催化性能.展开更多
基金supported by the National Natural Science Foundation of China(Grants No.21703185)the leading Project Foundation of Science Department of Fujian Province(Grants No.2018H0034)+1 种基金Fundamental Research Funds for the Central Universities(Xiamen University:20720170042)the“Double-First Class”Foundation of Materials and Intelligent Manufacturing Discipline of Xiamen University。
文摘Conversion-type reaction anode materials with high specific capacity are attractive candidates to improve lithium ion batteries(LIBs), yet the rapid capacity fading and poor rate capability caused by drastic volume change and low electronic conductivity greatly hinder their practical applications. To circumvent these issues, the successful design of yolk@shell Fe2 O3@C hybrid composed of a columnar-like Fe2O3 core within a hollow cavity completely surrounded by a thin, self-supported carbon(C) shell is presented as an anode for high-performance LIBs. This yolk@shell structure allows each Fe2O3 core to swell upon lithiation without deforming the carbon shell. This preserves the structural and electrical integrity against pulverization, as revealed by in situ transmission electron microscopy(TEM) measurement. Benefiting from these structural advantages, the resulting electrode exhibits a high reversible capacity(1013 m Ah g-1 after80 cycles at 0.2 A g-1), outstanding rate capability(710 m Ah g-1 at 8 A g-1) and superior cycling stability(800 m Ah g-1 after 300 cycles at 4 A g-1). A Li-ion full cell using prelithiated yolk@shell Fe2 O3@C hybrid as the anode and commercial Li CoO2(LCO) as the cathode demonstrates impressive cycling stability with a capacity retention of 84.5% after 100 cycles at 1 C rate, holding great promise for future practical applications.
基金Financial support was provided by the Chinese Academy of Sciences–The World Academy of Sciences(CAS-TWAS)president fellowship。
文摘The development of catalytic materials for the recycling CO_(2) through a myriad of available processes is an attractive field,especially given the current climate change.While there is increasing publication in this field,the reported catalysts rarely deviate from the traditionally supported metal nanoparticle morphology,with the most simplistic method of enhancement being the addition of more metals to an already complex composition.Encapsulated catalysts,especially yolk@shell catalysts with hollow voids,offer answers to the most prominent issues faced by this field,coking and sintering,and further potential for more advanced phenomena,for example,the confinement effect,to promote selectivity or offer greater protection against coking and sintering.This work serves to demonstrate the current position of catalyst development in the fields of thermal CO_(2) reforming and hydrogenation,summarizing the most recent work available and most common metals used for these reactions,and how yolk@shell catalysts can offer superior performance and survivability in thermal CO_(2) reforming and hydrogenation to the more traditional structure.Furthermore,this work will briefly demonstrate the bespoke nature and highly variable yolk@shell structure.Moreover,this review aims to illuminate the spatial confinement effect and how it enhances yolk@shell structured nanoreactors is presented.
文摘采用阳离子表面活性剂协助的自模板法合成了中空介孔Si O_2微球(HMSS),然后向含HMSS的悬浮液中加入醋酸钴溶液和氨水,让两种溶液经HMSS表面介孔进入空腔中反应生成Co_3O_4内核,合成了多核yolk-shell型Co_3O_4@m Si O_2(介孔Si O_2)纳米反应器.结合XRD、XPS、SEM、STEM、BET等手段,分析了纳米反应器的形貌、结构、元素形态和比表面积.结果显示纳米反应器均匀分散,粒径约为300nm,表面布满介孔,内部分布大量Co_3O_4纳米粒子,拥有极大的比表面积161m^2/g,远大于Co_3O_4纳米粒子的比表面积35m^2/g,能有效吸附双酚A(BPA),1h吸附容量达12.7mg/g.多核yolk-shell型Co_3O_4@m Si O_2纳米反应器能高效催化过一硫酸氢盐(PMS)降解BPA,2h降解率达81.8%,远高于Co_3O_4纳米粒子的降解率51.3%,同时能节省PMS的投加量,避免水中盐度过高.此外,合成的纳米反应器具有很好的再利用性,在p H值3~9范围内表现出稳定而高效的催化性能.
