Single atom catalysts(SACs)have become the frontier research fields in catalysis.The M_(1)-N_(x)-C_(y)based SACs,wherein single metal atoms(M1)are stabilized by N-doped carbonaceous materials,have provided new opportu...Single atom catalysts(SACs)have become the frontier research fields in catalysis.The M_(1)-N_(x)-C_(y)based SACs,wherein single metal atoms(M1)are stabilized by N-doped carbonaceous materials,have provided new opportunities for catalysis due to their high reactivity,maximized atomic utilization,and high selectivity.In this review,the fabrication methods of M_(1)-N_(x)-C_(y)based SACs via support anchoring strategy and coordination design strategy are summarized to help the readers understand the interaction mechanism of single atoms and support.Then,characterization technologies for identifying single metal atoms are presented.Besides,the environmental applications including management of harmful gases,water purification are discussed.Finally,future opportunities and challenges for preparation strategies,mechanisms and applications are concluded.We conclude this review by emphasizing the fact that M_(1)-N_(x)-C_(y)based SACs has the potential to become an important candidate for solving current and future environmental pollution problems.展开更多
Carboxymethyl chitosan/poly（ethylene oxide）（CCTS/PEO） composite is firstly reported as a water soluble binder for the application of 5V LiNi0.5Mn1.5O4 cathode in Li-ion batteries. Both CCTS and PEO show a high ele...Carboxymethyl chitosan/poly（ethylene oxide）（CCTS/PEO） composite is firstly reported as a water soluble binder for the application of 5V LiNi0.5Mn1.5O4 cathode in Li-ion batteries. Both CCTS and PEO show a high electrochemical oxidation potential of above 5.0 V（vs. Li/Li＋）. The electrochemical performances of LiNi0.5Mn1.5O4（LNMO） cathodes with CCTS/PEO composite binders of different mass rates are investigated, it is found that LiNi0.5Mn1.5O4 cathode with an optimized CCTS/PEO（85/15, w/w） composite exhibits a slightly better cycling performance than that of polyvinylidene fluoride（PVDF）, retaining 81.4% capacity as compared with 79.8% for PVDF at 0.5C rate after 200 cycles. LNMO with PEO/CCTS（85/15,w/w） exhibited the better rate capability than that of PVDF. These results demonstrate that CCTS/PEO composite can be potentially used as a water-soluble binder for 5 V LNMO cathode.展开更多
基金This work was partially supported by the National Natural Science Foundation of China(No.51979294)the U.S.Department of Agriculture(No.2018-68011-28371)+1 种基金the National Science Foundation(No.1833988)the Training Program for Excellent Young Innovators of Changsha(No.kq1905064).
文摘Single atom catalysts(SACs)have become the frontier research fields in catalysis.The M_(1)-N_(x)-C_(y)based SACs,wherein single metal atoms(M1)are stabilized by N-doped carbonaceous materials,have provided new opportunities for catalysis due to their high reactivity,maximized atomic utilization,and high selectivity.In this review,the fabrication methods of M_(1)-N_(x)-C_(y)based SACs via support anchoring strategy and coordination design strategy are summarized to help the readers understand the interaction mechanism of single atoms and support.Then,characterization technologies for identifying single metal atoms are presented.Besides,the environmental applications including management of harmful gases,water purification are discussed.Finally,future opportunities and challenges for preparation strategies,mechanisms and applications are concluded.We conclude this review by emphasizing the fact that M_(1)-N_(x)-C_(y)based SACs has the potential to become an important candidate for solving current and future environmental pollution problems.
基金supported by the K.C.Wong Education Foundation,National Natural Science Foundation of China(No.21573239)Science&Technology project of Guangdong province(No.2014TX01N014/2015B010135008)+1 种基金Guangzhou Municipal Project for Science&Technology(No.201509010018)the Natural Science Foundation of Guangdong Province(No.2015A030313721)
文摘Carboxymethyl chitosan/poly（ethylene oxide）（CCTS/PEO） composite is firstly reported as a water soluble binder for the application of 5V LiNi0.5Mn1.5O4 cathode in Li-ion batteries. Both CCTS and PEO show a high electrochemical oxidation potential of above 5.0 V（vs. Li/Li＋）. The electrochemical performances of LiNi0.5Mn1.5O4（LNMO） cathodes with CCTS/PEO composite binders of different mass rates are investigated, it is found that LiNi0.5Mn1.5O4 cathode with an optimized CCTS/PEO（85/15, w/w） composite exhibits a slightly better cycling performance than that of polyvinylidene fluoride（PVDF）, retaining 81.4% capacity as compared with 79.8% for PVDF at 0.5C rate after 200 cycles. LNMO with PEO/CCTS（85/15,w/w） exhibited the better rate capability than that of PVDF. These results demonstrate that CCTS/PEO composite can be potentially used as a water-soluble binder for 5 V LNMO cathode.
