Crystallographically vacancy‐induced MOF nanosheet as rational single‐atom support for accelerating CO_(2) electroreduction to CO

To attain a circular carbon economy and resolve CO_(2) electroreduction technology obstacles,single‐atom catalysts(SACs)have emerged as a logical option for electrocatalysis because of their extraordinary catalytic activity.Among SACs,metal–organic frameworks(MOFs)have been recognized as promising support materials because of their exceptional ability to prevent metal aggregation.This study shows that atomically dispersed Ni single atoms on a precisely engineered MOF nanosheet display a high Faradaic efficiency of approximately 100% for CO formation in H‐cell and three‐compartment microfluidic flow‐cell reactors and an excellent turnover frequency of 23,699 h^(−1),validating their intrinsic catalytic potential.These results suggest that crystallographic variations affect the abundant vacancy sites on the MOF nanosheets,which are linked to the evaporation of Zn‐containing organic linkers during pyrolysis.Furthermore,using X‐ray absorption spectroscopy and density functional theory calculations,a comprehensive investigation of the unsaturated atomic coordination environments and the underlying mechanism involving CO^(*) preadsorbed sites as initial states was possible and provided valuable insights.

Associations between Physical Activity,Depression,Self-Esteem,and Suicide Ideation in Adolescents

Background:In contemporary society,it has been widely witnessed that a surprising number of adolescents suffer emotional and mental health problems,and such turmoil is very often carried over into adulthood with serious implications for adjustment during the post-adolescent years.The purpose of the current study is to investigate the associations of physical activity with self-esteem,depression,and suicidal ideation.In addition,this study examined whether self-esteem and depression mediate the relationship between physical activity and suicide ideation in adolescents.Methods:The study participants were 946(male:527,female:419)who attended junior high and high schools in Seoul,Korea.The self-esteem scale,leisure time physical activity scale,the self-rating depression scale,and the suicide ideation scale were used to identify adolescents’mental health and physical activity.Descriptive analysis,correlation analysis,and Structural Equation Modeling were conducted to test the study hypothesis.Results:Results indicated that physical activity was significantly correlated with depression,self-esteem,and suicide ideation.Based on each variable’s correlations,the finding revealed that physical activity was significantly associated with self-esteem,depression,and suicide ideation.In addition,depression and self-esteem had significant mediating effects on the relationship between physical activity and suicide ideation.Conclusion:The study suggests that the suicide prevention intervention should incorporate physical activity involvement with self-esteem and depression to strengthen the protective combined effect of the intervention on suicide ideation and suicide attempts.