Spontaneously polarized crystals with intrinsic electric dipole moment have attracted immense interest as excellent functional materials for extensive applications.It is of great significance to engineer sustainable s...Spontaneously polarized crystals with intrinsic electric dipole moment have attracted immense interest as excellent functional materials for extensive applications.It is of great significance to engineer sustainable spontaneously polarized materials with fascinating characteristics and performance for activating air and water.Herein,a novel strategy based on the synergy of mechanical activation(MA)and biomimetic mineralization(BM)was created to construct spontaneously polarized ceramic.MA induced the structural damage of clay and promoted the dissolution of ions and the release of free proteins,contributing to the formation of silicate precursor in BM process.After high temperature firing,the silicate precursor in clay was converted to form KCa_(3)AlCa_(3)Si_(4)O_(16)(hexagonal crystal system,L^(6)symmetry type,and P63 space group)in the resulting spontaneously polarized ceramic.The non-centrosymmetric structure of KCa_(3)AlCa_(3)Si4O_(16)and the high intrinsic electric dipole moments contributed by K(1)polyhedrons resulted in high spontaneous polarization(0.2322μC/cm^(2))and far-infrared emissivity(0.951)of spontaneously polarized ceramic.In air,spontaneously polarized ceramic can activate H_(2)O and O_(2)molecules to form negative air ions owing to surface electric field.In water,spontaneously polarized ceramic can disaggregate large water clusters to form small water clusters ascribed to surface electric field and far-infrared emission;water pH can be regulated from weak acidity to approximate neutrality via the capture of electrons by H+ions to produce releasable hydrogen gas.This work provides great promise for rational design and synthesis of spontaneously polarized materials for functional applications.展开更多
China's rapid economic growth poses serious concerns over environmental degradation, especially in the context of higher pollution levels resulting from unprecedented industrial activity. It is commonly held that gov...China's rapid economic growth poses serious concerns over environmental degradation, especially in the context of higher pollution levels resulting from unprecedented industrial activity. It is commonly held that government policies are effective in the form of investment in pollution control and the imposition of a discharge fee on industrial units for the purpose of safety of environmental quality. In this study, we find that government policies do not prove to be successful in controlling air pollution in comparison to water pollution. Furthermore, air pollution is increasing, while water pollution is following a stable, decreasing curve. Hence, some reforms need to be implemented in government policies, particularly those concerning the effectiveness of investment in environmental protection and improving managerial skills in industry.展开更多
基金the National Natural Science Foundation of China(nos.22008041 and 22178074)the Natural Science Foundation of Guangxi Province,China(nos.2019GXNSFDA245020 and 2020GXNSFGA297001).
文摘Spontaneously polarized crystals with intrinsic electric dipole moment have attracted immense interest as excellent functional materials for extensive applications.It is of great significance to engineer sustainable spontaneously polarized materials with fascinating characteristics and performance for activating air and water.Herein,a novel strategy based on the synergy of mechanical activation(MA)and biomimetic mineralization(BM)was created to construct spontaneously polarized ceramic.MA induced the structural damage of clay and promoted the dissolution of ions and the release of free proteins,contributing to the formation of silicate precursor in BM process.After high temperature firing,the silicate precursor in clay was converted to form KCa_(3)AlCa_(3)Si_(4)O_(16)(hexagonal crystal system,L^(6)symmetry type,and P63 space group)in the resulting spontaneously polarized ceramic.The non-centrosymmetric structure of KCa_(3)AlCa_(3)Si4O_(16)and the high intrinsic electric dipole moments contributed by K(1)polyhedrons resulted in high spontaneous polarization(0.2322μC/cm^(2))and far-infrared emissivity(0.951)of spontaneously polarized ceramic.In air,spontaneously polarized ceramic can activate H_(2)O and O_(2)molecules to form negative air ions owing to surface electric field.In water,spontaneously polarized ceramic can disaggregate large water clusters to form small water clusters ascribed to surface electric field and far-infrared emission;water pH can be regulated from weak acidity to approximate neutrality via the capture of electrons by H+ions to produce releasable hydrogen gas.This work provides great promise for rational design and synthesis of spontaneously polarized materials for functional applications.
文摘China's rapid economic growth poses serious concerns over environmental degradation, especially in the context of higher pollution levels resulting from unprecedented industrial activity. It is commonly held that government policies are effective in the form of investment in pollution control and the imposition of a discharge fee on industrial units for the purpose of safety of environmental quality. In this study, we find that government policies do not prove to be successful in controlling air pollution in comparison to water pollution. Furthermore, air pollution is increasing, while water pollution is following a stable, decreasing curve. Hence, some reforms need to be implemented in government policies, particularly those concerning the effectiveness of investment in environmental protection and improving managerial skills in industry.