Layered manganese dioxide(δ-MnO_(2))is considered a promising ammonium ion capture electrode material for capacitive deionization(CDI)attributed to its high theoretical capacity and cost-effectiveness.Nevertheless,it...Layered manganese dioxide(δ-MnO_(2))is considered a promising ammonium ion capture electrode material for capacitive deionization(CDI)attributed to its high theoretical capacity and cost-effectiveness.Nevertheless,it continues to encounter challenges including rapid capacity degradation,structural instability,and Jahn-Teller effect.Herein,a crystal and electron synergistically regulation engineering strategy is proposed for the suppression of the Jahn-Teller effect and the improvement of ammonium ion storage dynamics in F doped MnO_(2)(MnOF).The induced action of F ions transforms the MnO_(2)structure from the original cubic[MnO_(6)]octahedron into an asymmetric[Mn(OF)_(6)]octahedron with electron redistribution,and generates a localized charge imbalance along the O-Mn-F pathway,which promotes electron transfer from Mn to F direction,accelerates electron transfer,and reduces the energy barrier of ammonium ion diffusion.As a result,the prepared MnOF exhibited a maximum salt adsorption capacity of 144.3 mg g^(−1)and an exceptionally high salt adsorption rate of 18.25 mg g^(−1)min^(-1),along with outstanding cycling stability.Besides,ex/in situ characterizations reveal that in MnOF,the formation/breaking of hydrogen bond is accompanied by the insertion/deinsertion of NH_(4)^(+).Therefore,the rational introduction of highly electronegative anions provides a new direction for the development of advanced CDI electrode materials.展开更多
Laser ablated boron atoms have been reacted with hydrogen sulfide and the reaction products condensed with argon at 4 K, which gave BS2, BS2-, HSBS, and HBS molecules. Reagent isotopic substitution （H2S, H234S, D2S, ...Laser ablated boron atoms have been reacted with hydrogen sulfide and the reaction products condensed with argon at 4 K, which gave BS2, BS2-, HSBS, and HBS molecules. Reagent isotopic substitution （H2S, H234S, D2S, 10 B, 11B） and variation of boron and hydrogen sulfide concentrations have been used to identify the major products. Both BS2-- and BS2 were identified as linear molecules with no significant difference in the structure parameters, but the B-S anti-symmetric stretching vibration of BS2 is significantly lower than that of BS2-, which is ascribed to pseudo Jahn-Teller effect. Theoretical calculation was employed to have an insight into the interaction nature of the bonds in the corresponding products.展开更多
基金financial support from the National Natural Science Foundation of China(22108032 and 22178055)the Dongguan Introduction Program of Leading Innovative and Entrepreneurial Talents+1 种基金the support of characterization from the Dongguan University of Technology Analytical and Testing Centerthe Guangdong Provincial Key Laboratory of Intelligent Disaster Prevention and Emergency Technologies for Urban Lifeline Engineering(2022)(Grant No.2022B1212010016).
文摘Layered manganese dioxide(δ-MnO_(2))is considered a promising ammonium ion capture electrode material for capacitive deionization(CDI)attributed to its high theoretical capacity and cost-effectiveness.Nevertheless,it continues to encounter challenges including rapid capacity degradation,structural instability,and Jahn-Teller effect.Herein,a crystal and electron synergistically regulation engineering strategy is proposed for the suppression of the Jahn-Teller effect and the improvement of ammonium ion storage dynamics in F doped MnO_(2)(MnOF).The induced action of F ions transforms the MnO_(2)structure from the original cubic[MnO_(6)]octahedron into an asymmetric[Mn(OF)_(6)]octahedron with electron redistribution,and generates a localized charge imbalance along the O-Mn-F pathway,which promotes electron transfer from Mn to F direction,accelerates electron transfer,and reduces the energy barrier of ammonium ion diffusion.As a result,the prepared MnOF exhibited a maximum salt adsorption capacity of 144.3 mg g^(−1)and an exceptionally high salt adsorption rate of 18.25 mg g^(−1)min^(-1),along with outstanding cycling stability.Besides,ex/in situ characterizations reveal that in MnOF,the formation/breaking of hydrogen bond is accompanied by the insertion/deinsertion of NH_(4)^(+).Therefore,the rational introduction of highly electronegative anions provides a new direction for the development of advanced CDI electrode materials.
文摘Laser ablated boron atoms have been reacted with hydrogen sulfide and the reaction products condensed with argon at 4 K, which gave BS2, BS2-, HSBS, and HBS molecules. Reagent isotopic substitution （H2S, H234S, D2S, 10 B, 11B） and variation of boron and hydrogen sulfide concentrations have been used to identify the major products. Both BS2-- and BS2 were identified as linear molecules with no significant difference in the structure parameters, but the B-S anti-symmetric stretching vibration of BS2 is significantly lower than that of BS2-, which is ascribed to pseudo Jahn-Teller effect. Theoretical calculation was employed to have an insight into the interaction nature of the bonds in the corresponding products.
