To investigate the effect of different structures of MOF on the catalytic performance of ammonium perchlorate(AP)thermal decomposition.By adding 2-methylimidazole(2-MI)as an inhibitor during the synthesis of MOF-5,a t...To investigate the effect of different structures of MOF on the catalytic performance of ammonium perchlorate(AP)thermal decomposition.By adding 2-methylimidazole(2-MI)as an inhibitor during the synthesis of MOF-5,a two-dimensional(2D)MOF material was prepared and characterized by SEM,EDS,XRD,FT-IR and other means.The prepared two-dimensional material was added to the AP raw material to investigate its effect on the AP thermal decomposition process.After DSC and TG test,it was found that the addition of this kind of 2D MOF material can completely eliminate the low-temperature decomposition peak of the AP-based composite and advance the high temperature decomposition peak to 296.5℃,and the apparent heat of decomposition increase to 905.6 J/g,which has a better catalytic effect than the bulk MOF-5.In addition,through the combustion test,it was found that 2D MOF,as a burning rate catalyst,can effectively enhance the burning rate of AP based solid propellant.展开更多
Low-efficiency charge transfer is a critical factor to limit the photocatalytic H_(2)evolution activity of semiconductor photocatalysts.The interface design is a promising approach to achieve high chargetransfer effic...Low-efficiency charge transfer is a critical factor to limit the photocatalytic H_(2)evolution activity of semiconductor photocatalysts.The interface design is a promising approach to achieve high chargetransfer efficiency for photocatalysts.Herein,a new 2 D/2 D atomic double-layer WS_(2)/Nb_(2)O_(5)shell/core photocatalyst(DLWS/Nb_(2)O_(5))is designed.The atom-resolved HAADF-STEM results unravel the presence of an unusual 2 D/2 D shell/core interface in DLWS/Nb_(2)O_(5).Taking advantage of the advanced femtosecond-resolved ultrafast TAS spectra,the average lifetime of charge carriers for DLWS/Nb_(2)O_(5)(180.97 ps)is considerably shortened as compared to that of Nb_(2)O_(5)(230.50 ps),strongly indicating that the 2 D/2 D shell/core interface enables DLWS/Nb_(2)O_(5)to achieve ultrafast charge transfer from Nb_(2)O_(5)to atomic double-layer WS_(2),thus yielding a high photocatalytic H_(2)evolution rate of 237.6 mmol/h,up to10.8 times higher than that of pure Nb_(2)O_(5)nanosheet.This study will open a new window for the development of high-efficient photocatalytic systems through the interface design.展开更多
文摘To investigate the effect of different structures of MOF on the catalytic performance of ammonium perchlorate(AP)thermal decomposition.By adding 2-methylimidazole(2-MI)as an inhibitor during the synthesis of MOF-5,a two-dimensional(2D)MOF material was prepared and characterized by SEM,EDS,XRD,FT-IR and other means.The prepared two-dimensional material was added to the AP raw material to investigate its effect on the AP thermal decomposition process.After DSC and TG test,it was found that the addition of this kind of 2D MOF material can completely eliminate the low-temperature decomposition peak of the AP-based composite and advance the high temperature decomposition peak to 296.5℃,and the apparent heat of decomposition increase to 905.6 J/g,which has a better catalytic effect than the bulk MOF-5.In addition,through the combustion test,it was found that 2D MOF,as a burning rate catalyst,can effectively enhance the burning rate of AP based solid propellant.
基金funded by the China Postdoctoral Science Foundation(pre-station,No.2019TQ0050)Applied Basic Research Program of Sichuan Province(No.2020YJ0068)+5 种基金the China Postdoctoral Science Foundation(No.2020M673186)National Natural Science Foundation of China(No.22002014)National Natural Science Foundation of China(No.11804248)the financial support from the National Natural Science Foundation of China(No.21971113)Natural Science Foundation of Tianjin(No.18JCQNJC03200)supported by MOE Tier 1 RG4/17 and MOE Tier 2 MOE2019-T2-2-105。
文摘Low-efficiency charge transfer is a critical factor to limit the photocatalytic H_(2)evolution activity of semiconductor photocatalysts.The interface design is a promising approach to achieve high chargetransfer efficiency for photocatalysts.Herein,a new 2 D/2 D atomic double-layer WS_(2)/Nb_(2)O_(5)shell/core photocatalyst(DLWS/Nb_(2)O_(5))is designed.The atom-resolved HAADF-STEM results unravel the presence of an unusual 2 D/2 D shell/core interface in DLWS/Nb_(2)O_(5).Taking advantage of the advanced femtosecond-resolved ultrafast TAS spectra,the average lifetime of charge carriers for DLWS/Nb_(2)O_(5)(180.97 ps)is considerably shortened as compared to that of Nb_(2)O_(5)(230.50 ps),strongly indicating that the 2 D/2 D shell/core interface enables DLWS/Nb_(2)O_(5)to achieve ultrafast charge transfer from Nb_(2)O_(5)to atomic double-layer WS_(2),thus yielding a high photocatalytic H_(2)evolution rate of 237.6 mmol/h,up to10.8 times higher than that of pure Nb_(2)O_(5)nanosheet.This study will open a new window for the development of high-efficient photocatalytic systems through the interface design.
