以丙基三氯硅烷、苯乙炔为原料,通过格利雅反应合成丙基三苯乙炔基硅烷单体(PTPES)。采用傅里叶红外光谱、核磁共振氢谱表征了其分子结构,非等温DSC法研究了单体的固化特性,并运用4种常见的动力学分析方法(Kissinger、Ozawa、Flynn-Wall...以丙基三氯硅烷、苯乙炔为原料,通过格利雅反应合成丙基三苯乙炔基硅烷单体(PTPES)。采用傅里叶红外光谱、核磁共振氢谱表征了其分子结构,非等温DSC法研究了单体的固化特性,并运用4种常见的动力学分析方法(Kissinger、Ozawa、Flynn-Wall-Ozawa、Friedman)获得了PTPES固化过程的动力学参数和模型。结果表明,PTPES单体的熔点为75℃,PTPES在固化过程中,符合自催化动力学模型,表面活化能为122.21 k J/mol,指前因子ln A为22.48 s^(-1),反应级数n、m分别为0.77、0.22。展开更多
Inspired by natural photosynthesis,fabricating high-performance S-scheme heterojunction is regarded as a successful tactic to address energy and environmental issues.Herein,NH_(2)-MIL-125(Ti)/Zn_(0.5)Cd_(0.5)S/NiS(NMT...Inspired by natural photosynthesis,fabricating high-performance S-scheme heterojunction is regarded as a successful tactic to address energy and environmental issues.Herein,NH_(2)-MIL-125(Ti)/Zn_(0.5)Cd_(0.5)S/NiS(NMT/ZCS/NiS)S-scheme heterojunction with interfacial coordination bonds is successfully synthesized through in-situ solvothermal strategy.Notably,the optimal NMT/ZCS/NiS S-scheme heterojunction exhibits comparable photocatalytic H_(2)evolution(PHE)rate of about 14876.7μmol h^(−1)g^(−1)with apparent quantum yield of 24.2%at 420 nm,which is significantly higher than that of recently reported MOFs-based photocatalysts.The interfacial coordination bonds(Zn–N,Cd–N,and Ni–N bonds)accelerate the separation and transfer of photogenerated charges,and the NiS as cocatalyst can provide more catalytically active sites,which synergistically improve the photocatalytic performance.Moreover,theoretical calculation results display that the construction of NMT/ZCS/NiS S-scheme heterojunction also optimize the binding energy of active site-adsorbed hydrogen atoms to enable fast adsorption and desorption.Photoassisted Kelvin probe force microscopy,in-situ irradiation X-ray photoelectron spectroscopy,femtosecond transient absorption spectroscopy,and theoretical calculations provide sufficient evidence of the S-scheme charge migration mechanism.This work offers unique viewpoints for simultaneously accelerating the charge dynamics and optimizing the binding strength between the active sites and hydrogen adsorbates over S-scheme heterojunction.展开更多
文摘以丙基三氯硅烷、苯乙炔为原料,通过格利雅反应合成丙基三苯乙炔基硅烷单体(PTPES)。采用傅里叶红外光谱、核磁共振氢谱表征了其分子结构,非等温DSC法研究了单体的固化特性,并运用4种常见的动力学分析方法(Kissinger、Ozawa、Flynn-Wall-Ozawa、Friedman)获得了PTPES固化过程的动力学参数和模型。结果表明,PTPES单体的熔点为75℃,PTPES在固化过程中,符合自催化动力学模型,表面活化能为122.21 k J/mol,指前因子ln A为22.48 s^(-1),反应级数n、m分别为0.77、0.22。
文摘Inspired by natural photosynthesis,fabricating high-performance S-scheme heterojunction is regarded as a successful tactic to address energy and environmental issues.Herein,NH_(2)-MIL-125(Ti)/Zn_(0.5)Cd_(0.5)S/NiS(NMT/ZCS/NiS)S-scheme heterojunction with interfacial coordination bonds is successfully synthesized through in-situ solvothermal strategy.Notably,the optimal NMT/ZCS/NiS S-scheme heterojunction exhibits comparable photocatalytic H_(2)evolution(PHE)rate of about 14876.7μmol h^(−1)g^(−1)with apparent quantum yield of 24.2%at 420 nm,which is significantly higher than that of recently reported MOFs-based photocatalysts.The interfacial coordination bonds(Zn–N,Cd–N,and Ni–N bonds)accelerate the separation and transfer of photogenerated charges,and the NiS as cocatalyst can provide more catalytically active sites,which synergistically improve the photocatalytic performance.Moreover,theoretical calculation results display that the construction of NMT/ZCS/NiS S-scheme heterojunction also optimize the binding energy of active site-adsorbed hydrogen atoms to enable fast adsorption and desorption.Photoassisted Kelvin probe force microscopy,in-situ irradiation X-ray photoelectron spectroscopy,femtosecond transient absorption spectroscopy,and theoretical calculations provide sufficient evidence of the S-scheme charge migration mechanism.This work offers unique viewpoints for simultaneously accelerating the charge dynamics and optimizing the binding strength between the active sites and hydrogen adsorbates over S-scheme heterojunction.
