以直接水热合成和低硅沸石高温水蒸气脱铝两种方法制备了不同Si/Al摩尔比的HZSM-5载体,考察了Ga2O3/HZSM-5催化剂上丙烷脱氢制丙烯的反应性能.结合XRD,N2气吸附,27Al MAS NMR和NH3-TPD等表征方法,讨论了催化剂酸性质和孔性质与性能的关...以直接水热合成和低硅沸石高温水蒸气脱铝两种方法制备了不同Si/Al摩尔比的HZSM-5载体,考察了Ga2O3/HZSM-5催化剂上丙烷脱氢制丙烯的反应性能.结合XRD,N2气吸附,27Al MAS NMR和NH3-TPD等表征方法,讨论了催化剂酸性质和孔性质与性能的关系.实验结果表明,减少催化剂表面的中强酸量可以显著提高反应的稳定性和丙烯的选择性;水蒸气脱铝所增加的介孔有同样的效果,这可能是由于介孔的存在有利于丙烯的脱附和扩散而抑制了寡聚、环化等副反应的发生,减少了表面积炭的可能性.展开更多
Heterojunctions composed ofβ-Ga2 O3 and ZnO films are fabricated on sapphire substrates by using the laser molecular beam epitaxy method.The heterojunction possesses excellent rectifying characteristics with an asymm...Heterojunctions composed ofβ-Ga2 O3 and ZnO films are fabricated on sapphire substrates by using the laser molecular beam epitaxy method.The heterojunction possesses excellent rectifying characteristics with an asymmetry ratio over 105.Prominent solar-blind photoresponse effect is also observed in the formed heterojunction.The photodetector exhibits a self-powered behavior with a fast response speed(rise time and decay time are 0.035 s and 0.032 s respectively)at zero bias.The obtained high performance can be related to the built-in field driven photogenerated electron-hole separation.展开更多
制备出高质量纳米晶是金属氧化物纳米晶的基础研究和技术运用的首要问题.在有机溶剂中,利用一步法能够合成出较高结晶度的立方相Ga2O3纳米晶,对该样品的微观形貌和光学性能进行了表征.研究表明,利用一步法获得的纳米晶具有单分散性,晶...制备出高质量纳米晶是金属氧化物纳米晶的基础研究和技术运用的首要问题.在有机溶剂中,利用一步法能够合成出较高结晶度的立方相Ga2O3纳米晶,对该样品的微观形貌和光学性能进行了表征.研究表明,利用一步法获得的纳米晶具有单分散性,晶格条纹明显,平均直径为6n m .在光学性能方面,立方相G a 2O 3纳米晶在紫外区域有较宽的吸收.此外,通过提高合成温度能够从紫外到蓝光范围内调节荧光光谱.展开更多
文摘以直接水热合成和低硅沸石高温水蒸气脱铝两种方法制备了不同Si/Al摩尔比的HZSM-5载体,考察了Ga2O3/HZSM-5催化剂上丙烷脱氢制丙烯的反应性能.结合XRD,N2气吸附,27Al MAS NMR和NH3-TPD等表征方法,讨论了催化剂酸性质和孔性质与性能的关系.实验结果表明,减少催化剂表面的中强酸量可以显著提高反应的稳定性和丙烯的选择性;水蒸气脱铝所增加的介孔有同样的效果,这可能是由于介孔的存在有利于丙烯的脱附和扩散而抑制了寡聚、环化等副反应的发生,减少了表面积炭的可能性.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.51572033,61774019,61704153,and 11404029)the Fund from the State Key Laboratory of Information Photonics and Optical Communications(BUPT),Chinathe Fundamental Research Funds for the Central Universities,China
文摘Heterojunctions composed ofβ-Ga2 O3 and ZnO films are fabricated on sapphire substrates by using the laser molecular beam epitaxy method.The heterojunction possesses excellent rectifying characteristics with an asymmetry ratio over 105.Prominent solar-blind photoresponse effect is also observed in the formed heterojunction.The photodetector exhibits a self-powered behavior with a fast response speed(rise time and decay time are 0.035 s and 0.032 s respectively)at zero bias.The obtained high performance can be related to the built-in field driven photogenerated electron-hole separation.
文摘制备出高质量纳米晶是金属氧化物纳米晶的基础研究和技术运用的首要问题.在有机溶剂中,利用一步法能够合成出较高结晶度的立方相Ga2O3纳米晶,对该样品的微观形貌和光学性能进行了表征.研究表明,利用一步法获得的纳米晶具有单分散性,晶格条纹明显,平均直径为6n m .在光学性能方面,立方相G a 2O 3纳米晶在紫外区域有较宽的吸收.此外,通过提高合成温度能够从紫外到蓝光范围内调节荧光光谱.