Metal oxide mesocrystals are the alignment of metal oxide nanoparticles building blocks into the ordered superstructure,which have potentially tunable optical,electronic,and electrical properties suitable for practica...Metal oxide mesocrystals are the alignment of metal oxide nanoparticles building blocks into the ordered superstructure,which have potentially tunable optical,electronic,and electrical properties suitable for practical applications.Herein,we report an effective method for synthesizing mesocrystal zinc oxide nanorods(ZnONRs).The crystal,surface,and internal structures of the zinc oxide mesocrystals were fully characterized.Mesocrystal zinc oxide nanorods/reduced graphene oxide(ZnONRs/rGO)nanocomposite superstructure were synthesized also using the hydrothermal method.The crystal,surface,chemical,and internal structures of the ZnONRs/rGO nanocomposite superstructure were also fully characterized.The optical absorption coefficient,bandgap energy,band structure,and electrical conductivity of the ZnONRs/rGO nanocomposite superstructure were investigated to understand its optoelectronic and electrical properties.Finally,the photoconductivity of the ZnONRs/rGO nanocomposite superstructure was explored to find the possibilities of using this nanocomposite superstructure for ultraviolet(UV)photodetection applications.Finally,we concluded that the ZnONRs/rGO nanocomposite superstructure has high UV sensitivity and is suitable for UV detector applications.展开更多
The effects of the supporting reagents hexamethylenetetramine(HMTA)and potassium chloride(KCl)mixed in zinc nitrate hexahydrate(Zn(NO3)2 6H2O)on the morphological,structural,and optical properties of the resulting Zn ...The effects of the supporting reagents hexamethylenetetramine(HMTA)and potassium chloride(KCl)mixed in zinc nitrate hexahydrate(Zn(NO3)2 6H2O)on the morphological,structural,and optical properties of the resulting Zn O nanostructures electrodeposited on graphene/glass substrates were investigated.The supporting reagent HMTA does not increase the density of nanorods,but it does remarkably improve the smoothness of the top edge surfaces and the hexagonal shape of the nanorods even at a low temperature of 75°C.Hydroxyl(OH-)ions from the HMTA suppress the sidewall growth of non-polar planes and promote the growth of Zn O on the polar plane to produce vertically aligned nanorods along the c axis.By contrast,the highly electronegative chlorine(Cl-)ions from the supporting reagent KCl suppress the growth of Zn O on the polar plane and promote the growth on non-polar planes to produce vertical stacking nanowall structures.HMTA was found to be able to significantly improve the crystallinity of the grown Zn O structures,as indicated by the observation of much lower FWHM values and a higher intensity ratio of the emission in the UV region to the emission in the visible region.Equimolar mixtures of Zn(NO3)2 6H2O and the supporting reagents HMTA and KCl seem to provide the optimum ratio of concentrations for the growth of high-density,uniform Zn O nanostructures.The corresponding transmittances for such molar ranges are approximately 55–58%(HMTA)and 63–70%(KCl),which are acceptable for solar cell and optoelectronic devices.展开更多
A series of zinc oxide(ZnO)nanorods arrays with different morphologies are synthesized on stainless steel mesh via a facile electrodeposition method.The influences of electrodeposition parameters on the diameter,lengt...A series of zinc oxide(ZnO)nanorods arrays with different morphologies are synthesized on stainless steel mesh via a facile electrodeposition method.The influences of electrodeposition parameters on the diameter,length,density and morphology of obtained ZnO nanorods are investigated systematically.The results indicate that the electrodeposition potential is the key factor for the morphology of the obtained ZnO nanorods,which further showed the effect on the photocatalytic property of the obtained samples.Meanwhile,the prepared ZnO nanorods array exhibits an excellent photocatalytic activity for methylene blue(MB)in ultraviolet light.The degradation efficiency for MB solution reaches 95.1%under the irradiation of ultraviolet light for 120 min.In addition,the photocatalytic property of the prepared ZnO nanorods can be extended to the visible light region after the modified with graphene oxide(GO).The obtained GO/ZnO composite also shows remarkable photocatalytic activity and photostability.The photodegradation efficiency for MB is 83.6%,and the catalytic performance retains 97.3% of its initial photocatalytic activity after five cycles.展开更多
以二氧化锗和二水合醋酸锌为原料,采用水热法制备了锗酸锌纳米棒,并将其与氧化石墨烯复合,制备了石墨烯包覆的锗酸锌纳米棒三维复合材料.SEM等测试表明,锗酸锌纳米棒均匀地穿插在石墨烯片中,阻止了石墨烯片之间相互堆垛,而石墨烯片层之...以二氧化锗和二水合醋酸锌为原料,采用水热法制备了锗酸锌纳米棒,并将其与氧化石墨烯复合,制备了石墨烯包覆的锗酸锌纳米棒三维复合材料.SEM等测试表明,锗酸锌纳米棒均匀地穿插在石墨烯片中,阻止了石墨烯片之间相互堆垛,而石墨烯片层之间相互连接,形成三维的空间导电网络,提高了材料的电子导电性.电化学测试表明,石墨烯片作为稳定的框架,能够有效缓冲活性物质在脱嵌锂过程中产生的体积变化,在500 m A·g^(-1)电流密度下循环190次后,Zn_2GeO_4@RGO复合材料的嵌锂容量仍有1189.5 m Ah·g^(-1);在3.2 A·g^(-1)的大电流密度下,嵌锂容量达到449.5m Ah·g^(-1),表明该复合材料具有优异的长循环稳定性和良好的倍率性能.展开更多
文摘Metal oxide mesocrystals are the alignment of metal oxide nanoparticles building blocks into the ordered superstructure,which have potentially tunable optical,electronic,and electrical properties suitable for practical applications.Herein,we report an effective method for synthesizing mesocrystal zinc oxide nanorods(ZnONRs).The crystal,surface,and internal structures of the zinc oxide mesocrystals were fully characterized.Mesocrystal zinc oxide nanorods/reduced graphene oxide(ZnONRs/rGO)nanocomposite superstructure were synthesized also using the hydrothermal method.The crystal,surface,chemical,and internal structures of the ZnONRs/rGO nanocomposite superstructure were also fully characterized.The optical absorption coefficient,bandgap energy,band structure,and electrical conductivity of the ZnONRs/rGO nanocomposite superstructure were investigated to understand its optoelectronic and electrical properties.Finally,the photoconductivity of the ZnONRs/rGO nanocomposite superstructure was explored to find the possibilities of using this nanocomposite superstructure for ultraviolet(UV)photodetection applications.Finally,we concluded that the ZnONRs/rGO nanocomposite superstructure has high UV sensitivity and is suitable for UV detector applications.
基金funded by Nippon Sheet Glass Corp.the Hitachi Foundation+4 种基金the Malaysia-Japan International Institute of TechnologyUniversiti Teknologi Malaysiathe Malaysian Ministry of ScienceTechnology and Innovationthe Malaysian Ministry of Education through various research Grants
文摘The effects of the supporting reagents hexamethylenetetramine(HMTA)and potassium chloride(KCl)mixed in zinc nitrate hexahydrate(Zn(NO3)2 6H2O)on the morphological,structural,and optical properties of the resulting Zn O nanostructures electrodeposited on graphene/glass substrates were investigated.The supporting reagent HMTA does not increase the density of nanorods,but it does remarkably improve the smoothness of the top edge surfaces and the hexagonal shape of the nanorods even at a low temperature of 75°C.Hydroxyl(OH-)ions from the HMTA suppress the sidewall growth of non-polar planes and promote the growth of Zn O on the polar plane to produce vertically aligned nanorods along the c axis.By contrast,the highly electronegative chlorine(Cl-)ions from the supporting reagent KCl suppress the growth of Zn O on the polar plane and promote the growth on non-polar planes to produce vertical stacking nanowall structures.HMTA was found to be able to significantly improve the crystallinity of the grown Zn O structures,as indicated by the observation of much lower FWHM values and a higher intensity ratio of the emission in the UV region to the emission in the visible region.Equimolar mixtures of Zn(NO3)2 6H2O and the supporting reagents HMTA and KCl seem to provide the optimum ratio of concentrations for the growth of high-density,uniform Zn O nanostructures.The corresponding transmittances for such molar ranges are approximately 55–58%(HMTA)and 63–70%(KCl),which are acceptable for solar cell and optoelectronic devices.
基金supported by the National Natural Science Foundation of China(Nos.51774217,51604202 and 51604201)the Shanghai Sailing Program(No.19YF1415800)the Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education,China(No.FMRU-lab-20-2).
文摘A series of zinc oxide(ZnO)nanorods arrays with different morphologies are synthesized on stainless steel mesh via a facile electrodeposition method.The influences of electrodeposition parameters on the diameter,length,density and morphology of obtained ZnO nanorods are investigated systematically.The results indicate that the electrodeposition potential is the key factor for the morphology of the obtained ZnO nanorods,which further showed the effect on the photocatalytic property of the obtained samples.Meanwhile,the prepared ZnO nanorods array exhibits an excellent photocatalytic activity for methylene blue(MB)in ultraviolet light.The degradation efficiency for MB solution reaches 95.1%under the irradiation of ultraviolet light for 120 min.In addition,the photocatalytic property of the prepared ZnO nanorods can be extended to the visible light region after the modified with graphene oxide(GO).The obtained GO/ZnO composite also shows remarkable photocatalytic activity and photostability.The photodegradation efficiency for MB is 83.6%,and the catalytic performance retains 97.3% of its initial photocatalytic activity after five cycles.
文摘以二氧化锗和二水合醋酸锌为原料,采用水热法制备了锗酸锌纳米棒,并将其与氧化石墨烯复合,制备了石墨烯包覆的锗酸锌纳米棒三维复合材料.SEM等测试表明,锗酸锌纳米棒均匀地穿插在石墨烯片中,阻止了石墨烯片之间相互堆垛,而石墨烯片层之间相互连接,形成三维的空间导电网络,提高了材料的电子导电性.电化学测试表明,石墨烯片作为稳定的框架,能够有效缓冲活性物质在脱嵌锂过程中产生的体积变化,在500 m A·g^(-1)电流密度下循环190次后,Zn_2GeO_4@RGO复合材料的嵌锂容量仍有1189.5 m Ah·g^(-1);在3.2 A·g^(-1)的大电流密度下,嵌锂容量达到449.5m Ah·g^(-1),表明该复合材料具有优异的长循环稳定性和良好的倍率性能.
