中国科学技术大学学报
中國科學技術大學學報
중국과학기술대학학보
JOURNAL OF UNIVERSITY OF SCIENCE AND TECHNOLOGY OF CHINA
2014年
8期
672-678
,共7页
方明亮%鲍捷%王超%杨晓喻%洪德雄%蔡亮%陈琳%孙治湖
方明亮%鮑捷%王超%楊曉喻%洪德雄%蔡亮%陳琳%孫治湖
방명량%포첩%왕초%양효유%홍덕웅%채량%진림%손치호
介孔%Co3 O4 纳米片%超级电容性能
介孔%Co3 O4 納米片%超級電容性能
개공%Co3 O4 납미편%초급전용성능
mesoporous%Co3 O4 nanosheet%supercapacitive property
利用X射线衍射(XRD )、透射电子显微镜(T EM )、恒温氮气吸附等技术,研究了不同焙烧温度下制备的介孔Co3 O4纳米片的物相和微结构特点,明确了焙烧温度影响介孔Co3 O4纳米片超级电容性能的微观机理.XRD和T EM 结果表明,不同焙烧温度下获得的产物均为尖晶石结构的介孔Co3 O4纳米片,且随着焙烧温度的升高,样品的结晶性增强.恒温氮气吸附结果表明,随着焙烧温度从300℃增加到500℃,介孔Co3 O4纳米片的BET 比表面积从27.9 m2/g降低到2.2 m2/g .电化学测试结果表明,400℃焙烧产物具有最优的超级电容性能,其比电容值为151 F/g ,是300和500℃焙烧产物比电容值的2倍左右.基于上述表征结果,我们提出样品结晶性和表面微结构的协同作用是决定介孔Co3 O4纳米片超级电容性能的关键因素:与300℃焙烧样品相比,400℃焙烧产物具有更好的结晶性,利于电极氧化还原反应过程中电子的传输迁移;与500℃焙烧样品相比,400℃焙烧产物具有更为适中的B E T比表面积,利于电解液参与电极反应.
利用X射線衍射(XRD )、透射電子顯微鏡(T EM )、恆溫氮氣吸附等技術,研究瞭不同焙燒溫度下製備的介孔Co3 O4納米片的物相和微結構特點,明確瞭焙燒溫度影響介孔Co3 O4納米片超級電容性能的微觀機理.XRD和T EM 結果錶明,不同焙燒溫度下穫得的產物均為尖晶石結構的介孔Co3 O4納米片,且隨著焙燒溫度的升高,樣品的結晶性增彊.恆溫氮氣吸附結果錶明,隨著焙燒溫度從300℃增加到500℃,介孔Co3 O4納米片的BET 比錶麵積從27.9 m2/g降低到2.2 m2/g .電化學測試結果錶明,400℃焙燒產物具有最優的超級電容性能,其比電容值為151 F/g ,是300和500℃焙燒產物比電容值的2倍左右.基于上述錶徵結果,我們提齣樣品結晶性和錶麵微結構的協同作用是決定介孔Co3 O4納米片超級電容性能的關鍵因素:與300℃焙燒樣品相比,400℃焙燒產物具有更好的結晶性,利于電極氧化還原反應過程中電子的傳輸遷移;與500℃焙燒樣品相比,400℃焙燒產物具有更為適中的B E T比錶麵積,利于電解液參與電極反應.
이용X사선연사(XRD )、투사전자현미경(T EM )、항온담기흡부등기술,연구료불동배소온도하제비적개공Co3 O4납미편적물상화미결구특점,명학료배소온도영향개공Co3 O4납미편초급전용성능적미관궤리.XRD화T EM 결과표명,불동배소온도하획득적산물균위첨정석결구적개공Co3 O4납미편,차수착배소온도적승고,양품적결정성증강.항온담기흡부결과표명,수착배소온도종300℃증가도500℃,개공Co3 O4납미편적BET 비표면적종27.9 m2/g강저도2.2 m2/g .전화학측시결과표명,400℃배소산물구유최우적초급전용성능,기비전용치위151 F/g ,시300화500℃배소산물비전용치적2배좌우.기우상술표정결과,아문제출양품결정성화표면미결구적협동작용시결정개공Co3 O4납미편초급전용성능적관건인소:여300℃배소양품상비,400℃배소산물구유경호적결정성,리우전겁양화환원반응과정중전자적전수천이;여500℃배소양품상비,400℃배소산물구유경위괄중적B E T비표면적,리우전해액삼여전겁반응.
Measurements of XRD (X-ray diffraction) ,TEM (transmission electron microscopy ) and N2 adsorption-desorption isotherms were combined to study the phase and microstructure of mesoporous Co3 O4 nanosheets synthesized at different temperatures . The mechanism of calcination temperature influencing the supercapacitive performance of the Co3 O4 nanosheets was also investigated .It is indicated from the XRD and TEM results that the as-prepared Co3 O4 nanosheets are in a pure spinel phase and in a mesoporous morphology, and the crystallinity increases with the calcination temperature. The N2 adsorption-desorption isotherms measurement shows a decrease of the specific surface area from 27.9 to 2.2mg as the calcination temperature increases from 300 to 500 ℃ . Electrochemical characterization reveals the best supercapacitor performance of the nanosheets obtained at 400 ℃ ,with a capacity of 151 F/g that is twice the values of the products calcined at 300 and 500 ℃ .Based on these results ,it was proposed that the synergistic effects of the crystallinity and the surface microstructure of the mesoporous microstructures are key factors for the supercapacitive performance of the Co3 O4 nanosheets .Compared with the nanosheets calcined at 300 ℃ ,the 400 ℃ sample possesses better crystallinity ,which is beneficial to the electron transfer during the redox reaction of the electrodes .In comparison with the nanosheets calcined at 500 ℃ ,the 400 ℃ calcined sheets have the proper BET specific surface area ,facilitating the participation of electrolyte in the electrode reaction .