光谱学与光谱分析
光譜學與光譜分析
광보학여광보분석
Spectroscopy and Spectral Analysis
2015年
11期
3036-3040
,共5页
李振亚%黄世明%顾牡%刘小林
李振亞%黃世明%顧牡%劉小林
리진아%황세명%고모%류소림
油相法%纳米晶%核壳结构%磷酸镧%发光性能
油相法%納米晶%覈殼結構%燐痠鑭%髮光性能
유상법%납미정%핵각결구%린산란%발광성능
High-temperature organic solution approach%Nanocrystals%Core/shell structure%LaPO4%Luminescent properties
采用油相合成法得到了疏水性、单分散的LaPO4∶Ce3+,LaPO4∶Ce3+/LaPO4和LaPO4∶Ce3+/LaPO4∶Ce3+/LaPO4核壳结构纳米晶。利用X射线衍射(XRD)、透射电镜(TEM )、傅里叶变换红外光谱(FTIR)和光致发光光谱(PL)等分析技术对产物的结构、形貌以及发光性能进行了表征。结果表明:所有样品均为单斜相结构,样品的衍射峰呈现宽化现象,可能由于合成的纳米颗粒尺寸较小;Ce3+掺杂LaPO4纳米晶显示了Ce3+的特征发射,在342 nm处是一个宽带谱,发光强度随着Ce3+掺杂浓度的增加先增加后减小,在浓度为6 at%时发光强度最大,发光强度减弱可能由于浓度猝灭导致的;LaPO4∶Ce3+/LaPO4和La‐PO4∶Ce3+/LaPO4∶Ce3+/LaPO4核壳结构纳米晶光致发光强度比LaPO4∶Ce3+纳米颗粒分别提高了41%和95%左右,这可能是由于纳米晶颗粒尺寸的变大及表面钝化效应共同作用的结果;样品的红外光谱数据显示,在1545和1461 cm-1处出现了分别对应于—COO -的非对称和对称伸缩振动的两个吸收峰,这两个峰的间隔为84 cm-1,样品表面有机物的修饰机制可能是羧基的氧原子以双齿模式与金属镧离子发生了配位。
採用油相閤成法得到瞭疏水性、單分散的LaPO4∶Ce3+,LaPO4∶Ce3+/LaPO4和LaPO4∶Ce3+/LaPO4∶Ce3+/LaPO4覈殼結構納米晶。利用X射線衍射(XRD)、透射電鏡(TEM )、傅裏葉變換紅外光譜(FTIR)和光緻髮光光譜(PL)等分析技術對產物的結構、形貌以及髮光性能進行瞭錶徵。結果錶明:所有樣品均為單斜相結構,樣品的衍射峰呈現寬化現象,可能由于閤成的納米顆粒呎吋較小;Ce3+摻雜LaPO4納米晶顯示瞭Ce3+的特徵髮射,在342 nm處是一箇寬帶譜,髮光彊度隨著Ce3+摻雜濃度的增加先增加後減小,在濃度為6 at%時髮光彊度最大,髮光彊度減弱可能由于濃度猝滅導緻的;LaPO4∶Ce3+/LaPO4和La‐PO4∶Ce3+/LaPO4∶Ce3+/LaPO4覈殼結構納米晶光緻髮光彊度比LaPO4∶Ce3+納米顆粒分彆提高瞭41%和95%左右,這可能是由于納米晶顆粒呎吋的變大及錶麵鈍化效應共同作用的結果;樣品的紅外光譜數據顯示,在1545和1461 cm-1處齣現瞭分彆對應于—COO -的非對稱和對稱伸縮振動的兩箇吸收峰,這兩箇峰的間隔為84 cm-1,樣品錶麵有機物的脩飾機製可能是羧基的氧原子以雙齒模式與金屬鑭離子髮生瞭配位。
채용유상합성법득도료소수성、단분산적LaPO4∶Ce3+,LaPO4∶Ce3+/LaPO4화LaPO4∶Ce3+/LaPO4∶Ce3+/LaPO4핵각결구납미정。이용X사선연사(XRD)、투사전경(TEM )、부리협변환홍외광보(FTIR)화광치발광광보(PL)등분석기술대산물적결구、형모이급발광성능진행료표정。결과표명:소유양품균위단사상결구,양품적연사봉정현관화현상,가능유우합성적납미과립척촌교소;Ce3+참잡LaPO4납미정현시료Ce3+적특정발사,재342 nm처시일개관대보,발광강도수착Ce3+참잡농도적증가선증가후감소,재농도위6 at%시발광강도최대,발광강도감약가능유우농도졸멸도치적;LaPO4∶Ce3+/LaPO4화La‐PO4∶Ce3+/LaPO4∶Ce3+/LaPO4핵각결구납미정광치발광강도비LaPO4∶Ce3+납미과립분별제고료41%화95%좌우,저가능시유우납미정과립척촌적변대급표면둔화효응공동작용적결과;양품적홍외광보수거현시,재1545화1461 cm-1처출현료분별대응우—COO -적비대칭화대칭신축진동적량개흡수봉,저량개봉적간격위84 cm-1,양품표면유궤물적수식궤제가능시최기적양원자이쌍치모식여금속란리자발생료배위。
Hydrophobic ,monodisperse LaPO4 ∶Ce3+ nanoparticles ,LaPO4 ∶Ce3+ /LaPO4 and LaPO4 ∶Ce3+ /LaPO4 ∶Ce3+ /LaPO4 core/shell structure nanocrystals were synthesized via a high‐temperature organic solution approach .The as‐synthesized samples were characterized by X‐ray diffraction (XRD) ,transmission electron microscopy (TEM ) ,Fourier transform infrared spectroscopy (FTIR) and photoluminescence spectroscopy (PL) .The results show that :all the samples are a monoclinic phase , Because of the size small nanoparticles ,the diffraction peaks of the sample occurs width phenomenon .The LaPO4 ∶Ce3+ nano‐crystals exhibits the characteristic emission of Ce3+ ions ,the photoluminescence intensity increases first and then decreases with the increasing doping concentration of Ce3+ ions ,and the best doping amount is 6 at% ,with the increasing doping amount ,the photoluminescence intensity decreases which may caused by the concentration quenching .Compared to LaPO4 ∶Ce3+ nanoparti‐cles ,the photoluminescence intensity of LaPO4 ∶ Ce3+ /LaPO4 and LaPO4 ∶ Ce3+ /LaPO4 ∶ Ce3+ /LaPO4 core/shell structure nanocrystals improves about 41% and 95% respectively ,this may be a synergy of larger particle size of nanocrystals and surface passivation effect .FTIR spectra data shows that the absorption peak at 1 545 and 1 461 cm-1 corresponded to the asymmetric and symmetric stretching vibration of —COO - ,the separation ,Δ,between the two peaks is 84 cm-1 ,The mechanism of the sample surface modification by the organics might be that the oxygen atoms of the carboxyl are coordinated with the lanthunum ions by a bidentate mode .