• <tr id="yyy80"></tr>
  • <sup id="yyy80"></sup>
  • <tfoot id="yyy80"><noscript id="yyy80"></noscript></tfoot>
  • 99热精品在线国产_美女午夜性视频免费_国产精品国产高清国产av_av欧美777_自拍偷自拍亚洲精品老妇_亚洲熟女精品中文字幕_www日本黄色视频网_国产精品野战在线观看 ?

    改進型溶膠-凝膠法制備粒徑可調(diào)高染料吸附量TiO2微球及其在染敏電池光散射層中的應用

    2013-10-17 03:03:04魏玉龍包春雄鄒志剛
    無機化學學報 2013年10期
    關鍵詞:南京大學微球南京

    黃 歡 魏玉龍 包春雄 高 皓 于 濤*, 鄒志剛

    (1南京大學固體微結(jié)構(gòu)物理國家重點實驗室,南京 210093)

    (2南京大學物理學院環(huán)境材料與再生能源研究中心,南京 210093)

    (3南京大學材料科學與工程系,南京 210093)

    With more fierce energy crisis,interests on sustainable and renewable energy is keeping growing nowadays,among which solar cells have risen a worldwide attention.In the past two decades,Dyesensitized solar cell(DSSC)has been considered as a promising alternative to conventional p-n junction solar cell due to its low-cost fabrication process and efficient solar energy conversion efficiency[1-3].A typical DSSC has a sandwich like structure consisting of a dyeadsorbed photoelectrode and a Pt counter electrode filled with an iodide/triiodide redox electrolyte.In the structure,the photoanode plays a crucial role in determining the light harvest and charge transport properties[4-7].By using nanoparticles with the size of 10~20 nm,photoelectrode of conventional TiO2-based DSSC obtains a large surface area and therefore increases the dye adsorption[8].However,photoanode fabricated using such nanoparticle form of TiO2is transparent to visible light and weak in visible light scattering due to the small particle size[9-11].Hence,large particles have been deposited on top of the nanocrystalline photoanode as a scattering layer[12-13].Recently,over 10%increase in the light-to-electricity conversion efficiency has been achieved by using 100nm-sized TiO2particles[14].Meanwhile,the introduction of large particles into the photoanode will limit the performance of DSSC due to insufficient surface area and correspondingly decrease dye adsorption.One way to solve this problem is to use nanoporous TiO2spheres to getgood scattering performance as well as effective dye adsorption.

    Synthesis of TiO2spheres with selective size and crystal phase is crucial to the performance of scattering layer[15].The phase of anatase is preferred than rutile for DSSC because of its larger band gap[16],while the monodispersed spherical TiO2with a minimum size variation (less than 10%)is also preferred.Several methods like hydrolysis method and templating method have been used to obtain TiO2spheres[4,17-18].However,synthesis of size-controlled monodispersed TiO2spheres is hard because hydrolysis speed is too fast.

    In the present work,size-controlled monodispersed TiO2spheres were achieved via controlled hydrolysis and condensation of appropriate precursors[19].The synthetic nanoporous TiO2-spheres of anatase phase with a diameter ranging from 100 nm to 475 nm were used as the scattering layers of DSSCs.By achieving the effect of scattering effect as well as the high amount of dye adsorption,DSSCs with scattering layers show superior light-electricity properties.By using the 475 nm-sized spheres,a 6.3%overall energy conversion efficiency hasbeen achieved,indicating a 30%increase compared to photoanode using only nanoparticle film (4.75%).The scattering layer was fabricated by electrophoresis deposition(EPD)method due to its good performance in forming uniform layers with controllable thickness[20-22].

    1 Experimental

    1.1 Synthesis of TiO2nanoparticles and porous TiO2Spheres with different sizes

    Preparation of TiO2nanoparticles:an amount of 6 g(0.1 mol)of acetic acid was added dropwise to 29.3g(0.1 mol)of titanium iso-propoxide under vigorous stirring for 15 min at room temperature.Then the precursor was poured into 200 mL water as quickly as possible with vigorous stirring.40 min was required to achieve a complete hydrolysis reaction.By adding 2 mL 65%nitric acid,the mixture was heated from room temperature to 80℃in the water bath within 30 min and peptized for 1 h.Then water was added to adjust the volume to 150 mL as well as to cool down the liquid mixture.After heating at 210 ℃ in the autoclave for 12 h,the mixture was washed with ethanol for three times and then dried at 80℃ for 12 h.

    Preperation of nanoporous TiO2spheres:to prepare the spherical titanium glycolate precursors,0.2 mL,0.5 mL,0.8 mL,1.1 mL titanium ビ isopropoxide(TIP,98%,Acros Organics)were added,respectively,to 10 mL ethylene glycol(EG,99.8%,Nanjing Chemical Reagent Ltd.).After stirring for 10 min,the samples were quickly poured into an acetone bath (200 mL)containing trace of water(0.5 mL)under strong stirring for 20 min to form spherical colloids.By centrifuging and washing with ethanol for three times,the samples were dried in the air for 12 h at 80℃.The samples were harvested by annealing at 500℃.

    1.2 Fabrication of dye-sensitized solar cells

    To prepare the photoanodesofDSSCs,the synthesized TiO2nanoparticles,ethyl cellulose,terpinol with a mass ratio of 1∶1∶2,respectively,were added into ethanol under vigorous stirring.The paste was made by rotary evaporation for 2 h in a 30 ℃ water bath.Then,the prepared paste was coated on the bare fluorinedoped tin oxide (FTO)glass using the doctor blade method.After drying for 10 min,the prepared film was calcined at 500℃for 30 min(ramp rate 10℃·min-1).

    The scattering layers with different sizes of TiO2spheres were fabricated by EPD method.In the process of electrophoretic treatment,the as-prepared film and a piece of bare FTO glass with a distance of 10 mm were used as the anode and cathode.Then the samples were placed parallelly in the suspension consisting of 100 mL acetone,10 mg iodine and 50 mg TiO2spheres.The EPD voltage was set at 15 V and held for various time to get different thicknesses of the scattering layer.The bilayer film was then sintered over the same heating profile as previously.The calcined TiO2electrode was immersed in a 3 ×10-4mol·L-1solution of N719(Solaronix S.A,Aubonne,Switzerland)in ethanol at room temperature for 24 hours.

    The counter electrode,a magnetron sputter platinum mirror,was then clipped onto the top of the TiO2photoanode to form a sandwich-like open cell.The electrolyte was composed of 1.0 mol·L-1BMII(1-butyl-3-methylimidazolium iodide),50 mmol·L-1LiI,30 mmol·L-1I2and 0.5 mol·L-1tert-butylpyridine in a mixed solvent of acetonitrile and valeronitrile.

    1.3 Characterizations

    To examine the crystallinity ofas-prepared particles,X-ray diffraction patterns were collected on a Rigaku Ultimal III X-ray diffractometer(Cu Kα,λ=0.154 18 nm)in the range of 10°~80°at a scan rate of 1°·min-1(2θ).TiO2spheres were observed through Field-emission scanning electron microscope(FE-SEM,FEI NANOSEM 230,15 kV).The BET surface area was measured on a Tristar micromeritics surface area analyzer.The film thickness was measured on a Dektak 6M stylus profiler.The transmission spectra were measured by a Cary 50 probe UV-Visible spectrophotometer.The test for photoelectric performance was taken on a Keithley 236 source measurement unit under AM 1.5 illumination with an active area of 0.132 cm2.The illumination was cast by Oriel 92251A-1000 sunlight simulator calibrated by the standard reference of a Newport 91150 silicon solar cell.The incident monochromatic photo to electron conversion efficiency (IPCE)were measured by a selfbuilt computerized apparatus[23].

    2 Results and discussion

    2.1 Characterization

    2.1.1 XRD analysis

    Compared with rutile TiO2,anatase TiO2is demonstrated to be more suitable for DSSCs[24].According to the XRD patterns shown in Fig.1,no diffraction peaks of rutile or brookite phases of TiO-2are found,the phases of synthesized TiO2nanoparticles and spheres are both pure anatase phase.The crystallite size of the samples can be estimated by the full width at half-maximum(FWHM)of the(101)peak of the anatase phase,based on the Scherrer equation.As a result,the calculated crystallite sizes of TiO2nanoparticles and spheres(NS475,NS225,NS175,NS100)are 11.2 nm and 12.9 nm,13.5 nm,13.2 nm,14.5 nm.

    Fig.1 XRD of TiO2powders for nanoparticle and sphere

    2.1.2 SEM analysis

    Fig.2(a)and Fig.2(c)present the FE-SEM images of the as-synthesized nanoporous TiO2spheres before and after annealing at 500℃.Obviously,the spheres synthesized before annealing exhibit a well-defined spherical morphology with smooth surfaces.After annealing,the spherical nanoporous TiO2are formed,turning the surface of the spheres to be rough.By changing the quantity of added TIP(0.2 mL,0.5 mL,0.8 mL,1.1 mL),different sizes of nanoporous TiO2spheres were achieved.As is shown in Fig.2(c~f),the sphere sizes with a narrow distribution of less than 15%are 475 nm,225 nm,175 nm,100 nm,respectively.From the results,we can see that the size of the TiO2spheres can be controlled by controlling the concentration of titanium glycolate precursors in acetone.Research has found that an increase in water content in the hydrolysis reaction produces a higher nucleation rate[25-27]which leading to the formation of larger spheres.With the amount of TIP increasing from 0.2 mL to 1.1 mL,the water content in acetone decreases relatively,which makes the size of the achieved nanoporous TiO2spheres decrease from 475 nm to 100 nm.

    2.1.3 BET surface area analysis

    The BET surface area of the TiO2nanoparticles and spheres(NS475,NS225,NS175,NS100)are 118 and 98,101,103,109 m2·g-1,respectively.Fig.3 shows the N2adsorption-desorption isotherm and pore size distribution of the 475 nm-sized TiO2spheres.The type-IV isotherm with H2-type hysteresis loops at high relative pressures (P/P0=0.65 ~0.95)indicates a mesoporous structure[28].According to the Barrett-Joyner-Halenda(BJH)model,the inset figure reveals a relative narrow pore size distribution in the range of 10~15 nm indicating that the TiO2spheres are nanoporous.

    Fig.2 FE-SEM images of(a)as-synthesized spheres before annealing at 500 ℃;(b)cross-section image of bi-layered DSSC;(c~f)TiO2spheres with size of 475 nm,225 nm,175 nm,100 nm

    Fig.3 Nitrogen sorption isotherms and pore size distribution(inset)of the nanoporous TiO2 spheres(475 nm)

    2.2 Photovoltaic performance test

    The as-synthesized nanoporous TiO2spheres and nanoparticles were employed as photoanodes to assemble the DSSCs.A layer of nanoparticles(NP)was madeusingthedoctorblademethod whilethe scattering layers with different sizes of spheres(NS100,NS175,NS225,NS475)were made by the EPD method.Fig.2(b)shows the cross-section FE-SEM image of the photoanode film.From the image,the thickness of the film is 12 μm.The 475nm-sized spheres(NS475)were used as the scattering layer,the thickness of which is 6 μm.For comparison,the thickness of a photoanode film assembled with NP was also controlled to 12 μm.The current density-voltage (J-V) curves of DSSCs fabricated with two photoanode films(NP,NP+NS475)are shown in Fig.4.The corresponding photovoltaic parameters of the two cells are summarized in Table 1,including thickness of NP layer and NS layer,open circuit voltage (VOC),short circuit current density(JSC),fill factor(FF),and efficiency(η).We can see that the DSSC made of NP possesses an efficiency of about 4.75% .In contrast,the DSSC made of NP+NS475 shows a higher value of efficiency of about 6.3%,which represents a 32.6%enhancement compared to the former one.

    Fig.4 I-V curves of DSSC devices made with NS100,NS175,NS225,NS475 as the scattering layers

    Different sizes of TiO2spheres (NS100,NS175,NS225,NS475)are employed as scattering layers in DSSCs(NP+NS100,NP+NS175,NP+NS225,NP+NS475)to study the scattering effect of TiO2spheres.The thickness of the nanoparticle layer and scattering layer were adjusted to 12 μm by controlling the time of electrophoresis deposition.Photovoltaic properties of the DSSCs are summarized in Fig.4 and Table 1.An obvious increase of JSC,from 10.0 mA·cm-2to 13.7 mA·cm-2,is observed when the scattering layer is used.With the size of spheres increasing,more visible light is scattered so as to generate more photoelectrons,which hasa positive effecton the photocurrent.The increasementin photocurrentalso resultsin an improvement in photo-current conversion efficiency from 4.75%to 6.3%.

    Table 1 Photovoltaic properties of the bi-layered DSSCs based on scattering layers with different sizes of spheres

    To further study the scattering effect of the spheres,transmission spectra of the samples are characterized and shown in Fig.5.From the spectra,it is clearly that,with the size of the spheres getting larger,the transmittance of the cell is getting lower,which meansthe larger-sized sphereshave a stronger scattering effect,attributed to enhancement of light harvesting by Mie scattering effect[29-31].

    Fig.5 Transmission spectra of photoanodes using different sizes of TiO2spheres as scattering layers

    The incident-photo-current conversion efficiency(IPCE)spectra of the DSSCs is shown in Fig.6 to provide more evidence of the scattering effect.The DSSCs within scattering layers show a significant increase in IPCE over the wavelength range of 400~600 nm compared with the DSSC without scattering layers,implying that scattering layers enhance the photoelectric conversion efficiency of DSSCs.With the size of the spheres getting larger,the value of IPCE increases,which isin wellagreementwith the transmission spectra and circuitcurrentdensity.Considering the amount of dye adsorption,the cells with scattering layers have almost the same dye-loading with the cell fabricated with nanoparticles,the amount of adsorbed dye per unit surface area(desorbed from the electrode by NaOH aqueous solution)are as follows:NP+NS100:4.60 ×10-7mol·m-2,NP+NS175:4.52 ×10-7mol·m-2,NP+NS225:4.47×10-7mol·m-2,NP+NS475:4.35×10-7mol·m-2,NP:4.71×10-7mol·m-2.The relative high amounts of dye adsorption help the scattering layers scattering more light as well as absorbing enough dye to generate more photoelectrons than NP,which results in higher IPCE values in turn.The IPCE of the cell NP+NS475 reaches as high as 75%at the wavelength of 520nm indicating its better photoelectric performance,which is in well agreement with the I-V curve.

    Fig.6 IPCE spectra of DSSCs:NP,NP+NS100,NP+NS175,NP+NS225,NP+NS475

    3 Conclusions

    In present work,size-controlled anatase nanoporous TiO2spheres with relative high dye-loading(100 nm,175 nm,225 nm,475 nm)were synthesized via a modified sol-gel method by controlling the concentration of the precursor.The as-synthesized spheres with different sizes can be used as scattering layers on a nanoparticle TiO2film by electrophoresis deposition method to form bi-layered dye-sensitized solar cells(DSSCs).Due to the effect of scattering effect as well as the high amount of dye adsorption,DSSCs with scattering layers show superior photoelectrical properties.It has been proved that the 475 nm-sized spheres have superior light scattering effect.Due to the scattering effect as well as the relative high dye-loading,an overall photoelectric conversion efficiency of 6.3%has been achieved,a 30%increase compared with the nanoparticle-based photoanode.

    [1]O′Regan B C,Gr?tzel M.Nature,1991,353:737-740

    [2]Gr?tzel M.Nature,2001,414:338-344

    [3]Gr?tzel M.Inorg.Chem.,2005,44:6841-6851

    [4]Wang H E,Zheng L X,Liu C P,et al.J.Phys.Chem.C,2011,115(21):10419-10425

    [5]Cheung K Y,Yip C T,Djurisic A B,et al.Adv.Funct.Mater.,2007,17:555-562

    [6]Wang Z S,Kawauchi H,Kashima T,et al.Chem.Rev.,2004,248:1381-1389

    [7]Liu B,Boercker J E,Aydil E S,et al.Nanotechnology,2008,19:1-7

    [8]Tan B,Wu Y.J.Phys.Chem.B,2006,110:15932-15938

    [9]Yong W,Yu T,Liu B Q,et al.Funct.Mater.Lett.,2012,5:1-6

    [10]Hore S,Vetter C,Kern R,et al.Sol.Energy Mater.Sol.Cells,2006,90:1176-1188

    [11]Chen D,Huang F,Cheng Y B,et al.Adv.Mater.,2009,21:2206-2210

    [12]Yang W G,Wan F R,Chen Q W,et al.J.Mater.Chem,2010,20:2870-2876

    [13]Huang F,Chen D,Zhang X L,et al.Adv.Funct.Mater.,2010,20:1-5

    [14]Wang Z S,Kawauchi H,Kashima T,et al.Chem.Rev.2004,248:1381-1389

    [15]Mou Pal,Garicia J,Santiago P,et al.J.Phys.Chem.C,2007,111:96-102

    [16]Kay A,Gratzel M.Solar Energy Mater.Solar Cell,1996,44:99-117

    [17]Wang P,Zakeeruddin S M,Moser J E,et al.J.Phys.Chem.B,2003,107(48):13280-13285

    [18]Jung H G,Kang Y S,Sun Y K,et al.Elect Acta,2010,55:4637-4641

    [19]Jiang X,Herricks T.Adv.Mater.,2003,15(14):1205-1209

    [20]Matthews D J,Kay A,Gratzel M.Chem.,1994,47:1869-1877

    [21]Grinis L J,Dor S,Ofir A,et al.Photochem.Photobiol.A,2008,198(1):52-59

    [22]TANG Ze-Kun(唐澤坤),HUANG Huan(黃歡),GUANG Jie(管杰),et al.Chinese J.Inorg.Chem.(Wuji Huaxue Xuebao),2012,28:2401-2406

    [23]Xue G G.J.Phys.D:Appl.Phys.,2013,45:425104

    [24]Park N G,Van de Lagemaat J,Frank A J.J.Phys.Chem.B,2000,104:8989-8994

    [25]Nagpal V J,Riffe J S,Davis R M.Colloids Surfaces,1994,87(1):25-31

    [26]Barringer E A,Bowen H K.Langmuir,1985,1(4):414-420

    [27]Parkar J C,Siegel R W.Mater J.Res.,1990,5(6):1246-1252

    [28]Park N G,Van de Lagemaat J,Frank A J,et al.J.Phys.Chem.B,2000,104:8989-8994

    [29]Ito S,Murakami T N,Comte P,et al.Thin Solid Films,2008,516(14):4613-4619

    [30]Qian J F,Liu P,Xiao Y,et al.Adv.Mater.,2009,21(36):3663-3667

    [31]Frank A J,Kopidakis N,Coord J,et al.Chem.Rev.,2004,248(13):1165-1179

    猜你喜歡
    南京大學微球南京
    南京比鄰
    “南京不會忘記”
    我校黨委書記柴林一行赴南京大學交流學習
    《南京大學學報數(shù)學半年刊》征稿簡則
    懸浮聚合法制備窄尺寸分布聚甲基丙烯酸甲酯高分子微球
    南京·九間堂
    金色年華(2017年8期)2017-06-21 09:35:27
    又是磷復會 又在大南京
    TiO2/PPy復合導電微球的制備
    Comprendre et s'entendre
    法語學習(2015年6期)2015-04-17 16:58:42
    échange humain sous le contexte de la mondialisation
    法語學習(2015年1期)2015-04-17 06:13:06
    亚洲色图av天堂| 午夜两性在线视频| 黑人巨大精品欧美一区二区蜜桃| 欧美日本中文国产一区发布| 一级,二级,三级黄色视频| 一进一出抽搐动态| 两个人看的免费小视频| 亚洲国产高清在线一区二区三 | 国产又色又爽无遮挡免费看| 十八禁网站免费在线| 91av网站免费观看| 老司机午夜十八禁免费视频| 老司机午夜福利在线观看视频| 久久久久国内视频| 国产一区在线观看成人免费| 长腿黑丝高跟| 美女高潮喷水抽搐中文字幕| 国产精品爽爽va在线观看网站 | 国产精品久久久人人做人人爽| 亚洲久久久国产精品| 国产精品香港三级国产av潘金莲| 日韩欧美一区二区三区在线观看| 99热只有精品国产| 琪琪午夜伦伦电影理论片6080| 香蕉丝袜av| 一级,二级,三级黄色视频| 亚洲人成电影免费在线| 一级作爱视频免费观看| 国产视频一区二区在线看| 精品高清国产在线一区| 91在线观看av| 女性被躁到高潮视频| 久久香蕉精品热| 老汉色∧v一级毛片| 91成人精品电影| 国产高清激情床上av| 99国产精品免费福利视频| 亚洲av日韩精品久久久久久密| 性色av乱码一区二区三区2| 国产精品 国内视频| 真人一进一出gif抽搐免费| 国产区一区二久久| 国产aⅴ精品一区二区三区波| 日韩欧美国产在线观看| 久久久久久免费高清国产稀缺| 日韩欧美一区二区三区在线观看| 在线观看免费日韩欧美大片| 高潮久久久久久久久久久不卡| 欧美成人午夜精品| 久久精品影院6| 久久九九热精品免费| 欧美国产日韩亚洲一区| 亚洲中文字幕日韩| АⅤ资源中文在线天堂| 99久久国产精品久久久| 午夜福利影视在线免费观看| 美女午夜性视频免费| 欧美成人性av电影在线观看| 国产成人啪精品午夜网站| www日本在线高清视频| 国产麻豆成人av免费视频| 制服人妻中文乱码| 老熟妇仑乱视频hdxx| 99在线人妻在线中文字幕| 香蕉国产在线看| 亚洲在线自拍视频| 97碰自拍视频| 午夜福利免费观看在线| 久久久国产成人精品二区| 国产亚洲精品av在线| 91成人精品电影| 日韩欧美免费精品| 成人国语在线视频| 亚洲色图av天堂| 在线观看免费视频网站a站| 亚洲一码二码三码区别大吗| 国产片内射在线| 国产视频一区二区在线看| 亚洲激情在线av| 久久精品成人免费网站| 亚洲第一电影网av| 国产视频一区二区在线看| 黄片小视频在线播放| 给我免费播放毛片高清在线观看| 欧美一级a爱片免费观看看 | 日本三级黄在线观看| 中文字幕av电影在线播放| 欧美性长视频在线观看| 午夜福利高清视频| 久久婷婷人人爽人人干人人爱 | 欧美国产日韩亚洲一区| 亚洲色图综合在线观看| 成年版毛片免费区| 日韩欧美国产一区二区入口| 久久狼人影院| 女性生殖器流出的白浆| 男女下面插进去视频免费观看| 一个人观看的视频www高清免费观看 | 丁香欧美五月| 99在线人妻在线中文字幕| 中国美女看黄片| 桃色一区二区三区在线观看| 黑人欧美特级aaaaaa片| 欧美不卡视频在线免费观看 | 国产精品野战在线观看| 757午夜福利合集在线观看| 纯流量卡能插随身wifi吗| 午夜福利一区二区在线看| 成在线人永久免费视频| 欧美在线一区亚洲| 精品国产一区二区久久| 夜夜夜夜夜久久久久| 三级毛片av免费| 国产av精品麻豆| 美女午夜性视频免费| 一个人免费在线观看的高清视频| 色精品久久人妻99蜜桃| 国产熟女午夜一区二区三区| 极品人妻少妇av视频| 日韩欧美在线二视频| 成人欧美大片| 亚洲一区中文字幕在线| 村上凉子中文字幕在线| 两个人免费观看高清视频| 长腿黑丝高跟| 在线观看午夜福利视频| 十分钟在线观看高清视频www| 中文字幕久久专区| 国产精品98久久久久久宅男小说| 国产男靠女视频免费网站| 在线天堂中文资源库| 国产精品 国内视频| 少妇的丰满在线观看| 精品久久久久久久人妻蜜臀av | 欧美av亚洲av综合av国产av| 国产一区二区三区综合在线观看| 午夜亚洲福利在线播放| av欧美777| 欧美日韩中文字幕国产精品一区二区三区 | 国产蜜桃级精品一区二区三区| 国产亚洲欧美在线一区二区| 亚洲精品久久国产高清桃花| 国产极品粉嫩免费观看在线| 亚洲avbb在线观看| 一级毛片高清免费大全| 亚洲熟女毛片儿| 男女做爰动态图高潮gif福利片 | 精品久久蜜臀av无| 精品国产国语对白av| 不卡一级毛片| 午夜福利一区二区在线看| 日韩欧美免费精品| 无人区码免费观看不卡| 日日夜夜操网爽| 日韩中文字幕欧美一区二区| 久久亚洲精品不卡| 国内毛片毛片毛片毛片毛片| 免费不卡黄色视频| 黑人操中国人逼视频| 亚洲精品在线美女| 女性生殖器流出的白浆| 色av中文字幕| 午夜视频精品福利| 黄频高清免费视频| 国产99久久九九免费精品| 免费看a级黄色片| 欧美在线一区亚洲| 午夜免费鲁丝| 神马国产精品三级电影在线观看 | 视频区欧美日本亚洲| 少妇的丰满在线观看| 侵犯人妻中文字幕一二三四区| 午夜福利在线观看吧| 人妻丰满熟妇av一区二区三区| 国产精品影院久久| 久久性视频一级片| 欧美国产精品va在线观看不卡| 日韩欧美一区二区三区在线观看| 亚洲一卡2卡3卡4卡5卡精品中文| 91在线观看av| 在线免费观看的www视频| 国产国语露脸激情在线看| 欧美性长视频在线观看| 免费在线观看完整版高清| 热99re8久久精品国产| 亚洲午夜理论影院| 宅男免费午夜| 性少妇av在线| 九色亚洲精品在线播放| 亚洲无线在线观看| 最新美女视频免费是黄的| 一区二区三区激情视频| 男女之事视频高清在线观看| 久久久久久久久免费视频了| 女人高潮潮喷娇喘18禁视频| 在线观看午夜福利视频| 欧美绝顶高潮抽搐喷水| 亚洲无线在线观看| 两个人看的免费小视频| 亚洲国产看品久久| 国产欧美日韩一区二区精品| 国产精品1区2区在线观看.| 黄色视频不卡| svipshipincom国产片| 亚洲国产欧美日韩在线播放| av网站免费在线观看视频| 啦啦啦韩国在线观看视频| 天天躁狠狠躁夜夜躁狠狠躁| 久久性视频一级片| 一本大道久久a久久精品| 国产精品,欧美在线| x7x7x7水蜜桃| 身体一侧抽搐| 又大又爽又粗| 欧美性长视频在线观看| 午夜福利免费观看在线| 在线播放国产精品三级| 久久人人精品亚洲av| 91av网站免费观看| 精品久久久久久久人妻蜜臀av | 女人被狂操c到高潮| 国产亚洲av高清不卡| 天天添夜夜摸| 国产成人av激情在线播放| 午夜影院日韩av| 青草久久国产| 国产熟女xx| 18禁国产床啪视频网站| 精品久久蜜臀av无| 乱人伦中国视频| 1024视频免费在线观看| 丝袜美足系列| 99国产精品免费福利视频| 91麻豆av在线| 亚洲伊人色综图| 这个男人来自地球电影免费观看| 少妇熟女aⅴ在线视频| 黄色女人牲交| 后天国语完整版免费观看| 亚洲av片天天在线观看| 搡老岳熟女国产| 丰满的人妻完整版| 国产精品久久久av美女十八| 久久中文字幕人妻熟女| 亚洲精华国产精华精| x7x7x7水蜜桃| 中文字幕高清在线视频| 韩国精品一区二区三区| 叶爱在线成人免费视频播放| 首页视频小说图片口味搜索| 天天一区二区日本电影三级 | 国产成人av教育| 熟妇人妻久久中文字幕3abv| 日韩 欧美 亚洲 中文字幕| 久久精品国产亚洲av高清一级| 无人区码免费观看不卡| 国产精品亚洲美女久久久| 两个人免费观看高清视频| 日韩av在线大香蕉| 免费在线观看日本一区| 亚洲精品一区av在线观看| 嫩草影院精品99| 欧美黄色淫秽网站| 激情在线观看视频在线高清| 午夜免费观看网址| 亚洲色图 男人天堂 中文字幕| 搡老熟女国产l中国老女人| 国产一卡二卡三卡精品| 人人妻人人澡人人看| 亚洲av五月六月丁香网| 久久久久久久午夜电影| 成人国语在线视频| 一二三四在线观看免费中文在| 欧美日韩中文字幕国产精品一区二区三区 | 日本撒尿小便嘘嘘汇集6| www日本在线高清视频| 在线观看一区二区三区| 一边摸一边抽搐一进一小说| 国内精品久久久久精免费| 亚洲国产高清在线一区二区三 | 久久婷婷成人综合色麻豆| 亚洲精品粉嫩美女一区| 欧美色欧美亚洲另类二区 | 欧美成人性av电影在线观看| 国产成人啪精品午夜网站| 久久香蕉精品热| 日韩视频一区二区在线观看| √禁漫天堂资源中文www| 国产亚洲av高清不卡| 国产精品一区二区三区四区久久 | 一级片免费观看大全| 日韩欧美国产在线观看| 亚洲一区二区三区色噜噜| 成人亚洲精品一区在线观看| 夜夜夜夜夜久久久久| 9热在线视频观看99| 中文字幕人妻丝袜一区二区| 久久久久国产一级毛片高清牌| 日韩免费av在线播放| 在线观看免费日韩欧美大片| 欧美成人午夜精品| 一级片免费观看大全| 亚洲专区字幕在线| 久久久国产精品麻豆| 精品一区二区三区av网在线观看| av视频免费观看在线观看| 少妇的丰满在线观看| 成人国产一区最新在线观看| 欧美人与性动交α欧美精品济南到| 777久久人妻少妇嫩草av网站| 国产亚洲精品久久久久5区| 国产激情欧美一区二区| 亚洲精品美女久久av网站| 精品久久久久久成人av| 午夜影院日韩av| 国产麻豆成人av免费视频| 精品一区二区三区视频在线观看免费| 精品无人区乱码1区二区| 色哟哟哟哟哟哟| 久久久久国内视频| 精品不卡国产一区二区三区| 亚洲五月天丁香| 国产精品乱码一区二三区的特点 | 国产精品99久久99久久久不卡| 久久人妻熟女aⅴ| 亚洲国产欧美网| 精品人妻在线不人妻| 嫁个100分男人电影在线观看| 757午夜福利合集在线观看| 亚洲av成人av| 首页视频小说图片口味搜索| 日韩欧美国产一区二区入口| x7x7x7水蜜桃| 国产男靠女视频免费网站| 国产国语露脸激情在线看| 黄色 视频免费看| 在线观看免费日韩欧美大片| 亚洲中文字幕一区二区三区有码在线看 | 精品久久蜜臀av无| 丁香欧美五月| 操出白浆在线播放| 欧美不卡视频在线免费观看 | 亚洲国产日韩欧美精品在线观看 | 咕卡用的链子| 亚洲片人在线观看| 午夜精品久久久久久毛片777| 女人爽到高潮嗷嗷叫在线视频| 亚洲精品久久成人aⅴ小说| 久9热在线精品视频| 久久精品亚洲熟妇少妇任你| 亚洲av美国av| 亚洲成国产人片在线观看| 不卡一级毛片| 最近最新免费中文字幕在线| 成人精品一区二区免费| 亚洲国产精品999在线| 好男人在线观看高清免费视频 | 成人国产一区最新在线观看| 又大又爽又粗| 国产精品乱码一区二三区的特点 | 精品久久久精品久久久| 一区二区日韩欧美中文字幕| 无人区码免费观看不卡| 国产一级毛片七仙女欲春2 | 99香蕉大伊视频| 美国免费a级毛片| 亚洲第一av免费看| 久久久久九九精品影院| 久久久久久久久中文| 欧美激情 高清一区二区三区| 国产精品亚洲av一区麻豆| 久久久久久人人人人人| a级毛片在线看网站| 国产亚洲精品综合一区在线观看 | 妹子高潮喷水视频| 一个人观看的视频www高清免费观看 | 伦理电影免费视频| 欧美av亚洲av综合av国产av| 69精品国产乱码久久久| 亚洲av五月六月丁香网| АⅤ资源中文在线天堂| 狂野欧美激情性xxxx| 丝袜在线中文字幕| 少妇裸体淫交视频免费看高清 | 亚洲片人在线观看| 久久久精品国产亚洲av高清涩受| 少妇熟女aⅴ在线视频| 国产亚洲欧美在线一区二区| √禁漫天堂资源中文www| 伊人久久大香线蕉亚洲五| 免费搜索国产男女视频| 好看av亚洲va欧美ⅴa在| 国产一区二区三区综合在线观看| 亚洲国产中文字幕在线视频| 一进一出抽搐gif免费好疼| 日日干狠狠操夜夜爽| 波多野结衣巨乳人妻| 国产精品久久久人人做人人爽| 国内精品久久久久久久电影| 亚洲电影在线观看av| 亚洲av第一区精品v没综合| 国产激情欧美一区二区| 久久天堂一区二区三区四区| 成人国语在线视频| 免费在线观看影片大全网站| 亚洲国产精品成人综合色| 中文字幕av电影在线播放| 免费av毛片视频| 91麻豆av在线| 嫩草影视91久久| 桃红色精品国产亚洲av| 欧美激情久久久久久爽电影 | 日日摸夜夜添夜夜添小说| 黄色女人牲交| 久久草成人影院| 天天躁夜夜躁狠狠躁躁| 亚洲精品久久国产高清桃花| 欧美 亚洲 国产 日韩一| 亚洲精品美女久久久久99蜜臀| 日韩一卡2卡3卡4卡2021年| 精品少妇一区二区三区视频日本电影| 久久久久久久午夜电影| 久久人人爽av亚洲精品天堂| 久久狼人影院| 99久久精品国产亚洲精品| 侵犯人妻中文字幕一二三四区| 久久人妻福利社区极品人妻图片| 精品第一国产精品| 国产在线观看jvid| 女警被强在线播放| 精品少妇一区二区三区视频日本电影| 老司机午夜福利在线观看视频| 91麻豆av在线| 午夜免费成人在线视频| 一区在线观看完整版| 看黄色毛片网站| 男女做爰动态图高潮gif福利片 | 国产精品乱码一区二三区的特点 | 亚洲情色 制服丝袜| 看免费av毛片| 国产精品久久久久久精品电影 | 日韩精品免费视频一区二区三区| 老司机午夜福利在线观看视频| 欧美日本亚洲视频在线播放| x7x7x7水蜜桃| 亚洲伊人色综图| 国产熟女午夜一区二区三区| 黑人巨大精品欧美一区二区mp4| av网站免费在线观看视频| 亚洲一区二区三区不卡视频| 久久精品人人爽人人爽视色| 一级毛片精品| 欧美激情极品国产一区二区三区| 欧美一级a爱片免费观看看 | 亚洲中文字幕日韩| 18美女黄网站色大片免费观看| www日本在线高清视频| 精品免费久久久久久久清纯| 熟妇人妻久久中文字幕3abv| 国产精品爽爽va在线观看网站 | 欧美一级毛片孕妇| 日韩精品青青久久久久久| 久久精品成人免费网站| 欧美 亚洲 国产 日韩一| 国产精品爽爽va在线观看网站 | 大码成人一级视频| 人人妻人人澡欧美一区二区 | 精品电影一区二区在线| 欧美成狂野欧美在线观看| 麻豆成人av在线观看| 日本a在线网址| 欧美乱色亚洲激情| 国产一区二区三区在线臀色熟女| 免费观看精品视频网站| 色综合亚洲欧美另类图片| 精品日产1卡2卡| 亚洲精品一区av在线观看| 国产精品秋霞免费鲁丝片| 999久久久国产精品视频| 午夜精品久久久久久毛片777| 丝袜在线中文字幕| 久久性视频一级片| 国产亚洲精品久久久久久毛片| 午夜福利在线观看吧| 少妇 在线观看| 18禁裸乳无遮挡免费网站照片 | av免费在线观看网站| 母亲3免费完整高清在线观看| 欧美激情久久久久久爽电影 | 欧美乱码精品一区二区三区| 精品久久久久久久毛片微露脸| 高清在线国产一区| 涩涩av久久男人的天堂| 免费看十八禁软件| 99国产精品一区二区三区| 亚洲九九香蕉| 天堂影院成人在线观看| 久久人人97超碰香蕉20202| 一本久久中文字幕| 欧美绝顶高潮抽搐喷水| 亚洲九九香蕉| 日韩欧美国产在线观看| 国产高清激情床上av| 亚洲七黄色美女视频| 国产精品野战在线观看| 亚洲成av片中文字幕在线观看| 亚洲av电影不卡..在线观看| 久久久久亚洲av毛片大全| 中文字幕人妻熟女乱码| 女同久久另类99精品国产91| 国产高清有码在线观看视频 | 18禁国产床啪视频网站| 大码成人一级视频| 自线自在国产av| or卡值多少钱| 91av网站免费观看| 日韩一卡2卡3卡4卡2021年| 久久婷婷成人综合色麻豆| 18禁黄网站禁片午夜丰满| 伊人久久大香线蕉亚洲五| 美女 人体艺术 gogo| 老汉色∧v一级毛片| 99热只有精品国产| a级毛片在线看网站| 欧美日本视频| 在线观看一区二区三区| 欧美黄色淫秽网站| 亚洲专区中文字幕在线| 视频区欧美日本亚洲| 亚洲一区高清亚洲精品| 精品福利观看| 欧美日韩乱码在线| 国产1区2区3区精品| 天天躁夜夜躁狠狠躁躁| 香蕉国产在线看| 激情视频va一区二区三区| 亚洲五月天丁香| 一级a爱视频在线免费观看| 两个人视频免费观看高清| 香蕉久久夜色| 琪琪午夜伦伦电影理论片6080| 日日爽夜夜爽网站| 欧美激情极品国产一区二区三区| 亚洲第一电影网av| 亚洲精品久久成人aⅴ小说| 国产麻豆69| 国产精品亚洲一级av第二区| 免费人成视频x8x8入口观看| 成人永久免费在线观看视频| 叶爱在线成人免费视频播放| 亚洲午夜理论影院| 一二三四社区在线视频社区8| 正在播放国产对白刺激| 久久精品aⅴ一区二区三区四区| 精品久久久久久成人av| 国产精品久久久av美女十八| 日本vs欧美在线观看视频| av中文乱码字幕在线| 99久久精品国产亚洲精品| 韩国精品一区二区三区| 亚洲色图 男人天堂 中文字幕| 老熟妇乱子伦视频在线观看| 国产黄a三级三级三级人| 日本三级黄在线观看| 国产精品影院久久| 国产av精品麻豆| 九色国产91popny在线| 久久国产乱子伦精品免费另类| 日本撒尿小便嘘嘘汇集6| 日本免费一区二区三区高清不卡 | 国产欧美日韩一区二区精品| 欧美亚洲日本最大视频资源| 1024视频免费在线观看| 脱女人内裤的视频| 国产精品,欧美在线| 久久久久精品国产欧美久久久| 亚洲国产精品sss在线观看| 国产av又大| 午夜福利影视在线免费观看| 视频区欧美日本亚洲| 热re99久久国产66热| 亚洲av日韩精品久久久久久密| 亚洲精品av麻豆狂野| 99re在线观看精品视频| 久久久久久亚洲精品国产蜜桃av| 色在线成人网| 在线观看免费午夜福利视频| 变态另类成人亚洲欧美熟女 | 无限看片的www在线观看| 电影成人av| 麻豆久久精品国产亚洲av| 国产麻豆69| 国产又色又爽无遮挡免费看| 久久久精品欧美日韩精品| 久久国产亚洲av麻豆专区| 国产精品自产拍在线观看55亚洲| 热re99久久国产66热| 欧美激情高清一区二区三区| 欧美日韩瑟瑟在线播放| 男人的好看免费观看在线视频 | 日本在线视频免费播放| 老汉色av国产亚洲站长工具| 咕卡用的链子| 久久天躁狠狠躁夜夜2o2o| 欧美亚洲日本最大视频资源| 精品一区二区三区四区五区乱码| 美女大奶头视频| 正在播放国产对白刺激| 91精品三级在线观看| 黑人操中国人逼视频| 亚洲aⅴ乱码一区二区在线播放 | 女人被狂操c到高潮| 精品国产美女av久久久久小说| 中文字幕av电影在线播放| 国产伦人伦偷精品视频|