功能模板导向合成介孔三氧化钨及其光电化学性能

以钨酸(H₂WO₄)为钨前驱体,十二烷胺(DDA)为模板剂,利用模板剂的结构导向功能,合成了比表面积为57.3 m²·g^-1的介孔三氧化钨(DDA-WO₃),是未用DDA制备的非介孔WO₃(H₂WO₄-WO₃)的2.35倍。X射线衍射(XRD)结果表明,400 ℃下煅烧的DDA-WO₃是具有单斜晶型结晶孔壁的无序介孔结构。此外,400~550 ℃下煅烧的DDA-WO₃的结晶度均高于同条件的H₂WO₄-WO₃。400 ℃下的DDA-WO₃/FTO(掺氟氧化锡)在1.0 V的Ag/AgCl偏压作用下,可以产生0.18 mA·cm^-2的饱和光电流,是H₂WO₄-WO₃/FTO(0.06 mA·cm^-2)的3倍。增强的光电化学(PEC)活性主要因为DDA-WO₃/FTO的大表面积降低了低结晶度对PEC性能的不利影响,成为影响PEC活性的主要因素。500 ℃煅烧导致了DDA-WO₃/FTO介孔结构的坍塌,但高的结晶度仍然保持其优越的PEC催化活性。     

TiO2/SnO2复合空心球在染料敏化太阳能电池中的应用

采用模板辅助法制备了SnO2/TiO2复合空心球,样品直径为1.5~4.0μm,比表面积达到了92.9 m^2·g^-1,复合空心球表现出优越的光散射性能.以这种复合空心球作为染料敏化太阳能电池的光阳极,电池的光电转换效率可达到7.72%,高于SnO2微米球(2.70%)和TiO2微米球(6.26%).此外,以锐钛矿型TiO2纳米晶作为底层,SnO2/TiO2复合空心球作为光散射层制备的双层结构光阳极,电池光电转换效率进一步提升至8.43%.     

Ag纳米颗粒表面等离子体共振增强DSSC电池的制备及性能研究

使用水热法制备了一系列不同含量Ag纳米颗粒掺杂的Ag-TiO2复合光阳极的染料敏化太阳能电池,同时,研究了不同含量Ag纳米颗粒掺杂对染料敏化太阳能电池的结构和性能的影响.实验结果表明：Ag的掺入增强了吸附在Ag-TiO2复合光阳极上的染料对光的吸收,显著地提高了对应电池的短路电流.在Ag掺入量为0.20%的时候,对应的电池具有最佳的性能,其短路电流为10.66mA/cm2,开路电压Voc为697mV,光电转换效率为5.59%,显著优于纯TiO2光阳极电池的效率.其性能的改善主要归因于掺入Ag纳米颗粒的表面等离子体共振吸收效应使电池光阳极对光的吸收增强所致.     

Boosting Photocatalytic Oxygen Evolution: Purposely Constructing Direct Z-Scheme Photoanode by Modulating the Interface Electric Field

Ti-Fe₂O₃ photoanode has received widespread attention in photoelectrochemical(PEC) water spilling because of its optimized oxidative and reductive capability of composites catalyst. However, its low efficiency could limit its development. Herein, in order to improve the efficiency of PEC water spilling, the all-solid-state direct Z-scheme Ti-ZnFe₂O₄/Ti-Fe₂O₃(TZFO/Ti-Fe₂O₃) nanorod arrays composited with the ideal energy band structure are synthesized by modulating the Fermi level of TZFO for PEC water splitting. The photophysical methods in this work, including the Kelvin probe measurement and transient photovoltage spectroscopy(TPV) measurement, are applied to explore the migration behavior of electric charges at the enhanced interface electric field. Finally, the Z-scheme charge transfer mechanism of TZFO/Ti-Fe₂O₃ photoanode is proved successfully. Benefiting from the desirable charge transfer at interface electric field, the TZFO/Ti-Fe₂O₃ exhibits the outstanding photocatalytic oxygen evolution reaction(OER) performance, and the photocurrent of 60TZFO/Ti-Fe₂O₃ photoanode reaches 2.16 mA/cm² at 1.23 V vs. reversible hydrogen electrode(RHE), which is three times higher than that of pure Ti-Fe₂O₃ photoanode. This work provides a facile approach of modulating interface electric field to optimize the Z-scheme charge-transfer process.     

SILAR法制备TiO2/CdS/Co-Pi水氧化光阳极及其性能

Asemiconductor heterostructure of TiO₂/CdS/cobalt phosphate water oxidation catalyst (Co-Pi WOC) photoanode was fabricated by the successive ionic layer adsorption and reaction (SILAR) procedure and photoassisted electro-deposition. The structure, morphologys and magnetic properties of the resultant particles were characterized using X-ray diffraction (XRD), scanning electron microscope (SEM), and X-ray photoelectron spectroscopy (XPS). CdS and Co-Pi quantum dots loaded on to the TiO₂ nanofilm. The TiO₂/CdS/Co-Pi photoanode had an initial photocurrent of 1.3 mA·cm^-2 and a stable level of 0.5 mA·cm^-2. A relatively stable level was maintained under visible light irradiation in neutral solution, especially at the low bias voltage of 0 V (vs Ag/AgCl). In this system, CdS quantum dots serve as the light absorber and generate electron holes; the Co-Pi WOC acts as a hole transfer layer that can transfer the hole for water oxidation; and the TiO₂ is the electron conductor for efficient charge transfer to the cathode to actualize proton reduction.     

SrTiO3/α-Fe2O3异质结光阳极光电转换性能

作为一类重要的光电极材料,α-Fe2O3在太阳能转化方面有着潜在的应用前景.但是,光生电子空穴对的再复合导致α-Fe2O3的光电量子产率很低.为了抑制光生电子空穴对的再复合,提高α-Fe2O3的光电量子产率,采用Spin-coating方法在透明导电玻璃FTO(SnO2:F)衬底上制备了SrTiO3/α-Fe2O3异质结薄膜光电极,并对该光电极进行了XRD、SEM、紫外-可见透射光谱的表征.在三电极光电化学测试系统中对薄膜的光电流-电压特性、入射光子电流转化效率(Incident photon to current efficiency,IPCE)对波长的依赖性进行了表征.在相同的Xe灯照射条件下,SrTiO3/α-Fe2O3异质结光电极的光电流及IPCE值大于单一的SrTiO3、α-Fe2O3各自的光电流及IPCE值,这与理论预测的结论一致.     

Porous Si/TiO2 nanowire photoanode for photoelectric catalysis under simulated solar light irradiation

Porous Si/TiO₂ nanowire photoanodes were prepared by a combination of hydrothermal synthesis and metal‐assisted chemical etching. Characterization of samples was conducted using scanning electron microscopy and X‐ray diffraction, the results showing that a porous Si/TiO₂ heterojunction structure was synthesized. Diffuse reflection spectra show that the porous Si/TiO₂ nanowire photoanodes have a strong absorption. Photocurrent measurement shows that the photocurrent of the porous Si/TiO₂ nanowire photoanodes at 6 h is higher than that of others in the measuring region. The photoelectric catalysis (PEC) activities of porous Si/TiO₂ nanowire photoanodes were evaluated in degradation experiments of methylene blue under simulated solar light irradiation, and the sample at 6 h shows the highest PEC activity. Meanwhile, the PEC activity of the porous Si/TiO₂ nanowire photoanode is higher than that of the single direct photocatalysis process or electric catalysis. The mechanism of the PEC of the porous Si/TiO₂ nanowire photoanodes has been explained.     

CuInS2量子点敏化ZnO基光阳极的制备与性能研究

采用两步法在导电玻璃(FTO)基板上制备纯氧化锌(ZnO)纳米棒和钇掺杂的氧化锌(ZnO∶Y)纳米棒,采用连续离子层吸附反应法(SILAR)在所制备的ZnO及ZnO∶Y纳米棒上沉积CuInS₂量子点制备ZnO/CuInS₂和ZnO∶Y/CuInS₂光阳极。利用X射线衍射仪(XRD)、扫描电子显微镜(SEM)、电子探针能谱仪(EDS)、紫外-可见分光光度计(UV-Vis)、电流密度-电压(J-V)曲线等技术手段对不同光阳极样品的晶相结构、微观形貌、化学组成、光吸收性能和太阳电池性能进行了表征。实验结果表明:所制备的ZnO纳米棒和ZnO∶Y纳米棒为六方纤锌矿结构。CuInS₂量子点敏化的ZnO纳米棒薄膜的光学带隙从3.22 eV减小为2.98 eV。CuInS₂量子点敏化ZnO∶Y太阳能电池的短路电流密度和光电转换效率比未掺杂的ZnO纳米棒组装的太阳能电池分别提高了6.5%和50.4%。     

ZnS/SiO2协同包覆光阳极制备高效率Zn-Cu-In-Se量子点敏化太阳能电池

通过光阳极协同包覆的策略抑制Zn?Cu?In?Se(ZCISe)量子点敏化太阳能电池(QDSC)中光阳极/电解液界面上的电荷复合过程,提高电荷收集效率和电池光伏性能。采用溶液法在ZCISe量子点敏化的光阳极表面依次沉积包覆ZnS和SiO₂双钝化层,实现较单一ZnS包覆层更有效的界面电荷复合抑制作用,从而提高QDSC的性能。在包覆ZnS/SiO₂双钝化层后,所组装的ZCISe QDSC光电转换效率由传统单一ZnS包覆的12.17%提高到13.23%,这归因于双钝化层对光阳极/电解液界面电荷复合过程的有效抑制,电荷收集效率得到相应提升。     

两步电泳沉积制备TiO2光阳极用于高效染料敏化太阳能电池

采用不同沉积电压制备TiO₂光阳极,研究电压对薄膜沉积速率、厚度和形貌的影响。通过台阶仪、光学照片、扫描电子显微镜（SEM）、电化学交流阻抗谱、开路电压衰减曲线对光阳极和电池进行系统表征,并测试了染料敏化太阳能电池器件的电流密度-电压（J-V）曲线,计算其光电转换效率。结果表明,提高沉积电压时,光阳极薄膜的沉积速率加快,膜厚也增加,但是电压过高时,薄膜会有裂缝和覆盖不全的问题,这会对电池的效率造成负面影响。综合考虑低沉积电压条件下薄膜均匀无裂缝和高沉积电压条件下沉积速率快的优点,采用先30 V电压、后60 V电压的电泳沉积方式来制备光阳极,结果呈现协同效果,既降低了制备时间又得到高质量的薄膜,在无其他修饰的情况下,电池的光电转换效率可以达到7.29%。