铝沉积还原制备蓝色二氧化钛

doi:10.15541/jim20170538

摘要/Abstract

摘要：

在光催化研究中, 提高光催化剂的催化效率, 降低催化剂成本吸引了广泛的研究兴趣。本研究通过铝沉积还原方法制备出表面铝原子修饰的蓝色二氧化钛。该蓝色二氧化钛具有一种独特的核壳结构, 纳米颗粒内部为结晶核, 外部为含有大量氧空位和一定量沉积铝原子的非晶层。在模拟太阳光照射下, 该蓝色二氧化钛表现出优异的光催化污染物降解和光电化学性能。在高真空条件下, 当蒸发的金属铝原子沉积在二氧化钛纳米颗粒上时, 可以进一步将Ti⁴⁺还原成Ti³⁺, 使得催化剂表面含有大量的氧空位等表面缺陷。此外, 适量的铝沉积在催化剂表面成为光生载流子阱, 促进光生载流子的分离和输运, 从而使得样品光催化活性增强。当沉积适量Al时, 样品TiO₂-Al_0.36表现出最为优异的光催化污染物降解性能, 在8 min内就可将甲基橙溶液完全降解, 且其光电流(1.47 mA·cm^-2)是本征二氧化钛(0.17 mA·cm^-2)的8倍以上, 展现出优异的光电化学性能。

关键词: 蓝色二氧化钛, 铝沉积还原, 光催化, 污染物降解, 光电化学

Abstract:

Improving catalysis efficiency and reducing production cost attract extensive interest for the study of photocatalyst. Herein a blue titania crystal with aluminum atoms modified on the surface was prepared by aluminum reduction and deposition. The blue titania displays a unique core-shell structure with crystallization nuclei inside and with oxygen vacancies and aluminum atoms outside. And the blue titania shows excellent photocatalytic and electrochemical performance under simulated sunlight. Under high vacuum, with vapored aluminum atoms being deposited on titania nanocrystals, Ti⁴⁺ is reduced to Ti³⁺, which creates a large number of oxygen vacancies on the surface. Additionally, moderate amounts of aluminum atoms coated on titania become photo-induced charge carrier traps, facilitating the separation and transport of charge carriers, which enhances the photocatalytic capability. TiO₂-Al_0.36 exhibits the best photocatalytic performance, degrading methyl orange in 8 min, and it shows excellent photochemical property with the photocurrent of 1.47 mA·cm^-2, which is more than 8 times as high as that of pristine titania (0.17 mA·cm^-2).

Key words: blue titania, aluminum reduction and deposition, photocatalysis, contaminant degradation, photoelectrochemistry

中图分类号:

TQ174

盛鹏, 赵广耀, 徐丽, 刘双宇, 王博, 刘海镇, 马光, 韩钰, 陈新. 铝沉积还原制备蓝色二氧化钛[J]. 无机材料学报, 2018, 33(9): 942-948.

SHENG Peng, ZHAO Guang-Yao, XU Li, LIU Shuang-Yu, WANG Bo, LIU Hai-Zhen, MA Guang, HAN Yu, CHEN Xin. Reductive Preparation of Blue TiO₂ via Deposition of Aluminum[J]. Journal of Inorganic Materials, 2018, 33(9): 942-948.

图/表 8

图1 本征P25和TiO2-x-Aly样品的XRD图谱

Fig. 1 XRD patterns of intrinsic P25 and TiO2-x-Aly

图2 本征P25和TiO2-x-Aly样品的TEM(a), (c), (e)和HRTEM (b), (d), (f)照片

Fig. 2 TEM (a), (c), (e) and HRTEM (b), (d), (f) images of intrinsic P25 and TiO2-x-Aly

表1 本征P25和TiO2-x-Aly样品的化学元素组成

Table 1 Elemental analysis of intrinsic P25 and TiO2-x-Aly

Samples	Elemental compositions/wt%
	XPS			ICP
	Ti	O	Al	Al
TiO₂(P25)	26.4	73.6	—	—
TiO_2-_x	39.4	60.6	—	—
TiO₂-Al_0.36	47.5	49.8	2.72	0.36
TiO₂-Al_1.37	35.8	59.0	5.19	1.37

图3 本征P25和TiO2-x-Aly样品的(a)实物照片和(b)紫外-可见-近红外漫反射吸收光谱图

Fig. 3 Photographs (a) and UV-Vis-NIR diffuse reflectance spectra of of intrinsic P25 and TiO2-x-Aly

图4 本征P25和TiO2-x-Aly样品的(a)拉曼光谱和(b)电子顺磁共振谱

Fig. 4 Raman (a) and EPR (b) spectra of intrinsic P25 and TiO2-x-Aly

图5 本征P25和TiO2-x-Aly样品的(a) Ti2p、(b) Ti2p3/2和(c) Al2p的XPS图谱以及(d) XPS价带边

Fig. 5 XPS spectra Ti2p (a), Ti2p3/2 (b), Al2p (c), and XPS valence band edge (d) of intrinsic P25 and TiO2-x-Aly

图6 本征P25和TiO2-x-Aly样品的(a)光致发光谱, (b)光催化甲基橙降解性能和(c) TiO2-Al0.36样品光催化甲基橙降解循环性能

Fig. 6 PL spectra (a), photocatalytic degradation of methyl orange (b) of intrinsic P25 and TiO2-x-Aly and photocatalytic degradation of methyl orange (c) of TiO2-Al0.36

图7 本征P25和TiO2-x-Aly样品的(a)模拟太阳光照射条件下的线性扫描伏安(LSV)曲线, (b)全光谱光照下样品的瞬态光电流响应曲线(0.23 V vs. SCE)和(c) 无光照、频率1 kHz下测得的Mott-Schottky曲线

Fig. 7 (a) LSV curves under simulated sunlight irradiation, (b) transient photocurrent curve under full spectra irradiation (0.23 V vs. SCE), and Mott-Schottky curve with no sunlight irradiation at 1 kHz of intrinsic P25 and TiO2-x-Aly

参考文献 46

[1]	GRATZEL M.Photoeletrochemical cells.Nature, 2001, 414(6861): 338-344.
[2]	HOFFMANN M R, MARTIN S T, CHOI W Y,et al. Environmental applications of semiconductor photocatalysis. Chemical Reviews, 1995, 95(1): 69-96.
[3]	FUJISHIMA A, HONDA K.Electrochemical photolysis of water at a semiconductor electrode.Nature, 1972, 238(5358): 37.
[4]	CHEN X, MAO S S.Titanium dioxide nanomaterials: synthesis, properties, modifications, and applications.Chemical Reviews, 2007, 107(7): 2891-2959.
[5]	LU X J, MOU X L, WU J J,et al. Improved-performance dye-sensitized solar cells using Nb-doped TiO2 electrodes: efficient electron injection and transfer. Advanced Functional Materials, 2010, 20(3): 509-515.
[6]	LU X J, HUANG F Q, MOU X L,et al. A general preparation strategy for hybrid TiO2 hierarchical spheres and their enhanced solar energy utilization efficiency. Advanced Materials, 2010, 22(33): 3719-3722.
[7]	SHANKAR K, BASHAM J I, ALLAM N K,et al. Recent advances in the use of TiO2 nanotube and nanowire arrays for oxidative photoelectrochemistry. The Journal of Physical Chemistry C, 2009, 113(16): 6327-6359.
[8]	HENDERSON M A.A surface science perspective on TiO2 photocatalysis.Surface Science Reports, 2011, 66(6/7): 185-297.
[9]	LIU L, CHEN X B.Titanium dioxide nanomaterials: self-structural modifications.Chemical Reviews, 2014, 114(19): 9890-9918.
[10]	MA Y, WANG X L, JIA Y S,et al. Titanium dioxide-based nanomaterials for photocatalytic fuel generations. Chemical Reviews, 2014, 114(19): 9987-10043.
[11]	CHEN C C, MA W H, ZHAO J C.Semiconductor-mediated photodegradation of pollutants under visible-light irradiation.Chemical Society Reviews, 2010, 39(11): 4206-4219.
[12]	CHEN X B, LIU L, HUANG F Q.Black titanium dioxide (TiO2) nanomaterials.Chemical Society Reviews, 2015, 44(7): 1861-1885.
[13]	DE ANGELIS F, DI VALENTIN C, FANTACCI S,et al. Theoretical studies on anatase and less common TiO2 phases: bulk, surfaces, and nanomaterials. Chemical Reviews, 2014, 114(19): 9708-9753.
[14]	DAHL M, LIU Y D, YIN Y D.Composite titanium dioxide nanomaterials.Chemical Reviews, 2014, 114(19): 9853-9889.
[15]	LIU G, YANG H G, PAN J,et al. Titanium dioxide crystals with tailored facets. Chemical Reviews, 2014, 114(19): 9559-9612.
[16]	PAN X Y, YANG M Q, FU X Z,et al. Defective TiO2 with oxygen vacancies: synthesis, properties and photocatalytic applications. Nanoscale, 2013, 5(9): 3601-3614.
[17]	REICHE H, BARD A J.Heterogeneous photosynthetic production of amino-acids from methane-ammonia-water at Pt-TiO2. implications in chemical evolution.Journal of the American Chemical Society, 1979, 101(11): 3127-3128.
[18]	LINSEBIGLER A L, LU G Q, YATES J T.Photocatalysis on TiO2 surfaces: principles, mechanisms, and selected results.Chemical Reviews, 1995, 95(3): 735-758.
[19]	CHEN X B, SHEN S H, GUO L J,et al. Semiconductor-based photocatalytic hydrogen generation. Chemical Reviews, 2010, 110(11): 6503-6570.
[20]	SCHNEIDER J, MATSUOKA M, TAKEUCHI M,et al. Understanding TiO2 photocatalysis: mechanisms and materials. Chemical Reviews, 2014, 114(19): 9919-9986.
[21]	TSAI C Y, HIS H C, BAI H, et al. Single-step synthesis of Al-doped TiO2 nanoparticles using non-transferred thermal plasma torch. Japanese Journal of Applied Physics, 2012, 51(1): 01AL01.
[22]	LEE J E, OH S M, PARK D W.Synthesis of nano-sized Al doped TiO2 powders using thermal plasma.Thin Solid Films, 2004, 457(1): 230-234.
[23]	LIU S Y, LIU G C, FENG Q G.Al-doped TiO2 mesoporous materials: synthesis and photodegradation properties.Journal of Porous Materials, 2010, 17(2): 197-206.
[24]	KIM S K, CHOI G J, LEE S Y,et al. Al-doped TiO2 films with ultralow leakage currents for next generation dram capacitors. Advanced Materials, 2008, 20(8): 1429-1435.
[25]	WANG Z, YANG C Y, LIN T Q,et al. Visible-light photocatalytic, solar thermal and photoelectrochemical properties of aluminium- reduced black titania. Energy & Environmental Science, 2013, 6(10): 3007-3014.
[26]	WANG M Q, GONG B, YAO X,et al. Preparation and microstructure properties of Al-doped TiO2-SiO2 gel-glass film. Thin Solid Films, 2006, 515(4): 2055-2058.
[27]	LI C Z, SHI L Y, XIE D M,et al. Morphology and crystal structure of Al-doped TiO2 nanoparticles synthesized by vapor phase oxidation of titanium tetrachloride. Journal of Non-Crystalline Solids, 2006, 352(38/39): 4128-4135.
[28]	TAYLOR M L, MORRIS G E, SMART R S.Influence of aluminum doping on titania pigment structural and dispersion properties.Journal of Colloid and Interface Science, 2003, 262(1): 81-88.
[29]	ISLAM M M, BREDOW T, GERSON A. Electronic properties of oxygen-deficient and aluminum-doped rutile TiO2 from first principles. Physical Review B, 2007, 76(4): 045217-1-9.
[30]	CHOI Y J, SEELEY Z, BANDYOPADHYAY A,et al. Aluminum- doped TiO2 nano-powders for gas sensors. Sensors and Actuators B: Chemical, 2007, 124(1): 111-117.
[31]	WANG Z, YANG C Y, LIN T Q,et al. H-doped black titania with very high solar absorption and excellent photocatalysis enhanced by localized surface plasmon resonance. Advanced Functional Materials, 2013, 23(43): 5444-5450.
[32]	CHEN X B, LIU L, YU P Y,et al. Increasing solar absorption for photocatalysis with black hydrogenated titanium dioxide nanocrystals. Science, 2011, 331(6018): 746-750.
[33]	LI L D, YAN J Q, WANG T,et al. Sub-10 nm rutile titanium dioxide nanoparticles for efficient visible-light-driven photocatalytic hydrogen production. Nature Communications, 2015, 6: 5881.
[34]	LEI F C, SUN Y F, LIU KT,et al. Oxygen vacancies confined in ultrathin indium oxide porous sheets for promoted visible-light water splitting. Journal of the American Chemical Society, 2014, 136(19): 6826-6829.
[35]	TSAI C Y, KUO T H, HIS H C.Fabrication of Al-doped TiO2 visible- light photocatalyst for low-concentration mercury removal.International Journal of Photoenergy, 2012(2): 483-490.
[36]	PARKER J C, SIEGEL R W.Raman microprobe study of nanophase TiO2 and oxidation-induced spectral changes.Journal of Materials Research, 1990, 5(6): 1246-1252.
[37]	LI BASSI A, CATTANEO D, RUSSO V, ,et al. Raman spectroscopy characterization of titania nanoparticles produced by flame pyrolysis: the influence of size. Journal of Applied Physics, 2005, 98(7): 074305-1-9.
[38]	CORONADO J M, MAIRA A J, CONESA J C,et al. EPR study of the surface characteristics of nanostructured TiO2 under UV irradiation. Langmuir, 2001, 17(17): 5368-5374.
[39]	XIONG L B, LI J L, YANG B, ,et al. Ti3+ in the surface of titanium dioxide: generation, properties and photocatalytic application. Journal of Nanomaterials, 2012: 831524-1-13.
[40]	CUI H, ZHAO W, YANG C Y,et al. Black TiO2 nanotube arrays for high-efficiency photoelectrochemical water-splitting. Journal of Materials Chemistry A, 2014, 2(23): 8612-8616.
[41]	YIN H, LIN T Q, YANG C Y,et al. Gray TiO2 nanowires synthesized by aluminum-mediated reduction and their excellent photocatalytic activity for water cleaning. Chemistry-A European Journal, 2013, 19(40): 13313-13316.
[42]	ZHU G L, LIN T Q, LU X J,et al. Black brookite titania with high solar absorption and excellent photocatalytic performance. Journal of Materials Chemistry A, 2013, 1(34): 9650-9653.
[43]	BERTOTI I, MOHAI M, SULLIVAN J L,et al. Surface characterization of plasma-nitrided titanium: an XPS study. Applied Surface Science, 1995, 84(4): 357-371.
[44]	RAHMAN M M, KRISHNA K M, SOGA T,et al. Optical properties and X-ray photoelectron spectroscopic study of pure and Pb-doped TiO2 thin films. Journal of Physics and Chemistry of Solids, 1999, 60(2): 201-210.
[45]	GESENHUES U.Al-doped TiO2 pigments: influence of doping on the photocatalytic degradation of alkyd resins.Journal of Photochemistry and Photobiology A-Chemistry, 2001, 139(2/3): 243-251.
[46]	LUO Z H, GAO Q H.Decrease in the photoactivity of TiO2 pigment on doping with transition-metals.Journal of Photochemistry and Photobiology A-Chemistry, 1992, 63(3): 367-375.