Facets Of TiO2 Research Articles

Tailored Alkali Resistance of DeNOx Catalysts by Improving Redox Properties and Activating Adsorbed Reactive Species

SummaryIt is still challenging to develop strongly alkali-resistant catalysts for selective catalytic reduction of NOx with NH3. It is generally believed that the maintenance of acidity is the most important factor because of neutral effects of alkali. This work discovers that the redox properties rather than acidity play decisive roles in improving alkali resistance of some specific catalyst systems. K-poisoned Fe-decorated SO42−-modified CeZr oxide (Fe/SO42−/CeZr) catalysts show decreased acidity but reserve the high redox properties. The higher reactivity of NHx species induced by K poisoning compensates for the decreased amount of adsorbed NHx, leading to a desired reaction efficiency between adsorbed NHx and nitrate species. This study provides a unique perspective in designing an alkali-resistant deNOx catalyst via improving redox properties and activating the reactivities of NHx species rather than routinely increasing acidic sites for NHx adsorption, which is of significance for academic interests and practical applications.

DFT Study on Atomic Layer Deposition of Cerium Dioxide on Hydroxylated Titanium Dioxide As Efficient Photocatalyst

Design of photocatalyst materials for hydrogen production is of great interest due to a lack of cost-effective candidates. Titanium dioxide (TiO2) is a well-known photocatalyst with good stability, reasonable photoactivity, and low cost. To improve the efficiency and selectivity, we apply a surface modification approaches using nanostructured Cerium dioxide (CeO2) deposited onto TiO2 by atomic layer deposition (ALD). The deposition of CeO2 onto TiO2 uses the precursor Tetrakis(2,2,6,6-tetramethyl-3,5-heptanedionato)cerium (IV) (Ce(TMHD)4) and co-reactant ozone.The atomic layer deposition (ALD) of CeO2 on TiO2 was carried out by experiments with an atmospheric pressure fluidized bed ALD reactor. The TiO2 substrate was pre-treated using a combination of ozone and humidified nitrogen flow pulses to investigate the effect of the increase of surface functional groups on CeO2 deposition. The physicochemical properties of the obtained CeO2/TiO2 photocatalysts were characterized using different methods and their photocatalytic activity was evaluated during photocatalytic hydrogen evolution reaction.We have also performed density functional theory (DFT) calculations to investigate the reaction mechanism of metal precursors Ce(TMHD)4 and tris(methylcyclopentadienyl)cerium (III) (Ce(MeCp)3) on hydroxylated rutile and anatase TiO2 surfaces. The hydroxyl saturation coverage on different TiO2 facets was first addressed. These facets include anatase a-TiO2(001) and a-TiO2(101) and rutile r-TiO2(100) and r-TiO2(110). Hydroxyl groups OH and H are initially binding to surface Ti and O atoms, respectively. On a-TiO2(001) hydroxyl recombination to form water results in a final coverage of 0.81ML, due to the shortest neighboring HO-H distance on all surfaces. The Gibbs energy is then calculated to elucidate the effect of pressure and temperature on the hydroxylated termination of TiO2 surfaces. The final hydroxyl coverage is as follows: 0.81ML on a-TiO2(001) surface, 1ML on a-TiO2(101) and r-TiO2(100) surfaces, and 0.75ML on r-TiO2(110) surface.Two precursors (Ce(TMHD)4 and Ce(MeCp)3) are adsorbed on hydroxylated TiO2 surfaces. After precursor adsorption and relaxation, the surface hydroxyl coverage changes with water formation. After Ce(THMD)4 adsorbed on r-TiO2(100) surface, the hydroxyl coverage is decreased from 1ML to 0.25ML with 12 H2O molecules formation. After Ce(MeCp)3 adsorbed on a-TiO2(101) surface, although the hydroxyl coverage is not changed, the hydroxyl orientation is modified, breaking the symmetry. For Ce(TMHD)4, direct ligand dissociation is applied to study the mechanism of eliminating the ligands. For Ce(MeCp)3, the ligand can be eliminated by hydrogen transfer. The barrier for hydrogen transfer is calculated using climbing image nudged elastic band (CI-NEB) method. The results show that for Ce(MeCp)3, the reaction is endothermic on a-TiO2(101) surface, but it is overall exothermic on the other three surfaces. The facets play an important role in the eliminating the ligand. We present DFT results on the activity of ceria-modified rutile TiO2 towards water dissociation and CO2 activation showing that this heterostructured catalyst can promote both reactions. This work will be important to reveal the mechanism and feasibility of atomic layer deposition of ceria on different TiO2 surface facets.

Enhancement of oxidative desulfurization performance over 3DOM H3PW12O40/TiO2 by HF treatment

Three-dimensional ordered (3DOM) H3PW12O40/TiO2 nanocomposites with anatase TiO2 exposed {001} facets are fabricated by HF treatment and applied as effective catalyst in oxidative desulfurization (ODS) process. The structure characterization results including SEM, TEM, XRD, N2 adsorption-desorption isotherms, XPS, and FT-IR confirm the different percentage of exposed {001} facets of anatase TiO2 and highly dispersion of Keggin-type phosphotungstic acid (HPW) on the 3DOM TiO2 framework. The ODS performance of as-fabricated catalysts suggests that the optimal ratio of the exposed {001} facets on anatase TiO2 is determined to be 26.83%, which exhibits superior catalytic activity for dibenzothiophene (DBT) than other catalysts. In addition, density functional theory (DFT) calculation has been applied to illustrate the influence of exposed {001} surface of anatase TiO2 on catalytic activity of catalyst.

Mechanism analysis of Au, Ru noble metal clusters modified on TiO2 (101) to intensify overall photocatalytic water splitting.

Accelerating the separation and migration of photo-carriers (electron–hole pairs) to improve the photo-quantum utilization efficiency in photocatalytic overall water splitting is highly desirable. Herein, the photo-deposition of Ru or Au noble metal clusters with superior electronic properties as a co-catalyst on the (101) facet of anatase TiO2 and the mechanism of intensifying the photocatalysis have been investigated by calculation based density functional theory (DFT). As a result, the as-synthesized Ru/TiO2 and Au/TiO2 exhibit high hydrogen evolution reaction (HER) activity. Such a greatly enhanced HER is attributed to the interfacial interactivity of the catalysts due to the existence of robust chemical bonds (Ru–O–Ti, Au–O–Ti) as electron-traps that provide the photogenerated electrons. In addition, the formation of new degenerate energy levels due to the existence of Ru-4d and Au-5d electronic impurity states leads to the narrowing of the band gap of the catalysts. In addition, the as-synthesized Au/TiO2 exhibits more faster HER rate than Ru/TiO2, which is attributed to the effects of surface plasmon resonance (SPR) as a synergistic effect of plasmon-induced ‘hot’ electrons that enhance the harvesting of the final built-in electric field and promote the migration and separation of the photo-carriers, which efficiently facilitates hydrogen evolution from the photocatalytic overall water splitting reaction.

Enhanced Antibacterial Property of Facet-Engineered TiO2 Nanosheet in Presence and Absence of Ultraviolet Irradiation.

Titania (TiO2) has attracted much attention recently for reducing bacterial diseases by the generation of reactive oxygen species (ROS) under UV irradiation. However, demand for higher photocatalytic activity due to higher recombination of electron and hole remains. The aims of this study were to make titania with higher antibacterial property and show the mechanisms of the bactericidal effect. In this study, we hydrothermally synthesized TiO2 nanosheets (NS) with highly-oriented structures. Samples were divided into five groups, depending on the fluorine/titanium ratio in the raw material, namely NS1.0, NS1.2, NS1.5, NS1.8, and NS2.0. Facet ratio and nanosheet size increased with an increase of fluorine/titanium ratio. The photocatalytic activity of TiO2 nanosheet was assessed by the generation of ROS. Hydroxyl radicals and superoxides were generated efficiently by ultraviolet light irradiation on NS1.5 and NS1.0, respectively. Antibacterial activity against Streptococcus mutans was assessed in the presence and absence of UV irradiation; NS1.0 showed superior antibacterial properties compared to commercially available TiO2 nanoparticles, under both conditions, due to the oxidation of intracellular components and cell membrane. These results together suggested TiO2 nanosheet induced bacterial cell death by oxidation, and TiO2 facet engineering resulted in enhancement of both photocatalytic and antibacterial activities of TiO2.

Interactions of Plasmonic Silver Nanoparticles with High Energy Sites on Multi‐Faceted Rutile TiO2 Photoanodes

AbstractThe plasmonic interactions between silver nanoparticles and various rutile TiO2 facets are studied by correlating Advanced Electron Microscopy and Electrochemical Impedance Spectroscopy (EIS) to help design a route towards an optimised polycrystalline film fabrication. By using an Electron Backscatter Diffraction (EBSD) detector, it was determined that using HF as directing agent during the hydrothermal growth of TiO2 promotes the formation of high‐angle grain boundaries. Silver photodeposition occurs preferentially at these boundaries, consistent with the presence of high energy sites on the (100)‐oriented rutile TiO2 nanorods. Further EIS study showed an increase in the photoelectrochemical activity in the visible range of the solar spectrum for the samples consisting of silver nanoparticles deposited on these grain boundaries.

Microwave-Assisted Synthesis of High-Energy Faceted TiO2 Nanocrystals Derived from Exfoliated Porous Metatitanic Acid Nanosheets with Improved Photocatalytic and Photovoltaic Performance.

A facile one-pot microwave-assisted hydrothermal synthesis of rutile TiO2 quadrangular prisms with dominant {110} facets, anatase TiO2 nanorods and square nanoprisms with co-exposed {101}/[111] facets, anatase TiO2 nanorhombuses with co-exposed {101}/{010} facets, and anatase TiO2 nanospindles with dominant {010} facets were reported through the use of exfoliated porous metatitanic acid nanosheets as a precursor. The nanostructures and the formation reaction mechanism of the obtained rutile and anatase TiO2 nanocrystals from the delaminated nanosheets were investigated. The transformation from the exfoliated metatitanic nanosheets with distorted hexagonal cavities to TiO2 nanocrystals involved a dissolution reaction of the nanosheets, nucleation of the primary [TiO6]8− monomers, and the growth of rutile-type and anatase-type TiO2 nuclei during the microwave-assisted hydrothermal reaction. In addition, the photocatalytic activities of the as-prepared anatase nanocrystals were evaluated through the photocatalytic degradation of typical carcinogenic and mutagenic methyl orange (MO) under UV-light irradiation at a normal temperature and pressure. Furthermore, the dye-sensitized solar cell (DSSC) performance of the synthesized anatase TiO2 nanocrystals with various morphologies and crystal facets was also characterized. The {101}/[111]-faceted pH2.5-T175 nanocrystal showed the highest photocatalytic and photovoltaic performance compared to the other TiO2 samples, which could be attributed mainly to its minimum particle size and maximum specific surface area.

Anatase TiO2(001)-(1 × 4) Surface Is Intrinsically More Photocatalytically Active than the Rutile TiO2(110)-(1 × 1) Surface

Aligning the intrinsic photocatalytic activities of various types of TiO2 facets is of great importance and interest in TiO2 photocatalysis. Herein, we report a comparative study of the intrinsic p...

Theoretical study of the adsorption characteristics and the environmental influence of ornidazole on the surface of photocatalyst TiO2

In this paper, density functional theory (DFT) was performed to study the adsorption properties of ornidazole on anatase TiO2(101) and (001) crystal facets under vacuum, neutral and acid-base conditions. We calculated the adsorption structure of ornidaozle on the anatase TiO2 surface, optimal adsorption sites, adsorption energy, density of states, electronic density and Milliken atomic charge under different conditions. The results show that when the N(3) atom on the imidazole ring is adsorbed on the Ti(5) atom, the largest adsorption energy and the most stable adsorption configuration could be achieved. According to the analysis of the adsorption configuration, we found that the stability of C(2)-N(3) bond showed a weakening trend. The adsorption wavelengths of the electronic transition between the valence band and conduction band of ornidazole on the TiO2 surface were in the visible light wavelengths range, showing that the TiO2 crystal plane can effectively make use of visible light under different conditions. We speculate the possibility of ornidazole degradation on the surface of TiO2 and found that the reactive site is the C-N bond on the imidazole ring. These discoveries explain the photocatalytic degradation of ornidazole by TiO2 and reveal the microscopic nature of catalytic degradation.

Boosting CO2 methanation activity on Ru/TiO2 catalysts by exposing (001) facets of anatase TiO2

Catalytic reduction of CO2 to methane has been recognized as one of the most important strategic reactions to produce highly valuable chemicals and for storage of renewable energy (power-to-gas). This study demonstrates a crystal facet-dependent catalytic reduction of CO2 to CH4 on ruthenium nanoparticles deposited over TiO2 nanocrystal with exposed (001) and (101) facets. Compared with TiO2 (101) nanocrystal with the same Ru loading, Ru nanoparticles supported by TiO2 (001) exhibited a highly enhanced CO2 conversion rate and significantly improved methanation reactivity, along with a considerable durability. The physicochemical properties of the samples were characterized by HR-TEM, XRD, BET, FT-IR, UV–vis, Raman, ICP, and temperature-programmed reaction with CO2, and CO2 + H2. In view of the difference in catalytic activity and the physicochemical properties of the supported Ru/TiO2 catalysts, the results uncovered that the nature of the catalyst support of Ru/TiO2 strongly affected the dispersion of Ru species and the synergistic effect between Ru and underlying TiO2 supporting materials due to the strong metal-support interaction, and thus affected their capability to activate CO2 and determined the catalytic activity for CO2 methanation. Our work demonstrated the important role of the exposed crystal facets of the underlying support and the resulting Ru particle which had a large effect on CO2 methanation.

Exposing TiO2 (001) crystal facet in nano Au-TiO2 heterostructures for enhanced photodegradation of methylene blue

Abstract This article reports an investigation on the effect of crystal facet of TiO2 in nano Au-TiO2 heterostructures for enhanced photocatalytic degradation of organic dyes. Here, nano Au-TiO2 heterostructures with two distinct TiO2 morphologies, i.e. nanospindles and nanocubes, were successfully prepared and utilized for photodegradation of methylene blue (MB). Based on the photocatalytic experiments, it is found that TiO2 nanospindles exhibited superior photocatalytic performance than TiO2 nanocubes which primarily due to the exposure of (001) crystal facet. It is observed that the exposure of (001) crystal facet was able to increase the photocatalytic reaction rate by four folds. Additionally, integration with Au nanoparticles was also found to have a synergistic effect in photodegradation activity due to the presence of surface plasmon resonance (SPR) effect. According to the result, Au-TiO2 nanospindles was found to be most efficient catalyst for photocatalytic degradation of MB with pseudo-first order reaction rate of 0.1570 min−1.

Gradient Sn-Doped Heteroepitaxial Film of Faceted Rutile TiO2 as an Electron Selective Layer for Efficient Perovskite Solar Cells.

The high-efficiency photocarrier collection at the interfaces plays an important role in improving the performance of perovskite solar cells (PSCs) because the photocarrier effective diffusion lengths in the lead halide perovskite absorbers usually surpass the incident depths of light. Developing the electron selective layer (ESL) that has good interfaces with photoactive perovskite and current collector layer-like fluorine-doped tin oxide (FTO) is actively pursued. Here, an unusual dense film of faceted rutile TiO2 single crystals with a gradient of the Sn4+ dopant grown heteroepitaxially on the FTO layer is obtained by a hydrothermal route and subsequent thermal treatment. Owing to the global features including low concentration of defects, atomically smooth coherent interface with FTO, and gradient doping-induced built-in electric field to promote the collection of photoelectrons in it, an optimal PSC with such a film as the ESL exhibits an efficiency of 17.2% with an open-circuit voltage of 1.1 V and fill factor of 76.1%, which are among the highest values of the PSCs with rutile TiO2 films as ESLs.

Study on the crystal plane effect of CuO/TiO2 catalysts in NH3-SCR reaction

Abstract In this work, TiO2 nano-octahedron and nano-rods were successfully synthesized, and Cu oxides were loaded on them. Structures of CuO/TiO2 catalysts were studied by XRD, TEM, and Raman techniques. It was founded that TiO2 nano-octahedron and nano-rods dominantly exposed (101) and (100) facets of TiO2, respectively. Cu cations located in tetrahedral vacant sites on (101) facet of TiO2 and coordinated with 4 neighbor oxygen, whereas it located in octahedral vacant sites on (100) facet of TiO2 and coordinated with 6 neighbor oxygen, which resulted in redox cycle Cu2++Ti3+⟵→Cu++Ti4+ and more acid sites on surface of CuO/TiO2 nano-octahedron, and thus the enhanced NH3-SCR performance.

Facet-Dependent Interfacial Charge Transfer in TiO2/Nitrogen-Doped Graphene Quantum Dots Heterojunctions for Visible-Light Driven Photocatalysis

Interfacial charge transfer is crucial in the efficient conversion of solar energy into fuels and electricity. In this paper, heterojunction composites were fabricated, comprised of anatase TiO2 with different percentages of exposed {101} and {001} facets and nitrogen-doped quantum dots (NGQDs) to enhance the transfer efficiency of photo-excited charge carriers. The photocatalytic performances of all samples were evaluated for RhB degradation under visible light irradiation, and the hybrid containing TiO2 with 56% {001} facets demonstrated the best photocatalytic activity. The excellent photoactivity of TiO2/NGQDs was owed to the synergistic effects of the following factors: (i) The unique chemical features of NGQDs endowed NGQDs with high electronic conductivities and provided its direct contact with the TiO2 surface via forming Ti–O–C chemical bonds. (ii) The co-exposed {101} and {001} facets were beneficial for the separation and transfer of charge carriers in anatase TiO2. (iii) The donor-acceptor interaction between NGQDs and electron-rich {101} facets of TiO2 could remarkably enhance the photocurrent, thus hindering the charge carriers recombination rate. Extensive characterization of their physiochemical properties further showed the synergistic effect of facet-manipulated electron-hole separation in TiO2 and donor-acceptor interaction in graphene quantum dots (GQDs)/TiO2 on photocatalytic activity.

α-Fe2O3 nanorods embedded with two-dimensional {0 0 1} facets exposed TiO2 flakes derived from Ti3C2TX MXene for enhanced photoelectrochemical water oxidation

The Sn-doped α-Fe2O3 nanorods were embedded with {0 0 1} facets exposed TiO2 flakes by a facile hydrothermal synthesis and post-calcination treatment (denoted as E-Sn-Fe2O3/TiO2). The {0 0 1} facets exposed TiO2 flakes were derived from the delaminated Ti3C2TX MXene (D-Ti3C2TX) without adding extra HF or F ions during hydrothermal synthesis because the surface of D-Ti3C2TX was natively terminated by –F functional groups. The Sn-doped hematite/surface-covered TiO2 (denoted as S-Sn-Fe2O3/TiO2) and Sn-doped hematite (denoted as Sn-Fe2O3) were also fabricated for comparison. Under simulated sunlight, the E-Sn-Fe2O3/TiO2 yielded a photocurrent density of 0.85 mA cm−2 at 1.23 V (vs. RHE) compared with 0.72 mA cm−2 and 0.42 mA cm−2 for S-Sn-Fe2O3/TiO2 and Sn-Fe2O3, respectively. The E-Sn-Fe2O3/TiO2 achieved an IPCE value of 18.6% at 380 nm (15.8% for S-Sn-Fe2O3/TiO2 and 10.4% for Sn-Fe2O3) and exhibited enhanced IPCE values at all measured wavelengths compared with the other two photoanodes. The unique architecture of embedded TiO2 can improve the interfacial contact between the α-Fe2O3 and TiO2 as well as the light harvesting of the α-Fe2O3 compared with the surface-covered TiO2, which contributes to the better charge-transport ability and enhanced PEC performance. The exposed {0 0 1} facets of TiO2 in the E-Sn-Fe2O3/TiO2 photoanode may also facilitate the charge transfer and improve the PEC performance.

PH effects of the arsenite photocatalytic oxidation reaction on different anatase TiO2 facets

TiO2 is one of the most cheap materials which can both adsorb arsenic and oxidize arsenite [As(III)] to arsenate [As(V)]. In this study, anatase TiO2 crystals with different main facets such as {101}, {001} and {100} are synthesized and used to investigate arsenic adsorption kinetics, adsorption isotherms, photocatalytic oxidation (PCO) process and the pH effects. The adsorption kinetics of arsenic on TiO2 crystals can be described by the pseudo second-order kinetic model. For the adsorption isotherms, the Langmuir model is better than the Freundlich model for arsenic on these TiO2 crystals. For the PCO process, the rate of As(III) oxidation can be denoted by the pseudo first-order kinetic model. It should be noted that at neutral condition the adsorption and PCO rates of the three kinds of TiO2 crystals follow the order of {101} > {001} > {100}. The pH effect is above all important for both the arsenic adsorption and its PCO. The highest PCO speed appears at high pH values such as at pH 11 or 12.

Prolonging charge-separation states by doping lanthanide-ions into {001}/{101} facets-coexposed TiO2 nanosheets for enhancing photocatalytic H2 evolution

Ultrathin TiO 2 nanosheets with coexposed {001}/{101} facets have attracted considerable attention because of their high photocatalytic activity. However, the charge-separated states in the TiO 2 nanosheets must be extended to further enhance their photocatalytic activity for H 2 evolution. Herein, we present a successful attempt to selectively dope lanthanide ions into the {101} facets of ultrathin TiO 2 nanosheets with coexposed {001}/{101} facets through a facile one-step solvothermal method. The lanthanide doping slightly extended the light-harvesting region and markedly improved the charge-separated states of the TiO 2 nanosheets as evidenced by UV-vis absorption and steady-state/transient photoluminescence spectra. Upon simulated sunlight irradiation, we observed a 4.2-fold enhancement in the photocatalytic H 2 evolution activity of optimal Yb 3+ -doped TiO 2 nanosheets compared to that of their undoped counterparts. Furthermore, when Pt nanoparticles were used as cocatalysts to reduce the H 2 overpotential in this system, the photocatalytic activity enhancement factor increased to 8.5. By combining these results with those of control experiments, we confirmed that the extended charge-separated states play the main role in the enhancement of the photocatalytic H 2 evolution activity of lanthanide-doped TiO 2 nanosheets with coexposed {001}/{101} facets. The lanthanide ions were selectively doped into the {101} facets of the TiO 2 nanosheets with coexposed {001}/{101} facets by using a one-step solvothermal method. These samples exhibited a remarkable enhancement of photocatalytic activity for H 2 evolution due to the prolonged charge-separation states, as evidenced by the kinetics analyses.

Construction of α-Fe2O3 and Fe/Co-N4 structures with faceted TiO2 nanocrystals for highly efficient degradation of sulfathiazole in water

The severe pollution and scarcity of clean water occurred worldwide. The photocatalysis on semiconductors is highly expected in decontamination or purification of water, although the performance of current semiconductors is extremely restricted by the low efficiency in utilization of sustainable solar energy. An effective strategy for this restriction is the construction of their surface heterojunctions. Unfortunately, the constructed heterojunctions have to be heterotypic because of the band discontinuities at the isotypic interface. Moreover, in most of cases, the constructing does not necessarily improve their performance efficiently due to the inertness of the ground state oxygen in trapping of the separated electrons. In this work, well-faceted TiO2 with coexposed (001) and (101) and selective deposition of α-Fe2O3 and Fe/Co-N4 on the (001) facets was acquired. The overall photocatalytic activity of the well-designed composite in degradation of sulfathiazole has enhanced significantly by as much as 5.91 times compared to the bare faceted TiO2, and remained almost the same in 40 recycle usages. The significant performance of the designedly constructed composite was attributed to the remarkably enhanced light absorption, efficient separation of photo-induced charge carriers, oxygen activation and trapping of separated electrons through the Fe/Co-N4 structure and the n-p-n dual heterojunction.

TiO2 Facets Shaped by Concentration-Dependent Surface Diffusion of Dopamine.

Facet engineering highlights the fundamental understanding of kinetic growth of facets with capping agents. Here, we provide a roadmap for modulating TiO2 facets using dopamine as a capping agent inspired by density functional theory calculations and molecular dynamics simulations. Our calculations revealed that the surface diffusion of dopamine and their facet-specific affinity direct the kinetic growth of TiO2{100} and {101} facets into a nonequilibrium crystal shape. Our TiO2 synthesis agreed well with the theoretical predictions, suggesting that the concentration-dependent diffusion is central in accurately tuning a desirable ratio of mixed facets. Our findings shed new light on the diffusion-limited kinetically controlled facet growth mechanism, and this fine-tuning of mixed facets on a single crystal provides a general approach to design and fabricate facets on metal oxides.

Adsorption and Photocatalytic Removal of Chromium on High-index TiO2 Facet

Chromium (Cr) contamination caused by industrial manufacturing poses a severe challenge in the environment. Titanium dioxide (TiO2) has potential application in Cr removal due to its adsorption and photocatalytic performance. High-index TiO2 with exposed {201} facet was synthesized using the solvothermal method and characterized by SEM, TEM, XRD, and XPS. The adsorption of Cr(Ⅲ/Ⅵ) and photocatalytic reduction of Cr(Ⅵ) on TiO2{201} was examined for the removal from water. The synthesized TiO2{201} was constructed by a dandelion-like hierarchical structure. The adsorption isotherms of Cr(Ⅲ) and Cr(Ⅵ) on TiO2{201} conformed to the Langmuir model, with maximum adsorption capacities of 22.7 mg·g-1 and 13.2 mg·g-1, respectively. The best fitted results from the Freundlich model show that the adsorption of Cr(Ⅲ) and Cr(Ⅵ) on TiO2{201} were favorable with the parameter of 1/n less than 0.5. The results of photocatalytic reduction show that TiO2{201} can reduce Cr(Ⅵ) to Cr(Ⅲ) under UV irradiation, and Cr(Ⅲ) was further precipitated on the surface of TiO2 in the form of Cr(OH)3 and Cr2O3, which was evidenced by XPS characterization. To explore the mechanism of photocatalytic reduction of Cr(Ⅵ), the effect of scavengers for photogenerated holes (EDTA-2Na) and electrons (KBrO3) on Cr(Ⅵ) reduction was studied, and the results suggested that photogenerated electrons were the main reductant.