Synthesis and Spectral Properties of Nd<Subscript>2</Subscript>O<Subscript>3</Subscript>-Doped Sodium Silicophosphate Glass

Combined UV-visible and FTIR spectral studies of undoped and Nd₂O₃ –doped sodium silicophosphate glasses were carried out to characterize the optical and structural properties of such glasses. The base undoped silicophosphate glass exhibits strong UV absorption which is due to the presence of unavoidable trace iron impurities (mainly Fe³⁺ ions) present contaminated within the raw materials used for the preparation of such glasses. Nd₂O₃ –doped glasses show characteristic absorption bands extending in the entire visible region which are attributed to the contribution of Nd³⁺ ions with distinct peaks which are almost constant with the increase of dopant. This comes from the combined compact glass structure containing two glass forming units and the shielding of the rare-earth ions. Infrared absorption spectra of the studied glasses reveal characteristic IR bands due to the combination of both silicate and phosphate groups. The introduction of Nd₂O₃ within the dopant level (2 %) produces no variations in the IR vibrational bands due to the presence of the two structural silicate and phosphate groups giving compactness of the network structure. The deconvoluted spectra reveal the presence of phosphate groups in a slightly high ratio due to the high content of P₂O₅ in the composition.     

Synthesis and structural refinement of fully dehydrated fully Zn<Superscript>2+</Superscript>-exchanged zeolite Y (FAU), |Zn<Subscript>35.5</Subscript>|[Si<Subscript>121</Subscript>Al<Subscript>71</Subscript>O<Subscript>384</Subscript>]-FAU

The single-crystal structure of |Zn_35.5|[Si₁₂₁Al₇₁O₃₈₄]-FAU per unit cell, a = 24.794(1), dehydrated at 673 K and 1 × 10^?6 Torr, has been determined by single-crystal X-ray diffraction techniques in the space group \( Fd\bar{3}m \) at 294(1) K. The structure was refined using all intensities to the final error indices (using the 930 reflections for which F _o > 4σ(F _o)) R ₁ = 0.0448 (based on F) and wR ₂ = 0.1545 (based on F ²). About 35.5 Zn²⁺ ions per unit cell are found at an unusually large number of crystallographic distinct positions, six. The 0.5 Zn²⁺ ion per unit cell is located at the center of double 6-ring (D6R, site I; Zn(I)-O(3) = 2.642(3) Å and O(3)-Zn(I)-O(3) = 81.23(12) and 98.77(12)°). Two different site-I′ positions (in the sodalite cavities opposite D6Rs) are occupied by 14 and 3 Zn²⁺ ions per unit cell, respectively; these Zn²⁺ ions are recessed 0.67 Å and 1.02 Å, respectively, into the sodalite cavities from their 3-oxygens plane (Zn(I′a)-O(3) = 2.094(3) Å, Zn(I′b)-O(3) = 2.23(5) Å, O(3)-Zn(I′a)-O(3) = 110.32(12)°, and O(3)-Zn(I′b)-O(3) = 100.9(30)°). Site-II′ positions (in the sodalite cavities opposite S6Rs) are occupied by 6 Zn²⁺ ions, each of which extends 0.63 Å into the sodalite cavities from their 3-oxygens plane (Zn(II′)-O(2) = 2.164(3) Å and O(2)-Zn(II′)-O(2) = 112.00(12)°). Twelve Zn²⁺ ions are found at two nonequivalent sites II (in the supercage) with occupancies of 7 and 5 ions, respectively; these Zn²⁺ ions are recessed 0.52 Å and 0.96 Å, respectively, into the supercage from their 3-oxygens plane (Zn(IIa)-O(2) = 2.138(12) Å, Zn(IIb)-O(2) = 2.28(4) Å, O(2)-Zn(IIa)-O(2) = 114.2(10)°, and O(2)-Zn(IIb)-O(2) = 103.7(25)°).     

Visible up-conversion luminescence of CaWO<Subscript>4</Subscript>: Er<Superscript>3+</Superscript>,Yb<Superscript>3+</Superscript> and emission enhancement by tri-doping of Li<Superscript>+</Superscript> ions

Er³⁺,Yb³⁺ co-doped CaWO₄ polycrystalline powders were prepared by a solid-state reaction and their up-conversion (UC) luminescence properties were investigated in detail. Under 980 nm laser excitation, CaWO₄: Er³⁺,Yb³⁺ powder exhibited green UC emission peaks at 530 and 550 nm, which were due to the transitions of Er³⁺ (²H_11/2)→Er³⁺ (⁴I_15/2) and Er³⁺ (⁴S_3/2)→Er³⁺ (⁴I_15/2), respectively. Effects of Li+ tri-doping into CaWO₄: Er³⁺,Yb³⁺ were investigated. The introduction of Li⁺ ions reduced the optimum calcinations temperature about 100 °C by a liquid-phase sintering process and the UC emission intensity was remarkably enhanced by Li⁺ ions, which could be attributed to the lowering of the symmetry of the crystal field around Er³⁺ ions.     

Fractionation of Soybean Globulins Using Ca<Superscript>2+</Superscript> and Mg<Superscript>2+</Superscript>: A Comparative Analysis

The substitution of CaCl₂ by MgCl₂ was undertaken in Deak’s two-step process of separating the soybean 11S and 7S globulins, aiming at higher purities and lower phytic acid (PA) contents of recovered protein fractions. The effects of pH and the addition of NaCl were also evaluated. Compared with CaCl₂, MgCl₂ reduced the PA content of the 11S-rich fraction by 63–71% but increased that of the 7S-rich fraction by 14–28%, depending on pH. Correspondingly, more Ca²⁺ was recovered in the 11S-rich fraction, while more Mg²⁺ co-precipitated with the 7S-rich fraction. NaCl increased the purity of the 11S-rich fraction and reduced its PA content, but the purity of the 7S-rich fraction was reduced by using 50–100 mM NaCl. Lowering pHs from 6.4 and 4.8 to 5.6 and 4.0 in the two precipitation steps increased the yield of both fractions. The optimized fractionating procedure was as follows: the 11S-rich fraction was precipitated at pH 5.8 by using 5 mM MgCl_2, 10 mM NaHSO₃ and 20 mM NaCl, followed by the precipitation of the 7S-rich fraction at pH 4.5. The new method provided both fractions with satisfactory protein yields (22% for 11S and 16% for 7S), purities (88% for 11S and 80% for 7S) and PA contents (0.356% for 11S and 0.882% for 7S).     

Roles of doping ions in persistent luminescence of SrAl<Subscript>2</Subscript>O<Subscript>4</Subscript>: Eu<Superscript>2+</Superscript>,<Emphasis Type="Italic">RE</Emphasis><Superscript>3+</Superscript> phosphors

The polycrystalline Eu²⁺ and Dy³⁺ codoped strontium aluminates SrAl₂O₄: Eu²⁺,Dy³⁺ were prepared by a solid-state reaction. The UV-excited photoluminescence, persistent luminescence, and thermoluminescence of the SrAl₂O₄: Eu²⁺,Dy³⁺ phosphors with different compositions and ion doping was studied and compared. The results showed that the Eu²⁺ ion doped in SrAl₂O₄: Eu²⁺,Dy³⁺ phosphors is not only the UV-excited luminescent center but also the persistent luminescent center. The Dy³⁺ ion introduced into SrAl₂O₄: Eu²⁺ crystal matrix can hardly yield any luminescence under UV excitation but acts as an electron trap with a suitable depth for persistent luminescence. The Dy³⁺ codoping would effectively enhance the persistent luminescence and thermoluminescence. Different codoping RE ³⁺ ions have a different effect on persistent luminescence. Only the RE ³⁺ ions (for example, Dy³⁺ and Nd³⁺), which have suitable optical electronegativity, can form suitable electron traps and effectively improve the persistent luminescence of SrAl₂O₄: Eu²⁺. Based on the above observations, a persistent luminescence mechanism, electron transfer model, was proposed and illustrated. The text was submitted by the authors in English.     

Structure and Luminescence Properties of Eu<Superscript>3+</Superscript>-Doped Cubic Mesoporous Silica Thin Films

Eu³⁺ ions-doped cubic mesoporous silica thin films with a thickness of about 205 nm were prepared on silicon and glass substrates using triblock copolymer as a structure-directing agent using sol–gel spin-coating and calcination processes. X-ray diffraction and transmission electron microscopy analysis show that the mesoporous silica thin films have a highly ordered body-centered cubic mesoporous structure. High Eu³⁺ ion loading and high temperature calcination do not destroy the ordered cubic mesoporous structure of the mesoporous silica thin films. Photoluminescence spectra show two characteristic emission peaks corresponding to the transitions of ⁵D₀-⁷F₁ and ⁵D₀-⁷F₂ of Eu³⁺ ions located in low symmetry sites in mesoporous silica thin films. With the Eu/Si molar ratio increasing to 3.41%, the luminescence intensity of the Eu³⁺ ions-doped mesoporous silica thin films increases linearly with increasing Eu³⁺ concentration.     

Design of Efficient Ce<Subscript>x</Subscript>M<Subscript>1−x</Subscript>O<Subscript>2−δ</Subscript> (M = Zr,Hf, Tb and Pr) Nanosized Model Solid Solutions for CO Oxidation

Abstract  

Nanosized Ce_xM_1−xO_2−δ (M = Zr, Hf, Tb and Pr) solid solutions were prepared by a modified coprecipitation method and thermally treated at different temperatures from 773 to 1073 K in order to ascertain the thermal behavior. The structural and textural properties of the synthesized samples were investigated by means of X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM), BET surface area, X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy (RS) techniques. The catalytic efficiency has been performed towards oxygen storage/release capacity (OSC) and CO oxidation activity. The characterization results indicated that the obtained solid solutions exhibit defective cubic fluorite structure. The solid solutions of ceria–hafnia, ceria–terbia and ceria–praseodymium exhibited good thermal stability up to 1073 K. A new Ce_0.6Zr_0.4O₂ phase along with Ce_0.75Zr_0.25O₂ was observed in the case of ceria–zirconia solid solution due to more Zr⁴⁺ incorporation in the ceria lattice at higher calcination temperatures. The reducibility of ceria has been increased upon doping with Zr⁴⁺, Hf⁴⁺, Tb^3+/4+ and Pr^3+/4+ cations. This enhancement is more in case of Hf⁴⁺ doped ceria. Among various solid solutions investigated, the ceria–hafnia combination exhibited better OSC and CO oxidation activity. The high efficiency of Ce–Hf solid solution was correlated with its superior bulk oxygen mobility and other physicochemical characteristics.     

Effect of Fe<Superscript>3+</Superscript> doping on the performance of TiO<Subscript>2</Subscript> mechanocoated alumina bead photocatalysts

Ferric ion was introduced to the commercial photocatalyst P25 (Degussa) by ultrasonic wet impregnation technique. The concentration of the dopant was varied from 0.0 to 3.0% Fe/Ti ratio. The doped TiO₂ was then loaded to alumina balls using mechanical coating technique and followed by calcination in air at 400, 450, 500 and 550 °C. The fabricated photocatalyst was characterized by X-ray diffraction, N₂ adsorption-desorption isotherms, scanning electron microscopy, UV-Vis diffuse reflectance spectroscopy, X-ray adsorption near edge structure and photoluminescence spectroscopy. The photocatalytic activity was tested by following the degradation of methylene blue (MB). It was found that the Fe³⁺ doped TiO₂/Al₂O₃ has a combination of anatase and rutile phase and free of iron oxide phases. The optimum calcination temperature is 400 °C with 0.1% Fe³⁺ concentration. The catalyst addresses the entrainment in photocatalytic reactors, eliminating the need for a post filtration process.     

Effects of adding B<Subscript>2</Subscript>O<Subscript>3</Subscript> as a flux on phosphorescent properties in synthesis of SrAl<Subscript>2</Subscript>O<Subscript>4</Subscript>: (Eu<Superscript>2+</Superscript>, DY<Superscript>3+</Superscript> phosphor

SrAl₂O₄: (Eu²⁺, Dy³⁺) phosphor was prepared by solid state reaction. B₂O₅ as a flux was added in SrAl₂O₄:(Eu ²⁺, Dy³⁺) in order to accelerate a solid state reaction. In this paper, the effects of B₂O₃ on the crystal structure and the phosphorescent properties of the material have been evaluated. The synthesized phosphor exhibited a broad band emission spectrum peaking at 520 nm, and the spectrum peak showed little effect by the B₂O₃ contents. The maximum afterglow intensity of the SrAl₂O₄: (Eu²⁺, Dy³⁺) phosphor was obtained at the B₂O₃ content of 5%. Adding the B₂O₃ caused uniform distortion to the crystal structure of the phosphor and resulted in reducing the lengths of a and c axes and Β angle of the SrAl₂O₄ crystal. The uniform distortion was accompanied with crystal defects which can trap the holes generated by the excitation of Eu²⁺ ions. The afterglow characteristic of the SrAl₂O₄: (Eu²⁺, Dy³⁺) phosphor was thus enhanced.     

Influence of Cobalt Doping on the Physical Properties of Zn<Subscript>0.9</Subscript>Cd<Subscript>0.1</Subscript>S Nanoparticles

Zn_0.9Cd_0.1S nanoparticles doped with 0.005–0.24 M cobalt have been prepared by co-precipitation technique in ice bath at 280 K. For the cobalt concentration >0.18 M, XRD pattern shows unidentified phases along with Zn_0.9Cd_0.1S sphalerite phase. For low cobalt concentration (≤0.05 M) particle size, d _XRD is ~3.5 nm, while for high cobalt concentration (>0.05 M) particle size decreases abruptly (~2 nm) as detected by XRD. However, TEM analysis shows the similar particle size (~3.5 nm) irrespective of the cobalt concentration. Local strain in the alloyed nanoparticles with cobalt concentration of 0.18 M increases ~46% in comparison to that of 0.05 M. Direct to indirect energy band-gap transition is obtained when cobalt concentration goes beyond 0.05 M. A red shift in energy band gap is also observed for both the cases. Nanoparticles with low cobalt concentrations were found to have paramagnetic nature with no antiferromagnetic coupling. A negative Curie–Weiss temperature of −75 K with antiferromagnetic coupling was obtained for the high cobalt concentration.     

Synthesis and photoluminescent properties of Sm3+-doped SnO2 nanoparticles

SnO₂ ceramic nanoparticles homogeneously doped with Sm³⁺ ions were synthesized via a sol-gel method, followed by drying and annealing in air. X-ray diffractometry, FT-IR spectrometry and transmission electron microscopy were used to characterize the nanoparticulate samples. After annealing, both doped and undoped SnO₂ nanopowders were shown to adopt the rutile tetragonal crystal form and to exhibit characteristic Sn–O–Sn vibrations. The average particle size was found to be in the region of 23–28 nm. Photoluminescence analysis at room temperature demonstrated strong enhancement of the visible emission from Sm³⁺, via energy transfer from the SnO₂ host matrix to the dopant. The maximum emission efficiency was observed for a concentration of 1.5 atom% Sm³⁺.     

Preparation and electrochemical performance of Li-rich layered cathode material,Li[Ni<Subscript>0.2</Subscript>Li<Subscript>0.2</Subscript>Mn<Subscript>0.6</Subscript>]O<Subscript>2</Subscript>, for lithium-ion batteries

The Li-rich layered cathode material, Li[Ni_0.2Li_0.2Mn_0.6]O₂, was synthesized via a “mixed oxalate” method, and its structural and electrochemical properties were compared with the same material synthesized by the sol–gel method. X-ray diffraction (XRD) shows that the synthesized powders have a layered O₃–LiCoO₂-type structure with the R-3m symmetry. X-ray photoelectron spectroscopy (XPS) indicates that in the above material, Ni and Mn exist in the oxidation states of +2 and +4, respectively. The layered material exhibits an excellent electrochemical performance. Its discharge capacity increases gradually from the initial value of 228 mA hg⁻¹ to a stable capacity of over 260 mA hg⁻¹ after the 10th cycle. It delivers a larger capacity of 258 mA hg⁻¹ at the 30th cycle. The dQ/dV curves suggest that the increasing capacity results from the redox-reaction of Mn⁴⁺/Mn³⁺.     

Crystallization and luminescence properties of Eu<Superscript>2+</Superscript> doped diopside glass ceramics

Eu²⁺ doped glass ceramics have been prepared and characterized. The crystallization and optical properties of the glass ceramics were studied by XRD, SEM, and fluorescence spectra. The precipitated crystalline phase in the glass ceramics was prismatic diopside (CaMgSi₂O₆) and plate-like cristobalite (β-SiO₂). As the heat treatment time increases, the content of crystals increases gradually. Fluorescence measurements showed that Eu²⁺ ions entered into the diopside crystalline phase and induced a much stronger emission in the glass ceramics than that in the corresponding glass. With increase of Eu²⁺ content, concentration quenching was observed.     

Microstructure and properties of novel ReO<Subscript>2</Subscript> /polyimide nanocomposite films

A series of Rhenium (VII, Re⁷⁺) compound-doped polyimide (PI) nanohybrid films had been successfully fabricated from methyltrioxorhenium (MTO) and polyamic acid (PAA) via the solution direct-dispersing method, followed by a stepwise thermal imidization process. X-ray photoelectron spectroscopy (XPS) confirmed that MTO had decomposed into Re (IV) oxidation state (ReO₂). Field emission scanning electron microscopy (FE-SEM) showed that for the differrent hybrid films, the ReO₂ nanoparticles which formed by MTO decomposing well dispersed in polyimide matrix with a size of 40–60 nm. Thermal analysis indicated that the introduction of MTO decreased the thermal stability and the glass transition temperature (T_g) because of the unstable MTO. DMTA and static tensile measurements showed that the storage modulus and the elongation at break of nanocomposite films had a maximum value when the 1% of MTO was doped in PI, while the tensile strength decreased with increasing MTO content on the whole.     

Shielding Behavior of Gamma-Irradiated MoO<Subscript>3</Subscript> or WO<Subscript>3</Subscript>-Doped Lead Phosphate Glasses Assessed by Optical and FT Infrared Absorption Spectral Measurements

Undoped and MoO₃- or WO₃- doped lead phosphate glasses were prepared by the melting-annealing technique. The glasses were characterized through UV-visible and infrared measurements which were repeated after gamma irradiation. Optical spectrum of binary lead phosphate glass shows distinct ultraviolet bands correlated with unavoidable trace iron impurities within the chemicals used for the preparation of the glasses. UV-visible absorption spectra of MoO₃- or WO₃- doped glasses exhibit additional UV-visible bands which are related to the presence of four oxidation states of the two transition metal (molybdenum or tungsten) ions (Mo³⁺, Mo⁴⁺, Mo⁵⁺, Mo⁶⁺, W³⁺, W⁴⁺, W⁵⁺, W⁶⁺). The extra UV band is related to hexavalent (5d⁰) state while the rest of the visible bands are related to (350–440 nm - trivalent state), (450, 550, 650 nm - tetravalent state) while the broad band centered at about 770 nm (pentavalent state). The intensities of the absorption bands are observed to change with the transition metal content and their valencies. Infrared absorption spectra reveal distinct vibrational bands which are assigned to phosphate groups with sharing of Pb-O vibrations within both the range 460–620 cm^-1 and the range 900–1100 cm^-1 revealing a compact network structure. Gamma irradiation causes a minor increase in intensity of one of the UV band due to suggested photo-oxidation of some trace ferrous ions to additional ferric ions but the remaining spectral curve remains unaffected which is obviously related to some shielding effects of heavy atomic weight of PbO. This heavy metal oxide (PbO) is assumed to retard or prohibit the free passage of free electrons or positive holes generated during the irradiation process.     

Functionalized Mesoporous SBA-15 with CeF<Subscript>3</Subscript>: Eu<Superscript>3+</Superscript> Nanoparticle by Three Different Methods: Synthesis,Characterization, and Photoluminescence

Luminescence functionalization of the ordered mesoporous SBA-15 silica is realized by depositing a CeF₃: Eu³⁺ phosphor layer on its surface (denoted as CeF₃: Eu³⁺/SBA-15/IS, CeF₃: Eu³⁺/SBA-15/SI and CeF₃: Eu³⁺/SBA-15/SS) using three different methods, which are reaction in situ (I-S), solution impregnation (S-I) and solid phase grinding synthesis (S-S), respectively. The structure, morphology, porosity, and optical properties of the materials are well characterized by X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy, N₂ adsorption, and photoluminescence spectra. These materials all have high surface area, uniformity in the mesostructure and crystallinity. As expected, the pore volume, surface area, and pore size of SBA-15 decrease in sequence after deposition of the CeF₃: Eu³⁺ nanophosphors. Furthermore, the efficient energy transfer in mesoporous material mainly occurs between the Ce³⁺ and the central Eu³⁺ ion. They show the characteristic emission of Ce³⁺ 5d → 4f (200–320 nm) and Eu^{3+ 5}D₀ → ⁷F _J (J = 1–4, with ⁵D₀ → ⁷F₁ orange emission at 588 nm as the strongest one) transitions, respectively. In addition, for comparison, the mesoporous material CeF₃: Eu³⁺/SBA-15/SS exhibits the characteristic emission of Eu³⁺ ion under UV irradiation with higher luminescence intensity than the other materials.     

Enhancement of Sm3+ emission by SnO2 nanocrystals in the silica matrix

Silica xerogels containing Sm³⁺ ions and SnO₂ nanocrystals were prepared in a sol–gel process. The image of transmission electron microscopy (TEM) shows that the SnO₂ nanocrystals are dispersed in the silica matrix. The X-ray diffraction (XRD) of the sample confirms the tetragonal phase of SnO₂. The xerogels containing SnO₂ nanocrystals and Sm³⁺ ions display the characteristic emission of Sm³⁺ ions (⁴G_5/2 → ⁶H _J (J = 5/2, 7/2, 9/2)) at the excitation of 335 nm which energy corresponds to the energy gap of the SnO₂ nanocrystals, while no emission of Sm³⁺ ions can be observed for the samples containing Sm³⁺ ions. The enhancement of the Sm³⁺ emission is probably due to the energy transfer from SnO₂ nanocrystals to Sm³⁺ ions.     

Reductively Induced Catalytic DNA Cleavage of Water Soluble Rh<Superscript>III</Superscript>-Br<Subscript>8</Subscript>TMPyP

Abstract  

The Rh^III(Br₈TMPyP)⁵⁺ showed a catalytic DNA cleavage in the presence of ascorbic acid. The UV–visible, Cyclic Votlammetric (CV) and Electron Spin Resonance (ESR) data confirmed involvement of the reduced form of the Rh^III-Br₈TMPyP, Rh^III(Br₈TMPyP)^4+· radical, in the catalytic cycle. Gel-electrophoresis, results revealed that, Rh^III(Br₈TMPyP)⁵⁺ could cleave DNA at 0.01–0.1 μM levels which is significantly higher than that of other metalloporphyrins.     

Structural and Activity Investigation into Al<Superscript>3+</Superscript>, La<Superscript>3+</Superscript> and Ce<Superscript>3+</Superscript> Addition to the Phosphomolybdate Heteropolyanion for Isobutane Selective Oxidation

Abstract  

Twelve phosphomolybdate compounds were synthesized via cationic exchange and were of the form: M _x H_3–3x [PMo₁₂O₄₀] (M = Al, La or Ce; 0 ≤ x ≤ 1). These compounds were analyzed by XRD and adsorption isotherm. Aluminum addition causes a primitive cubic phase, while lanthanum and cerium yield body-centered structures. La and Ce addition reduces surface area of phosphomolybdate structure. Temperature-programmed experiments for the selective oxidation of isobutane yielded methacrolein, 3-methyl-2-oxetanone (lactone), acetic acid (not with aluminous compounds), propene (only with aluminous compounds), carbon dioxide and water. The preference for propene rather than acetic acid formation with Al³⁺ may be due to the smaller cation size, or primitive cubic structure. These products form via two distinct reaction processes, labeled categories 1 and 2. Category 1 formation is associated with isobutane forming products on the surface, but reaction rate determined by bulk migration of charged particles. Category 2 formation is concerned with isobutane penetrating deep within the bulk of the substrate and forming products which subsequently desorb in a series of bell-shaped humps. Methacrolein forms via both category 1 and 2, whilst all other products form via category 2 exclusively. Kinetic analysis showed apparent activation barriers for category 1 methacrolein formation range from 67 ± 2 kJ mol⁻¹ to >350 kJ mol⁻¹, and occur in groups with small, medium and large activation barriers. The addition of +3 metal cations to the phosphomolybdate anion increase thermal stability, significantly decreasing deactivation; IR spectroscopy shows that the Keggin structure remains intact during temperature-programmed experiments with the Al, La and Ce salts.     

Photocatalytic Activity of a TiO<Subscript>2</Subscript> Photocatalyst Doped with C<Superscript>4+</Superscript> and S<Superscript>4+</Superscript> Ions Having a Rutile Phase Under Visible Light

C⁴⁺ and S⁴⁺-codoped titanium dioxide (TiO₂) having a rutile phase was prepared. By doping C⁴⁺ and S⁴⁺ ions into a TiO₂ lattice, the absorption edge of rutile TiO₂ powder was largely shifted from 400 to 700 nm. 2-Methylpyridine and methyleneblue were photocatalytically oxidized at high efficiency on C⁴⁺ and S⁴⁺-doped TiO₂ under visible light at a wavelength longer than 5 nm.