Impurity Energy Research Articles

Oxygen Dependence of Formation, Electronic State Transition, and Spin Polarization for Anatase TiO2: A Comprehensive Study

The stability, geometry, microstructure, and specie combination together with the electronic states of the anatase TiO2 with oxygen defect content of 0%, 3.125%, 6.25%, and 12.5% have been intensively studied within the framework of the density functional theory method. The results show that the TiO2 with an oxygen defect is not as stable as intrinsic TiO2. The compound formation enthalpy Ef and the oxygen defect formation energy value tend to be larger for a higher defect content, and the oxygen defect gets harder to be formed. The bonds within the TiO6 polyhedron are different and not geometrically symmetrical. The bond strengths show distinct diversity, and the primitive cell of anatase TiO2 show spatial expansion when there are oxygen defects. All bands moved down to the low energy region, and two impurity energy band levels emerged for the anatase TiO2 with oxygen defect. The energy band gap is decreased from 3.085 eV to 1.165 eV, 1.0015 eV, and 0.43 eV. There are generally 7 peaks for the spin density of states function, corresponding to their 5 main bands. For the anatase TiO2 with an oxygen defect content of 12.5%, the spin density of states functions are not horizontal ordinate symmetrical near −1.12 eV and 0.31 eV. They are formed by oxygen defect energy levels, which is the result of the Ti d and O p state electron polarization. Transitions from weak paramagnetic to antiferromagnetic are found for the anatase TiO2 with oxygen defect.

Efficient Ni and Fe doping process in ZnO with enhanced photocatalytic activity: A theoretical and experimental investigation

Zn1-xNixO and Zn1-xFexO structures were synthesized by the microwave-assisted hydrothermal method. The best photocatalytic degradation of rhodamine B (RhB) and 4-nitrophenol (4-NP) were achieved by the Zn0.96Ni0.04O and Zn0.99Fe0.01O. The specificity of each dopant showed significance in the positions of the impurity energy levels, which ended up influencing the electron-hole separation and transport, as demonstrated by the photoluminescence emissions. The morphological analysis revealed that besides inhibiting the growth of particles, the incorporation of dopant ions into the ZnO lattice triggered a nucleation process, consequently changing their morphology. Density functional theory (DFT) calculations showed that the Fe3+ 3d orbitals generate energy levels below the conduction band (CB) while for Ni2+, the levels were found to be spread in a broad energy range above the valence band (VB). The synergistic effect of band gaps alteration, inhibition of electron-hole pair recombination and appearance of new trapping energy sites justifies the superior photocatalytic activity.

Photocatalytic degradation of organic pollutants in water by N-doping ZnS with Zn vacancy: enhancement mechanism of visible light response and electron flow promotion.

In order to improve the visible light response, N-doping ZnS (N-ZnS) nanospheres with Zn vacancy and porous surface were prepared by a simple one-pot hydrothermal method. Characterizations and density functional theory simulations showed excellent visible light response of N-ZnS. N-doping introduced impurity energy levels, which led to orbital hybridization and changed the original dipole moment. The presence of ortho Zn vacancy (O-Znv) can effectively reduce e--h+ recombination and photocorrosion. Furthermore, O-Znv caused lattice distortion (twisted the -S-Zn-N-(O-Znv)-S-Zn-S- chemical bond chain), resulting in "vacancy effect" to accelerate e- flow. Under visible light, the photocatalytic degradation efficiency of tetracycline (TC) and 2,4-dichlorophenol (2,4-DCP) was 90.31% and 60.84%, respectively. TOC degradation efficiency was 31.4% and 25.6%, respectively. Combined with Fukui index and LC-MS methods, it was found that TC and 2,4-DCP were degraded under the constant attack of active substances such as ·OH. This work can provide a reference for the application of catalytic materials in the field of visible light photocatalysis.

U7Co 3d impurity energy level mediated photogenerated carriers transfer in Bi2S3/ZnS:Co/TiO2 photoanode

Photogenerated carriers' transfer efficiency as one of the most important criteria determines the efficiency of a photoanode for photoelectrochemical (PEC) water splitting. Energy barrier-free charge transfer of photogenerated carriers is achieved in a core–shell heterostructure of Bi2S3/ZnS:Co/TiO2, in which the arrayed TiO2 nanorods are covered with the Co doped ZnS inner layer and the Bi2S3 outer layer. The dual-shell structure ensures high photoconversion efficiency in PEC water splitting. The impurity energy state of Co in ZnS connects the conduction band edges of Bi2S3 and TiO2 to convey photogenerated electrons, without electrons hopping to Zn orbits at higher energy positions. The ABPE value of 1.07% at 1.23 V vs. RHE demonstrates the improved photoconversion efficiency of Bi2S3/ZnS:Co/TiO2 heterostructure. This work offers a photoanode construction strategy for the enhancement of the PEC water splitting via introducing impurity energy states at interlayer for barrier-free photogenerated charge migrating.

Influence of doping Sn direction and concentration on vanadium pentoxide based on density functional theory

Based on the first-principles calculation method of density functional theory, the influence of different directions and concentrations of Sn doping on V2O5 was discussed. The doping formation energy, electronic density of states, and isosurface charge density of different Sn doping directions and doping concentration structures are calculated. The calculation results of five different crystal orientation doping models show that the doped structure along the [111] crystal orientation has a smaller doping formation energy of 1.879 eV, which has the best electrical properties and the largest charge density. And the charge distribution is the most concentrated. It is most conducive to the formation of conductive filaments. In addition, as the doping concentration increases, the charge density gradually increases. When the doping concentration is 3.174%, the peak impurity energy level is the highest and the band gap is the smallest. At the same time, there is a tendency to form conductive filaments in the direction of charge extension [111], and the resistance change characteristics of vanadium pentoxide are best improved. The research results of this paper can provide certain theoretical guidance for improving the performance of resistive random access memory based on vanadium pentoxide.

First-principles study of defect formation energies in LaOXS2 (X=Sb,Bi)

We theoretically investigate defect formation energies in LaO$X$S$_2$ ($X=$Sb, Bi) using first-principles calculation. We find that the oxygen vacancy is relatively stable, where its formation energy is higher in $X=$ Sb than in $X=$ Bi. An interesting feature of $X=$ Sb is that the vacancy of the in-plane sulfur atom becomes more stable than in $X=$ Bi, caused by the formation of an Sb$_2$ dimer and the electron occupation of the impurity energy levels. The formation energies of cation defects and anion-cation antisite defects are positive for the chemical equilibrium condition used in this study. Fluorine likely replaces oxygen, and its defect formation energy is negative for both $X=$ Sb and Bi, while that for $X=$ Sb is much higher than $X=$ Bi. Our study clarifies the stability of several point defects and suggests that the in-plane structural instability is enhanced in $X=$ Sb, which seems to affect a structural change caused by some in-plane point defects.

Influence of Nd concentrations on the structural, electronic and optical properties of anatase TiO2: A first-principles approach

Titanium dioxide (TiO2) and TiO2 doped with impurities offer good potential for many applications such as photoanode in dye-sensitized solar cells (DSSCs) and photocatalysts used in hydrogen production and degradation of organic pollutants. First-principles calculations on the structural, electronic and optical properties of pure anatase TiO2 with different Nd concentrations are performed using 2 × 1 × 1 supercell with a stoichiometry of Ti1-xNdxO2 (x = 0, 0.0625, 0.125 and 0.1875). The doping effect to the properties of TiO2 can be observed from the changes in the structural parameters, modification of the band structure, presence of impurity energy levels (IELs) in density of states (DOS) and difference in optical properties results. At a higher Nd concentration doping, the band gap of Nd-doped TiO2 decreases as a result of the overlapping of states among Nd 4f, Ti 3d and O 2p, which can enhance the light absorption activity in the visible light region. These findings indicate that Nd-doped TiO2 can increase the performance of photocatalyst and photovoltaic due to its capability to harvest visible light.

Electronic structure properties of boron–doped and carbon–boron–codoped TiO2(B) for photocatalytic applications

A path to enhance the efficiency of photocatalytic devices is by doping the active semiconductor in order to maximize the light absorption. However, impurities could increase the recombination of photoinduced charge carriers, in order that a careful analysis on the effects of those impurities it is necessary. On this research, density functional theory calculations were applied to analyze the structure and electronic characteristics of B–doped and C+B–codoped TiO2(B) considering the lowest formation energy of substitutional impurities. Our calculations suggest that the swapping of a boron or carbon atom for an oxygen atom (B@O or C@O) is energetically more favorable than the replacement of titanium atoms. The obtained results seem to indicate that the boron substitution into O2C and O3C1 sites leads to its migration towards interstitial sites in both mono and codoping, thus causing a great geometrical distortion compared to pure TiO2(B). Furthermore, impurity states in the band gap were obtained after B@O doping and C+B–codoping, producing an improvement of the optical properties, so it can be assumed that this nanomaterial might act as a photoelectrode after an adequate design optimization that facilitates the charge carrier separation.

Highly improved nonlinear optical responses of reduced graphene oxide via the decoration of Ni doped ZnS nanoparticles

The application of graphene and graphene-like materials in photonics has attracted extensive attention in recent years. However, their nonlinear optical (NLO) properties need to be improved urgently. Herein, we demonstrate a method to improve the NLO properties of reduced graphene oxide (RGO) via the decoration of Ni transition element doped ZnS nanoparticles on RGO sheet. The samples of Ni doped ZnS decorated RGO (Ni-ZnS/RGO) composites with different Ni doping concentrations and ZnS particles sizes were synthesized via a facile solvothermal method. The NLO responses of Ni-ZnS/RGO composites were investigated via the Z-scan technique under a picosecond laser at 1064 nm. The results indicated that Ni-ZnS/RGO composites exhibited saturation absorption and positive nonlinear refraction properties, and they could be adjusted by controlling the doping concentration of Ni and the size of ZnS nanoparticles. The maximum saturation absorption coefficient, nonlinear susceptibility and nonlinear refractive index of Ni-ZnS/RGO among all the samples were obtained to be − 2.5 × 10−10 mW−1, 3.2 × 10−13cm2/W and 14.1 × 10−14cm2/W, which were 25, 18 and 23 times of those of RGO, and 3.6, 11.7 and 4.2 times of those of ZnS doped with 2.5%Ni, respectively. They were also much greater than those of the direct sum of the two independent units, RGO and Ni-doped ZnS. These highly improved NLO responses of Ni-ZnS/RGO composites were ascribed to the inhibition of the direct electron-hole recombination due to the introduction of Ni doped impurity energy levels within the band gap of ZnS, as well as the charge transfer and synergism between ZnS and RGO. The results of this investigation may promote the development and applications of Ni-ZnS/RGO materials in photonic devices.

Binding energy, polarizability, and diamagnetic response of shallow donor impurity in zinc blende GaN quantum dots

In this theoretical investigation, the binding energy, the binding energy Stark-shift, the dipole moment, the polarizability, and the diamagnetic susceptibility related with a confined shallow donor impurity in zinc blende GaN conical-shaped quantum dots are calculated under the effect of an electric field applied along the z-direction. Calculations have been made by using a variational approach within the infinite confining potential model and considering the parabolic conduction band and the effective mass approximations. The results suggest important dependencies of the calculated physical properties on the variation of the dot dimensions, axial impurity position, and the intensity of the applied electric field. It is observed that: i) the binding energy Stark shift increases up to a maximum value and then decreases with increasing the strength of the electric field, and it is strongly influenced by the impurity position and geometrical parameters, ii) for a fixed electric field value, the binding energy Stark shift is always an increasing function of the dot height, and iii) for fixed electric field values, the binding energy Stark shift shows a mixed behavior concerning the dot radius, i.e., for low field strength, the binding energy is always a growing function of the radius, and for large field strengths, such physical quantity grows with the radius up to a maximum and then decreases. Furthermore, the electric field (the strong quantum confinement) enhances slightly (diminishes) the diamagnetic susceptibility of impurity.

Improved thermal stability and infrared emissivity of high-entropy REMgAl11O19 and LaMAl11O19 (RE=La, Nd, Gd, Sm, Pr, Dy; M=Mg, Fe, Co, Ni, Zn)

• Three dense bulk high-entropy REMgAl 11 O 19 and LaMAl 11 O 19 ceramics are designed and successfully prepared via solid state reaction in a single step. • The factors affecting the phase stability of LaMgAl 11 O 19 are firstly investigated via the electronic structure. • Enhanced thermal stability and infrared emissivity properties are demonstrated for the first time. • Mechanism for excellent thermal stability and infrared emissivity properties is revealed for the first time. LaMgAl 11 O 19 (LMA), characterized by high melting point, low density and thermal conductivity as well as good infrared emissivity, is regarded as a potential candidate for the thermal protection of hypersonic vehicles. Nevertheless, the unsatisfied phase stability at high temperature results in declining of the emissivity below 6 μm, which limits the extensive applications of LaMgAl 11 O 19 . In order to overcome this obstacle, three dense bulk high-entropy ceramics, (La 0.2 Nd 0.2 Gd 0.2 Sm 0.2 Pr 0.2 )MgAl 11 O 19 (HE LMA-1), (La 0.2 Nd 0.2 Gd 0.2 Sm 0.2 Dy 0.2 )Mg Al 11 O 19 (HE LMA-2) and La(Mg 0.2 Fe 0.2 Co 0.2 Ni 0.2 Zn 0.2 )Al 11 O 19 (HE LMA-3), were designed and successfully prepared through solid state reaction at 1700 °C for 4 h in one step. XRD analyses show that the phase compositions of HE LMA-1, HE LMA-2 and HE LMA-3 are single-phase solid solutions with the relative density of 95.61%, 95.49% and 94.31%, respectively. Heat treatment experiments demonstrate that the phase composition of HE LMA-1 remains a single phase after high-temperature heating, while second phase appears in other two samples. The stability of HE LMA-1 is attributed to small average size difference δ (∼4%) of constitute elements. Intriguingly, the average emissivity of HE LMA-1 in the range of 3–6 μm reaches 0.9, which is significantly higher than that of LMA and other two HE LMA samples. The emissivity of all samples remains above 0.95 from 6 to 10 μm. In the far infrared region (10–14 μm), although the emissivity of these specimens decreases slightly, it still exceeds 0.85. The UV–Vis absorption spectra indicate that the formation of many discrete impurity energy levels with small intervals in HE LMA-1 promotes the f electrons to transit between adjacent impurity energy levels and conduction band, which enhances the infrared emission of HE LMA-1 below 6 μm. In a word, with improved phase stability and thermal emissivity in infrared range, high-entropy REMgAl 11 O 19 , especially (La 0.2 Nd 0.2 Gd 0.2 Sm 0.2 Pr 0.2 )MgAl 11 O 19 (HE LMA-1), is a promising candidate in thermal protection coatings of hypersonic vehicles.

Suppression of impurity magnetization by the saddle points

We study the localized magnetic states of an impurity in the semi-Dirac-like system where the saddle point (SP) is present. It is found that with increasing the saddle point energy (SPE), the impurity magnetization region diminishes greatly, and reaches a minimum at the SPE equal to the impurity energy. When continuing to increase the SPE, the impurity magnetization region rapidly becomes large. Correspondingly, an explicit decrease with the SPE close to the impurity energy is also observed in the magnetic moment of the impurity. This suppression behavior for the magnetization of the impurity can be understood from the SP induced mitigation of asymmetry on the density of state at impurity energy. In contrast, when the SP vanishes, due to the opening of the gap, the magnetic region exhibits a monotonous decay when the conduction band edge goes up through the impurity energy. The combined effect of the SP and the Coulomb interaction at the impurity on the local magnetization is also investigated.

A DFT+U study of site dependent Fe-doped TiO2 diluted magnetic semiconductor material: Room-temperature ferromagnetism and improved semiconducting properties

This article reports the crystal structure, impurity formation energy, electronic property, magnetic property, and dopant configuration site dependence of ferromagnetic temperature Tc of anatase (Ti15FeO32, Ti14Fe2O32, and Ti13Fe3O32) by first-principles calculations based on density functional theory (DFT) with Hubbard onsite correction (DFT+U). The estimated formation energy validated the structural stability of the Fe-doped TiO2 with 2.08% (Ti15FeO32), 4.17% (Ti14Fe2O32), and 6.25% (Ti13Fe3O32) concentrations at the Ti sites. The electronic structure analysis reveals that the bandgap in the doped system changed from a wide bandgap of 3.23 eV (pristine TiO2) to slightly lower bandgaps of 3.13, 3.08, and 3.04 eV with Fe concentrations of 2.08%, 4.17%, and 6.25%, respectively. The calculated partial density of states also show the hybridization of O with 2p- and Fe 3d-orbitals near the conduction band minimum and generate the impurity energy level reducing the bandgap. Furthermore, the estimated Curie temperature (Tc) varied depending on the Fe–Fe interactions, the concentration of the Fe dopants, and doping sites. For instance, Tc is calculated to be 343.57 K for 2.08% Fe at the symmetric point of the crystal while estimated to be 323.84 and 393.297 K for 4.17% at the nearest neighbor and the next-nearest neighbor configurations. Due to the increase of the Fe concentration to 6.25%, the calculated Tc monotonically improved to 342.5 and 513.174 K at the nearest neighbor and the next-nearest neighbor of the Fe-site, respectively. These indicate that all the calculated findings estimate the ferromagnetic transition temperature Tc to above room temperature. Moreover, the system’s total magnetization reveals the augmentation of a number of unpaired electrons as a result of rise in oxygen vacancies and, hence, there could be more holes when the Fe content gets higher, perhaps generating more bound magnetic polarons that favor the critical temperature, Tc.

Максимальная прыжковая электропроводность на постоянном токе по водородоподобным примесям в полупроводниках

A quasi-classical model for calculating DC (direct current) electrical conductivity in crystalline semiconductors with hydrogen-like impurities is developed at the transition from band conduction to impurity hopping conduction with decreasing temperature. This transition from the minimum band conductivity to the maximum hopping conductivity via impurities has the form of a characteristic ``kink'' in the temperature dependence of the electrical resistivity. The idea of the calculation is to preliminarily determine the transition temperature Tj using the standard approach within the framework of the two-band model. The shift of the top of the v-band (the bottom of the c-band) into the depth of the band gap due to the formation of a quasi-continuous band of allowed energy values from the excited states of acceptors (donors) is taken into account. This leads to a decrease in the value of a thermal ionization energy of the main shallow impurities due to a decrease in the maximum localization radius of a hole on an acceptor (an electron on a donor) with increasing impurity concentration. The values of the observed maximum hopping conductivity and drift hopping mobility corresponding to the temperature Tj are calculated. The numerical calculation within the framework of the proposed model is consistent with the known experimental data on the electrical conductivity and Hall coefficient of moderately compensated p-Ge crystals doped by neutron transmutation and non-intentionally compensated metallurgically doped n-Ge, as well as n- and p-Si crystals on the insulator side of the Mott insulator–metal concentration phase transition.

Ab initio study of fullerene based single molecule nano junctions

In this paper, we explored various fullerene molecules (C20 and impurity added C20) based single molecule nano-junctions using ab initio framework with density functional theory (DFT). In coulomb regime, various fullerenes are placed over the dielectric, in between source and drain for weaker coupling. The HOMO, LUMO values, charge stability diagrams and total energy vs. gate voltage of pristine and impurity added fullerene nano-junction (IAF) are studied. The conductive behaviour of pristine and IAF in coulomb blockade regime are addressed. This work features the fullerene based materials in molecular nano-junctions for ultrahigh speed switching and sensing applications.

Maximum hopping direct current conductivity via hydrogen-like impurities in semiconductors

A quasi-classical model for calculating DC (direct current) electrical conductivity in crystalline semiconductors with hydrogen-like impurities is developed at the transition from band conduction to impurity hopping conduction with decreasing temperature. This transition from the minimum band conductivity to the maximum hopping conductivity via impurities has the form of a characteristic "kink" in the temperature dependence of the electrical resistivity. The idea of the calculation is to preliminarily determine the transition temperature Tj using the standard approach within the framework of the two-band model. The shift of the top of the v-band (the bottom of the c-band) into the depth of the band gap due to the formation of a quasi-continuous band of allowed energy values from the excited states of acceptors (donors) is taken into account. This leads to a decrease in the value of a thermal ionization energy of the majority shallow impurities due to a decrease in the maximum localization radius of a hole on an acceptor (an electron on a donor) with increasing impurity concentration. The values of the observed maximum hopping conductivity and drift hopping mobility corresponding to the temperature Tj are calculated. The numerical calculation within the framework of the proposed model is consistent with the known experimental data on the electrical conductivity and Hall coefficient of moderately compensated p-Ge crystals doped by neutron transmutation and non-intentionally compensated metallurgically doped n-Ge, as well as n- and p-Si crystals on the insulator side of the Mott insulator--metal concentration phase transition. Keywords: bulk crystals of germanium and silicon, hydrogen-like acceptors and donors, holes and electrons, band and hopping motion of charge carriers.

Ultrathin structure of oxygen doped carbon nitride for efficient CO2 photocatalytic reduction

Photocatalytic conversion of carbon dioxide into fuels and valuable chemicals is a promising method for carbon neutralization and solving environmental problems. Through a simple thermal-oxidative exfoliation method, the O element was doped while exfoliated bulk g-C3N4 into ultrathin structure g-C3N4. Benefitting from the ultrathin structure of g-C3N4, the larger surface area and shorter electrons migration distance effectively improve the CO2 reduction efficiency. In addition, density functional thory computation proves that O element doping introduces new impurity energy levels, which making electrons easier to be excited. The prepared photocatalyst reduction of CO2 to CO (116 μmol g−1 h−1) and CH4 (47 μmol g−1 h−1).

Experiment and simulation of infrared emissivity properties of doped LaAlO3

AbstractIn this study, LaAlO3 doped with Sr/Co/Mn was prepared by sol‐gel method, with its infrared (IR) radiative properties and variation mechanism investigated by X‐ray powder diffraction, X‐ray photoelectron spectroscopy, IR, scanning electron microscopy. Meanwhile, the electronic band structure was simulated by Cambridge Serial Total Energy Package. The conclusions are as follows: the order of emissivity in the near‐IR band is La0.67Sr0.33Al0.67Mn0.33O3> La0.67Sr0.33Al0.67Co0.33O3> LaAl0.67Mn0.33O3> LaAl0.67Co0.33O3> LaAlO3. In 0–2.5 μm at room temperature, the emissivity of La0.67Sr0.33Al0.67Mn0.33O3 can reach 0.9504. The emissivity increase mechanism lies in the further free carrier absorption caused by numerous small polarons formed by the Sr‐Mn co‐doping and increased concentration of electron‐oxygen vacancies. Meanwhile, the Sr‐Mn co‐doping causes lattice distortion and strengthens the lattice vibration absorption. The band gap of La0.67Sr0.33Al0.67Mn0.33O3 is 0.910 eV, much smaller than 3.445 eV of LaAlO3, favorable to the valence band electron transition, generating more electron‐oxygen vacancy pairs and promoting free carrier absorption. La0.67Sr0.33Al0.67Mn0.33O3 conduction band migrates to the lower energy region, while Mn3d impurity energy level appears. Thanks to the band gap reduction, dielectric function imaginary peaks, and absorption coefficient peaks are red‐shifted. Due to its high emissivity, La0.67Sr0.33Al0.67Mn0.33O3 has a high utilization value and broad potential application.

Calculations of in-gap states of ferromagnetic spin chains on s -wave wide-band superconductors

Magnetic impurities create in-gap states on superconductors. Recent experiments explore the topological properties of one-dimensional arrays of magnetic impurities on superconductors, because in certain regimes p-wave pairing can be locally induced leading to new topological phases. A by-product of the new accessible phases is the appearance of zero-energy edge states that have non-Abelian exchange properties and can be used for topological quantum computation. Despite the large amount of theory devoted to these systems, most treatments use approximations that render their applicability limited when comparing with usual experiments of 1-D impurity arrays on wide-band superconductors. These approximations either involve tight-binding-like approximations where the impurity energy scales match the minute energy scale of the superconducting gap and are many times unrealistic, or they assume strongly-bound in-gap states. Here, we present a theory for s-wave superconductors based on a wide-band normal metal, with any possible energy scale for the magnetic impurities. The theory is based on free-electron Green's functions. We include Rashba coupling and compare with recent experimental results, permitting us to analyze the topological phases and the experimental edge states. The infinite-chain properties can be analytically obtained, giving us a way to compare with finite-chain calculations. We show that it is possible to converge to the infinite limit by doing finite numerical calculation, paving the way for numerical calculations not based on analytical Green's functions.

Fabrication of tunable oxygen vacancies on BiOCl modified by spiral carbon fiber for highly efficient photocatalytic detoxification of typical pollutants

Flower-like spiral carbon fiber (SCF)/BiOCl composite photocatalysts with adjustable oxygen vacancies (OVs) were successfully fabricated via SCF surface modification of BiOCl. The sample composition and the photogenerated carrier separation efficiency were tested by various characterization methods. Compared with BiOCl, SCF/BiOCl photocatalysts display higher level of OVs and produce more superoxide radicals. The presence of OVs leads to the formation of an impurity energy level between the energy band of BiOCl. In addition, the SCF can transfer some of the photogenerated electrons produced by BiOCl. With the synergistic effect of OVs and SCF, an effective separation of photogenerated carriers is achieved. Photocatalytic activity of the samples was evaluated by the removal of inorganic pollutants (Cr (VI)) and organic pollutants (phenol and Tetracycline (TC)). The activity results show that SCF/BOC-1.75 for TC, phenol and Cr (VI) is 3.2, 2.5 and 10.6 times of that of the neat BOC; 0.9, 1.8 and 4.9 times of that of P25 under simulated sunlight illumination, respectively. The primary active species in the reaction system were investigated and the reaction mechanism was deduced.