Pure Bismuth Oxychloride Research Articles

Fabrication of a novel microflower BiOCl composite incorporated with rosemary powder for enhanced oxygen vacancies and visible-light photocatalytic efficiency

Incorporating metallic or nonmetallic compounds is a promising method for enhancing the oxygen vacancies (OVs), charge transport, and visible light absorption of a bismuth oxychloride (BiOCl) semiconductor. This research aims to improve the properties of BiOCl by incorporating rosemary powder (RPC). BiOCl photocatalysts with enhanced OVs were synthesized through the addition of 1–4 wt% of RPC using a one-pot solvothermal process. The addition of 3 % RPC resulted in the formation of very small particles on the BiOCl lamellar structures, which were aligned with the (002) plane of carbon quantum dots (CQDs). The uniformly distributed CQDs transformed the BiOCl microstructure from a two-dimensional lamellar structure to a three-dimensional floral structure, leading to an increased surface area and pore volume. The incorporation of RPC enhanced the visible light absorption capacity of BiOCl. The carbon atoms in RPC readily attach to oxygen atoms in the Bi-O bond, disrupting the Bi-O lattice bond and forming OVs. The addition of RPC contributed to a higher number of OVs, which impacted both the energy difference between the valence and conduction bands and their locations. This resulted in better charge transfer and enhanced active species formation. The 3 %-RPC-BOC photocatalyst had the highest efficiency, achieving a 98 % degradation of rhodamine B (RhB) and a 45 % removal of organic carbon within 48 min under visible light. This composite also had excellent stability and reusability, as its crystal structure remained unaltered even after conducting 7 cycles. The primary active species of 3 %-RPC-BOC system is the superoxide radical (·O2-), while the hydroxyl radical (·OH) and hole (h+) operate as minor active species. Additionally, the 3 %-RPC-BOC achieved a high tetracycline (TC) removal rate of 82.1 %, which is 2.21 times higher than that of pure BiOCl.

Attached meso-tetra (4-carboxyphenyl) porphyrin copper (II) to BiOCl for enhanced photocatalytic performance in antibiotics degradation

Bismuth oxychloride (BiOCl) has been considerably accepted as a photocatalyst due to its excellent photoelectrochemical properties, low cost and corrosion resistance. However, its further application has not progressed due to limited visible-light utilization and quick recombination of photoexcited carriers. In this work, a series of meso-tetra (4-carboxyphenyl) porphyrin copper (II) (CuTCPP) hybridized BiOCl composites (CuTCPP/BiOCl) were synthesized to use as an efficient visible-light responsive photocatalyst for the degradation of antibiotics pollutants in the wastewater systems. The characterization results confirmed that the 2D fusiform-shaped CuTCPP nanosheets were successfully inserted into hierarchical flower-like BiOCl. The photocatalytic degradation of several typical antibiotics (tetracycline, enrofloxacin and ciprofloxacin) demonstrated that CuTCPP/BiOCl showed better photocatalytic activities than pure BiOCl. Further, 0.5 wt% CuTCPP/BiOCl manifested the optimal photocatalytic efficiency for decomposing the antibiotics, and its degradation rate constant was about 2.84 times higher than that of pristine BiOCl. The significantly improved photocatalytic performance was mainly due to the promotion of visible light harvesting and enhanced separation of photogenerated carriers after the introduction of the macrocyclic CuTCPP. The radical substances determination confirmed that active •O2−, h+ and •OH existed in the photocatalytic removal of antibiotic, in which •O2− was the main reactive oxidizing species. The excellent degradation efficiency of CuTCPP/BiOCl reveals its great potential as photocatalysts for use in the alleviation of antibiotic contaminants and wastewater purification.

Construction of BiOCl/reduced graphene oxide nanocomposites heterojunction with abundant oxygen vacancies for efficient photocatalytic organic pollutant removal

Precisely manipulating defects in semiconductor is an effective way to improve their photocatalytic activity. In this work, bismuth oxychloride (BiOCl)/reduced graphene oxide (RGO) nanocomposites with abundant oxygen vacancies (OVs) are successfully constructed by a facile solvothermal method. BiOCl nanosheets are uniformly distributed on the RGO with superior conductivity. The RGO served as a pivotal charge transmission bridge substantially accelerates the transfer of photogenerated charge carriers, resulting in the improvement of the charge separation efficiency. The abundant oxygen vacancies in BiOCl/RGO nanocomposites increase light harvesting and enhance the adsorption of O2 to promote the formation of superoxide free radicals (·O2−). By virtue of these merits, the unique BiOCl/RGO nanocomposite shows excellent degradation efficiency. When the mass ratio of RGO was 2 %, 99.07 % of 20 mg/L(100 mL) methyl orange (MO) was removed after 80 min, which was much higher than that of pure BiOCl.

Laser ablation synthesis of BiOCl/Ag/WO3 nanocomposite to evaluate its photocatalysis performance

Bismuth oxychloride (BiOCl)/silver (Ag)/tungsten oxide (WO3) nanocomposite was produced by laser ablation to enhance photocatalytic performance. The ternary nanocomposite showed a superior photocatalytic activity for methylene blue (MB) degradation under visible light compared to pure BiOCl and BiOCl/Ag with degradation up to 74%, 62%, and 52 %, respectively. The addition of Ag improved the dispersibility of BiOCl and WO3, which reduced the recombination of electron–hole pairs and can be responsible for higher photocatalytic activity.

Advancing sustainable solutions: Harnessing polyaniline/BiOCl/GO ternary nanocomposites for solar-powered degradation of organic pollutant and photocatalytic hydrogen generation

Recently, polyaniline-based photocatalysts have gained great attention due to their narrow band gap (E = 1.77 eV), which enables them to absorb a significant amount of visible light (∼43%) in the solar spectrum. In this study, we have synthesized a ternary nanocomposite (PANI/BiOCl/GO) through an oxidative polymerization approach, incorporating polyaniline (PANI), graphene oxide (GO), and bismuth oxychloride (BiOCl). Different weight percentages of composites (GO/BiOCl: 0.5%, 1%, 2.5%, and PANI: 99.5%, 99%, 97.5%) were prepared and named as 0.5PBG, 1PBG, and 2.5PBG, respectively. The ternary nanocomposite's successful development, crystallinity, purity, porosity, and optical properties were evaluated through several spectroscopic and surface analysis techniques, including UV–Vis-DRS, PL, XRD, XPS, BET, and EDS analysis. FESEM and HRTEM images unveiled the porous characteristics of PANI, the morphology of exfoliated GO layers, and the nanoplate-like structure of BiOCl. The ternary nanocomposite was finally tested for its ability to degrade an organic dye, rhodamine-b (Rhb), and in the process also generate solar-light-driven green hydrogen by water half-splitting. The composite achieved about 90% detoxification (assigned from GC-TCD by analyzing the evolved CO2 gas after degradation) and 96% color removal of Rhb dye within 120 min. The degradation of Rhb by 1PBG displayed a first-order reaction, featuring a rate constant 7.25 times higher than that observed for pure PANI, 3.8 times higher than for pure GO, and 3.9 times higher than for pure BiOCl. Thus, the ternary composites achieve a good amount of synergy. Significantly, this reaction rate constant is 4.7 times greater than the rate observed with commercially used TiO2–P25 photocatalyst. Various reaction parameters including solution pH, different illumination areas, catalyst dosage, and the study of scavengers were investigated to understand their effects on the degradation reaction. The photocatalyst's reusability effectiveness was evaluated over 6 cycles, and its stability was subsequently confirmed through XRD and ICP-OES analysis. The LC-MS study revealed the identification of various intermediates and end products following the degradation reaction. The nanocomposite also produced 1000 ppm of hydrogen gas with an apparent quantum efficiency (AQE) of 17.97% when CH3OH was used as a sacrificial agent, 500 ppm (AQE of 9.69%) in the acidic conditions, and 600 ppm (AQE of 11.63%) in the basic conditions. In a broader perspective, this endeavor paves the way for exploring fresh opportunities in the utilization of this ternary nanocomposite. Its potential extends beyond accelerating dye degradation to encompass diverse solar-driven applications as well.

One-pot construction of S–Mo co-doped BiOCl toward simultaneously decreasing size, tuning energy band structure, and promoting charge separation for efficient photocatalytic degradation of organic pollutants

Bismuth oxychloride (BiOCl), although it has exhibited intensely potential used in photocatalyst for environmental remediation, owns wide bandgap and the fast photocharge recombination that limits its effective application. Doping BiOCl used in metal and non-metal elements simultaneously, as a feasible strategy in designing novel visible-light photocatalysts, was conductive to effectively overcome the as-above defects. The present work constructed S-Mo co-doped BiOCl-- with abundant reactive sites via one-pot hydrothermal method. The as-prepared S–Mo co-doped BiOCl sample presents the best-visible light-driven photodegradation performance, and its kinetic constant (k) is about 16.8 times (for rhodamine B) and 6.5 times (for tetracycline hydrochloride) higher than that of pure BiOCl, respectively. By contrast, S-Mo co-dopant induced the decrease of nanosheets size and endowed the large specific surface areas, which favors the increased reactive sites. Further analysis with the aid of experiments and density function theory calculations indicated that the intermediate level induced by S 2p orbitals could narrow the bandgap and promote the excitation of electron from conduction band to valance band via providing the middle springboard on the one hand, and the Mo energy states was conducive to promote the separation of charge carriers by acted as the acceptor for the photoinduced electrons on the other hand. Consequently, the potential origin of the improved visible-light-driven performance lies in the more superoxide radicals for oxidizing organic pollutants caused by the simultaneous enhancement of visible light absorption as well as charge separation resulted from the further optimization of energy band structure that associated with the doping energy level of S-Mo co-doping in BiOCl. This work demonstrated that S and Mo co-doping BiOCl is of highly promising candidate for the further progress of environmental remediation.

A novel BiOCl (110)/rGO/Ag3PO4 (111) heterostructure for efficient detoxification of 2,4-dichlorophenol

An effective method using nontoxic and efficient photocatalysts are crucial for wastewater treatment. Bismuth oxychloride (BiOCl) is considered as one of the valuable photocatalysts due to its unique layered plate like structure, however higher recombination and unsatisfied visible light absorption efficiency seriously affecting its applications. Addition of tetrahedral silver phosphate (Ag3PO4) which is known for its superior photocatalytic efficiency under visible light is believed to be the solution for the issue. Upon further adding of reduced graphene oxide (rGO) could form a bridging structure and enhance the activity. Considering the merits of these materials the BiOCl (110)/rGO/Ag3PO4 (111) heterojunction has been successfully constructed for 2,4-dichlorophenol (DCP) enhanced detoxification. The efficiency in degradation was found to be 94.8% by BiOCl/rGO/Ag3PO4 (k = 0.01879 min−1) that was greater to that of pure Ag3PO4 (∼1.9 times; k = 0.00818 min−1) and pure BiOCl (∼2.8 times; k = 0.00642 min−1) after 60 min of visible light irradiation. The mechanism of degradation was explained through the principle of heterojunction energy-band theory. Furthermore, 2,4-dichlorophenol (2,4-DCP) degradation products identification was carried out by ESI/LC-MS to propose the degradation pathway. Furthermore, the phytotoxicity of the intermediate products was investigated by estimating the germination index (GI) values on Phaseolus vulgaris (P. vulgaris) at different time intervals and the GI values were found to be 10.79% and 80.17% before and after degradation respectively. Thus, our results revealed that efficient and significant toxicity reduction was observed in this photodegradation.

Simple hydrolysis synthesis of copper oxide and bismuth oxychloride composites and visible light photodegradation of ciprofloxacin

In this paper, the high-performance photocatalytic copper oxide and bismuth oxychloride composite material is prepared with a simple hydrolysis method and is studied by various characterization methods. The results show that the moderately loaded copper oxide significantly enhances the degradation performance, visible light response ability, and interface charge transfer ability of bismuth oxychloride semiconductors, and the recombination of electron-hole pairs is obviously inhibited. Especially, when the content of added copper oxide is about 0.04 mmol, the composite material has a saturated adsorption rate of 53.07% for ciprofloxacin. Under the irradiation of visible light for 60 minutes, the removal rate of composite material for Ciprofloxacin reaches 93.15%, which is that of pure bismuth oxychloride 6.2 times. The photocatalytic effect is improved dramatically. After five times of recycling, the material presents favorable stability and outstanding photocatalytic activity. The possible photocatalytic mechanism is discussed that Superoxide radical is the leading radical group playing the significant role in the press of photocatalytic degradation of ciprofloxacin.

Chemical precipitation synthesis of Bi0.7Fe0.3OCl nanosheets via Fe (III)-doped BiOCl for highly visible light photocatalytic performance

It remains a challenge to improve the photocatalytic activity of bismuth oxychloride (BiOCl) under visible light irradiation. In this work, BiOCl was changed by doping iron ions with a simple chemical precipitation method. During fabrication, under acidic conditions (pH = 3), bismuth nitrate and ferric chloride were mixed together and then annealed at 400 ℃, 450 ℃, 500 ℃ and 550 ℃, respectively. Finally, Bi0.7Fe0.3OCl with uniform doping of Fe (III) was obtained. The properties of Bi0.7Fe0.3OCl samples were characterized by XRD, SEM, TEM, XPS, and UV–vis. Bi0.7Fe0.3OCl nanomaterials synthesized at different temperatures were compared for their photocatalytic performance through investigating the degradation of a dye (Rhodamine B) under visible light. The experimental results showed that doping with Fe (III) can improve the visible light catalytic efficiency of BiOCl. Bi0.7Fe0.3OCl-450 had the best RhB removal rate, reaching 74 % within 3 h, which was about 4.8 times higher than pure BiOCl. This work may provide a promising method for preparing metal-doped BiOCl materials with efficient photocatalytic performance by generating large quantities of electron-holes during the photoreaction process.

BiOCl/cattail carbon composites with hierarchical structure for enhanced photocatalytic activity

Bismuth oxychloride (BiOCl) has great potential as a photocatalytic material. It is worthy to improve its photocatalytic performance by a simple and feasible method. In this work, withered cattail is carbonized directly at 800 ℃ in nitrogen atmosphere to obtain cattail carbon with good conductivity, which could be a good acceptor of photogenerated electrons. Through the one-step facile co-precipitation route with stirring at room temperature followed by the treatment of acetic acid, ultrathin nanosheets of BiOCl were synthesized and grew on the surface of cattail carbon. The BiOCl/cattail carbon composites have well-contacted heterojunction interface, hierarchical structure, high specific surface area and enhanced utilization of visible light, which allow the composites to separate the photogenerated electron-holes efficiently. Thus the BiOCl/cattail carbon composites could show excellent photocatalytic activity, which could remove rhodamine B completely within one hour under visible light. The degradation rate of the composite could achieve about 17 times higher than that of pure BiOCl. Mechanism test showed that both OH and h+ active species could work together to degrade organic pollutants. Therefore, our work combines readily available and inexpensive biochar materials with BiOCl, which provides a strategy for the low-cost synthesis of efficient BiOCl-based photocatalytic materials that can be used in large-scale industrial production to be applied in the treatment of organic wastewater.

Hydrothermal synthesis of W-doped BiOCl nanoplates for photocatalytic degradation of rhodamine B under visible light

Doping bismuth oxychloride (BiOCl) with other elements can help improve its photocatalytic performance. The present study used a simple one-step hydrothermal method to synthesize tungsten-doped BiOCl nanosheets. The results showed the negligible effects of W-doping on the crystal structure, morphology and specific surface area of BiOCl. Diffuse reflectance spectroscopy (DRS), however, showed increases in light absorption and a shift in the absorption edge towards higher wavelengths in the presence of W. Measuring the photocatalytic performance of the samples in decomposing an aqueous solution of rhodamine B (RhB) under light irradiation showed that doping BiOCl with W preserves photocatalytic performance under both UV irradiation and visible-light irradiation, whereas pure BiOCl showed negligible photocatalytic activities under visible-light irradiation. The high photocatalytic activity of BiOCl doped with W compared to that of pure BiOCl is explained by the reduction in band gap and increase in light absorption due to the formation of W energy bands in the forbidden energy gap of BiOCl. A plausible mechanism was proposed for the photocatalytic activity of W-doped BiOCl in decomposing RhB under visible light.

Hydrogen influenced the structural and optical properties of Ni-doped BiOCl nanocomposite: creation of FM properties

Bismuth oxychloride (BiOCl) nanocomposite powders doped with nickel ions were synthesized by sol–gel route using bismuth carbonate. The study focused on the determination the essential conditions required to create stable room-temperature ferromagnetic (RT-FM) properties in host BiOCl crystalline medium by means of doping with Ni2+ ions (BiOCl:Ni). This work was based on the following ideas; the presence of Ni2+ dopant impurity ions in BiOCl crystalline lattice could support the dissociation of H2 molecules during the hydrogenation process that can develop the crystalline–electronic medium (CEM) of BiOCl for carrying out the spin–spin (S.S) long-range interaction between dopant Ni2+ ions and thus create FM properties. Structural, optical, and magnetic properties of pure and Ni-doped BiOCl nanocomposite samples were systematically investigated. The structural properties were studied by X-ray diffraction (XRD) method. The optical properties were investigated by diffuse reflection spectroscopy (DRS). The study disclosed the conditions necessary to create RT-FM properties in hydrogenated BiOCl:Ni nanopowders. The physical explanations and discussions were given in the framework of bound magnetic polaron (BMP) theory. Thus, BiOCl nanocrystalline powder could be used as a potential candidate for optical applications with tailored magnetic properties.

Preparation of upconversion Yb3+ doped microspherical BiOI with promoted photocatalytic performance

Bismuth oxychloride (BiOI) has a good visible light responsive property due to their relatively narrow band gap, and its photocatalytic performance was further improved by doping ytterbium ions (Yb3+). This may be due to strong optical absorption in UV–visible light, effective separation of the photoinduced electron-hole pairs, and the capacity to up-convert Near-IR light into visible-light of Yb3+ ions. In this study, a facile solvothermal method was adopted to synthesize Yb3+ ions doped BiOI photocatalysts. The doped photocatalysts with molar ratios of 0, 0.5, 1, 1.5, 2 and 2.5% Yb3+ ions were prepared. The 2% Yb3+ ions doped BiOI exhibited the highest photocatalytic degradation efficiency on degrading Rhodamine B, which was two times higher than that of pure BiOI. Also Yb3+ ions doped BiOI showed high photocatalytic degradation on herbicide isoproturon. The prepared photocatalysts were characterized by SEM, XRD, UV–vis DRS. It indicated that the doping ions entered the lattice of BiOI crystals and improved the photocatalytic performance. The photocatalytic mechanism was also studied. This work provided the potential application of Yb3+ doped BiOI for the degradation of organic contaminants.

Effect of doping on structural, optical and photocatalytic properties of bismuth oxychloride nanomaterials

Silver (Ag)/Nickel (Ni)/Vanadium (V) doped bismuth oxychloride (BiOCl) with a doping concentration of 2, 4 and 6 wt% was synthesized using wet chemical method. In this paper, their structural, morphological, compositional, optical and photocatalytic properties are studied. The crystallite size of pure and doped BiOCl was calculated using XRD analysis and was found to be in the range 25–40 nm. For Ag doped BiOCl nanocatalyst the crystallite size was the smallest, around 26 nm. The morphology of the as prepared doped samples was studied using SEM and AFM characterization and was found to be a 3D flower-like hierarchical structures having length 100–500 nm and thickness around 20–50 nm. No intermediate phases were formed, and this was confirmed by XRD and FTIR analysis. Decolourization of methylene blue (MB) dye within 5 h due to the addition of doped BiOCl in the presence of UV–visible light was studied using UV–visible spectroscopy. A higher photocatalytic activity of metal (Ag, Ni and V) doped BiOCl was observed in the initial 1 h by decomposition of MB dye to 50 %. The Ag doped BiOCl exhibited superior photocatalytic activity. In the present work, doped BiOCl emerged as a promising photocatalyst for degradation of organic pollutants in water and for environmental remediation. Raman and PL spectra of doped BiOCl revealed higher intensity peaks and blue shift with the increase in concentration of dopants.

Solar photocatalytic degradation of sulfanilamide by BiOCl/reduced graphene oxide nanocomposites: Mechanism and degradation pathways

Flower-like bismuth oxychloride (BiOCl) catalysts were synthesized with a facile hydrolysis reaction, where the synthesized BiOCl products were further decorated with the prepared graphene oxide (GO) to form novel BiOCl/reduced graphene oxide (BiOCl/RGO) composites. The as-synthesized materials were well characterized with the aid of various techniques, before they were used as photocatalysts for the degradation of sulfanilamide (SN) aqueous solution. The BiOCl/RGO composites contained 1 wt% RGO exhibited superior photocatalytic response, where the degradation rate of SN at 82.7% stayed 30% higher than that of pure BiOCl. The enhanced photocatalytic performances of BiOCl/RGO composites were neither related to the surface area values nor the bandgap of the fabricated photocatalysts, but associated with the enhanced visible light absorption and advanced electron transfer ability. On a basis of the analysis on the SN intermediate products by HPLC, IC, FTIR, 1H NMR, 13C NMR and MS, the degradation pathway of SN was speculated, where it was confirmed that the main intermediate product of SN was sulfanilic acid.

Enhanced Photocatalytic Activity of BiOCl Hybridized with g-C3N4

A g-C3N4/bismuth oxychloride (BiOCl) heterojunction was prepared by ultrasonic method. The microstructure, morphology, properties, and photocatalytic activity of the heterojunction were characterized using X-ray diffraction, UV–Vis diffuse reflection spectroscopy, field emission scanning electron microscopy, Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy and electro-chemical experiments. After hybridized with g-C3N4, the absorption edge of g-C3N4/BiOCl showed a red shift that reached 440 nm, with a band gap (Eg) calculated to be 2.82 eV. Under visible-light irradiation, the hybrid photocatalyst also showed activity for methylene-blue photodegradation that was approximately 6.3 times higher than the activity of pure BiOCl. The mechanism of photocatalytic activity enhancement involved increased separation of electrons and holes between g-C3N4 and BiOCl. This work significantly contributed to the improvement in photocatalytic activity of BiOCl.

Enhanced visible light photocatalytic activity of BiOCl by compositing with g-C3N4

A novel visible light-driven heterojunction photocatalyst composed of graphitic carbon nitride (g-C3N4) and bismuth oxychloride (BiOCl) was synthesized. The resulting g-C3N4/BiOCl composite was characterised by X-ray diffraction, field emission scanning electron microscopy, Fourier transform infrared spectroscopy, and ultraviolet-visible diffuse reflection spectroscopy. Under visible light irradiation, g-C3N4/BiOCl composites displayed a markedly higher photocatalytic activity than pure BiOCl in the degradation of phenol and p-chlorophenol. Among the hybrid photocatalysts, g-C3N4/BiOCl with 50% mass ratio of g-C3N4 exhibited the highest photocatalytic activity for the decolourisation of phenol. Enhanced photocatalytic performance resulted from the effective separation of photogenerated electron–hole pairs because of the heterojunction build-up between g-C3N4 and BiOCl.

Study of structural, electronic and optical properties of tungsten doped bismuth oxychloride by DFT calculations.

First-principle calculations have been carried out to investigate structural stabilities, electronic structures and optical properties of tungsten doped bismuth oxychloride (BiOCl). The structures of substitutional and interstitial tungsten, and in the form of WO6-ligand-doped BiOCl are examined. The substitutional and interstitial tungsten doping leads to discrete midgap states within the forbidden band gap, which has an adverse effect on the photocatalytic properties. On the other hand, the WO6-ligand-doped BiOCl structure induces a continuum of hybridized states in the forbidden gap, which favors transport of electrons and holes and could result in enhancement of visible light activity. In addition, the band gap of WO6-BiOCl decreases by 0.25 eV with valence band maximum (VBM) shifting upwards compared to that of pure BiOCl. By calculating optical absorption spectra of pure BiOCl and WO6-ligand-doped BiOCl structure, it is found that the absorption peak of the WO6-ligand-doped BiOCl structure has a red shift towards visible light compared with that of pure BiOCl, which agrees well with experimental observations. These results reveal the tungsten doped BiOCl system as a promising material in photocatalytic decomposition of organics and water splitting under sunlight irradiation.

Efficient visible light photocatalytic activity of CdS on (001) facets exposed to BiOCl

Cadmium sulphide (CdS) quantum dots (QDs), sensitizing hierarchical bismuth oxychloride (BiOCl) photocatalysts, were synthesized via a facile solvothermal approach and characterized in detail. The as-prepared CdS–BiOCl photocatalyst possessed an extended light absorption range and efficient charge separation properties simultaneously compared with pure BiOCl, especially in the visible light region. The results revealed that the newly formed oxygen vacancies will play an important role in the visible light degradation process, which resulted in the efficient separation of photogenerated electron–hole pairs, and a large increase in photocatalytic activity.

WO 3/BiOCl, a novel heterojunction as visible light photocatalyst

A bismuth oxychloride (BiOCl) nanostructure is prepared by a new low temperature route using sodium dodecyl sulfate as template and urea as hydrolytic agent. A novel heterojunction is developed between BiOCl and tungsten oxide (WO 3) to make it an efficient visible light photocatalyst. The catalysts were characterized by X-ray diffraction analysis, Raman spectroscopy, thermogravimetric analysis, energy-dispersive X-ray spectroscopy, scanning electron microscopy, transmission electron microscopy, and N 2 sorption isotherms. The WO 3/BiOCl heterojunction system extends the absorption edge to the visible region efficiently. BiOCl works as a main photocatalyst while WO 3 acts as the photosensitizer absorbing visible light in the WO 3/BiOCl composite. The individual BiOCl and WO 3 show very low photocatalytic efficiency under visible light irradiation but their heterojunction provides unexpectedly high efficiency in decomposing rhodamine B as compared to Degussa P25, pure BiOCl, and WO 3.