Pure α-Bi2O3 Research Articles

Structural, Optical, Electrical and Photocatalytic Investigation of n-Type Zn2+-Doped α-Bi2O3 Nanoparticles for Optoelectronics Applications.

Herein, n-type pure and Zn2+-doped monoclinic bismuth oxide nanoparticles were synthesized by the citrate sol-gel method. X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), photoluminescence (PL) analysis, ultraviolet-visible (UV-vis) spectroscopy, and Hall effect measurements were used to study the effect of Zn2+ on the structural, optical, and electrical properties of nanoparticles. XRD revealed the monoclinic stable phase (α-Bi2O3) of all synthesized samples and the crystallite size of nanoparticles increased with increasing concentration of dopant. Optical analysis illustrated the red shift of absorption edge and blue shift of band gap with increasing concentration of dopant. Hall Effect measurements showed improved values (2.79 × 10-5 S cm-1 and 6.89 cm2/V·s) of conductivity and mobility, respectively, for Zn2+-doped α-Bi2O3 nanoparticles. The tuned optical band gap and improved electrical properties make Zn2+-doped α-Bi2O3 nanostructures promising candidates for optoelectronic devices. The degradation of methylene blue (MB, organic dye) in pure and zinc-doped α-Bi2O3 was investigated under solar irradiation. The optimum doping level of zinc (4.5% Zn2+-doped α-Bi2O3) reveals the attractive photocatalytic activity of α-Bi2O3 nanostructures due to electron trapping and detrapping for solar cells.

Boosted visible light dye-decontamination and colossal dielectric constant features of Bi2O3: Role of In, Cu and Li-dopants

This study focused on improving the optical, dielectric properties, and photocatalytic efficiency of Bi2O3, a prominent photocatalyst with challenges like limited visible light absorption and rapid electron-hole pair recombination. Using an adapted sol-gel technique, pure Bi2O3, In, Cu and Li-doped Bi2O3 visible-light-driven photocatalyst were synthesized. X-ray diffraction (XRD) confirmed monoclinic Bi2O3 formation. The inclusion of In, Cu, and Li ions into the Bi2O3 lattice was evidenced by alterations in diffraction peak intensities, lattice parameters, and changes in average crystallite size. Vibrational spectra corroborated the formation of pure α-Bi2O3 with slight shifts in transmittance bands, aligning with the XRD findings. Morphological investigation via scanning electron microscopy (FE-SEM-EDX) confirmed the purity of the synthesized nanocompositions and unveiled that the doping induces distinct morphological changes in Bi2O3 nanoparticles, resulting in increased porosity and formation of round and needle-like shapes (In-doped), coalescence of particles (Cu-doped), and fused agglomerates with altered particle size distribution (Li-doped). Optical analysis demonstrated a red shift in the band gap energy of α-Bi2O3 (initially 2.90 eV), with In, Cu, and Li doping, resulting in band gaps of 2.77 eV, 2.78 eV, and 2.88 eV, respectively, accompanied by high refractive indices exceeding 2.0, rendering them suitable for optical applications. Both Cu and Li doping led to enhanced relative permittivity (εʹ) values, with the Li-doped sample displaying remarkable εʹ values at low frequencies (up to 1000 Hz). The In, Cu and Li doping has the effect of reducing PL (photoluminescence) emission intensity while simultaneously diminishing radiative recombination and promoting the separation of photogenerated charge carriers. The doped samples demonstrated superior degradation performance, with In-doped and Cu-doped samples achieving degradation efficiencies of 99% and 91%, respectively, within 180 min. This remarkable performance can be attributed to their visible-light-responsive band gaps, increased electron-hole trapping sites, and distinct morphological features.

Simple and Easy Control-Synthesis of Pure α-Bi2O3 and Bi2O2CO3: Morphological, Optical and Solar Photon-Energy Photocatalytic Studies

Simple and Easy Control-Synthesis of Pure α-Bi2O3 and Bi2O2CO3: Morphological, Optical and Solar Photon-Energy Photocatalytic Studies

Phyto-mediated synthesis of pure phase α-Bi2O3 nanostructures using Rubus ellipticus plant extract: photocatalytic activity and antimicrobial efficacy

Phyto-mediated synthesis of pure phase α-Bi2O3 nanostructures using Rubus ellipticus plant extract: photocatalytic activity and antimicrobial efficacy

Ceftriaxone sodium degradation by carbon quantum dots (CQDs)-decorated C-doped α-Bi2O3 nanorods

A novel carbon quantum dots decorated C-doped α-Bi2O3 photocatalyst (CBO/CQDs) was synthesized by solvothermal method. The synergistic effect of adsorption and photocatalysis highly improved contaminants removal efficiencies. The ceftriaxone sodium degradation rate constant (k) of CBO/CQDs was 11.4 and 3.2 times that of pure α-Bi2O3 and C-doped α-Bi2O3, respectively. The interstitial carbon doping generated localized states above the valence band, which enhanced the utilization of visible light and facilitated the separation of photogenerated electrons and holes; the loading of CQDs improved the charge carrier separation and extended the visible light response; the reduced particle size of CBO/CQDs accelerated the migration of photogenerated carriers. The •O2− and h+ were identified as the dominant reactive species in ceftriaxone sodium degradation, and the key role of •O2− was further investigated by NBT transformation experiments. The Fukui index was applied to ascertain the molecular bonds of ceftriaxone sodium susceptible to radical attack, and intermediates analysis was conducted to explore the possible degradation pathways. The toxicity evaluation revealed that some degradation intermediates possessed high toxicity, thus the contaminants require sufficient mineralization to ensure safe discharge. The present study makes new insights into synchronous carbon dopping and CQDs decoration on modification of α-Bi2O3, which provides references for future studies.

PH-induced structural evolution, photodegradation mechanism and application of bismuth molybdate photocatalyst

In this work, we have elucidated the pH-induced structural evolution of bismuth molybdate photocatalyst based on a hydrothermal synthesis route. With increasing the pH value of precursor solution, pure Bi2MoO6 was synthesized at pH 2–5, Bi2MoO6-Bi4MoO9 mixture was obtained at pH 7–9, pure Bi4MoO9 was obtained at pH 11, and pure α-Bi2O3 was derived at pH 13. The as-derived samples mainly present particle-like shapes but with different particle sizes (except the observation of Bi2MoO6 nanowires in sample S-pH9). The photocatalytic performances between the samples were compared via the degradation of methylene blue (MB) under irradiation of simulated sunlight. The Bi2MoO6 sample synthesized at pH 2 exhibited the highest photodegradation performance (η(30 min) = 89.8 %, kapp = 0.05007 min−1) among the samples. The underlying photocatalytic mechanism and degradation pathways of MB were systematically analyzed. Moreover, the photodegradation performance of the Bi2MoO6 photocatalyst was further evaluated at different acidic-alkaline environments as well as in degrading various color and colorless organic pollutants, which provides an important insight into its practical application.

Application of Bi2O3/TiO2 heterostructures on glycerol photocatalytic oxidation to chemicals

The aqueous-phase glycerol photocatalytic oxidation under ultraviolet irradiation was studied to reduce the fossil energy or electricity usage. Here, the glycerol is transformed into several valuable products over the new Bi2O3/TiO2 composite heterostructure which was well produced by employing maleic acid as an organic binder. The prepared α-Bi2O3/TiO2 composites revealed higher photocatalytic activity for the conversion of glycerol (88.7%) compared with TiO2 (69.7%) under ultraviolet irradiation at 8 h which could be attributed to their relative positions of the energy bands. Nevertheless, all the Bi2O3/TiO2 heterostructures had the same photocatalytic transformation of glycerol and gave similar distribution of generated valuable products. Moreover, the photocatalytic activity of the β-Bi2O3/TiO2 heterostructure had been compared to those of pure TiO2, α-Bi2O3, β-Bi2O3 and α-Bi2O3/TiO2 for the photooxidation of glycerol under the same conditions.

α-Bi2O3 nanosheets: An efficient material for sunlight-driven photocatalytic degradation of Rhodamine B

Herein, we report the sunlight driven photocatalytic degradation of toxic organic dye, Rhodamine B using α-Bi2O3 nanosheets as an effective photocatalyst. The α-Bi2O3 nanosheets were prepared by simple annealing assisted thermal decomposition method and characterized by several techniques in order to understand its morphological, compositional, structural and optical properties. Morphological, structural and compositional investigations confirmed the formation of sheet-like morphologies, high-crystalline monoclinic crystal structure, and pure α-Bi2O3, respectively. The synthesized α-Bi2O3 nanosheets exhibited a high photocatalytic degradation of a toxic organic dye, i.e. Rhodamine B (RhB). Under optimal reaction conditions, ∼95% photocatalytic degradation of RhB (10 mg/L, pH 10) was observed in 180 min using 0.75 g/L catalyst dosage under sunlight irradiation. According to the findings, the synthesized catalyst had outstanding photocatalytic properties and can be used to cleanse textile wastewater under direct sunlight.

Study of in vitro cytotoxic performance of biosynthesized α-Bi2O3 NPs, Mn-doped and Zn-doped Bi2O3 NPs against MCF-7 and HUVEC cell lines

Green-synthesized nanoparticles can be applicable in designing an effective, efficient, and low-risk treatment for cancer. In this regard, we introduced a novel and eco-friendly method for preparing pure α-Bi2O3, Mn-doped Bi2O3, and Zn-doped Bi2O3 nanoparticles with potent cytotoxic activity through the application of Salvadora persica extract as the green reactive, reducing, and capping agent. The biosynthesis and characterization of our product was supported by the results of powder X-ray Powder Diffraction (PXRD), Energy Dispersive X-Ray (EDAX), Field Emission Scanning Electron Microscopy (FESEM), Transmission Electron Microscopy (TEM), Fourier-Transform Infrared (FT-IR), and Raman analysis. The outcomes of SEM analysis displayed the porous morphology of pure α-Bi2O3 nanoparticles, whereas the doping of Zn and Mn turned their structure into a conical shape. The TEM results presented the hexagonal shape of pure α-Bi2O3 NPs with a particle size mean of 46 nm. Additionally, the Zn-doped Bi2O3 nanoparticles consisted spherical particles with 32 nm of size mean, while the Mn-doped Bi2O3 NPs were approximately hexagonal with a particle size mean of 41 nm. The success of doping process was proven by the EDX analysis. Next to their high potential in cytotoxic performance against cancer cell line, the results of MTT assay confirmed the potent cytotoxic activity of synthesized nanoparticles against breast cancer (MCF-7) and human umbilical vein endothelial (HUVEC) cells as well. Considering these observations, these products can be suggested as a proper candidate for biological and medical applications.

Sub-level engineering strategy of nitrogen-induced Bi2O3/g-C3N4: a versatile photocatalyst for oxidation and reduction.

Herein, the α-Bi2O3 nanocrystal decorated by nitrogen dopant and its heterojunction nanocomposite with g-C3N4 (N0.1/Bi2O3/g-C3N4) is successfully fabricated for the first time, for photo-oxidation of RhB and photo-reduction of Cr(VI) to Cr(III). The resulting N0.1/Bi2O3/g-C3N4 (3%) nanocomposite showed an optimal Cr(VI) photo-reduction and RhB photo-oxidation rates under visible-light irradiation, being 3-4 times higher than that of pure α-Bi2O3. The results from XPS confirmed the substitution of nitrogen with various oxidation states from N3+ to Nx+ (x < 5), due to the existence of different nitrogen oxides including N-O, O-N=O, and NO3- in the crystal structure. We investigated the reaction mechanism using catalytic tests, impedance spectroscopy, EPR technique, and density functional calculations. The DFT calculations presented the appearance of a new mid-gap hybrid of p states, comprised of N 2p, O 2p, and Bi 6P states, which enhance light absorption capacity and narrow band gap. The theoretical results were in excellent agreement with experimental UV-Vis data. The N0.1/Bi2O3/g-C3N4 nanocomposite exhibited acceptable practical application value and recycling ability for removal of the contaminants. Such improved photocatalytic activity is originated from the modified band positions, new electron evolution pathway, introducing defects in α-Bi2O3 by insertion of N atoms into the Bi sites, and the enhanced charge carrier mobility between N0.1/Bi2O3 and g-C3N4. The strategy to form nitrogen-doped bismuth-based nanocomposites may open a new opportunity to design atomic-level electronic defects by feasible methods to obtain a versatile photocatalyst material with simultaneous photo-reduction and photo-oxidation ability for removal of Cr(VI) and organic dyes from water.

Facile synthesis of α/β-Bi2O3 hetero-phase junction by a solvothermal method for enhanced photocatalytic activities

A novel α/β-Bi2O3 hetero-phase junction (xBB) was successfully prepared by a simple in-situ growth method without further calcination, in which α-Bi2O3 served as the substrate for the growth of β-Bi2O3 nanosheets. The nanocomposites were well characterized by XRD, SEM, TEM, UV–vis DRS, XPS, EIS, etc. The characterizations testified that the bismuth oxides of two crystal phases were in close contact, and the hetero-phase junction was formed. The photocatalytic performance was evaluated by degradation of rhodamine B (RhB) and tetracycline hydrochloride (TC-HCl) under visible light illumination. With the optimum mass ratio, 0.5BB sample exhibited the highest photocatalytic activity, the removal rates were 82.7 % for TC-HCl in 120 min and 94.9 % for RhB in 90 min, and a rate constant of 0.0297min−1 was evaluated for RhB degradation, which were higher than that of pure α-Bi2O3 (0.0019 min−1) and β-Bi2O3 (0.0028 min−1) by a factor of 15.6 and 11.9, respectively. The synthetic method provides a promising route for the in-situ construction of hetero-phase junction nanocomposites.

Combustion synthesis of porous bismuth oxide

Bismuth oxides with a micro porous structure were prepared by a simple combustion reaction between oxidizer (bismuth nitrate) and fuel (citric acid). These porous bismuth oxides were prepared at different values of the stoichiometric coefficient. The as-prepared products were characterized by X-ray diffraction (XRD), and scanning electron microscopy (SEM). The results show that many pores distributed in tetragonal bismuth oxides (β-Bi2O3) granules which have varied crystallinity and particle sizes at different oxidizer/fuel ratio. Increasing the fuel concentration improved the crystallinity and purity of β-Bi2O3. A further calcination could also increase the particle size, crystallinity and transform the phase structure from β-Bi2O3 to pure α-Bi2O3.

Preparation and characterization of phase pure monoclinic ɑ-Bi2O3 nanoparticles and influence of Ni2+and Cu2+ impregnation on their photocatalytic properties

Nowadays, pharmaceutical waste, Naproxen (NPX) as well as the dye fuchsin blue (FB) become hazardous pollutant due to their toxic behavior. Because of toxicity, the efficient removal of them from water has become one of the most vital challenge. Yet, due to high cost, low degradation efficiency, of the known catalyst restrict their real life applications. In this perspective, metal ions impregnated (Ni2+ and Cu2+) Bi2O3 heterostructures have been investigated as a potential material for photocatalytic degradation of NPX and FB. These materials are synthesized by simple wet-impregnation method and thoroughly characterized by various methods such as XRD, DLS, SEM, EDS, HRTEM, XPS, etc. The diffraction patterns confirm formation of phase pure α-Bi2O3 nanoparticles. The zeta potential (−25 mV) of Bi2O3 nanoparicles confirms presence of negatively charges oxide groups in its surface that can act as anchors for divalent anions. The impregnated hybrids shows considerably smaller zeta potential values (−15 and −17 mV for Ni2+-Bi2O3 and Cu2+-Bi2O3 respectively). The XPS studies reveal presence of surface bound divalent metal ions. The adsorption edge of Ni2+-Bi2O3 and Cu2+-Bi2O3 nanostructures were shifted slightly towards lower frequency. The photoluminescence spectrum impregnated materials shows significant quenching compare to pristine Bi2O3. suggesting lesser degree electron-hole recombination upon metal loading. Due to the photocatalytic degradation efficiencies of both Ni2+-Bi2O3 (87% for FB and 79% for NPX) and Cu2+-Bi2O3 (73% for FB and 70% for NPX) heterostructures are significantly higher compare to the pristine one (43% for FB and 40% for NPX). The photo-degradation process obeys the pseudo first order kinetics. Due to simpler synthesis and enhanced activity metal ion loaded Bi2O3 photocatalysts can be potential photo-catalysts for removing NPX and FB from wastewater.

Preparation of Z-scheme CuBi2O4/Bi2O3 nanocomposites using electrospinning and their enhanced photocatalytic performance

Using electrospinning process, the Z-scheme CuBi2O4/Bi2O3 nanocomposite photocatalysts were prepared. The microstructure, composition, and photoelectrochemical performance were studied. The results show that the morphology of nanofibers consisted in α-Bi2O3 and CuBi2O4 changes with the variation of Cu(NO3)2 content and the photoelectrochemical performance of the nanocomposites are better than that of pure α-Bi2O3 and CuBi2O4. The photocatalytic activity of the samples were evaluated. Compared with pure α-Bi2O3 and CuBi2O4, the photocatalytic degradation rate of methyl orange over BCO/BO-2 (Cu:Bi = 1:8) is greatly enhanced, which mainly caused by the formation of Z-scheme heterojunction that can improve the separation rate of photoexcited carries. Apart from this, the introduction of CuBi2O4 that can expand the light absorption range, and the rough surface of composite that can increase the number of active site promote the photocatalytic activity of BCO/BO-2. In addition, the main active species in the photocatalytic process are h+ and ·OH.

Enhancing photocatalysis of NO gas degradation over g-C3N4 modified α-Bi2O3 microrods composites under visible light

In this study, we modified g-C3N4 bulk by the α-Bi2O3 microrods (MRs) via simple green routes. The as-synthesized Bi2O3/g-C3N4 composite is indicated a high photoactivity in visible light region. In addition, the NO photocatalytic removal efficiency of Bi2O3/g-C3N4 composite is significantly improved compared to pure g-C3N4 materials. Herein, a 39.1% NO with a 500 ppb concentration is removed by Bi2O3/g-C3N4 composite, which is approximately 1.6 times higher than both pure α-Bi2O3 and g-C3N4 after 30 min under visible light. The NO2 conversion yield is just 6.8% that is approximately 1.7 times smaller than that of pure g-C3N4. Moreover, the stability of the Bi2O3/g-C3N4 composite is still high after 5 cycles.

α-Bi2O3/β-Ni(OH)2 composites: Effective solar light photocatalysts for organic pollutants degradation

α-Bi2O3/β-Ni(OH)2 composites exhibited perfect photocatalytic properties for organic pollutants degradation under sunlight irradiation. Pure α-Bi2O3 and β-Ni(OH)2 were prepared by coprecipitation method and then mechanically mixed in different proportions to form α-Bi2O3/β-Ni(OH)2 composites. The XRD and FTIR analyses have well emphasized the formation of monoclinic α-Bi2O3 and hexagonal β-Ni(OH)2 phases with high crystallinity. The SEM micrographs of α-Bi2O3 and β-Ni(OH)2 powders displayed a rod and sheet shaped grains, respectively. The band gap of the pure α-Bi2O3 was estimated to be 2.87 eV. Pure β-Ni(OH)2 revealed three absorption bands in the UV–visible light region. α-Bi2O3/β-Ni(OH)2 composites have a more intense absorption in the visible light region compared to pure α-Bi2O3 sample. Modification of α-Bi2O3 by β-Ni(OH)2 induced a superior photocatalytic activity especially at β-Ni(OH)2 content of 12 wt% in α-Bi2O3 (BN-12 composite). This composite showed high efficiencies of 99%, 96%, 91% and 90% for methylene blue, Congo red, methyl orange and 4-niropheniol degradation in 80, 80, 180 and 300 min under sunlight irradiation, respectively. The remarkable photocatalytic activity of the α-Bi2O3/β-Ni(OH)2 composite was attributed to the new states in charge separation, charge transportation and the intensive absorption of visible light. α-Bi2O3/β-Ni(OH)2 composite (BN-12) has a great potential in removing of cationic and anionic dyes beside phenolic compounds from wastewater.

New efficient sunlight photocatalysts based on Gd, Nb, V and Mn doped alpha-Bi2O3 phase

A novel composition of Mn doped α-Bi2O3 exhibited excellent solar light photocatalytic activities for 4-nitrophenol (4-NP), Congo red (CR) and methylene blue (MB) degradation. All the prepared samples were indexed as monoclinic structure of α- Bi2O3 phase with high crystallinity. The noticed decreases in the unit cell volume and the shifts of (-102) plane of α-Bi2O3 indicated to the effective incorporation of dopants. Pure α-Bi2O3 particles revealed sheets and sponge shapes. Highly uniform rods like structure plus porous sheets were seen in V and Mn doped α-Bi2O3 samples. The visible light photo-absorption properties of pure α-Bi2O3 were greatly enhanced through doping by V and Mn ions. The red shifts in the band gap of α-Bi2O3 were attributed to the substitution of Bi3+ by Gd3+, Nb3+, V3+ and Mn2+/3+ ions which formed new electronic states into α-Bi2O3 structure. Pure α-Bi2O3 attained degradation efficiencies of 62, 69 and 38 % for CR, MB and 4-NP in 90, 90 and 270 min, respectively. All doped α-Bi2O3 samples exhibited better photocatalytic activity comparing to pure α-Bi2O3. Novel Mn doped α-Bi2O3 displayed superior photocatalytic activities of 97, 99 and 94 % for CR, MB and 4-NP degradation, respectively. It possesses good stability and reusability for four cycles. The photocatalytic measurements in the presence of EDTA, benzoquinone and isopropanol as scavengers reflected the vital roles of O2ˉ˙ and ˙OH radicals. The superior photocatalytic of Mn doped α-Bi2O3 was ascribed to the enhancements in visible light absorption, surface morphology and inhibition of electron-hole pairs by traps centers.

Investigating the efficiency of α-Bismuth zinc oxide heterostructure composite/UV-LED in methylene blue dye removal and evaluation of its antimicrobial activity.

Heterostructured α-Bismuth zinc oxide (α-Bi2O3–ZnO) photocatalyst was fabricated by a facile and cost-effective, ultrasound assisted chemical precipitation method followed by hydrothermal growth technique. As synthesized α-Bi2O3–ZnO photocatalyst showed enhanced photocatalytic performance for the MB dye degradation in contrast to pure ZnO and α-Bi2O3. Light emitting diodes (UV-LED) were used in the experimental setup, which has several advantages over conventional lamps like wavelength selectivity, high efficacy, less power consumption, long lifespan, no disposal problem, no warming-up time, compactness, easy and economic installation. XRD study confirmed the presence of both the lattice phases i.e. monoclinic and hexagonal wurtzite phase corresponding to α-Bi2O3 and ZnO in the α-Bi2O3–ZnO composite photocatalyst. FESEM images showed that α-Bi2O3–ZnO photocatalyst is composed of dumbbell like structures of ZnO with breadth ranging 4–5 μm and length ranging from 10 to 11 μm respectively. It was observed that α-Bi2O3 nanoparticles were attached on the ZnO surface and were in contact with each other. Low recombination rate of photo-induced electron-hole pairs, due to the migration of electrons and holes between the photocatalyst could be responsible for the 100% photocatalytic efficiency of α-Bi2O3–ZnO composite. In addition, photocatalyst was also observed to show the excellent antimicrobial activity with 1.5 cm zone of inhibition for 1 mg L−1 dose, against the human pathogenic bacteria (S. aureus).

Fabrication of dual Z-scheme MIL-53(Fe)/α-Bi2O3/g-C3N4 ternary composite with enhanced visible light photocatalytic performance

Z-scheme heterojunction photocatalyst can simultaneously reduce the recombination of photo-generated electron-hole pairs and preserve its outstanding redox ability during the process of photocatalytic reaction. In this study, Z-scheme MIL-53(Fe)/α-Bi2O3/g-C3N4 photocatalyst was successfully fabricated via an accessible method and comprehensive characterized by XRD, FT-IR, SEM, TEM, XPS, N2 adsorption-desorption isotherms, UV–vis diffuse reflection spectroscopy and photoelectrochemical analysis. The as-obtained MIL-53(Fe)/α-Bi2O3/g-C3N4 composite exhibited superior photocatalytic activity for amino black 10B degradation than that of pure g-C3N4, α-Bi2O3, MIL-53(Fe) and α-Bi2O3/g-C3N4 binary composite under visible light irradiation and the photodegradation rate would achieve the maximum when the mass fraction of MIL-53(Fe) was 32% in ternary composite. The enhanced photocatalytic performance of MIL-53(Fe)/α-Bi2O3/g-C3N4 ternary composite could be mainly ascribed to improved visible light absorption range and the construction of an effective interfacial heterojunction driven by direct solid-state dual Z-scheme mechanism, which significantly facilitates the separation and transfer of photo-generated charge carriers. Eventually, the as-prepared ternary composite was confirmed to have prominent stability and reusability after consecutive 4 recycling run.

Synthesis and photocatalytic activity of composite magnetic photocatalyst MnxZn1-xFe2O4/α-Bi2O3

ABSTRACTIn this paper, a new magnetic photocatalyst MnxZn1-xFe2O4/α-Bi2O3 is synthesized by the dip-calcination technology, using manganese zinc ferrite as a magnetic substrate. It is beneficial to separate the composite from liquid solution under an extra magnetic field. This heterojunction of composite MnxZn1-xFe2O4/α-Bi2O3 presents remarkable photocatalytic activity and prominent photocatalysis for degradation of Rhodamine B (RhB), far exceeding the pure α-Bi2O3. Especially, the introduction of MnxZn1-xFe2O4 not only reduces the bandgap of photocatalyst α-Bi2O3, but also improves its response in the visible region. Importantly, the magnetic photocatalyst is capable of being used repeatedly, and the photocatalytic activity would remain above 90% after 3 cycles. Such an outstanding stability and retrievability of composite are mainly ascribed to the soft-magnetic material MnxZn1-xFe2O4, enhancing separation of photoinduced electron hole pairs. This work will replace the traditional semiconductor photocatalyst for a convenient recycling and removal of contaminants from wastewater in the future.