Bi2O3 Films Research Articles

Highly oriented as-grown beta-phase bismuth oxide for optical MEMS

AbstractReactive sputtering of bismuth has been used to form highly oriented beta-phase Bi2O3 thin films at 120 °C. Notably, the films consist of nearly vertical ~ 50 nm diameter nano-filaments of highly aligned β phase pure bismuth oxide. The optical characteristics of the films include a direct optical bandgap of 3.95 eV at 300 K and nearly negligible optical absorption in the wavelength range from 500 to 3000 nm. Nanoindentation experiments show that the mechanical characteristics of the films include reduced modulus and hardness values of 90 and 4.5 GPa, respectively. As fabricated, the films exhibit tensile stress which in combination with a relatively high refractive index value in the range of 2.4–2.5 makes the realized Bi2O3 films structurally and optically suitable for fabrication of optical microelectromechanical (MEMS) devices with applications in the visible to mid-infrared wavelength region, such as MEMS-based Fabry–Pérot microspectrometers, which is demonstrated through simulations. Graphical Abstract

SRIM simulation of hydrogen ions interaction with bismuth oxide nanoparticles doped with rare earth elements

Simulation methods have received much attention across various fields in recent years. The rare-earth lutetium tantalate (LuTaO4) doped “Bismuth Oxide (Bi2O3) thin films were deposited onto polymer substrates using a SRIM program.” The SRIM program was used to calculate some physical characteristics of Bi2O3 films at energies between 1.0 MeV and 20 MeV. The “electronic and nuclear stopping powers” of LuTaO4, Bi2O3, C10H8O4, and LuTaO4/ Bi2O3/C10H8O4 samples were investigated. These findings show that rare earth doping may improve the performance of composite materials. The interaction of ion beams with matter can result in a wide variety of phenomena. The deposition of Bi2O3 films doped with LuTaO4 on C10H8O4 led to changes in the “electronic and nuclear stopping powers” and range in the materials. Published data were compared with the results obtained and the calculations parameters were provided.

N,S-modified ZnO and Bi2O3 thin films supported on titanium mesh as photoanodes

The effect of S doping on the physicochemical and photoelectrochemical properties of ZnO and Bi2O3 films has been studied. Two procedures were used for the synthesis of S-ZnO and S-Bi2O3 thin films on Ti mesh, obtaining lamellar shape nanocrystals for S-ZnO film. The presence of TiO2 anatase phase and wurtzite (ZnO and S-ZnO film) and TiO2 anatase and α-Bi2O3 (Bi2O3 and S- Bi2O3) was observed. The inclusion of sulfur and nitrogen atoms as part of the lattice of the films was evidenced by XPS analysis.

Influence of Ag2O doping on structural and optical properties of thin Bi2O3 films prepared by pulse laser deposition technique

Influence of Ag2O doping on structural and optical properties of thin Bi2O3 films prepared by pulse laser deposition technique

Signal oscillations in helium scattering by bismuth atoms in the low energy range

Low Energy Ion Scattering (LEIS) analysis of bismuth selenide (Bi2Se3), a strong 3D topological insulator, revealed oscillations of the detected signal in dependence on primary ion beam energy. Bismuth is a part of the group of elements where oscillatory behaviour was already noticed, such as gallium, indium, or lead. Generally, it is ascribed to quasi-resonant charge exchange processes between primary ion and target atom. Moreover, clear differences exist between data for target atoms in elemental form and for atoms in compound form. A study of Bi signal yields in different material forms was performed for primary He+ projectiles within the energy range from 0.50 to 6.00 keV. A foil of pure Bi, Bi2Se3, Bi2O3 and thin Bi films deposited on several substrates (SiO2, CuOx) by Molecular Beam Epitaxy were analysed. The energy shift in the position of oscillations was observed when the oxygen atoms were present at the surface and bonded to Bi atoms. A description of the Bi ion yield variation is provided to facilitate the quantification process in LEIS.

Bismuth-oxide nanoparticles: study in a beam and as deposited.

Bi2O3 is a promising material for solid-oxide fuel cells (SOFC) due to the high ionic conductivity of some phases. The largest value is reached for its δ-phase, but it is normally stable at temperatures too high for SOFC operation, while nanostructured oxide is believed to have more suitable stabilization temperature. However, to manufacture such a material with a controlled chemical composition is a challenging task. In this work, we investigated the fabrication of nanostructured Bi2O3 films formed by deposition of free Bi-oxide nanoparticles created in situ. The particle-production method was based on reactive sputtering and vapour aggregation. Depending on the fabrication conditions, the nanoparticles contained either a combination of Bi-metal and Bi-oxide, or only Bi-oxide. Prior to deposition, the free particles were probed in the beam - by synchrotron-based photoelectron spectroscopy (PES), which allowed assessing their composition "on the-fly". The nanoparticle films obtained after deposition were studied by PES, scanning electron microscopy, transmission electron microscopy, and electron diffraction. The films' chemical composition, grain dimensions, and crystal structure were probed. Our analysis suggests that our method produced Bi-oxide films in more than one polymorph of Bi2O3.

Regulation of Bi2O3 phase structure improves the self-powered UV-blue dual‐band photoresponse of Bi2O3/TiO2 photodetectors and the imaging application

Bi2O3 semiconductors with excellent optical and electrical properties can be used in photodetectors (PDs). For different phase structures of Bi2O3 with corresponding optoelectronic properties in Bi2O3 due to differences in crystal structure and energy band structure, it is important to control the phase structure to obtain high-performance Bi2O3-based PDs. Herein, Bi2O3 nanosheet films with α and β phase structures controlled by the annealing temperature are deposited on the surface of TiO2 nanorod arrays (NRs) to construct ultraviolet (UV)-blue self-powered PDs. The effects of the energy band structure, Fermi level and carrier mobility of Bi2O3 films with different phase structures on the performance of Bi2O3/TiO2 PDs are investigated by combining theoretical calculations and experimental. The β-Bi2O3/TiO2 PDs with strong built-in electric field, large carrier mobility, small interfacial transfer resistance and long carrier lifetime exhibit excellent photoresponse characteristics. The PD demonstrates a responsivity of 26.7 mA W−1 and detectivity of 5.93 × 1011 Jones under 365 nm illumination. In addition, the imaging application of β-Bi2O3/TiO2 PD is explored by extending the photocurrent mapping values of a single PD unit to a complex array of optical information image processing in complex environments utilizing the UV-blue dual-band self-powered photoresponse properties of the PDs.

Structural and optical characteristics of α-Bi2O3/ Bi2O(3-x):Ho3+ thin films deposited by pulsed laser deposition for improved green and near-infrared emissions and photocatalytic activity

Pulsed laser deposited films on glass substrate deposited at different substrate temperatures (Ts) and partial pressures of oxygen, Ho3+-doped Bi2O3 films were produced. The degradation capability of the Rhodamine B dye using the Bi2O3:Ho3+ films was explored. The impact of the Bi2O3:Ho3+ content on the dye degradation performance was analyzed. The X-ray powder diffraction patterns showed that the films deposited at 400 °C had an α-Bi2O3 phase. The impacts of various Ts and O2 partial pressures were correlated with the surface morphology and the thickness of the films using results of field emission scanning electron microscope. The thin films deposited at a low O2 partial pressure of 5–20 mTorr at Ts = 400 °C exhibited nano-needles with an average size of 80 nm and a length of ∼750 nm. The estimated band gap of the prepared films was found to vary between 2.6 and 3.0 eV. The photoluminescence (PL) of the Bi2O3:Ho3+ thin films excited at 450 nm showed an intense green band emission observed at 548 nm, and the feeble emissions at 654 and 753 nm were ascribed to the transitions of Ho3+. The nano-needle particles of the α-Bi2O3:Ho3+ exhibited a maximum PL intensity for the 20 mTorr O2 partial pressure thin film. The films prepared in vacuum and with an O2 partial pressure of 5 mTorr exhibited a 41 % dye degradation efficiency during a duration of 270 min of the photocatalysis experiment.

The Role of Annealing Treatment on Crystallographic, Optical, and Electrical Features of Bi2O3 Thin Films Prepared Using Reactive Plasma Sputtering Technology

Bismuth oxide (Bi2O3) has attracted considerable research interest in test thin films made utilizing the reactive plasma sputtering (RPS) technology-assisted annealing treatment, allowing the development of diverse BixOx thin films. SEM, phase X-ray diffraction patterns, UV-Vis spectrometers, and D.C. two-probes are used to identify the crystallographic structure and assess the films’ optical-electrical properties. The XRD examination showed that forming Bi2O3 films with an amorphous to multiphase crystalline structure for sputtering time of 40 min was due to soda glass substrate temperature at a range of 30–35°C. Thin films of Bi2O3 crystal structures improved with annealing heat treatment at 200, 300, 400, and 500°C. Yet the formation of crystalline phase (β-Bi2O3 with δ-Bi2O3) Bi2O3 nanostructures occurred at higher temperatures. SEM images showed transparent particles highly affected by annealing temperatures. The nanostructures were about 102–510 nm long, and the diameter was 50–100 nm. The Bi2O3 film optical band gaps and nanostructures ranged from 2.75 to 3.05 eV. The annealing temperature differences affected the crystallite sizes, optical band gaps, and surface roughness. The findings showed that these differences caused the phase transition in Bi2O3 structures. The electrical calculation revealed that the electrical conductivity improved with annealing temperatures of 150–250°C while declining with temperature (300–500)°C with typical semiconductor films.

Selective formation of crystal polymorphs in Er3+-doped Bi2O3 thin films and their photoluminescence properties

The process conditions for selectively forming crystal polymorphs in Er3+-doped Bi2O3 films deposited on Si, SiO2, and C-plane sapphire substrates were systematically investigated. Bi2O3:Er films were deposited at either room temperature or 300 °C and subsequently post annealed to promote crystallization. The critical factor controlling the crystal polymorphs was Er content. When the Er content was less than 1.5 at.%, only α-Bi2O3 phase nucleated upon post annealing. Deposition at 300 °C somewhat lowered the oxidization state, under which β-Bi2O3 structure appeared at lower temperatures and α-Bi2O3 structure appeared at higher temperatures. When the films were doped with over 2 at.% Er3+ ions, the excess Er2O3 stabilized the δ-Bi2O3 structure as the lowest temperature phase. The universal phase transition scheme with increasing annealing temperature was δ-Bi2O3 → β-Bi2O3 → α-Bi2O3. The δ → β transition proceeded through splitting each diffraction peak of δ-Bi2O3 into two components of β-Bi2O3, indicating a correlation between the structures of β-Bi2O3 and δ-Bi2O3. The γ-Bi2O3 phase appeared only in films on Si(100) substrates and after vacuum annealing, suggesting the formation of sillenite (Bi12SiO20). Deposition on C-plane sapphire by using H2O as the oxygen source gas produced a highly (111)-oriented δ-Bi2O3 structure, whereas deposition with O2 yielded a randomly oriented δ-Bi2O3 structure. At Er content exceeding 4 at.%, δ-Bi2O3 was the primary phase in the films on SiO2. The photoluminescence (PL) activity of dopant Er3+ under excitation at a wavelength of 532 nm strongly depended on the crystal polymorphs. α-Bi2O3:Er exhibited intense and stable PL spectra consisting of eight Stark splitting lines. PL from γ-Bi2O3:Er exhibited much weaker two emission lines. δ-Bi2O3:Er and β-Bi2O3:Er films were not emission-active at all. However, δ-Bi2O3:Er film on SiO2 with an Er content of 4 at.% exhibited an intense and broad emission at 1530 and 1560 nm.

Guayule Natural Rubber Latex and Bi2O3 Films for X-ray Attenuating Medical Gloves

Existing natural latex radiation-attenuating gloves (RAGs) contain a high loading of radiation attenuation filler that reduces their mechanical properties to below Food and Drug Administration (FDA) medical glove requirements. RAGs are commonly formulated using Hevea natural rubber latex and lead-based fillers. The former can cause life-threatening allergic responses and the latter are known for their toxicity. In this work, a new lead-free RAG formulation based on circumallergenic guayule natural rubber latex (GNRL) and non-toxic radiation attenuation filler bismuth trioxide (Bi2O3) was developed. GNRL films with Bi2O3 loadings ranging from 0 to 300 PHR at different thicknesses were prepared. Radiation attenuation efficiencies (AE) at 60, 80, 100, and 120 kVp were determined and attenuation isocontour curves predicted film thickness and Bi2O3 loading required to meet or exceed the radiation attenuation requirements of ASTM D7866 and commercial RAGs. Optimal curing conditions for GNRL/Bi2O3 films with 150 PHR Bi2O3 were investigated by varying curing temperatures and time from 87 °C to 96 °C and 65 min to 90 min, respectively. In general, as the loading of the filler increased, the density of the films increased while the thickness decreased. GNRL/Bi2O3 films with 150 PHR Bi2O3 and 0.27 mm provided 5% more AE than RAG market average attenuation at the same thickness. The films with 150 PHR Bi2O3 cured under near-optimal conditions (90 °C/85 min, and 87 °C/65 min) met both the radiation attenuation standard (ASTM D7866) and the natural latex surgeon and examination glove standards (ASTM D3577 and D3578, respectively). Thus, gloves made using our formulations and protocols demonstrated potential to meet and surpass medical natural latex glove standards, offer a single product for both infection control and radiation protection instead of double-gloving, provide a greater degree of comfort to the user, and simultaneously reduce contact reactions and eliminate potential latex allergic reaction.

C-doped TiO2 nanotubes with pulsed laser deposited Bi2O3 films for photovoltaic application

Anodization was used to obtain a nanotubular TiO 2 photoanode on F–SnO 2 glass. Subsequent annealing in the CH 4 atmosphere promoted the C-doping and improved the crystallinity of the TiO 2 nanotubes. The pulsed laser deposition was applied to cover the nanotubes with Bi 2 O 3 , serving as a hole transport material. X-ray photoelectron spectroscopy analyses of the doped samples reveal a shift in the valence band's maximum position towards lower binding energy as compared to those observed for the undoped samples (annealed in the air). The doping positively affects the absorption by shifting the absorption edge to 567 nm. I – V measurements under illumination show that the C-doping of TiO 2 increases the current density following the absorbance results. The highest open circuit voltage was reached for the samples with the 300 °C-deposited Bi 2 O 3 layer, pointing to better quality of the p-n junction, hence of the contact between Bi 2 O 3 and TiO 2 . This in situ annealing provided the formation of close contact between Bi 2 O 3 and TiO 2 , which enabled a faster charge transport as compared to the contact obtained with no annealing or even with post annealing. • C-doping of anodized TiO 2 NTs supported on FTO by annealing in CH 4 . • PLD to cover TiO 2 NTs with Bi 2 O 3 film, serving as a hole transport material. • XPS: Shift of VBM to lower BE for the doped vs. the undoped NTs (annealed in air). • DRS: Absorption red shift from 430 nm (undoped NTs) to 567 nm (doped NTs). • Best PV performances: C-doped TiO 2 with Bi 2 O 3 deposited at 300 °C in situ .

Crystal-phase-specific near-infrared photoluminescence from Er3+-doped Bi2O3 thin films

Er3+-doped Bi2O3 films were sputter deposited on Si(100) substrates at room temperature with H2O vapor as an oxygen source gas. Crystal phases appearing after postannealing in an O2 atmosphere included single-phases of α-Bi2O3, γ-Bi2O3, and δ-Bi2O3, as well as a mixed phase of α-Bi2O3 and γ-Bi2O3. Selection of the crystal phase was possible in terms of H2O pressure and postannealing temperature. Photoluminescence spectra from Er3+ ions excited at a laser wavelength of 532 nm revealed distinct spectral features specific to the crystal phases. A clear crystal-field splitting feature consisting of eight emission lines was observed in PL spectra from sufficiently oxidized α-Bi2O3:Er films, indicating that Er3+ ions occupied low-symmetry C2v sites of Bi3+. The optimum annealing temperature for optical activation of Er3+ ions was between 400 and 450 °C. The emission intensity of α-Bi2O3:Er deposited with H2O was seven times higher than that of α-Bi2O3:Er deposited with O2 probably because larger numbers of Er3+ could substitute Bi3+ sites under reduced condition. Increasing deposition temperature lowered the emission intensity due to the loss of OH and H species from the as-deposited films. The emission spectra of γ-Bi2O3:Er were featureless and its emission intensity was one order of magnitude lower than that of α-Bi2O3:Er. The low-temperature phase of δ-Bi2O3:Er turned out to be entirely emission inactive. Reactions at the interface between the Bi2O3 film and the Si substrate were promoted upon postannealing at 500 °C. The resulting Bi2SiO5:Er exhibited a weak emission spectrum with four emission lines, which reflected occupation at tetragonal Bi3+ sites in the (Bi2O2)2− layers.

Unprecedented solar water splitting of dendritic nanostructured Bi2O3 films by combined oxygen vacancy formation and Na2MoO4 doping

We demonstrate the synergetic effect of Na2MoO4-doping and vacuum-annealing on dendritic nanostructured bismuth oxide (Bi2O3) thin films prepared by electrodeposition for visible-light-assisted photoelectrochemical (PEC) water oxidation. After evaluating various extents of Na2MoO4-doping as well as vacuum-annealing temperatures, it was evidenced that both Na2MoO4-doping and vacuum-annealing significantly improved the efficiency and PEC water oxidation performance. Compared to the undoped Bi2O3 photoanode, the optimized Na2MoO4-doped Bi2O3, after vacuum-annealing, resulted in more than 25-fold enhancement in the photoanodic current density to 1.06 mA/cm2 at 1.23 VRHE under AM1.5 G illumination. The PEC enhancement is credited mainly to the increased PEC surface active sites in the Na2MoO4-doped vacuum annealed sample. Confirmed by combined XPS and Mott-Schottky (M − S) analysis, vacuum annealing resulted in surface oxygen vacancies that can contribute to the photocatalytic activity. Besides, Na2MoO4-doping resulted in reduced dimensions of the dendritic structure, revealed by FE-SEM and XRD measurements, resulting in larger surface area and, therefore, larger surface/electrolyte contact. This dual strategy (metal doping + vacuum annealing) can be generalized to assemble photoanodes of other materials used for the production of solar fuels. Our results make a valuable step towards efficient Bi2O3/BiVO4 pn heterojunctions.

Bismuth Oxide Films for X-ray shielding: Effects of particle size and structural morphology

Lead (Pb) as a traditional shielding material is limited due to its toxicity and heaviness. Recently, nanomaterials in different forms have attracted considerable attention for radiation shielding applications, due to their prominent chemical and physical properties. This work aims to evaluate the effects of size and morphology on the X-ray shielding performance. Both micro- and nano-sized Bi2O3 films with different morphologies (e.g. particles, wires, flowers) were synthesized via a ball milling process and a hydrothermal treatment, respectively. X-ray transmission tests were conducted using a superficial X-ray unit at energies of 30, 50 and 80 kVp (effective energies converted as 14, 24 and 29 keV), which were then compared with mass attenuation coefficient of Bi2O3 obtained from XCOM database. The results showed that the nanoflower (388 ± 30 nm) Bi2O3 film gave the best X-ray shielding performance among all three energies (60.49% improvement at 30 kVp, especially) compared to the bulk Bi2O3 film, indicating the synergy effects of both particle size and morphologies impact on low energies of X-ray attenuation. Moreover, the nanoparticle (830 ± 30 nm) Bi2O3 film enhanced the X-ray attenuation, up to 13.27% at 30 kVp relative to microparticle (1.21 ± 0.14 μm) films. However, the nanoflower (388 ± 30 nm) Bi2O3 film gave the best X-ray shielding performance (45.93% and 47.49% improvement at 30 kVp, respectively) compared to the microwire (1.30 ± 0.13 μm) and nanoparticle (830 ± 30 nm) Bi2O3 film, due to its large surface-to-volume ratio, showing that morphological variations can significantly impact the X-ray transmission to enhance the radiation shielding performance compared to the particle size. Theoretical data from XCOM database compared with experimental measurements showed the limitation of simulation as it can only calculate the ideal condition of regular distributions in materials with standardized geometry. This work concluded that the synergy effect of the particle size and morphology should be considered when designing effective radioprotective garments.

Characterization of Bi2O3 thin films for doping photoluminescent Er3+ ions

Undoped and Er3+-doped Bi2O3 thin films were sputter-deposited on Si(100) substrates. Sufficiently oxidized Bi2O3 films with refractive indices between 2.17−2.23 were obtained at a wavelength of 633 nm; these values are comparable to those of bulk Bi2O3 crystals. While the film composition was stable for deposition temperatures between room temperature (RT) and 450 °C, the refractive index steeply decreased above 450 °C and reached 1.4 at 600 °C. The lowering of the optical transmittance spectra indicated aggregation of metallic Bi and darkening of the film. All films exhibited X-ray diffraction patterns of α-Bi2O3. The direct and indirect bandgap energies derived from the Tauc plots were 3.4–3.7 eV and 1.9–2.5 eV, respectively, depending on the O2 flow rate and deposition temperature. Upon excitation of Er3+-doped Bi2O3 films at 532 nm, Er3+ emissions peaking at 1537 and 1541 nm appeared, and the photoluminescence spectra included fine structures reflecting crystal-field splitting. Resonant excitation of Er3+ 4f levels and indirect excitation via the defect levels of Bi2O3 followed by energy transfer to Er3+ contributed to the emission. The films deposited at RT with Er concentrations of 2 at.% had the emission intensity of Er3+, but concentration quenching strongly suppressed the Er3+ emission because the doped Er3+ ions stayed inside the Bi2O3 crystals. At deposition temperatures above 400 °C, the concentration quenching was mitigated possibly because out-diffusion of Er3+ ions reduced the effective number of Er3+ ions in the Bi2O3 crystalline domains.

Effects of precursor concentration on the microstructural, optical and photoelectrochemical properties of Bi2O3 films synthesized by sol-gel method

β-Bi2O3 films were prepared by sol-gel method process from solutions with different precursor concentration (M = 0.05–0.20). The films were characterized by X-rays diffractions (XRD), field emission electron microscopy (FESEM), atomic force microscopy (AFM), UV–vis spectroscopy, photoluminescence spectroscopy (PL), photoelectrochemical (PEC) and electrochemical impedance measurements. The Bi2O3 deposited film had single phase β-Bi2O3 on ITO substrate while it exhibited mixed phases of ε-, δ- and β-Bi2O3 on glass substrate. By increasing M above 0.05, more XRD patterns were observed and lattice parameter c increased. Besides, crystallite size of films increased first from 19.2 to 26.4 nm at M = 0.05 – 0.15 and then decreased to 19.4 nm at M = 0.20. From AFM, the films consisted of polyhedron-like shape islands with height and distribution increased with increment of M. The surface roughness increased from 10.3 to 18.5 nm for film with M = 0.05 and 0.15, respectively, and then decreased to 14.8 nm for film M = 0.20. Optical band gap decreased from 3.24 eV for film M = 0.05 to 2.89 eV for film M = 0.20. From PEC, photocurrent of films increased with increment of M and had maximum value 3.8 × 10−4 A/cm2 for film M = 0.20 at 0 V versus Ag/AgCl. Electrochemical impedance analysis showed a gradual reduction of charge transfer resistance with increasing M. Finally, β-Bi2O3 films with tailored microstructure were prepared which make it attractive for many applications.

Dynamic study of phase transition in Bi2O3 epitaxial film induced by electrolyte gating

Electrolyte gating with ionic liquids has been broadly applied in various fields in recent years. However, it remains under debate since defect-controlling and electrochemical doping are conventionally disputed to interpret the corresponding mechanism. In this work, we provide the synergistic mechanism that oxygen vacancy migration and element-doping together drive the formation of metallization. The prepared Bi2O3 films experienced insulator-metal transition and structural transformation by field-induced ionic liquid. The consequent structural transition in the Bi2O3 film was dynamically monitored by XRD, and the results indicated that an extraordinary metal Bi phase was formed during the electrolyte gating process, which was further verified by HR-TEM and XPS. Our current findings will boost the development of electrolyte gating and bring insight into other metal oxides in ionic liquid gating experiment.

One-pot hydrothermal synthesis of Bi2O3-WO3 p-n heterojunction film for photoelectrocatalytic degradation of norfloxacin

A p-n heterojunction film of Bi2O3-WO3 with enhanced photoelectrocatalytic (PEC) activity was successfully constructed by a facile one-pot hydrothermal synthesis. The as-prepared Bi2O3-WO3 heterojunction film exhibited flower-like microstructures. Compared with pristine Bi2O3 and WO3 films, the Bi2O3-WO3 composite film exhibited enhanced absorption in the visible region. The formation of Bi2O3-WO3 p-n heterojunction facilitates the interfacial transfer of electrons as well as the separation of charge carries. As a result, the Bi2O3-WO3 film showed high photocurrent response under visible light illumination. Furthermore, the enhanced visible light PEC performance of Bi2O3-WO3 film was evaluated by the decoloration of Rhodamine B. When the Bi2O3-WO3 film was applied to norfloxacin removal, the degradation efficiency reached 88.4% after 6 h PEC process under visible light illumination. According to nine intermediates identified by liquid chromatograph-mass spectrometric analysis, a possible PEC degradation mechanism for norfloxacin was proposed.

Growth of Bi2O3 Films by Thermal- and Plasma-Enhanced Atomic Layer Deposition Monitored with Real-Time Spectroscopic Ellipsometry for Photocatalytic Water Splitting

Ultrathin Bi2O3 films were grown by thermal- and plasma-enhanced ALD by using [Bi(tmhd)3] as bismuth precursor. The use of an O2 plasma instead of H2O as oxidant increases the growth per cycle (GPC...