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Enhanced photocatalytic performance of TiO2 NTs decorated with chrysanthemum-like BiOI nanoflowers
摘要： The BiOI nanosheets/chrysanthemum-like nanoflowers were successfully deposited on the surface of TiO2 nanotube arrays (TiO2 NTs) by the successive ionic layer adsorption and reaction (SILAR) method, and the morphology and visible light response of samples with different SILAR deposition cycles were investigated in detail. The as-prepared BiOI/TiO2 NTs significantly enhanced photoelectrocatalytic (PEC) activity for the removal of Methyl orange (MO), Rhodamine B (RhB), Methylene blue (MB) and Cr(VI). The as-prepared Sample-7 with chrysanthemum-like nanostructures showed the high visible light photocurrent density of 120.06 μA/cm2, photovoltage of ?203.61 mV/cm2, PEC efficiencies of 45%, 62%, 79% and 77% for the removal of MO, RhB, MB and Cr(VI), respectively. The high PEC performances could be ascribed to the excellent visible light response and charge carrier transportation in chrysanthemum-like BiOI nanoflowers. By further probing the charge separation and transportation behaviors, the experiments of the energy band structure and active species trapping were carried out. A possible p-n heterojunction photocatalytic mechanism was proposed, which not only benefited the efficient separation of photogenerated electrons but also demonstrated the advanced capacity for the PEC removal of organic dyes and heavy metal ions.
关键词： BiOI,Photoelectrochemical performance,TiO2 nanotube arrays,Nanoflowers
更新于2025-11-19 16:56:35
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Insight into visible light-driven photocatalytic performance of direct Z-scheme Bi2WO6/BiOI composites constructed in -situ
摘要： Bi2WO6/BiOI composites with enhanced photocatalytic performance were constructed in-situ by a hydrothermal routine. The Bi2WO6/BiOI composites were studied by Brunauer -Emmett-Teller (BET), X-ray di?raction patterns (XRD), UV–Vis di?use re?ectance spectra (DRS), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), surface photovoltage spectroscopy (SPS), electron spin-resonance (ESR) spectroscopy and X-ray photoelectron spectroscopy (XPS). The results support the coexistence of Bi2WO6 and BiOI in the composites. All the Bi2WO6/BiOI composites display higher separation rate of photoinduced carriers than BiOI. OH and·O2? were formed in the composite photocatalytic system. Finally, a direct Z-scheme was proposed for the Bi2WO6/BiOI composites.
关键词： Separation of photoinduced carriers,Bi2WO6,Heterojunctions,Visible light photocatalytic property,BiOI
更新于2025-09-23 15:23:52
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Preparation of interstitial carbon doped BiOI for enhanced performance in photocatalytic nitrogen fixation and methyl orange degradation
摘要： Carbon-doped BiOI (C-BiOI) photocatalysts were successfully synthesized via a hydrothermal method with Bi(NO3)3·5H2O, KI, and glucose as raw materials for the first time. The synthesized samples had excellent photocatalytic activities in the degradation of methyl orange (MO) and the reduction of N2 to NH3. To reveal the origin of the superior photoactivity, the C-BiOI was examined by multi techniques, including N2-adsorption, XRD, SEM, TEM, Raman, XPS, DRS, PL, EIS and transient photocurrent response. The characterization results indicated that the carbon clusters entered the interlayers of BiOI crystal during preparation. The doped carbon interfered the lattice periodicity and generated vacancies in the BiOI structure, resulting in the decreased band gap and increased efficiency in charge separation, both of which could significantly hasten the photocatalytic reaction. Additionally, the introduced carbon affected the morphology of BiOI and increased its specific surface area, which may also benefit the photocatalytic process. The carbon content was crucial to the promotion effect. Under visible light, the optimized carbon-doped BiOI (C-BiOI-2) presented an MO degradation rate of 0.136 min-1, which was 4.44 times higher than that of pure BiOI. However, for the photocatalytic N2 fixation, due to the contribution of surface carbon in N2 adsorption, the C-BiOI sample containing higher carbon content (C-BiOI-3) displayed superior performance than C-BiOI-2. The NH3 generation rate under simulated sunlight reached 311 μmol g?1h?1, which was about 3.7-fold of that of BiOI. This work may shed some insight into the designing and understanding of carbon-doped semiconductor photocatalysts.
关键词： interstitial doping,C-BiOI,photocatalytic N2 fixation,visible light
更新于2025-09-23 15:23:52
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A cathodic photovoltammetric sensor for chloramphenicol based on BiOI and graphene nanocomposites
摘要： A visible light-activated photocathode fabricated with p-type semiconductor bismuth oxyiodide (BiOI) and graphene (G) was employed to investigate the photovoltammetric behavior of chloramphenicol (CAP). The result indicated that the voltammetric reduction peak of CAP increased to a limiting current platform under photoirradiation, owing to photoelectrocatalytic reduction of CAP on the BiOI-G photocathode. As a result, the cathodic photovoltammogram became sigmoidal in shape. Furthermore, the influences of graphene content in BiOI-G composites, scan rate and light intensity on the photovoltammetric behavior of CAP on the BiOI-G photocathode were systematically investigated. Based on such a BiOI-G electrode, a cathodic photovoltammetric sensor for CAP was proposed, which exhibited a current response linearly proportional to CAP concentration in the range of 0.5 to 50 μmol L-1, with a detection limit (3S/N) of 0.14 μmol L-1. Moreover, the photovoltammetric sensor displayed good reproducibility and high stability. The applicability of the proposed sensor was demonstrated by determining CAP in eye drop and environmental water samples.
关键词： Photovoltammetry,Photoelectrochemical sensor,Chloramphenicol,BiOI,Graphene
更新于2025-09-23 15:23:52
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In-situ approach to fabricate BiOI photocathode with oxygen vacancies: Understanding the N2 reduced behavior in photoelectrochemical system
摘要： The adsorption and activation of N2 on the catalyst surface is a major problem in the process of photoelectrochemical (PEC) N2 reduction. Herein, we report a strategy to fabricate intrinsic BiOI (I-BiOI) photocathode with oxygen vacancies (OVs) (R-BiOI) by a facile in-situ method, and the R-BiOI was successfully selected as the model matrix for understanding the role of OVs in the PEC N2 reduction system for the first time. The correlation between carrier concentration/Lewis-base/active sites and OVs was in-depth demonstrated by Mott-Schottky plots and photoelectrochemical impedance spectroscopy (PEIS) results, meanwhile the Linear-sweep-voltammetry (LSV) data further confirmed the selectivity for active N2 over R-BiOI photocathode. The tandem built from BiVO4 photoanode and R-BiOI photocathode presented the desirable production rate of ammonia at about 1.4 mmol/m2/h, which is 1.3 and 2.9 times than that of I-BiOI (1.1 mmol/m2/h) and Pt (0.48 mmol/m2/h). Our findings have initially developed the proposed mechanism for the behavior of solar-electron-ammonia conversion and offered an alternative potential route for green N2 fixation.
关键词： Active sites,Lewis-base,Oxygen vacancies,BiOI,Photoelectrochemical (PEC) N2 fixation
更新于2025-09-23 15:23:52
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Synthesis of C-In2O3/BiOI composite and its enhanced photocatalytic degradation for methyl blue
摘要： In this work, C-In2O3/BiOI composite is synthesized and used as a high performance photocatalyst for photocatalytic degradation of methyl blue (MB) in wastewater. The C-In2O3/BiOI composites demonstrate 5 times higher photocatalytic performance than the pristine BiOI and In2O3 for MB degradation under the irradiation of visible light. Furthermore, the C-In2O3/BiOI composites have excellent cycling stability. Such enhanced photoactivity is due to the significantly enhanced separation efficiency of photogenerated. This work provides some significance in the design and construction of environmentally benign catalysts with excellent photocatalytic degradation of toxic pollutants.
关键词： C-In2O3/BiOI,Methyl blue,Photocatalysis,Visible light
更新于2025-09-23 15:22:29
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Glass fiber supported BiOI thin-film fixed-bed photocatalytic reactor for water decontamination under solar light irradiation
摘要： BiOI powder has been proved to be an efficient photocatalyst, but the difficulty in removing it from water after reaction limits its application in real water treatment. To solve this problem, a thin-film fixed-bed reactor (TFFBR) was set-up by developing a BiOI thin film on glass fiber cloth (GFC). The composition and structure of the as-prepared films were characterized with X-ray diffraction, X-ray photoelectron spectroscopy, field emission microscopy, transmission electron microscopy and Fourier transform infrared spectroscopy. The BiOI thin film was made by painting a silica sol containing BiOI on GFC, which could be tailored to desired sizes to accommodate the TFFBR. The mass of BiOI on the GFC increased with the number of iterations of the painting process. SiO2 sol glued the BiOI particles tightly onto the GFC, making the thin film strong enough to resist fluid flushing in the TFFBR. The photocatalytic activity of the BiOI thin film was investigated by degrading bisphenol A (BPA) under simulated sunlight. Ninety eight percent of BPA (20 mg/L in 2 L) was degraded by the BiOI thin film sample of seven layers (GFC-7) on the TFFBR within 8 hr irradiation. The GFC-7 displayed good photocatalytic ability toward artificial sewage containing BPA in a wide pH range (5–9), and also demonstrated excellent durability and reusability. The working conditions were optimized and it was found that the thickness of the fluid film and residence time over the thin film were key factors affecting the photocatalytic efficiency.
关键词： Photocatalytic film,Sol–gel,BPA,TFFBR,BiOI
更新于2025-09-23 15:22:29
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Abundant manganese complex-anchored BiOI hybrid photocatalyst for visible light-driven CO <sub/>2</sub> reduction
摘要： An abundant manganese complex-anchored BiOI hybrid system for CO2 photocatalytic conversion was constructed. Layered BiOI and tricarbonyl Mn bipyridyl complex with carboxyl acid groups were connected with covalent bonds and used as visible light antenna and CO2 reduction reaction centers, respectively. The covalent connection of this hybrid system benefits the transfer of electrons from the semiconductor to the Mn complex. The anchoring group (carboxyl) is the key to CO2 reduction for the direct coupling of the two units, facilitating the transfer of electrons from BiOI to the manganese complexes. The photocatalytic properties and stability of the tricarbonyl Mn–bipyridyl complex were significantly enhanced with the aid of anchored BiOI. A high turnover number (TON = 74) of HCOO? formation from CO2 could be achieved using this hybrid system under visible light irradiation.
关键词： CO2 reduction,Photocatalysis,BiOI,Mn tricarbonyl bipyridyl complex
更新于2025-09-23 15:22:29
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Monolayer Epitaxial Heterostructures for Selective Visible-Light-Driven Photocatalytic NO Oxidation
摘要： Construction of vertical heterostructures by stacking two-dimensional (2D) layered materials via chemical bonds can be an effective strategy to explore advanced solar-energy-conversion systems. However, it remains a great challenge to fabricate such heterostructures based on conversional oxide-based compounds, as they either do not possess a 2D layered structure or are not suitable for epitaxial growth due to large lattice mismatch. Here, a vertical heterostructure of bismuth oxyhalide semiconductors fabricated through a heteroepitaxial anion exchange method is reported. Monolayer Bi2WO6 is epitaxially grown on the exposed surface of BiOI to inhibit photocorrosion and introduce active sites. Theoretical and experimental results reveal that electrons generated under visible-light irradiation can directly transfer to surface coordinatively unsaturated (CUS) Bi atoms, which contribute to the adsorption and activation of reactant molecules. As a result, the Bi2WO6/BiOI vertical heterostructures exhibit significantly enhanced visible-light-driven NO oxidation activity compared with BiOI and Bi2WO6.
关键词： epitaxial heterostructures,NO oxidation,photocatalysis,Bi2WO6,BiOI
更新于2025-09-23 15:22:29
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Preparation of BiOI microspheres in 2-propanol/ethylene glycol by microwave method with high visible-light photocatalytic activity
摘要： BiOI microspheres were synthesized by using mild conditions under microwave irradiation and applying short reaction times. The effect of the reaction medium in the final morphology of BiOI was revised modifying the relative concentrations of 2-propanol and ethylene glycol (EG) used as solvents. The as-prepared samples were characterized by X-ray powder diffraction, scanning electron microscopy, diffuse reflectance spectroscopy, N2 adsorption–desorption isotherms and photoluminescence measurements. The photocatalytic activity of BiOI was evaluated in the oxidation reaction of nitric oxide (NO) under visible-light irradiation. In particular, the samples with morphology of 3D flower-like microspheres prepared with EG showed the highest activity for NO removal (83%), maintaining its performance after several photocatalytic cycles. Besides the morphology of BiOI samples, the high photocatalytic activity was associated with the large surface area and the low rate of charge recombination observed in samples prepared with EG. The use of scavenger agents allowed to determine the predominant participation of holes (h+), electrons (e?) and superoxide ion (·O2?) in the reaction mechanism of the NO oxidation.
关键词： NOx,Microwave,Photocatalysis,BiOI
更新于2025-09-23 15:21:21