BiVO4 Nanoparticles Research Articles

Synergistic impacts of novel tantalum doping in BiVO4 for effective photocatalytic applications, antimicrobial activity, and antioxidant aspect

This paper reports the production of pure and Ta-doped (1 %, 2 %, 3 %, and 4 %) BiVO4 nanoparticles (NPs) for MB dye degradation. UV–Vis, FTIR, SEM, PL, and XRD techniques were used to analyze the samples. Photocatalysts (BiVO4, Ta-doped BiVO4) NPs have been used to study the photocatalytic activity of these materials for the degradation of methylene blue (MB) in response to visible light. The band gap reduction from 2.7 to 1.98 eV and the photogeneration of electron-hole pairs have also been demonstrated by UV–visible and PL spectroscopy. According to FTIR spectroscopy analysis, Bismuth, Tantalum, Vanadium, Oxygen, and Carbon are all present in the synthesized material. As the dopant concentration rises, the XRD data show that the crystallite size decreases. The crystallite size of the optimal (4 % Ta-doped BiVO4) is 23 nm, whereas the crystallite size of the 2 % Ta-doped BiVO4 is 39 nm. The SEM image shows that particle size reduces when dopant concentration rises. In comparison to previous synthesized materials, the 4 % Ta-doped BiVO4 NPs have a smaller band gap, crystalline size, and recombination rate. Therefore, using the co-precipitation process, 4 % Ta-doped BiVO4 NPs degrade the MB dye (86 %) in 120 min, making them an ideal material. The findings of this study will be applied to wastewater treatment.

Nano-eco catalysis: carbendazim degradation by engineered BiVO4 nanoparticles

This study utilized the solvothermal approach for the effective synthesis of BiVO4 nanoparticles. Morphological examination of BiVO4 was conducted via scanning electron microscopy (SEM), while the elemental composition was determined using energy dispersive x-ray spectroscopy (EDX). The crystallinity and functional groups were assessed through x-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR), respectively.The synthesized material’s efficacy in UV-induced breakdown of carbendazim was investigated. The study explored various factors affecting the photodegradation process, including radiation duration, initial concentration of carbendazim, catalyst dosage, and catalyst regeneration. Interesingly, 97% degradation of carbendazim was observed at optimized conditions. These results emphasise the potential of BiVO4 nanoparticles as catalysts for environmental remediation applications, especially in the degradation of harmful contaminants.

Synthesis of V2O5 nanowires decorated with BiVO4 nanoparticles via a simple spin-coating method

Synthesis of V2O5 nanowires decorated with BiVO4 nanoparticles via a simple spin-coating method

Strain-Induced Photocatalytic H2 Production over BiVO4 in Pure Water without Any Cocatalyst.

In this study, BiVO4 nanosheets (BiVO4-NS) were prepared by a facile hydrothermal method. It is found that sonication-induced strain can effectively promote the H2 production over BiVO4-NS in the presence of pure water without any cocatalysts. With the assistance of the sonication, the H2 production over BiVO4-NS is 1.344 mmol·g-1 after 3 h simulated sunlight irradiation, which is 24.8 times higher than that of BiVO4-NS without sonication (0.054 mmol·g-1). In addition, the products of water oxidation are determined to be hydroxyl radicals and hydrogen peroxide. Moreover, BiVO4-NS also shows obviously enhanced photoactivity than that of the commercially available BiVO4 nanoparticles (BiVO4-C). The improved photoactivity of BiVO4-NS is attributed to the effective charge separation and low charge transfer resistance. The underlying mechanism of sonication-promoted water splitting is investigated by a variety of controlled experiments. The results show that ultrasonic waves can produce obvious strain inside the sample, which results in lattice distortion of BiVO4. Therefore, the conduction band of BiVO4 is obviously negative shifted, which is beneficial for H2 production. In addition, the strain in BiVO4 also produces local polarization of the sample, which effectively promotes the charge transfer and separation process. It is hoped that our study could provide a new strategy for achieving efficient photocatalytic water splitting.

Utilizing samarium doped BiVO4 microspheres for solar-Powered photocatalysis and Microbial Defense

Due to their unique features and numerous uses, samarium-doped bismuth vanadate (BiVO4) photocatalysts have recently attracted a lot of interest from researchers in the area of photocatalysis. In this work, the synthesis of BiVO4 nanoparticles, both unmodified and doped with Sm3+, using a co-precipitation technique, is thoroughly examined. It is worth mentioning that the photocatalytic efficacy of Sm3+-doped BiVO4 nanoparticles was higher than that of pure BiVO4 nanoparticles. This is because the band gap was reduced and the synergistic effects of Sm3+ ions worked together to effectively suppress the recombination of photo-generated charge carriers. Improving charge carrier migration and separation, and thus photocatalytic performance is dependent on the introduction of samarium dopants. Additionally, samarium-doped bismuth vanadate was investigated for its antibacterial properties, and it was shown that it could eliminate bacteria and other germs in both watery and airborne settings using photocatalytic activity. When Sm3+ ions were added to the BiVO4 matrix, the antibacterial activity was significantly increased when tested against a variety of gram-positive and gram-negative bacteria, including, but not limited to, Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Proteus vulgaris. Most importantly, the photocatalyst showed remarkable stability and recyclability; at a doping level of 7 wt% Sm3+-doped BiVO4 performed optimally. This work presents a simple method for synthesizing BiVO4 nanoparticles by co-precipitation, which shows great potential for the effective removal of organic pollutants and microbes from polluted water sources. The generated nanoparticles may be either pure or doped with Sm3+.

Investigation of a visible-light-driven molecularly imprinted photoelectrochemical sensing platform for ultrasensitive and selective detection of diflubenzuron utilizing an in-situ grown 3D hierarchical structure

An ultrasensitive molecularly imprinted polymer-photoelectrochemical (MIP-PEC) sensing platform has been successfully fabricated for the detection of diflubenzuron (DBZ) under visible-light irradiation. The noval photoactive material was a ternary Bi2S3/BiVO4/TiO2 nanotube arrays (BVT) heterojunction, grown in-situ on a Ti substrate. The distinct architecture of BVT featured BiVO4 nanoparticles anchored onto TiO2 nanotube arrays and wrapped by Bi2S3 nanofibers. This innovative design, coupled with the aligned energy bands of BVT, significantly boosted visible-light absorption, and photo-induced charge separation and transfer, leading to an enhanced photocurrent response surpassing that of binary and single-component systems. The sensing platform displayed remarkable sensitivity and a broad detection range for DBZ with a linear range of 0.01–1000 ng mL−1 and a limit of detection of 1.25 pg mL−1. Its selectivity was further validated by comparable photocurrent responses in the presence of interfering substances, highlighting its accuracy in detecting DBZ in complex matrices. Additionally, the sensing platform demonstrated excellent stability and reproducibility, ensuring reliable results over multiple measurements. Evaluation of the sensing platform in real samples, including tap water and apples, has confirmed its high accuracy with recovery rates between 94.4 % and 103.4 %. Therefore, this visible-light-driven MIP-PEC sensing platform exhibits considerable potential for application in ultrasensitive detection of DBZ. This work offers novel insights into the in-situ preparation of high-performance sensors for applications in food safety and environmental monitoring.

Sonochemical synthesis, characterization, and infrared-driven photocatalytic performance of 2%Er/x%Yb co-doped BiVO4 nanoparticles (x=2–10%)

This study investigates the influence of Yb co-doping on the photocatalytic performance of 2% Er-doped BiVO4 nanoparticles under infrared light for wastewater treatment. Er/Yb co-doping induces a phase transformation from monoclinic to tetragonal BiVO4, significantly enhancing infrared light absorption and photocatalytic activity. The optimal Yb concentration for maximizing activity is found to be 2%, achieving a one-order-of-magnitude improvement compared to undoped BiVO4. Up-conversion processes involving Yb and Er ions play a crucial role in this enhancement, converting low-energy infrared photons into higher-energy visible emissions that drive photocatalysis. These findings demonstrate a promising strategy for developing highly efficient and sustainable photocatalysts for wastewater treatment utilizing the abundant yet underexplored infrared region of the solar spectrum.

Highly dispersed BiVO4 nanoparticles supported by pseudoboehmite for effective removal of antibiotics

BiVO4/pseudoboehmite (PB) composite catalysts were innovatively prepared using the cost-effective PB as support by a facile hydrothermal method. BiVO4 nanoparticles with an average size of 12 nm are highly dispersed on the surface of PB. Compared to pure BiVO4, the composite BiVO4/6 %PB exhibits high specific surface area (32.9 m2/g) about double that of pure BiVO4 (15.1 m2/g) which can provide more adsorption and photocatalytic reaction sites. Meanwhile, the composite has enhanced photogenerated electron-hole separation and transfer efficiency. As a result, it has a superior performance of antibiotics removal in water than pure BiVO4. The tetracycline hydrochloride (TCH) removal efficiency of BiVO4/6 %PB can reach 87 % within 2 h with high stability (<7 % decay after four cycles) under LED lamp (380–780 nm) irradiation as well as high selectivity. Specifically, the adsorption efficiency and photocatalytic rate constant are respectively triple and double that of pure BiVO4. Simultaneously, the BiVO4/6 %PB also possesses high removal efficiency of amoxicillin (76 %). Our results indicate that the selection of cost-effective PB as catalyst support offers a new solution to solve the aggregation problem of BiVO4 nanoparticles and the composite obtained contributes to an economic and efficient BiVO4-based photocatalyst for antibiotics removal in sewage treatment.

Green synthesis of bismuth vanadate nanostructures for efficient photocatalytic and biological studies

In the current investigation, BiVO4 nanoparticles were prepared via a simple combustion approach followed by annealing at 400°C using rain tree pod extract. The physicochemical and morphological features were examined through spectroscopic techniques. Optical studies were carried out using a UV–visible spectrophotometer, revealing a bandgap of 2.4 eV. Photocatalytic efficiency was assessed through degradation studies using methylene blue (MB) dye under visible photon irradiation, demonstrating an impressive 94 % degradation rate. Consequently, this synthesized bismuth vanadate serves as an outstanding photocatalyst under visible irradiation. Furthermore, these nanoparticles exhibited favorable responses in antifungal, antibacterial, and molecular docking studies. Bismuth vanadate nanoparticles had substantial antifungal efficacy, with the Bi2 version successfully suppressing Aspergillus Niger at a 50 % concentration. At 100 mg/ml, Bi2 showed a 6 mm zone of inhibition against Gram-positive Staphylococcus aureus and a 5 mm zone against Gram-negative Escherichia coli for antibacterial evaluation. The protein 7BLY and Bismuth vanadate had four hydrogen bond interactions and a strong binding affinity, as shown by molecular docking, of −5.0 Kcal/mol. Therefore, bismuth vanadate nanoparticles synthesized through green methods show promise in combating fungal and bacterial infections, as well as potential applications in various fields.

Modified successive ionic layer adsorption and reaction for interconnected bismuth vanadate nanograins: Highly active visible light harvesting photoanodes

A modified successive ionic layer adsorption and reaction (SILAR) method is developed for depositing interconnected bismuth vanadate (BiVO4) nanoparticles with improved visible light harvesting activity. Facile control of preparative parameters like deposition cycles, anionic precursor, pH and deposition temperature significantly altered BiVO4 surface morphology. BiVO4 thin films prepared with Na3VO4 anionic precursor show dispersed nanoparticles type morphology and that deposited with NaVO3 precursor displays 3D interconnected nanoparticles morphology. The BiVO4 photoanodes with 3D interconnected nanoparticles morphology exhibits an excellent photocurrent density of 5.19 mA cm−2 at 1.23 V vs. RHE with superior photostability and improved applied bias photon to current efficiency (ABPE) (1.50 %) compared to dispersed nanostructured BiVO4 photoanodes. The excellent photoelectrochemical (PEC) characteristics of BiVO4 photoanodes with 3D interconnected nanoparticle morphology can be ascribed to porous morphology, optimum thickness, narrow band gap energy and favorable electronic band structure for water splitting. The current study illustrates the usefulness of the modified SILAR approach for depositing 3D interconnected BiVO4 nanoparticle morphology in a single step that is superior and efficient to previously reported multistep processes.

Enhanced electrophoretic deposition of hydrophobic BiVO4 photocatalytic coatings using Cu2+ ions as stabilizing agent

In this work, we report the preparation of monoclinic bismuth vanadate (BiVO4) coatings through an electrophoretic deposition process (EPD) using Cu2+ ions as a charge-stabilizing agent. BiVO4 was prepared through a rapid coprecipitation route, yielding rounded nanoparticles with sizes smaller than 100 nm. The bismuth vanadate nanoparticles were dispersed in isopropyl alcohol for electrophoretic deposition onto aluminum plates using a constant applied voltage of 12 V for 30 min. The results have shown that the deposited amount of BiVO4 nanoparticles increases with the initial concentration of the Cu(NO3)2⋅5H2O additive. According to XPS analysis, EPD coatings exhibit the presence of metallic copper due to the reduction of Cu2+ ions on the BiVO4 during the electrophoretic deposition process. The photocatalytic properties of BiVO4 coatings were assessed in the degradation of the antibiotic tetracycline under simulated solar irradiation. The BiVO4 coating prepared with an initial concentration of 0.5 mM of Cu(NO3)2⋅5H2O exhibited the highest photocatalytic performance, achieving a degradation efficiency of approximately 92 % after 240 min of irradiation. Furthermore, the BiVO4 coatings displayed superhydrophobic properties, as determined by measuring static water contact angles.

Ideal Structures of Isolated BiVO4 Nanoparticles on WO3 Nanocorals to Enhance Photoelectrochemical Hydrogen Evolution

Metal oxide nanoparticles (NPs) of n-type semiconductors have recently garnered significant attention in the photoelectrochemical (PEC) field. In this study, isolated BiVO4 NPs on anodized WO3 nanocorals are investigated with respect to the formation mechanism of the NPs and the correlation between particle size and PEC efficiency. The sizes and distances of the BiVO4 NPs on the WO3 nanocorals are controlled via spin-coating and heat-treatment. The optimized BiVO4 NPs, with ideal sizes of 10 nm and distances of 100 nm between them, exhibit satisfactory electron and hole diffusion lengths, suppressing electron–hole recombination and promoting the exposure of WO3 to ultraviolet light. Furthermore, high-quality BiVO4, without the formation of by-products due to the optimized concentrations of Bi and V in the precursor solution, results in a 2.3-fold higher photocurrent density and H2 production, and a 6-fold higher incident photon-to-current conversion efficiency (IPCE) compared to those of pristine WO3 nanocorals.

Combined experimental and first principles look into (Ce, Mo) doped BiVO4

Here we investigated the effects of Ce and Mo doping on hydrothermally synthesized bismuth vanadate BiVO4 nanoparticles (NPs). The existence of monoclinic scheelite and tetragonal zircon phases of NPs was validated from Rietveld refinement of the powdered X-ray diffraction, room temperature Raman, and Fourier-transform infrared spectroscopy. The co-doping of Bi and V sites with respective Ce and Mo dopants in a mixed tetragonal zircon and monoclinic scheelite phases of BiVO4 lattice was corroborated from high-resolution transmission electron microscopy and X-ray photoelectron spectroscopy. The photoluminescence measurements revealed enhancement of photo-generated carrier recombination in (Ce, Mo) co-doped BiVO4 NPs which may have hampered its photocatalytic efficiency in degrading the methylene blue dye. The simulations based on Hubbard U corrected density functional theory (DFT+U) suggest that Mo and Ce co-doping introduced deep impurity states which may have facilitated the photo-generated carrier recombination detrimental to photocatalytic performance. The UV-vis diffuse reflectance measurements provided evidence for the presence of these defect states. In summary, this work may have presented a comprehensive experimental analysis of (Ce, Mo) doped BiVO4 supported by DFT simulations.

A TiO2 nanotube photoanode (blue TiO2 nanotube/RuO2/BiVO4) for efficient acetaminophen degradation and nitrogen removal

To simultaneously remove organic carbon and nitrogen, especially from wastewater containing organic amine compounds, a nanotube photoanode was prepared by depositing RuO2 and BiVO4 nanoparticles in and on a blue TiO2 nanotube substrate (BTNT/RuO2/BiVO4). The synthesized materials were systematically characterized by scanning electron microscope, energy-dispersive X-ray, X-ray diffraction, X-ray photoelectron spectroscopy, and electrochemical tests. Acetaminophen, a commonly used pharmaceutical with an amine group, was used as the model pollutant to examine the performance of the prepared electrodes. The results indicated that acetaminophen could be degraded by 100 % in 180 min over BTNT/RuO2/BiVO4 with a rate constant of 0.0338 min−1, which was 25.0 and 1.1 times higher than those obtained over BTNT/BiVO4 and BTNT/RuO2, respectively. Meanwhile, 81.3 % of total nitrogen could be removed. Compared with BTNT/BiVO4 and BTNT/RuO2, BTNT/RuO2/BiVO4 had a significant synergistic effect, and the synergy index reached to 47.7 %. Additionally, BTNT/RuO2/BiVO4 exhibited good stability, high current efficiency (63.2 %) and low energy consumption (0.020 kWh·g COD−1). The good performance of BTNT/RuO2/BiVO4 was mainly attributed to the enhanced formation of ClO· resulted from the synergistic interaction between RuO2 and BiVO4 due to the spatial confinement effect. Lastly, a possible reaction mechanism via ClO· over BTNT/RuO2/BiVO4 was proposed.

Bi/BiVO4 tailoring molecular oxygen activation for SPR-promoted photocatalytic contaminant removal

In recent years, photocatalytic technology has been gained widespread attention in contaminants removal due to its green, low-carbon, sustainable properties. Bismuth vanadate (BiVO4) with decahedral shapes has emerged as a promising photocatalyst with unique photoinduced charges directional transfer. In this study, a simple wet chemical reduction method was used to load stable Bi0 nanoparticles in situ on the surface of decahedral BiVO4 to enhance the charges movement for molecular oxygen activation and tetracycline photodegradation. The formed Bi0 nanoparticles induced abundant oxygen vacancy defect states and surface plasmon resonance effects on BiVO4 nanoparticles surface. In aid of the special function of a surface heterojunction, decahedral BiVO4 can be photoexcited to produce more photogenerated carriers, and its separation efficiency is greatly improved, thus enhancing both the oxidative activity and photocatalytic activity. In the photocatalytic degradation process, superoxide radicals (∙O2−) showed the most significant contribution, and singlet oxygen (1O2) played junior role in tetracycline hydrochloride (TC) removal. 1O2 is obtained by ∙O2− and hole energy conversion, and some of it is produced by tetracycline photodecomposition under alkaline conditions. The BBV0.4 photocatalytic system has the best catalytic activity under weakly alkaline conditions, and the synergistic effect of photocatalysis and photodecomposition greatly improves the mineralization rate of TC. The large numbers of ∙O2− and 1O2 reactive oxygen species produced by BBV0.4 activation of oxygen play a crucial role in the photodegradation of TC via demethylation, deoxidation, deamination, ring-opening, and carbonylation to complete mineralization. This work studies in depth the change in the decahedral BiVO4 photocatalytic mechanism caused by the in situ introduce of bismuth metal, providing an efficient and environmentally friendly reference method for the rapid removal of tetracycline hydrochloride under alkaline conditions.

Highly efficient visible-light driven dye degradation via 0D BiVO4 nanoparticles/2D BiOCl nanosheets p-n heterojunctions

The construction of hybrid heterojunction photocatalysts is an effective strategy to improve the utilization of photogenerated carriers and photocatalytic activity. To enhance the separation distance of photogenerated carriers and accelerate the effective separation at the heterojunction of the interface, a unique 0D-2D hierarchical nanostructured p-n heterojunction was successfully fabricated in this work. BiOCl (BOC) nanosheets (p-type) were in situ grown on BiVO4 (BVO) nanoparticles (n-type) using the microemulsion-calcination method for highly efficient visible-light-driven organic dye degradation. Compared with pure BVO (the degradation rate of rhodamine B (RhB): about 32.0% in 55 min, the mineralization rate: 24.9% in 120 min), the RhB degradation rate can reach about 99.5% in 55 min and the mineralization rate of 62.1% in 120 min by utilizing BVO/25%BOC heterojunction photocatalyst under visible light irradiation. Various characterizations demonstrate that the formation of BVO/BOC p-n heterojunction greatly facilitates photogenerated carriers separation efficiency. Meanwhile, the results of the scavenging experiments and electron spin resonance tests indicate that ·O2− and h+ are the prominent active species for Rh B degradation. In addition, possible degradation pathways for Rh B were proposed using LC-MS tests. This work proves that building low dimensional p-n heterojunction photocatalysts is a promising strategy for developing photocatalysts with high efficiency.

A novel approach towards biosynthesis of BiVO4 nanoparticles and their anticancer, antioxidant, and photocatalytic activities

A novel approach towards biosynthesis of BiVO4 nanoparticles and their anticancer, antioxidant, and photocatalytic activities

Sensitive photochemical detection of Pb2+ based on the "on-off-on" strategy coupled with adsorption

A photoelectrochemical (PEC) sensor, utilizing the semiconductor BiVO4 and gold nanoparticles (AuNPs) modified with glutathione (GSH), was successfully fabricated for the sensitive detection of Pb2+ ions. The calcinated BiVO4-modified indium tin oxide (ITO) electrode (ITO/BiVO4) generated a low cathodic photocurrent response under light irradiation. The photocurrent at ITO/BiVO4/AuNPs photoelectrode increased significantly due to the plasmon enhancement of AuNPs and the electron transfer. This enhancement photocurrent intensity was largely suppressed by introducing GSH to form ITO/BiVO4/AuNPs/GSH. It minimized the base photocurrent of the photoelectrode. Upon the addition of Pb2+ ions in the cell, they were adsorbed on the electrode surface through the interaction with the two carboxyl groups in GSH. Subsequently, Pb2+ ions, serving as electron acceptors, underwent reduction under light irradiation, leading to increase in photocurrent intensity again. Therefore, a signal "on-off-on" PEC sensor was developed for the detection of Pb2+ ions. The concentration of Pb2+ ions show a good linearity between 0.1 pM and 10 μM with a detection limit of 0.08 pM (S/N = 3). The prepared PEC sensor shows high sensitivity, a wide linear range, and good selectivity. This work provides a promising platform for the analytical detection of heavy metal ions.

Preparation of Surface Dispersed WO3/BiVO4 Heterojunction Arrays and Their Photoelectrochemical Performance for Water Splitting.

In this work, a surface dispersed heterojunction of BiVO4-nanoparticle@WO3-nanoflake was successfully prepared by hydrothermal combined with solvothermal method. We optimized the morphology of the WO3 nanoflakes and BiVO4 nanoparticles by controlling the synthesis conditions to get the uniform BiVO4 loaded on the surface of WO3 arrays. The phase composition and morphology evolution with different reaction precursors were investigated in detail. When used as photoanodes, the WO3/BiVO4 composite exhibits superior activity with photocurrent at 3.53 mA cm-2 for photoelectrochemical (PEC) water oxidation, which is twice that of pure WO3 photoanode. The superior surface dispersion structure of the BiVO4-nanoparticle@WO3-nanoflake heterojunction ensures a large effective heterojunction area and relieves the interfacial hole accumulation at the same time, which contributes to the improved photocurrents together with the stability of the WO3/BiVO4 photoanodes.

Machine learning, a powerful tool for the prediction of BiVO4 nanoparticles efficiency in photocatalytic degradation of organic dyes

Wastewater pollution caused by organic dyes is a growing concern due to its negative impact on human health and aquatic life. To tackle this issue, the use of advanced wastewater treatment with nano photocatalysts has emerged as a promising solution. However, experimental procedures for identifying the optimal conditions for dye degradation could be time-consuming and expensive. To overcome this, machine learning methods have been employed to predict the degradation of organic dyes in a more efficient manner by recognizing patterns in the process and addressing its feasibility. The objective of this study is to develop a machine learning model to predict the degradation of organic dyes and identify the main variables affecting the photocatalytic degradation capacity and removal of organic dyes from wastewater. Nine machine learning algorithms were tested including multiple linear regression, polynomial regression, decision trees, random forest, adaptive boosting, extreme gradient boosting, k-nearest neighbors, support vector machine, and artificial neural network. The study found that the XGBoosting algorithm outperformed the other models, making it ideal for predicting the photocatalytic degradation capacity of BiVO4. The results suggest that XGBoost is a suitable model for predicting the photocatalytic degradation of wastewater using BiVO4 with different dopants.