Bi2MoO6 Research Articles

A facile solvothermal syntheses of NiFe layered double hydroxide-Bi2MoO6 heterostructure/reduced graphene oxide with efficient photodegradation for tetracycline.

A heterojunction of NiFe layered double hydroxide (NiFe LDH)-Bi2MoO6 (BMO) loaded on reduced graphene oxide (RGO) sheets was synthesized via an eco-friendly solvothermal reaction. The structural characterization shows that NiFe LDH-BMO heterojunctions are well-distributed on the surface of silk-like transparent RGO sheets. The modification of BMO by NiFe LDH and RGO greatly enhances the photocatalytic performance of BMO for degradation of tetracycline (TC) under visible light. The photocatalyst prepared with 3wt% RGO shows the highest activity and cycle stability. TC can be completely removed in 80min, which is about 8.7 times that pure BMO, and showing excellent reusability even after five cycles. The excellent enhancement of photocatalytic performance of NiFe LDH-BMO/RGO composite is attributed to the unique sheet-on-sheet hierarchical heterostructure combined with RGO sheets, facilitating the visible light absorption and photogenerated charge carriers separation.

Bi2MoO6 and Ag nanoparticles immobilized on textile by plasma-derived innovative techniques to generate antimicrobial activity

In this study, we expose various techniques based on cold plasma discharge (CPD), and more precisely aqueous-phase plasma-aided grafting (APPAG), to efficiently modify the surface of polymers as well as fabric made of natural fibers. Several directions were investigated to ultimately add a functional coating providing an antimicrobial effect to textiles. Our strategy relies on the immobilization of silver nanoparticles (AgNPs) and Bi2MoO6 (BMO) – a robust inorganic photocatalyst that can be activated by visible light – microflowers, at the surface of cotton fabric fibers. Notably, an in situ complexation-assisted precipitation route (ISCAP – an original method derived from CPD) was successfully employed to generate a very uniform coating of silver nanoparticles at the surface of organic substrates. As we demonstrate in this study, the surface functionalization with BMO and silver provides a significant protection against bacteria in dark conditions, through a bacteriostatic effect of nano silver, and under low-intensity artificial visible light (thanks to the photocatalytic effect of BMO/Ag), hence suitable for an indoor environment such as hospitals. Our composite nanomaterial, cotton/BMO/AgNPs, was assessed through antibacterial testing with Escherichia coli (E. coli) and Staphylococcus aureus (S. Aureus), showing a pronounced antimicrobial effect with both strains. This study opens prospects for the functionalization of natural or artificial fiber materials with possible applications in the field of biomedical protective equipment such as bandages, masks or technical cloths; or even photocatalysis.

Oxygen Vacancy-Mediated Growth of Amorphous Discharge Products toward an Ultrawide Band Light-Assisted Li-O2 Batteries.

Photoassisted electrochemical reaction is regarded as an effective approach to reduce the overpotential of lithium-oxygen (Li-O2 ) batteries. However, the achievement of both broadband absorption and long term battery cycling stability are still a formidable challenge. Herein, an oxygen vacancy-mediated fast kinetics for a photoassisted Li-O2 system is developed with a silver/bismuth molybdate (Ag/Bi2 MoO6 ) hybrid cathode. The cathode can offer both double advantages for light absorption covering UV to visible region and excellent electrochemical activity for O2 . Upon discharging, the photoexcited electrons from Ag nanoplate based on the localized surface plasmon resonance (LSPR) are injected into the oxygen vacancy in Bi2 MoO6 . The fast oxygen reaction kinetics generate the amorphous Li2 O2 , and the discharge plateau is improved to 3.05V. Upon charging, the photoexcited holes are capable to decompose amorphous Li2 O2 promptly, yielding a very low charge plateau of 3.25V. A first cycle round-trip efficiency is 93.8% and retention of 70% over 500 h, which is the longest cycle life ever reported in photoassisted Li-O2 batteries. This work offers a general and reliable strategy for boosting the electrochemical kinetics by tailoring the crystalline of Li2 O2 with wide-band light.

Ferroelectrics in Photocatalysis.

The rapid development of industrialization and population has brought water, air-pollution and energy crises. Solar-driven catalysis is expected to relieve these issues. However, limited by poor light harvesting, serious charge recombination of semiconductors, and high surface reaction barriers, the low efficiency of solar conversion is far from satisfactory for industrial needs. Ferroelectrics are considered to be promising photocatalysts to overcome these shortcomings. Herein, perovskite ferroelectrics such as BaTiO3 , PbTiO3 , BiFeO3 and LiNbO3 , layered bismuth-based ferroelectrics like Bi2 WO6 and Bi2 MoO6 , and other ferroelectrics are introduced, and their crystal structure, polarity source and synthetic method are highlighted. Subsequently, research progress in ferroelectrics for photocatalysis is summarized, including pollution degradation, water splitting and CO2 reduction. Finally, the current challenges and future prospects of ferroelectric photocatalysts are provided. The purpose of this review is not only to provide a timely summary for the application of ferroelectrics in photocatalysis, but also to present deep insight and a guideline for future research work into ferroelectrics.

Selective Production of Secondary Amine by the Photocatalytic Cascade Reaction Between Nitrobenzene and Benzyl Alcohol over Nanostructured Bi2 MoO6 and Pd Nanoparticles Decorated with Bi2 MoO6.

The synthesis of secondary amine by the photoalkylation of nitrobenzene with benzyl alcohol using a simple light source and sunlight is a challenging task. Herein, a one-pot cascade protocol is employed to synthesize secondary amine by the reaction between nitrobenzene and benzyl alcohol. The one-pot cascade protocol involves four reactions: (a) photocatalytic reduction of nitrobenzene to aniline, (b) photocatalytic oxidation of benzyl alcohol to benzaldehyde, (c) reaction between aniline and benzaldehyde to form imine, and (d) photocatalytic reduction of imine to a secondary amine. The cascade protocol to synthesize secondary amine is accomplished using Bi2 MoO6 and Pd nanoparticles decorated Bi2 MoO6 catalysts. The surface characteristics, oxidation states, and elemental compositions of the materials are characterized by several physicochemical characterization techniques. Optoelectronic and photoelectrochemical measurements are carried out to determine the bandgap, band edge potentials, photocurrents, charge carrier's separation, etc. An excellent yield of secondary amine is achieved with simple household white LED bulbs. The catalyst also exhibits similar or even better activity in sunlight. The structure-activity relationship is established using catalytic activity data, control reactions, physicochemical, optoelectronic characteristics, and scavenging studies. Bi2 MoO6 and Pd nanoparticles decorated Bi2 MoO6 exhibit excellent photostability and recyclability. The simple catalyst design with a sustainable and economical light source for the synthesis of useful secondary amine from the nitrobenzene and benzyl alcohol would attract the researchers to develop similar catalytic protocols for other industrially important chemicals.

2D Piezoelectric Bi2 MoO6 Nanoribbons for GSH-Enhanced Sonodynamic Therapy.

Reducing the scavenging capacity of reactive oxygen species (ROS) and elevating ROS production are two primary goals of developing novel sonosensitizers for sonodynamic therapy (SDT). Hence, ultrathin 2D Bi2 MoO6 -poly(ethylene glycol) nanoribbons (BMO NRs) are designed as piezoelectric sonosensitizers for glutathione (GSH)-enhanced SDT. In cancer cells, BMO NRs can consume endogenous GSH to disrupt redox homeostasis, and the GSH-activated BMO NRs (GBMO) exhibit an oxygen-deficient structure, which can promote the separation of electron-hole pairs, thereby enhancing the efficiency of ROS production in SDT. The ultrathin GBMO NRs are piezoelectric, in which ultrasonic waves introduce mechanical strain to the nanoribbons, resulting in piezoelectric polarization and band tilting, thus accelerating toxic ROS production. The as-synthesized BMO NRs enable excellent computed tomography imaging of tumors and significant tumor suppression in vitro and in vivo. A piezoelectric Bi2 MoO6 sonosensitizer-mediated two-step enhancement SDT process, which is activated by endogenous GSH and amplified by exogenous ultrasound, is proposed. This process not only provides new options for improving SDT but also broadens the application of 2D piezoelectric materials as sonosensitizers in SDT.

Facile interface engineering of hierarchical flower spherical-like Bi-metal–organic framework microsphere/Bi2MoO6 heterostructure for high-performance visible–light photocatalytic tetracycline hydrochloride degradation

The self-assembled Bi-based metal–organic framework microspheres (Bi-MOF-M) by nanorods were successfully constructed by the glycol-assisted solvothermal method. Using Bi-MOF-M as a homologous template, a petal-like Bi2MoO6 (BMO) layer was grown in situ on its surface to facilely construct a chemically bonded heterojunction interface, realizing a micro/nano hierarchical flower spherical-like Bi-MOF-M/BMO heterojunction composite photocatalyst. The as-prepared series of Bi-MOF-M/BMO-x catalysts show higher visible light catalytic performance for tetracycline hydrochloride (TC) degradation. Among them, Bi-MOF-M/BMO-0.3 has the optimal catalytic activity, and the degradation efficiency can reach 93.6% within 60 min of light irradiation with superior mineralization ability and structural stability, and the degradation kinetic constant is 6.12 times that of Bi-MOF-M and 5.69 times that of BMO, respectively. The homologously grown Bi-MOF-M/BMO chemically bonded heterojunction not only effectively broadens the spectral absorption range and enhances the absorption intensity but also promotes the efficient separation of photogenerated carriers through forming a favorable interfacial electric field and well-matched energy band alignment. A reasonable mechanism for the visible light degradation of TC by the Bi-MOF-M/BMO composite catalyst with h+ and 1O2 as the main reactive species is proposed. The micro/nano hierarchical structure of the Bi-MOF/BMO catalyst allows it to exhibit the easy recovery advantage of micron-scale materials while maintaining the high catalytic activity of the primary nano-components.

Preparation of Nanoflake Bi2MoO6 Photocatalyst Using CO(NH2)2 as Structure Orientation and Its Visible Light Degradation of Tetracycline Hydrochloride

Bi2MoO6 (BMO) via the structure-directing role of CO(NH2)2 is successfully prepared via a facile solvothermal route. The structure, morphology, and photocatalytic performance of the nanoflake BMO are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), fluorescence spectrum analysis (PL), UV-vis spectroscopy (UVvis) and electrochemical test. SEM images show that the size of nanoflake BMO is about 50 ~ 200 nm. PL and electrochemical analysis show that the nanoflake BMO has a lower recombination rate of photogenerated carriers than particle BMO. The photocatalytic degradation of tetracycline hydrochloride (TC) by nanoflake BMO under visible light is investigated. The results show that the nanoflake BMO-3 has the highest degradation efficiency under visible light, and the degradation efficiency reached 75 % within 120 min, attributed to the unique hierarchical structure, efficient carrier separation and sufficient free radicals to generate active center synergies. The photocatalytic reaction mechanism of TC degradation on the nanoflake BMO is proposed.

Preparation of g-C3N4/BMO heterojunction for visible photocatalytic degradation of O-Nitrophenol and actual pharmaceutical wastewater

A novel Bi2MoO6 (BMO) modified g-C3N4 heterostructure composite photocatalyst (g-C3N4/BMO) was prepared by hydrothermal method. The orthorhombic crystal phase of the material was studied by the X-ray diffraction assay (XRD). The microscopic morphology of the material was investigated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM), indicating a heterojunction structure of the composite. The electrons and holes separation was evaluated by photo-luminescence (PL) and photocurrent measurements. The removal rate of O-Nitrophenol was as high as 97.3% over the catalyst with the optimal ratio of 1: 0.09 (BMO:g-C3N4) in 180 min. COD removal percentage of actual pharmaceutical wastewater was as high as 71.40%. The active species in the photocatalytic system were studied, indicating superoxide radicals (·O2-) and holes (h+) as the main active species.

Photoreduction properties of novel Z-scheme structured Sr0.8La0.2(Ti1-δ 4+Ti δ 3+)O3/Bi2MoO6 composites for the removal of Cr(vi).

Novel Z-scheme structured Sr0.8La0.2(Ti1−δ4+Tiδ3+)O3/Bi2MoO6 (LSTBM) composites were prepared via a facile two-step solvothermal method. Several characterization techniques were employed to investigate the phases, microstructures, compositions, valence states, oxygen vacancies, surface oxygen absorption, energy band structures and lifetime of photoproduced carriers. It was found that the lifetime and transfer of the photoproduced carriers of LSTBM were better than those of Bi2MoO6 (BMO) and Sr0.8La0.2(Ti1−δ4+Tiδ3+)O3 (LSTO). The LSTBM with a molar ratio of BMO/(LSTO + BMO) = 0.07 (denoted as LSTBM7) showed 1.9 and 3.1 times removal rates than those for BMO and LSTO, respectively. Importantly, the built-in electric field in the heterojunction of LSTBM and Ov-s, especially in Ov-s on the higher-Fermi-level side of the heterojunction, had co-played roles in prolonging the lifetime and improving the transfer of photogenerated carriers. The photoproduced e− played a dominant role in reducing Cr(vi) to Cr(iii) and the produced Cr(iii) tends to form Cr(OH)3 and adsorb onto the surface of the photocatalyst to decrease the nucleation energy. The possible reduction route for Cr(vi) to Cr(iii) over LSTBM7 was figured out. This study implies that inducing Ov-s on the higher-Fermi-level side of the Z-scheme heterojunction is a more effective route for separating the photogenerated electrons and holes and improving the transfer of photogenerated carriers.

Interplay of adsorption, photo-absorption, electronic structure and charge carrier dynamics on visible light driven photocatalytic activity of Bi2MoO6/rGO (0D/2D) heterojunction

In the present research Bi2MoO6(BMO) QDs (0D) and reduce graphene oxide nanosheet (2D) (BMO/rGO)(0D/2D) heterojunction with different weight ratio of GO nanosheet were synthesized using facile method. XRD, UV–vis spectroscopy, XPS, FTIR, BET, PL, TRPL, TEM/HRTEM, ESR and photoelectrochemical (PEC) measurements were used for the characterization and understanding the enhancement effect on photoactivity of the synthesis photocatalyst. The BMO (0D) QDs provide more active sites and short diffusion length of photogenerated charges. Whereas, 2D rGO nanosheet presents complementary surface area to allow the formation of distinct heterojunction with majority of the 0D QDs by preventing agglomeration of particles and excellent conductivity. TEM images explicitly showed the uniform distribution of 0D BMO particles of size 8−10 nm over 2D rGO which lead to formation of distinct Schottky junction. These exclusive properties of 0D/2D heterojunction result in effective degradation of organic pollutants such as Rhodamine-B dye, p-nitrophenol a phenol group and acetaminophen a pharmaceuticals compound with 100 %, 94 % and 87 % in 180 min; and degradation rate achieved was 9.35, 8.60 and 7.53 as compared to 0D BMO QDs under simulated solar light irradiation. The scavenging experiments revealed that h+ and O2• - radicals are main reactive species involved in the photodegradation along with contribution from photogenerated e−. The increased photocatalytic efficiency is ascribed to enlarge solar light absorption, increased adsorption, increased surface area, conductivity with substantial contribution of photo-induced charge separation and transfer in BMO/rGO (0D/2D) heterojunction.

Ag-decorated 3D flower-like Bi2MoO6/rGO with boosted photocatalytic performance for removal of organic pollutants

A series of unique 3D flower-like Bi2MoO6 (BMO)/reduced graphene oxide (rGO) heterostructured composites decorated with varying amounts of Ag nanoparticles (NPs) were fabricated. Their morphological characteristics, structural features, energy band structures and photoelectrochemical properties were systematically studied. All the Ag/BMO/rGO ternary composites (AgBG-y; y = 1%, 2% and 3%) demonstrated greater photocatalytic activity towards efficient removal of our selected organic models [methyl orange (MO), rhodamine B (RhB) and phenol], as compared with the BMO/rGO binary composites (BG-x; x = 0.25, 2, 4 and 5). Particularly, AgBG-2%, which was synthesized with the addition of 2 wt% rGO and 2 wt% Ag in BMO, possessed superior photocatalytic activity. The fitted rate constants (k) for the photocatalytic degradation of RhB, MO and phenol using AgBG-2% were estimated to be 0.0286, 0.0301 and 0.0165 min−1, respectively, which were over one order of magnitude greater than those obtained using pure BMO. Several factors may contribute to the observed enhancement, including greater specific surface area, enhanced light absorption, promoted spatial separation of electron–hole (e−–h+) pairs and their suppressed recombination, especially benefiting from the synergistic effects among BMO, rGO and Ag NPs. Our work suggests that the rational design of BMO/rGO/Ag ternary composite was an effective strategy to boost the photocatalytic activity of the resulting catalyst towards the highly efficient removal of organic pollutants from water. This work presents the construction of Ag NPs-decorated 3D flower-like Bi2MoO6 (BMO)/reduced graphene oxide (rGO) ternary composites as effective photocatalysts for efficient removal of organic pollutants under solar light irradiation. The separation efficiency of photogenerated charge carriers is significantly promoted by the synergistic effect of Ag NPs, BMO and rGO.

Facile synthesis and extended visible light activity of oxygen and sulphur co-doped carbon nitride quantum dots modified Bi2MoO6 for phenol degradation

A novel one-pot solvothermal route was employed to construct O and S co-doped graphitic carbon nitride quantum dots (OSCNQDs) hybridized with Bi2MoO6 (BMO) photocatalyst and utilized to catalyse aqueous phenol from simulated wastewater under extended visible light exposure. The photodegradation analysis depicted that the (OSCNQDs/BMO) nanohybrid exhibited incremented photocatalysis of phenol (98 %) under visible light illumination which is due to the effective coupling and formation of Z-scheme heterostructure which rendered superior space isolation and retained high redox abilities. The OSCNQDs might contribute to the extended absorption of visible light as well as increased adsorption of phenol on the surface of photocatalyst. As a result, the nanohybrid displayed prominent absorption in visible region, improved space charge isolation and superior photoactivity which can be utilized as an effective approach for the photo-assisted degradation of organic pollutants.

Modulation of Bi2 MoO6 -Based Materials for Photocatalytic Water Splitting and Environmental Application: a Critical Review.

Highly active photocatalysts driving chemical reactions are of paramount importance toward renewable energy substitutes and environmental protection. As a fascinating Aurivillius phase material, Bi2 MoO6 has been the hotspot in photocatalytic applications due to its visible light absorption, nontoxicity, low cost, and high chemical durability. However, pure Bi2 MoO6 suffers from low efficiency in separating photogenerated carriers, small surface area, and poor quantum yield, resulting in low photocatalytic activity. Various strategies, such as morphology control, doping/defect-introduction, metal deposition, semiconductor combination, and surface modification with conjugative π structures, have been systematically explored to improve the photocatalytic activity of Bi2 MoO6 . To accelerate further developments of Bi2 MoO6 in the field of photocatalysis, this comprehensive Review endeavors to summarize recent research progress for the construction of highly efficient Bi2 MoO6 -based photocatalysts. Furthermore, benefiting from the enhanced photocatalytic activity of Bi2 MoO6 -based materials, various photocatalytic applications including water splitting, pollutant removal, and disinfection of bacteria, were introduced and critically reviewed. Finally, the current challenges and prospects of Bi2 MoO6 are pointed out. This comprehensive Review is expected to consolidate the existing fundamental theories of photocatalysis and pave a novel avenue to rationally design highly efficient Bi2 MoO6 -based photocatalysts for environmental pollution control and green energy development.

Facile synthesis of indium hydroxide nanosheet/bismuth molybdate hierarchical microsphere heterojunction with enhanced photocatalytic performance

Various Bi2MoO6 (BM)-based heterojunctions have been constructed to enhance the photocatalytic performance, but hydroxide/BM heterojunctions were rarely reported. To illustrate function of hydroxides in the heterojunctions for charge separation and photoactivity enhancement, In(OH)3/BM heterojunctions were simply prepared for the first time via in situ growth of In(OH)3 nanosheets on surfaces of BM hierarchical microspheres in a chemical precipitation process at the room temperature. Construction of the heterojunction benefits from formation of In-O-Bi/Mo bonds at the interface between BM and In(OH)3. Photoluminescence spectroscopy, time-resolved fluorescence spectroscopy, and photoelectrochemical tests demonstrate that the In(OH)3/BM heterojunction exhibits considerably accelerated separation of photoinduced charge carriers which results in increased generation rates of reactive oxygen species and enhanced photocatalytic degradation efficiencies for Rhodamine B, salicylic acid, and resorcinol, in comparison with pure BM. The heterojunction shows high chemical stability and satisfactory recyclability. This work provides a new BM-based heterojunction and, more importantly, deep insight into function of hydroxides in the heterojunction, which can direct preparation of other hydroxide-containing heterojunctions.

Constructing novel ternary composites of carbon quantum dots/Bi2MoO6/graphitic nanofibers with tunable band structure and boosted photocatalytic activity

Novel ternary carbon quantum dots (CDs)/Bi2MoO6 (BMO)/graphitic carbon nanofibers (GNFs) composites (CDs/BMO/GNFs) were prepared by a facile hydrothermal method and studied for use as photocatalysts. The morphological, structural and physicochemical properties of the as-prepared photocatalysts were examined in detail; that the CDs-decorated BMO particles anchored on the surfaces of modified GNFs to form heterojunctions. The photocatalytic activity of the resultant CDs/BMO/GNFs was superior for the degradation of three different organics, including Rhodamine B (RhB), methylene blue (MB) and phenol, as well as the reduction of a heavy metal ion Cr(VI), when compared with the corresponding binary composites (BMO/GNFs and CDs/BMO) and pure BMO. Our study revealed that the photocatalytic performance of ternary composite CDs/BMO/GNFs was significantly affected by the loadings of CDs or/and GNFs in BMO. Especially, the optimized sample C5/BMO/GNF-0.2, which was synthesized with a Bi/C molar ratio of 0.2 and the addition of 5 mL CDs, exhibited the best activity in the photocatalytic degradation of RhB. It was found that 99.4% of RhB was removed after 70-min exposure to the simulated solar light irradiation. This was attributed to the synergistic effects between components (CDs, BMO and GNFs) and heterojunctions, resulting in an efficient spatial separation of the photogenerated electrons and holes. A possible photocatalytic mechanism of C5/BMO/GNF-0.2 was proposed that the photogenerated holes, O2− and OH radicals contributed to the photocatalysis, which was supported by the radical quenching experiment and electron spin resonance analysis.

Enhanced electrochemical performance via PPy encapsulated 3D flower-like bismuth molybdate nanoplates for high-performance supercapacitors

Novel three-dimensional (3D) flower-like Bi2MoO6 (BMO) nanoplates were successfully synthesized by a hydrothermal method using ethylenediaminetetraacetic acid (EDTA) as a capping agent. The growth mechanism of the 3D flower-like BMO nanoplates was investigated by varying the amount of EDTA during the reaction. The electrochemically conductive BMO/polypyrrole (PPy) hybrid composite was further prepared by in-situ oxidative polymerization method by adding the pyrrole monomer into the aqueous solution of pristine BMO. The X-ray diffraction patterns of the PPy polymer did not show any change on the phase form of the pristine BMO. The electrochemical properties of the PPy coated BMO hybrid composite electrode as well as the prepared 3D flower-like BMO nanoplate electrode were evaluated in 1 M KOH electrolyte solution. The specific capacitance of the BMO/PPy hybrid composite electrode exhibited the higher specific capacitance value (1253 F g−1), which is much higher than the pristine 3D flower-like BMO nanoplate electrode (725 F g−1) at a current density of 1 A g−1. Furthermore, the BMO/PPy hybrid composite electrode maintained 70.4% of capacitance retention after 2000 cycles with respect to the initial specific capacitance value at a higher current density (15 A g−1), which indicates that the electrode material has good cycling stability.

Efficient Degradation of Phenol and 4-Nitrophenol by Surface Oxygen Vacancies and Plasmonic Silver Co-Modified Bi2 MoO6 Photocatalysts.

In this work, the surface plasmon resonance effect of metallic Ag, surface oxygen vacancies (SOVs), and Bi2 MoO6 (BMO) material were rationally combined to construct new oxygen-vacancy-rich Ag/Bi2 MoO6 (A/BMO-SOVs) photocatalysts. Their synergistic effect on the photocatalytic degradation of phenol and 4-nitrophenol under visible-light irradiation (λ≥420 nm) was also investigated. TEM, EPR, and Raman spectra demonstrate the co-existence of metallic Ag nanoparticles, surface oxygen vacancies, and Bi2 MoO6 due to a controlled calcination process. The experimental results disclose that the 2 %A/BMO-SOVs-375 sample exhibited the highest photocatalytic activity for the degradation of both phenol and 4-nitrophenol under visible-light irradiation, achieving nearly 100 and 80 % removal efficiency, respectively, and demonstrated the apparent reaction rate constants (kapp ) 183 and 26.5 times, respectively, higher than that of pure Bi2 MoO6 . The remarkable photodegradation performance of A/BMO-SOVs for organic substances is attributed to the synergistic effect between the surface oxygen vacancies, metallic Ag nanoparticles, and Bi2 MoO6 , which not only improves the visible-light response ability, but also facilitates charge separation. Thus, this work provides an effective strategy for the design and fabrication of highly efficient photocatalysts through integrating surface oxygen vacancies and the surface plasmon resonance effect of nanoparticles, which has the potential for both water treatment and air purification.

Highly selective ppb-level H2S sensor based on the walnut-like Bi2MoO6 at low temperature

The walnut-like Bi2MoO6 (BMO) hollow microspheres, assembled by nanosheets, were synthesized by a facile solvothermal method based on MoO3 hollow spheres. The Bi2MoO6 compound was calcined at the temperature of 200 °C, 400 °C and 450 °C (denoted as BMO-200, BMO-400 and BMO-450) to measure the gas-sensing properties. The sensor based on BMO-400 exhibits a significant selectivity, a high stability and response, a good repeatability and humidity-resistivity and a better linear relationship to H2S gas at the concentration range of 1–100 ppm level and 0.1–100 ppb level at a low operating temperature of 133 °C. In addition, the detection limit of the sensor towards H2S gas is as low as 0.1 ppb (S = 1.98). According to the sensing mechanism discussed based on X-ray photoelectron spectroscopy (XPS) and gas chromatography-mass spectrometry (GC–MS) analyses, the improvement of response may be attributed to the high oxygen content adsorbed on the surface of the Bi2MoO6 material and the unique hollow structure.

One-step synthesis of Bi2MoO6/reduced graphene oxide aerogel composite with enhanced adsorption and photocatalytic degradation performance for methylene blue

Bi2MoO6/reduced graphene oxide aerogel (BMO/GA) composite with enhanced adsorptivity and photocatalysis has been successfully synthesized through a simple one-step solvothermal method. During solvothermal synthesis, Bi2MoO6 (BMO) as an efficient photocatalyst, which size was controllable, was uniformly distributed and well embedded into the pores of the 3D porous structure reduced graphene oxide aerogel (GA) and formed the 3D porous structure BMO/GA composite. The methylene blue (MB) was selected as a simulated pollutant, and the removal rate of BMO/GA composite toward MB was about 2.1 times as high as the pure BMO, which reached up 98.3% in 100 min. The BMO/GA composite with greatly improved adsorptivity and photocatalytic activity has some advantages of low-cost, ease of preparation and facile of recovery from target contaminant solution. The excellent adsorption and photocatalytic degradation performance of BMO/GA composite is mainly owing to the BMO can be exactly embedded into the pores of GA and the RGO provided conductive electron channels for dispersing electrons. The synergistic effect of BMO and GA on enhancing the adsorption and photocatalytic degradation toward MB was also discussed by a proposed photocatalytic mechanism.