Due to the increasing antibiotic resistance and the lack of broad-spectrum antibiotics, there is an urgent requirement to develop fresh strategies to combat multidrug-resistant pathogens. Herein, defect-rich bismuth molybdate heterojunctions [zero-dimensional (0D) Bi4MoO9/two-dimensional (2D) Bi2MoO6, MBO] were designed for rapid capture of bacteria and synergistic photocatalytic sterilization. The as-prepared MBO was experimentally and theoretically demonstrated to possess defects, heterojunctions, and irradiation triple-enhanced photocatalytic activity for efficient generation of reactive oxygen species (ROS) due to the exposure of more active sites and separation of effective electron-hole pairs. Meanwhile, dopamine-modified MBO (pMBO) achieved a positively charged and rough surface, which conferred strong bacterial adhesion and physical penetration to the nanosheets, effectively trapping bacteria within the damage range and enhancing ROS damage. Based on this potent antibacterial ability of pMBO, a multifunctional hydrogel consisting of poly(vinyl alcohol) cross-linked tannic acid-coated cellulose nanocrystals (CPTB) and pMBO, namely CPTB@pMBO, is developed and convincingly effective against methicillin-resistant Staphylococcus aureus in a mouse skin infection model. In addition, the strategy of combining a failed beta-lactam antibiotic with CPTB@pMBO to photoinactivation with no resistance observed was developed, which presented an idea to address the issue of antibiotic resistance in bacteria and to explore facile anti-infection methods. In addition, CPTB@pMBO can reduce excessive proteolysis of tissue and inflammatory response by regulating the expression of genes and pro-inflammatory factors in vivo, holding great potential for the effective treatment of wound infections caused by drug-resistant bacteria.

Nickel (hydr)oxide (NiOH) is known to be good co-catalyst for the photoelectrochemical oxidation of water, and for the photocatalytic oxidation of organics on different semiconductors. Herein we report a greatly improved activity of Bi2MoO6 (BMO) by nickel hexammine perchlorate (NiNH). Under visible light, phenol oxidation on BMO was slow. After NiNH, NiOH, and Ni2+ loading, a maximum rate of phenol oxidation increased by factors of approximately 16, 8.8, and 4.7, respectively. With a BMO electrode, all catalysts inhibited O2 reduction, enhanced water (photo-)oxidation, and facilitated the charge transfer at solid-liquid interface, respectively, the degree of which was always NiNH > NiOH > Ni2+. Solid emission spectra indicated that all catalysts improved the charge separation of BMO, the degree of which also varied as NiNH > NiOH > Ni2+. Furthermore, after a phenol-free aqueous suspension of NiNH/BMO was irradiated, there was a considerable Ni(III) species, but a negligible NH2 radical. Accordingly, a plausible mechanism is proposed, involving the hole oxidation of Ni(II) into Ni(IV), which is reactive to phenol oxidation, and hence promotes O2 reduction. Because NH3 is a stronger ligand than H2O, the Ni(II) oxidation is easier for Ni(NH3)6+ than for Ni(H2O)6+. This work shows a simple route how to improve BMO photocatalysis through a co-catalyst.

Here, a pH-sensitive biocompatible nanocarrier system is synthesized by the combination of Bi2MoO6 nanoparticles, NH2-graphene oxide (GO), and polyethylene glycol (PEG) for loading and delivery of daunorubicin (DNR) into breast cancer cells. DNR is loaded onto the nanocarrier surface via covalent bonding, exhibiting pH-sensitive behavior so that in acidic pH, nearly 86.85% of the drug is released, but in biological pH, only about 15% of the drug is released. The resulting Bi2MoO6/NH2-GO/PEG/DNR has a high drug loading content (33.29%) and encapsulation efficiency (99.75%). By examining the toxicity of the nanocarrier-loaded drug, no adverse effect is observed on healthy cells HUVEC, and the survival rate of cancer cells MCF-7 decreases with increasing the nanocarrier concentration. Moreover, the free drug is found to be more toxic than DNR attached to the nanocarrier. The complement activation (C3 and C4 levels), prothrombin time and activated partial thromboplastin time analyses also indicate its excellent blood compatibility. The hemolysis analysis (HRs),used to evaluate the nanocarrier compatibility. the results show that even in high concentrations(5-100 μg/ml), the percentage of hemolysis is below 1.8%, which indicates that the nanocarrier is safe to blood cells. These results evidence the therapeutic nature of the biocompatible Bi2MoO6/NH2-GO/PEG, proposing it as an efficient anticancer nanocarrier for drug delivery and other biomedical application purposes.

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.

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 3 wt% RGO shows the highest activity and cycle stability. TC can be completely removed in 80 min, 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.

Selective and sensitive dopamine (DPA) sensor was developed using hydrothermally prepared functionalized multi-walled carbon nanotube-coated bismuth molybdate (f-MWCNT@BMO). The f-MWCNT@BMO-reinforced electrode exhibited an outstanding electrocatalytic activity towards DPA oxidation. The nanocomposite-reinforced electrode displayed a rapid response towards DPA sensing and possessed the minimized potential of (Epa + 0.285 V vs Ag/AgCl) in 0.1 M phosphate buffer (PB). The electrochemical results of prepared sensors were analyzed using the differential pulse voltammetry method (DPV). As a result, the f-MWCNT@BMO-reinforced electrode exhibited a widelinear range of 10 nM - 814 μM with a very low detection limit of 3.4 nM towards DPA oxidation. The developed sensor shows excellent selectivity in presence of similar functional group biomolecules. The detection of DPA in real samples was evaluated in human serum, as the results of the proposed sensor possessed good recoveries.

Hydrogen has attracted increasing attention as clean energy for fuel cells over the past decade. Photoelectrochemical (PEC) water splitting is considered the most feasible production method but its practical efficiency depends significantly on the photogeneration rate of electron (e-) and hole (h+) on a semiconductor photoanode and the rapid separation of these charge carriers. A proper match of small and large bandgap positions is also necessary. This paper presents a three-dimensional core-shell heterostructured tungsten trioxide/bismuth molybdate/cobalt phosphate (WO3/Bi2MoO6/Co-Pi) photocatalyst synthesized using simultaneous hydrothermal and electrodeposition techniques. Uniform Bi2MoO6 nanoflakes formed on WO3 nanoplates as evidenced by various micro-spectroscopic techniques. The as-prepared WO3/Bi2MoO6/Co-Pi hetero-photocatalyst exhibited significantly high photoelectrochemical activity, where its photocurrent efficiency was 4.6 times greater than that of the constituent WO3. Such drastic improvement in the PEC properties can be corroborated by the appropriate bandgap alignment among WO3, Bi2MoO6, and Co-Pi, resulting in a sufficient charge carrier density with efficient, fast charge-transport complementing their structural-morphological synergy. Furthermore, a heterojunction charge-transfer mechanism was proposed to verify the role of the co-catalyst, Co-Pi, in enhancing the photocurrent at the WO3/Bi2MoO6 photoanode under the same applied bias.

Herein, we fabricated a feasible and accurate sensing platform for the quantification of toxic organic pollutant 2-nitroaniline (2-NA) in water samples through electrocatalyst made up of bismuth molybdate (Bi2MoO6, BMO) functionalized carbon nanofiber (f-CNF) modified electrode. The preparation of BMO/f-CNF composite is of two methods, such as co-precipitation (C-BMO/f-CNF) and ultrasonication method (U-BMO/f-CNF). The physicochemical properties of the composites were characterized by XRD, FTIR, Raman, BET, FE-SEM, and HR-TEM techniques. At U-BMO/f-CNF, the charge transfer resistance was low (Rct = 12.47 Ω) compared to C-BMO/f-CNF because nanosized U-BMO particles correctly aim at the defective sites of the f-CNF surface wall. Further, the electrocatalytic activity of C&U-BMO/f-CNF composites was examined by cyclic voltammetry (CV) and differential pulse voltammetry techniques (DPV) for the electrochemical detection of 2-nitroaniline (2-NA). The U-BMO/f-CNF/GCE shows a higher cathodic current, wide dynamic linear range of 0.01-168.01 µM, and superior electrocatalytic activity with a low detection limit (0.0437 µM) and good sensitivity (0.6857 μA μM-1 cm-2). The excellent selectivity nature of U-BMO/f-CNF/GCE was observed in the presence of various organic pollutants and a few toxic metal cations. The practical applicability such as stability, repeatability towards 2-NA outcomes with accepted results. Besides, the practical viability of as proposed U-BMO/f-CNF sensor was investigated in soil and lake water samples delivers good recovery results. Hence from these analyses, we conclude that U-BMO/f-CNF/GCE potential for the determination of hazardous environmental pollutant 2-NA.

The use of crystal facets of photocatalysts is well known as a promising strategy for the design of new photocatalysts with interesting physicochemical features for energy production applications. In this work, Bi2MoO6 thin films were synthesized by two methods, electrodeposition and sonoelectrodeposition. Preferential growth orientation depended on synthesis method. Results suggested that sonoelectrodeposition led to dominate the crystal facet {1 0 0} growth with self-assembled nanoplate morphologies while growth orientation in the {0 1 0} facet was dominant in electrodeposition in the absence of ultrasonic waves. As a highlight result, the {1 0 0} facet shows a smaller band gap, higher photocatalytic water splitting than the {0 1 0} facet. Efficient separation of charge pairs and long life time of photogenerated electrons was observed to be intrinsic features of the {1 0 0} facets. The higher charge transfer was confirmed by a higher photocurrent from linear sweep voltammetry and a smaller Nyquist radius arc. Ultrasound plays a key role in growth orientation and led to a production of homogeneous films with nanoplates which self-assembled together to form a flower-like structure. While in the absence of ultrasound the film has coral-like structure. Highly stable sonoelectrodeposited films exhibited incident photon-to-electron conversion efficiency (IPCE) of 22.4% at the specific wavelength of 500 nm. The sonoelectrodeposition method could act as a promising method for forming new films with specific crystal facet selection and developing as highly efficient photoanodes for PEC water splitting.

Herein, a systematic study of the enhanced physicochemical properties of lanthanide doped (La-doped) bismuth molybdate (Bi2MoO6) is performed. For this purpose, Bi2MoO6 and La-doped Bi2MoO6 were prepared by the sol-gel method. BiCl3, Na2MoO4·2H2O, and LaCl3·7H2O were taken as the main precursors while sodium dodecyl sulfate was used as a surfactant. Both Bi2MoO6 and La-doped Bi2MoO6 were calcined at 650 °C for 2 h. These prepared materials were characterized by spectroscopic techniques such as UV-VIS, FT-IR, XRD, photoluminescence, XPS, along with other techniques such as SEM, TEM, TGA, etc. The investigation of luminescence behavior revealed that the La-doped Bi2MoO6 nanocomposite exhibited much greater luminescence compared to the undoped Bi2MoO6. The photocatalytic behavior of the prepared materials was explored by studying the degradation of methylene blue (MB) at room temperature. The degradation of MB with Bi2MoO6 and La-doped bismuth molybdate were observed to be 68% and 75% @ 45 s, respectively, indicating an enhancement of catalytic performance due to the La doping.