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Hexagonal molybdenum oxide (h-MoO 3) nanocrystals with a flower-like hierarchical structure have been successfully synthesized by a solution based self assembly route. The as-synthesized h-MoO 3 was recognized as a photocatalyst for the photocatalytic degradation of methylene blue (MB) under various experimental conditions. Initially, the as-synthe...
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... width at half maximum (FWHM) of respective (hkl) planes. To determine the crystallite size, graph was plotted between (b hkl cosy hkl ) 2 along Y axis and (4 siny hkl ) 2 along X-axis. From the linear fit to the data, D hkl was extracted from the Y-intercept and the crystallite size is found to be 46 nm. The FT-IR spectrum of h-MoO 3 is shown in Fig. 2. The vibrational peaks observed between 1000 cm À1 and 900 cm À1 , is ascribed to MoQO characteristic stretching vibration of the hexagonal phase. 29 A broad and complex band peaked at 600 cm À1 corresponds to the Mo-O vibration of h-MoO 3 . A small band ...
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... Science & Technology at 3434 cm À1 and a sharp band at 1616 cm À1 correspond to the stretching and the bending vibrations of hydrogen bonded -OH group of water molecules. The distinct peaks at 3219 cm À1 and at 1404 cm À1 are attributed to the stretching and the bending vibrations of N-H in NH 4 + (inset Fig. 2). 30,31 Particle morphology, elemental and size ...
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... Still, a few reports have also used them to decontaminate water [14]. Even though several reports are available which are explaining the amazing photocatalytic activity of molybdenum trioxide (MoO3) [15], though, few studies are there to examine the photocatalytic activity of MoO2 [16]. Surface active ingredients are important tools to carve the morphological structure of nanoparticles, which in turn alters the property of material [17]. ...
This work reports the synthesis of molybdenum nanoparticles (Mo NPs) through green routes using horse gram seed extracts and characterized by GC-MS, electronic (UV-visible) spectroscopy, IR, XRD and SEM techniques. Their potent applications as in vitro anticancer agent against HeLa cell lines and photocatalytic degradation of methyl orange (MO) and methyl violet (MV) dyes were also evaluated. The anti-malignant properties of Schiff base ligands [2-fluorobenzaldehyde semicarbazone (L1H) and 2-fluorobenzaldehyde thiosemicarbazone (L2H) with molybdenum metal precursor [dioxobis(2,4-pentanedionato)molybdenum] were also explored and their Mo complexes after conversion into nano form as both ligands, L1H and L2H approve their binding property based on molecular docking studies.
... XRD peak shifting can be caused by lattice strain, crystal structural defects, and changes in inter-planar distance. According to Chithambararaj et al. [12], strain in the lattice structures might alter the inter-planar distance, causing the peak location to move. After gamma irradiating the WO3 films, the inter planer distance of WO3 for the (200) plane rises from 3.6457 Å to 3.6671 Å at 600mJ and from 3.6774Å to 3.7086Å at 800mJ. ...
... The activation energy Ea1 and Ea2 for WO3 films decreased after gamma irradiation; it also decreased with the increase of the laser energy, as seen in Table 5. This may be due to the increase in absorption and the decrease in energy gap with gamma irradiation and as the laser energy increased [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. Figure 8: Arrhenius plot of the conductivity for the un-irradiated and gamma irradiated WO3 thin films at laser energies of (600 and 800)mJ. ...
The deposition process and investigation of the physical properties of tungsten trioxide (WO3) thin films before and after gamma irradiation are presented in this paper. The WO3 thin films were deposited, using the pulse laser deposition technique, on glass substrates at laser energies of 600mJ and 800mJ. After deposition, the samples were gamma irradiated with Co60. The structural and optical properties of polycrystalline WO3 thin films are presented and discussed before and after 5kGy gamma irradiation at the two laser energies. X-ray diffraction spectra revealed that all the films consisted of WO3 crystallized in the triclinic form; the dislocation density and lattice strain increased with the absorbed dosage of gamma irradiation. The optical constants, the average diameter and the surface roughness of the WO3 films were calculated before and after gamma irradiation and for the two laser energies. It was found that the WO3 thin films conductivity increased by γ-irradiated and with the increase of the laser energy.
... The estimated photocurrent rate constants using a simple first-order kinetic approach also demonstrated the slower photocurrent decay for g-C 3 N 4 /MoO 3 , compared to the bare semiconductor ( Figure S3). This is in line with the matched band alignment reported in the literature for both semiconductors [19,44,45]. It also confirms that the preparation of the heterojunction via a solid-state dispersion of both phases is adequate to provide a close interfacial contact between them and to facilitate the flow of the charge carriers in the solid state without the need of a mediator in solution. ...
... It has a band gap of 2.8-3.6 eV, depending on the oxygen vacancies. The relatively low VB edge level of MoO 3 has a strong oxidation ability (i.e., the high oxidation power of photoholes), but the electrons in the CB edge are unable to reduce water to hydrogen due to slow electron mobility [45][46][47][48]. This causes the surface accumulation of electrons in the CB upon illumination of MoO 3 , increasing the recombination rate and ultimately reducing the photocatalytic performance. ...
The adequate optical properties, low cost, and thermal stability of graphitic carbon nitride and molybdenum oxide make them both promising materials for photocatalytic applications. However, they both suffer from strong recombination of their photogenerated charge carriers. Therefore, searching for strategies that enable an efficient charge carrier separation is desirable for improving the photocatalytic performance of both semiconductors. In this work, we have synthesized a g-C3N4/MoO3 heterojunction by a facile solid dispersion approach to the pristine semiconductors that allows a uniform dispersion of the two phases in the heterojunction. The resulting hybrid photocatalyst exhibits light absorption features similar to pristine g-C3N4 and presents an improved separation of the photogenerated charge carriers, likely through a Z-scheme between both semiconductor phases, as inferred by photoelectrochemical measurements. As a result, the g-C3N4/MoO3 heterojunction showed better photocatalytic activity than the individual semiconductors and good cycling stability for the degradation of methylparaben and its reaction intermediates. We drew these conclusions based on total organic carbon (TOC) measurements.
... The preferred orientation (200) moved towards a smaller diffraction angle, 2θ, compared to the pure BaO sample that had lesser absorbed doses of 25 kGy and 50 kGy. Moreover, the position of prominent peak (200) of irradiated BaO is 42.92 • for 75 kGy, which moved towards a higher diffraction angle, 2θ respect to pristine BaO sample as seen in Fig. 2. Strains in the lattice framework and changing inter-planar distance values are the causes of this shift phenomenon [24]. Fig. 2 illustrates how the intensity of the (200) peak gradually declined as the overall absorbed dose of gamma-rays increased. ...
In this current assessment, BaO synthesized from Moringa Oleifera leaves were irradiated using 0–75 kGy gamma radiation and investigated its physical impacts. The x-ray diffraction (XRD) data demonstrated the synthesis of tetragonal BaO, and no phase deviation was observed after irradiation. As doses are increased, the overall crystallite size were decreased due to an increase in defects and disorders. The tetragonal BaO was evident in Fourier transform infrared (FTIR) spectra prior to and following irradiation, while peak intensities and wavenumbers varied considerably. The as-prepared BaO showed a spherical shape morphology, and Field emission scanning electron microscopy (FESEM) indicated no vital deviations in it after irradiation. As irradiation shifts from 0 to 75 kGy, optical bandgap was increased from 4.55 to 4.93 eV, evaluated using Kubelka-Munk (K-M) equation from UV–vis–NIR spectrophotometer. Opto-electronic and photonic devices have challenges in extreme radiation conditions, such as space and nuclear environments. So, these assessments suggested that BaO can withstand high levels of gamma photon and could be a good option for photonic and optoelectronic instruments in an extreme gamma-ray exposed conditions.
... Molybdenum oxide, namely MoO 3 , is a substantially used key component in the photochemical research. It shows wider applications in the fields of sensors, batteries (LIB), organic solar cells and light emitting diodes, electrochromic and spintronics devices, pollutant degradation, CO 2 reduction, catalytic oxidation of O 2 , H 2 evolution, magneto-optic devices and as photocatalyst [11][12][13][14][15][16][17]. The primary setback that leads to e − /h + pair recombination, low conversion potency and low absorption is larger bandgap, which is evident in the absorption of only UV light and thereby hinders the efficacy of the catalyst. ...
Over the past few decades, metal oxides have attracted significant research attention due to their wide-ranging applicability in nearly every field of study. In the present study, we focus on photochemical reactions promoted by using nanoscale MoO3, TiO2 and MoO3/TiO2 nanocomposite. The nanocomposite facilitated charge separation and elevated photo-destruction efficiency of [Cu(dien)(1-MeIm)Cl]Cl complex in a mixed solvent medium via an interlayer pathway. The synthesized complex and the nanomaterials were validated by various instrumental techniques. The lifetime of charge carriers (τ = 36 ns) is higher than bare materials proving its superior photo efficacy. Introduction of 40% acetonitrile (ACN:H2O) solvent gave a higher photoreduction rate constant for Cu(II) complex by MoO3/TiO2 (5.733 × 10–2 s⁻¹) denoting the better photocatalytic nature of nanocomposite rather than the prepared bare nanomaterials. The findings from the study unambiguously reveal that even a small amount of surface incorporation significantly shifts the material for blue LED application. Thus, it paves the way for unleashing its diverse uses, comprehending its distinctive attributes and investigating its possibilities.
... Crystallite size was calculated by plotting the graph of (β*/ d*) 2 along Y-axis and β*/d* 2 X-axis and determined from the slope of the linear fit, while micro-deformation was determined by the Y-axis intercept. [26] The crystallite size of PdÀ NiTiO 3 was found of the order 39 � 2 nm and in the case of PtÀ NiTiO 3 , it is of the order of 38 � 2 nm. When crystals grow larger, the lattice strain also decreases. ...
... [11] When Ni 2 + , Pd 2 + , and Pt 2 + ions are concatenated with NiTiO 3 , lattice distortions occur, giving rise to peak shifting and widening in the Raman spectra, suggesting the formation of PdÀ NiTiO 3 and PtÀ NiTiO 3 heterojunction photocatalysts. This process is illustrated in Figure S2, in which weak Raman peaks appear at 292, 465, 612 and 708 cm À 1 corresponding to NiTiO 3 , in contrast to ten strong peaks observed in the [26,29] The development of progressively distinct Raman peaks observed as the temperature rises, indicating that structural order is increasing. [30] Crystallinity of these titanates were influenced by calcination temperature and duration. ...
... The synthesized NiTiO 3 has a relatively small bandgap value, making it a more visible light harvesting material. [26] The optical properties of titanates did not exhibit any significant trends as a function of Pd or Pt content. ...
Modification of nickel titanate nanocubes with metal nanocrystals is a viable approach to build a Schottky heterojunction for efficient hydrogen generation. The deconvoluted XPS spectrum of Pt 4 f (peaks at 72.0 and 75.5 eV corresponding to Pt° and Pt²⁺) and Pd 3d3/2 (335.4 and 336.7 eV corresponding to Pd° and Pd²⁺) and presence of lattice fringes in HRTEM at 2.19 Å of Pd°, reveal the formation of heterojunction in Pd−NiTiO3 and Pt−NiTiO3 nanocubes. The solar hydrogen generation investigation exhibits 2‐fold enhancement in HER (130 and 165 μmol g⁻¹ h⁻¹ while using Pt−NiTiO3 and Pd−NiTiO3, respectively) than that of bare NiTiO3 (88 μmol g⁻¹ h⁻¹). The creation of heterojunctions between titanates and metal nanoparticles, facilitating efficient transport of photo‐generated electron to empty or partially filled d or f orbitals of metals, thereby lowering electron‐hole recombination rate, as revealed by shorter average lifetime 29 ns (Pd−NiTiO3) than 64 ns (NiTiO3). Further, the unison of faster charge transfer kinetics as revealed by the Nyquist plot, more negative flatband potential (Efb −0.3 vs. RHE) leading to appropriate band bending, reduced overpotential requirement, higher oxygen vacancies (19.46 %) and uniform dispersion of metal atoms on NiTiO3 surfaces that are acting as trapping centers etc. are enabling improved hydrogen generation in the case of Pd−NiTiO3.
... Moreover, MoO 3 nanoparticles exhibit commendable chemical stability and possess excellent metallic electrical conductivity (Fazio et al., 2018). These characteristics have rendered them highly promising candidates for various applications, including gas sensors (Bai et al., 2012), supercapacitors, Liion batteries, chromic devices (Chithambararaj et al., 2013), and electrochemical sensing (Balasubramanian et al., 2019;Fazio et al., 2018;Kamble et al., 2021). In a related study, Patil et al. developed an electrochemical sensor modified with multi-walled carbon nanotubes (MWCNTs) for the detection of CDH in pharmaceutical and urine samples (Patil et al., 2011). ...
... The resulting final product was then collected and subjected to washing with ethanol and DI water. Finally, the collected products were dried in an oven at 45 °C for a period of 30 min, thus yielding the desired nanostructured MoO 3 nanorods (Chithambararaj et al., 2013). ...
... These nuclei then undergo anisotropic growth, facilitated by the presence of NH 4 + and OH − at the edges and corners, ultimately yielding a one-dimensional (1D) crystal structure. In the subsequent stage, the 1D nanostructures self-assemble via Ostwald's ripening, culminating in the formation of hexagonal nanorods composed of MoO 3 (Chithambararaj et al., 2013). ...
Insufficient research has been conducted on the comprehensive detection of cetirizine dihydrochloride (CDH) in water bodies, while also overlooking the exploration of response time. Addressing these research gaps is crucial to enhance our understanding and detection capabilities of CDH in water. Consequently, the objective of this study was to develop an electrochemical sensor utilizing molybdenum trioxide (MoO3) nanointerfaced glassy carbon working electrode for the sensitive detection of CDH in water samples. The characterization of the MoO3 nanorods was conducted through morphological analysis using scanning electron microscopy, structural examination employing X-ray diffraction, and elemental analysis utilizing X-ray photoelectron spectroscopy. The integration of the MoO3 nanointerfaced sensor resulted in an enhanced electrochemical response during cyclic voltammetry, amperometry, and differential pulse voltammetry, attributed to its catalytic activity, electron transfer capability, and conductive nano-bioenvironment. The sensor demonstrated a detection potential of 0.927 V (vs Ag/AgCl) within a rapid response time of less than 50 s. Furthermore, the linear range of detection spanned from 10 to 70 µM, with a limit of detection as low as 194 ± 1.25 nM. The remarkable anti-interference properties of the MoO3 material further highlight the applicability of the fabricated sensor in real sample analysis. Successful validation of the developed sensor was achieved through the detection of CDH in water samples obtained from the Kaveri River.
... These films also exhibited photoinduced hydrophilicity upon irradiation with 254 nm UV (Fig. S2). Methylene blue was oxidatively degraded by active radicals (•OH, •O 2 − ) and/or H 2 O 2 [42][43][44], and E. coli degradation proceeded via oxidative damage to DNA, proteins, and cell membranes by •OH, •O 2 − , and H 2 O 2 [7,45,46]. Hence, the increase in photocatalytic ability after the weathering test was potentially related to an increase in the number of hydroxyl radicals generated. ...
Transparent and flexible photocatalytic films have attracted considerable attention in recent years. We previously prepared a film with titanium dioxide (TiO 2 ) and an anchor layer of phenylphosphonate-modified polysilsesquioxane (PhPPS-low), which had a phosphonate group and a phenyl substituent; this film exhibited transparency and flexibility. In this study, we reported the differences in the hydroxy group ratio on the phosphorous atoms and the presence or absence of phenylene moieties. Three organophosphonate-modified polysilsesquioxanes (APPS-low, APPS-high, and PhPPS-high) were synthesized. All photocatalytic films using APPS-high, APPS-low, and PhPPS-high exhibited photodegradation of methylene blue and photocatalytic bactericidal effects on Escherichia coli , and hydroxyl radical generation was confirmed. In particular, the photocatalytic film with PhPPS-high showed the highest photocatalytic ability.
... As a result of the disintegration of these aromatic molecules, volatile, low-molecularweight compounds such as CO 2 formed. An overview of the whole process of systematic degradation is shown in Fig. S5 [50]. Furthermore, it was believed that the N-CH 3 the terminal bonding is the first bond in the MB to break, which induce the oxidation of CH 3 into HCOOH or HCHO. ...
Herein, we described for the first time, an efficient biogenic synthesis of APTs-AgNPs using acid protease from Melilotus indicus leaf extract. The acid protease (APTs) has an essential role in the stabilization, reduction, and capping of APTs-AgNPs. The crystalline nature, size, and surface morphology of APTs-AgNPs were examined using different techniques such as XRD, UV, FTIR, SEM, EDS, HRTEM, and DLS analysis. The generated APTs-AgNPs demonstrated notable performance as dual functionality (photocatalyst and antibacterial disinfection). By destroying 91 % of methylene blue (MB) in <90 min of exposure, APTs-AgNPs demonstrated remarkable photocatalytic activity. APTs-AgNPs also showed remarkable stability as a photocatalyst after five test cycles. Furthermore, the APTs-AgNPs was found to be a potent antibacterial agent with inhibition zones of 30(±0.5 mm), 27(±0.4 mm), 16(±0.1 mm), and 19(±0.7 mm) against Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria, respectively, under both light and dark conditions. Furthermore, APTs-AgNPs effectively scavenged 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals, demonstrating their potent antioxidant activity. The outcomes of this study thus demonstrates the dual functionality of APTs-AgNPs produced using the biogenic approach method as a photocatalyst and an antibacterial agent for effective microbial and environmental control.
... Moreover, going beyond the state-of-the-art, we present a systematic investigation of the role of spatial constraint offered by ME droplets on the crystallization of MoO 3 by comparing the results obtained within ME droplets with those by batch approach (i.e., macroreactor), as detailed below. Molybdenum(VI) oxide, a wide band gap semiconductor employed in various fields of application (e.g., photocatalysis [16][17][18], photochromic and electrochromic devices [19][20][21], and gas sensors [22,23]), is known to crystallize in three main polymorphs, depending on the crystallographic arrangement of MoO 6 building blocks: α-MoO 3 , β-MoO 3 , and h-MoO 3 . The thermodynamically stable orthorhombic α-MoO 3 (space group Pnma) is characterized by a 2D layered structure of zigzag chains of MoO 6 distorted octahedra sharing edges and corners [24]. ...
... Molybdenum oxide, possibly hydrated, can be synthesized via chemical precipitation by the acidification of Mo(VI) solutions [16,27,[29][30][31] or via the decomposition of peroxomolybdate precursors [21,[32][33][34]. Its hexagonal polymorph h-MoO 3 is often prepared in hydrothermal conditions [17,21,30,33,34], or, in general, the reported procedures involve heating the reaction mixture above 70-100 • C [16,27,29,31]. ...
... Molybdenum oxide, possibly hydrated, can be synthesized via chemical precipitation by the acidification of Mo(VI) solutions [16,27,[29][30][31] or via the decomposition of peroxomolybdate precursors [21,[32][33][34]. Its hexagonal polymorph h-MoO 3 is often prepared in hydrothermal conditions [17,21,30,33,34], or, in general, the reported procedures involve heating the reaction mixture above 70-100 • C [16,27,29,31]. On the contrary, herein we address the synthesis of crystalline h-MoO 3 at room temperature both in batch conditions (i.e., simple mixing of the precursors) and in the confined space of inverse miniemulsion droplets, to unveil the effects of ME spatial constraint. ...
Enclosed nanoscale volumes, i.e., confined spaces, represent a fascinating playground for the controlled synthesis of inorganic materials, albeit their role in determining the synthetic outcome is currently not fully understood. Herein, we address the synthesis of MoO3 nano- and microrods with hexagonal section in inverse miniemulsion droplets and batch conditions, evaluating the effects of spatial confinement offered by miniemulsion droplets on their crystallization. Several synthetic parameters were systematically screened and their effect on the crystal structure of h-MoO3, as well as on its size, size distribution and morphology, were investigated. Moreover, a direct insight on the crystallization pathway of MoO3 in both synthetic conditions and as a function of synthetic parameters was provided by an in situ time-resolved SAXS/WAXS study, that confirmed the role of miniemulsion confined space in altering the stepwise process of the formation of h-MoO3.
