Pure Spheres Research Articles

A comparative study of femtosecond pulsed laser ablation of meloxicam in distilled water and in air

The increasing prevalence of water insoluble or poorly soluble drugs calls for the development of new formulation methods. Common approaches include the reduction of particle size and degree of crystallinity. Pulsed laser ablation is a clean technique for producing sub-micrometre sized drug particles and has the potential to induce amorphization. We studied the effect of femtosecond pulsed laser ablation (ELI ALPS THz pump laser system: λc = 781 nm, τ = 135 fs) on meloxicam in distilled water and in air. The ablated particles were characterized chemically, morphologically and in terms of crystallinity. We demonstrated that femtosecond laser ablation can induce partial amorphization of the particles in addition to a reduction in particle size. In the case of femtosecond pulsed laser ablation in air, the formation of pure meloxicam spheres showed that this technique can produce amorphous meloxicam without the use of excipients, which is a unique result. We also aimed to describe the ablation processes in both investigated media.

The antibacterial effects of terbium vanadate-silver peroxide nanostructures against surgical wounds infected by Staphylococcus aureus and Pseudomonas aeruginosa infections in a rat model

In this research, terbium vanadate-silver peroxide (TbVO4-AgO) nanostructures were prepared by precipitation method. Glucose was used as the green and biocompatible capping agent to prepare TbVO4-AgO nanostructures, making it more suitable for animal model research. XRD, EDS, SEM, TGA, FT-IR and TEM results confirmed preparation of highly pure spheres like TbVO4-AgO nanostructures with an average size of 38–44 nm. The antibacterial properties of TbVO4-AgO nanostructures againstPseudomonas aeruginosa ATCC 27853 andStaphylococcus aureusATCC 29213 were investigated. Antibacterial properties of TbVO4-AgO nanostructures againstStaphylococcus aureusshowed the values of MIC and MBC are 312 µg/ml and 625 µg/ml, respectively.The case was up to 156 µg/ml for pseudomonas aeruginosa. For further review, then we produced ointment making use of TbVO4-AgO nanostructures and mixing procedure. In animal test step with making a wound in rat, we investigated anti-bacterial properties of ointment made by nonosized material. The findings illustrated that the use of TbVO4-AgO nanostructures ointment in comparison with mupirocin and gentamicin ointment ones along with control group led to decrease of wound area from 1 cm2 to zero in 7 days. The results showed dose-dependent cytotoxicity. Moreover, TbVO4-AgO nanostructures with concentration of 8 mg/ml inhibited the growth of 50% of cells (IC50 = 8000 µg/ml)

Application of the 3D DEM in the modelling of fractures in pre-flawed marble specimens during uniaxial compression

The results of modelling fractures in pre-flawed marble cylinder specimens under uniaxial compression are presented in this study. The discrete element method (DEM) was used to investigate crack propagation and coalescence in marble specimens with pre-existing open cracks at various angles to the horizontal. The results of numerical three-dimensional (3D) simulations were directly compared to laboratory investigations. Pure spheres and clumps composed of spheres mimicking marble were used in mesoscopic fracture estimates. The formation of wing and secondary cracks under load were studied. The influence of smaller grains and the ratio between contact cohesion and contact normal strength were investigated. The geometric qualities of the initial faults and the interlocking effect influenced the strength, post-peak response, and crack propagation patterns in the marble specimens. The computational and experimental results were found to be in satisfactory agreement. The DEM simulations showed that the results were significantly influenced by the ratio of cohesive to tensile normal contact stress. The results also showed a correlation with the particle shape (spheres versus clumps).

Synergistic effect of NiS/g-C3N4 nanocomposite for high‐performance asymmetric supercapacitors

Fabricating a new electrode material with high capacitive aspects is critical to improving a high-performance energy storage device. The transition metal sulfide-based nanocomposite electrode materials are possible for the construction of high-performance hybrid supercapacitors owing to the large surface area and its peculiar Faradic battery-type charge storage behavior. In this work, the NiS/g-C3N4 hybrid was prepared through a one-pot hydrothermal method, and g-C3N4 was synthesized via a thermal method. The NiS/g-C3N4 shows the morphology of both sheet-like g-C3N4 and sphere-like NiS nanostructures. The compacted sheet and sphere structure of NiS/g-C3N4 hybrid composite shows outstanding electrochemical performance as a supercapacitor electrode. Consequently, the prepared NiS/g-C3N4 hybrid composite electrode materials reach their superior specific capacity (Cs) at 2661.25 C g−1 at 1 A g−1 in 3 M KOH aqueous electrolyte, which is comparatively higher than that of pure NiS spheres (722.50 C g−1 at 1 A g−1). The assembled NiS/g-C3N4//AC Hybrid device (HD) exhibited a maximum specific capacity of 181.8 C g−1 at 1 A g−1 and their energy density and power density of 53.09 W h kg−1 and 31537.5 W kg−1, respectively. The constructed NiS/g-C3N4//AC Hybrid device delivers outstanding cyclic retention of 95% after 10,000 cycles. The above results suggest that the NiS/g-C3N4 hybrid composite has good chemical stability, cyclic retention, and auspicious electrode material for the next generation of energy storage applications.

Aldehyde-Functional Diblock Copolymer Nano-objects via RAFT Aqueous Dispersion Polymerization.

We report the rational design of aldehyde-functional sterically stabilized diblock copolymer nano-objects in aqueous solution via polymerization-induced self-assembly. More specifically, reversible addition-fragmentation chain transfer aqueous dispersion polymerization of 2-hydroxypropyl methacrylate is conducted using a water-soluble precursor block in which every methacrylic repeat unit contains a pendent oligo(ethylene glycol) side chain capped with a cis-diol unit. Systematic variation of the reaction conditions enables the construction of a pseudo-phase diagram, which ensures the reproducible targeting of pure spheres, worms, or vesicles. Selective oxidation of the pendent cis-diol groups using aqueous sodium periodate under mild conditions introduces geminal diols (i.e., the hydrated form of an aldehyde obtained in the presence of water) into the steric stabilizer chains without loss of colloidal stability. In the case of diblock copolymer vesicles, such derivatization leads to the formation of a worm population, indicating partial loss of the original morphology. However, this problem can be circumvented by cross-linking the membrane-forming block prior to periodate oxidation. Moreover, such covalently stabilized aldehyde-functionalized vesicles can be subsequently reacted with either glycine or histidine in aqueous solution, followed by reductive amination to prevent hydrolysis of the labile imine bond. ζ potential measurements confirm that this derivatization significantly affects the electrophoretic behavior of these vesicles. Similarly, the membrane-crosslinked aldehyde-functionalized vesicles can be reacted with a model globular protein, bovine serum albumin, to produce "stealthy" protein-decorated vesicles.

Application of solvent evaporation technique for pure drug crystal spheres preparation

An innovative application of the solvent evaporation technique was suggested. Solvent evaporation technique is a technique for drug encapsulation and nanosphere preparation. The widely used technique is also facing the problem of low actual drug entrapment percent, which is not economic from the industrial view. The goal of this work is trying to use the advantage of this technique concerning the product sphericity and the ability to control particle size, to prepare a drug as pure crystals spheres. Ibuprofen is selected as a model drug. The spheres are formed by using Polyvinyl pyrrolidone (PVP) or Polyethylene glycol (PEG) as an anti-aggregating agent but not formed on using tween or span. Particle size and actual drug content depend on the concentrations the anti-aggregating agent used. Surfaces of the drug crystal spheres are porous with empty sphere internal structure on using PVP but spongy and rough on using PEG. The drug has its identity chemical form in the drug crystal spheres. IR scan of spheres prepared on using PEG showed a characteristic ether peak. DSC showed melting endothermic peak of PEG, but X-ray showed minor change in the drug crystal patterns. Drug release profiles from crystal spheres prepared with the same anti-aggregating agent are close to each other. The drug release profiles from drug crystal spheres prepared by using PEG are more controlled than that prepared by using PVP. The drug release mechanism is diffusion. It was concluded that, the same technique could be suggested for preparation of other biomedical material in pure crystals spheres with controlled particle size. These properties may encourage to prepare very small particles with spherical shape for inhalation or injection as an innovative particle technology application for the widely used technique.

Synthesis and Aqueous Solution Properties of Shape-Shifting Stimulus-Responsive Diblock Copolymer Nano-Objects

We report the synthesis of poly(N-(2-acryloyloxyethyl)pyrrolidone)-poly(4-hydroxybutyl acrylate) (PNAEP85-PHBAx) diblock copolymer nano-objects via reversible addition–fragmentation chain transfer (RAFT) aqueous dispersion polymerization of 4-hydroxybutyl acrylate (HBA) at 30 °C using an efficient two-step one-pot protocol. Given the relatively low glass transition temperature of the PHBA block, these nano-objects required covalent stabilization prior to transmission electron microscopy (TEM) studies. This was achieved by core crosslinking using glutaraldehyde. TEM analysis of the glutaraldehyde-fixed nano-objects combined with small-angle X-ray scattering (SAXS) studies of linear nano-objects confirmed that pure spheres, worms or vesicles could be obtained at 20 °C in an acidic aqueous solution by simply varying the mean degree of polymerization (x) of the PHBA block. Aqueous electrophoresis, dynamic light scattering and TEM studies indicated that raising the dispersion pH above the pKa of the terminal carboxylic acid group located on each PNAEP chain induced a vesicle-to-sphere transition. 1H NMR studies of linear PNAEP85-PHBAx nano-objects indicated a concomitant increase in the degree of partial hydration of PHBA chains on switching from pH 2-3 to pH 7-8, which is interpreted in terms of a surface plasticization mechanism. Rheological and SAXS studies confirmed that the critical temperature corresponding to the maximum worm gel viscosity could be tuned from 2 to 50 °C by adjusting the PHBA DP. Such tunability is expected to be useful for potential biomedical applications of these worm gels.

Emergence of Hexagonally Close-Packed Spheres in Linear Block Copolymer Melts.

The hexagonally close-packed (HCP) sphere phase is predicted to be stable across a narrow region of linear block copolymer phase space, but the small free energy difference separating it from face-centered cubic spheres usually results in phase coexistence. Here, we report the discovery of pure HCP spheres in linear block copolymer melts with A = poly(2,2,2-trifluoroethyl acrylate) ("F") and B = poly(2-dodecyl acrylate) ("2D") or poly(4-dodecyl acrylate) ("4D"). In 4DF diblocks and F4DF triblocks, the HCP phase emerges across a substantial range of A-block volume fractions (circa fA = 0.25-0.30), and in F4DF, it forms reversibly when subjected to various processing conditions which suggests an equilibrium state. The time scale associated with forming pure HCP upon quenching from a disordered liquid is intermediate to the ordering kinetics of the Frank-Kasper σ and A15 phases. However, unlike σ and A15, HCP nucleates directly from a supercooled liquid or soft solid without proceeding through an intermediate quasicrystal. Self-consistent field theory calculations indicate the stability of HCP is intimately tied to small amounts of molar mass dispersity (Đ); for example, an HCP-forming F4DF sample with fA = 0.27 has an experimentally measured Đ = 1.04. These insights challenge the conventional wisdom that pure HCP is difficult to access in linear block copolymer melts without the use of blending or other complex processing techniques.

Comparative 3D DEM simulations of sand\u2013structure interfaces with similarly shaped clumps versus spheres with contact moments

Three-dimensional simulations of a monotonic quasi-static interface behaviour between initially dense cohesionless sand and a rigid wall of different roughness during tests in a parallelly guided direct shear test under constant normal stress are presented. Numerical modelling was carried out by the discrete element method (DEM) using clumps in the form of convex non-symmetric irregularly shaped grains. The clumps had an aspect ratio of 1.5. A regular grid of triangular grooves (asperities) along the wall with a different height at the same distance was assumed. The numerical results with clumps were directly compared under the same conditions with our earlier DEM simulations using pure spheres with contact moments with respect to the peak and residual interface friction angle, width of the interface shear zone, ratio between grain slips and grain rotations, distribution of contact forces and stresses. The difference between the behaviour of clumps and pure spheres with contact moments proved to be noticeable in the post-peak regime due to a different particle shape. The rolling resistance model with pure spheres was proved to be limited for capturing particle shape effects. Three different boundary conditions along the interface were proposed for micropolar continua, considering grain rotations and grain slips, wall grain moments and wall grain forces, and normalized interface roughness. The numerical results in this paper offer a better understanding of the interface behaviour of granular bodies in DEM and FEM simulations.

Synthesis of Highly Transparent Diblock Copolymer Vesicles via RAFT Dispersion Polymerization of 2,2,2-Trifluoroethyl Methacrylate in n-Alkanes.

RAFT dispersion polymerization of 2,2,2-trifluoroethyl methacrylate (TFEMA) is performed in n-dodecane at 90 °C using a relatively short poly(stearyl methacrylate) (PSMA) precursor and 2-cyano-2-propyl dithiobenzoate (CPDB). The growing insoluble poly(2,2,2-trifluoroethyl methacrylate) (PTFEMA) block results in the formation of PSMA–PTFEMA diblock copolymer nano-objects via polymerization-induced self-assembly (PISA). GPC analysis indicated narrow molecular weight distributions (Mw/Mn ≤ 1.34) for all copolymers, with 19F NMR studies indicating high TFEMA conversions (≥95%) for all syntheses. A pseudo-phase diagram was constructed to enable reproducible targeting of pure spheres, worms, or vesicles by varying the target degree of polymerization of the PTFEMA block at 15–25% w/w solids. Nano-objects were characterized using dynamic light scattering, transmission electron microscopy, and small-angle X-ray scattering. Importantly, the near-identical refractive indices for PTFEMA (1.418) and n-dodecane (1.421) enable the first example of highly transparent vesicles to be prepared. The turbidity of such dispersions was examined between 20 and 90 °C. The highest transmittance (97% at 600 nm) was observed for PSMA9–PTFEMA294 vesicles (237 ± 24 nm diameter; prepared at 25% w/w solids) in n-dodecane at 20 °C. Interestingly, targeting the same diblock composition in n-hexadecane produced a vesicle dispersion with minimal turbidity at a synthesis temperature of 90 °C. This solvent enabled in situ visible absorption spectra to be recorded during the synthesis of PSMA16–PTFEMA86 spheres at 15% w/w solids, which allowed the relatively weak n→π* band at 515 nm assigned to the dithiobenzoate chain-ends to be monitored. Unfortunately, the premature loss of this RAFT chain-end occurred during the RAFT dispersion polymerization of TFEMA at 90 °C, so meaningful kinetic data could not be obtained. Furthermore, the dithiobenzoate chain-ends exhibited a λmax shift of 8 nm relative to that of the dithiobenzoate-capped PSMA9 precursor. This solvatochromatic effect suggests that the problem of thermally labile dithiobenzoate chain-ends cannot be addressed by performing the TFEMA polymerization at lower temperatures.

The Potential Use of Core-Shell Structured Spheres in a Packed-Bed DBD Plasma Reactor for CO2 Conversion

This work proposes to use core-shell structured spheres to evaluate whether it allows to individually optimize bulk and surface effects of a packing material, in order to optimize conversion and energy efficiency. Different core-shell materials have been prepared by spray coating, using dense spheres (as core) and powders (as shell) of SiO2, Al2O3, and BaTiO3. The materials are investigated for their performance in CO2 dissociation and compared against a benchmark consisting of a packed-bed reactor with the pure dense spheres, as well as an empty reactor. The results in terms of CO2 conversion and energy efficiency show various interactions between the core and shell material, depending on their combination. Al2O3 was found as the best core material under the applied conditions here, followed by BaTiO3 and SiO2, in agreement with their behaviour for the pure spheres. Applying a thin shell layer on the cores showed equal performance between the different shell materials. Increasing the layer thickness shifts this behaviour, and strong combination effects were observed depending on the specific material. Therefore, this method of core-shell spheres has the potential to allow tuning of the packing properties more closely to the application by designing an optimal combination of core and shell.

Shape induced segregation and anomalous particle transport under spherical confinement

Colloidal or nanoparticle mobility under confinement is of central importance for a wide range of physical and biological processes. Here, we introduce a minimal model of particles in a hydrodynamic continuum to examine how particle shape and concentration affect the transport of particles in spherical confinement. Specifically, an immersed boundary-general geometry Ewald-like approach is adopted to simulate the dynamics of spheres and cylinders under the influence of short- and long-range fluctuating hydrodynamic interactions with appropriate non-slip conditions at the confining walls. An efficient O(N) parallel finite element algorithm is used, thereby allowing simulations at high concentrations, while a Chebyshev polynomial approximation is implemented in order to satisfy the fluctuation–dissipation theorem. A concentration-dependent anomalous diffusion is observed for suspended particles. It is found that introducing cylinders in a background of spheres, i.e., particles with a simple degree of anisotropy, has a pronounced influence on the structure and dynamics of the particles. First, increasing the fraction of cylinders induces a particle segregation effect, where spheres are pushed toward the wall and cylinders remain near the center of the cavity. This segregation leads to a lower mobility for the spheres relative to that encountered in a system of pure spheres at the same volume fraction. Second, the diffusive-to-anomalous transition and the degree of anomaly quantified by the power law exponent in the mean square displacement vs time relation both increase as the fraction of cylinders becomes larger. These findings are of relevance for studies of diffusion in the cytoplasm, where proteins exhibit a distribution of size and shapes that could lead to some of the effects identified in the simulations reported here.

Self-assembly synthesis of CuO/ZnO hollow microspheres and their photocatalytic performance under natural sunlight

The ZnO nanostructure is difficult to apply in sewage treatment because of its low photocatalytic efficiency, narrow spectrum response, high photogenerated carrier recombination rate, and difficult retrieval from aqueous solution. CuO coupling could improve both the absorption of visible light and photocatalytic performance of ZnO nanoparticles. In this paper, the ZnO/CuO hollow microspheres was fabricated by a self-assembly method without a template. The experimental results showed that ZnO/CuO hollow microspheres (4 μm) were successfully prepared via the hydrothermal method. CuO coupling greatly ameliorated the photocatalytic performance of ZnO microspheres under natural solar light or visible light, and the photodegrading rate in natural solar light was approximately 6 times greater than that of pure ZnO spheres. In addition, ZnO/CuO spheres showed good photocatalytic stability. The enhanced catalytic activity is associated with the reduced impedance of the ZnO sphere via CuO coupling, which promotes the separation of e−/h+ carriers and enlarges the spectrum response to visible light.

Synthesis and in vitro biodegradation of pure octacalcium phosphate spheres

AbstractOctacalcium phosphate (OCP) is a key precursor of biological apatite in hard tissues with excellent osteoconductive and biodegradable properties for bone regeneration. OCP spherical granules are expected to be useful as drug delivery carriers, since OCP has high specific surface area. Although there have been some reports of OCP sphere preparation, methods for preparing pure OCP spheres are limited. The objective of this study is the preparation of spherical granules of pure OCP and assessment of their in vitro biodegradation in physiological conditions. We successfully prepared spherical pure OCP granules with a size of ~500 µm without any organic additives by simple immersion of α‐tricalcium phosphate spherical granules in pH 5.0 acetate buffered solutions at 60°C. The granules had core‐shell structure composed of OCP crystals different particle size. The spherical granules showed 20%‐40% in vitro degradation in physiological conditions; however, the phase transition of OCP was not significantly observed.

Utilization of a CO2 Storage Material: Shape-Controlled Preparation of CaCO3 Microspheres

Homogeneous CaCO3 microspheres were controllably synthesized via a simple hydrothermal method without using extraneous additives by Ca(OH)2 saturated solution reacted with CO2 storage material (CO2SM), which was obtained by absorbing CO2 gas in a system containing equimolar ethylenediamine (EDA) and polyethylene glycol 400 (PEG). Specifically, homogeneous pure vaterite spheres were obtained by using 160 g/L CO2SM solution at 100 °C and a reaction time of two hours. It is noteworthy that the EDA and PEG, which are released from CO2SM, have dual functions as a CO2 absorber and crystal regulator in the process of controlling the crystallization of CaCO3 crystals.

Mucin adsorption on vaterite CaCO3 microcrystals for the prediction of mucoadhesive properties

Porous vaterite CaCO3 crystals are widely used as containers for drug loading and as sacrificial templates to assemble polymer-based nano- and micro-particles at mild conditions. Special attention is paid nowadays to mucosal delivery where the glycoprotein mucin plays a crucial role as a main component of a mucous. In this work mucoadhesive properties of vaterite crystals have been tested by investigation of mucin binding to the crystals as a function of (i) time, (ii) glycoprotein concentration, (iii) adsorption conditions and (iv) degree of mucin desialization. Mucin adsorption follows Bangham equation indicating that diffusion into crystal pores is the rate-limiting step. Mucin strongly binds to the crystals (ΔG = −35 ± 4 kJ mol−1) via electrostatic and hydrophobic interactions forming a gel and thus giving the tremendous mucin mass content in the crystals of up to 16%. Despite strong intermolecular mucin-mucin interactions, pure mucin spheres formed after crystal dissolution are unstable. However, introduction of protamine, actively used for mucosal delivery, makes the spheres stable via additional electrostatic bonding. The results of this work indicate that the vaterite crystals are extremely promising carriers for mucosal drug delivery and for development of test-systems for the analysis of the mucoadhesion.

Phase Per Colation Transition and Emission of Excitons in Films With CdS Quantum Dots on SiO2 Surface

Topologically disordered films based on binary mixtures of SiO2 nanoparticles with CdS quantum dots on their surface with different surface and volume concentrations are studied. For the first time, a percolation transition of excitons has been observed in the CdS quantum dots array on a quasi-two-dimensional surface and the features of its formation have been described qualitatively. A percolation transition of excitons in a fi lm based on a binary mixture of pure SiO2 spheres and those coated with quantum dots (SiO2/CdS), which is analogous to the phase transition of metal and dielectric macroparticles, has also been observed. It is shown that the percolation transition in such a system occurs at a critical concentration of nanoparticles of one sort (nc ~ 0.6), which is almost twice as high as in the macroparticle system (~0.29). This is due to the interaction between nanoparticles (van der Waals forces and electrostatic forces) and the chemical nature of the binding ligand.

Improved capacitance of NiCo2O4/carbon composite resulted from carbon matrix with multilayered graphene

The optimized electric and ionic conductivity of metal oxides with pseudo-capacitive properties can greatly improve their electrochemical performances and can effectively amplify their applications in super-capacitors. Carbon spheres with multilayered graphene formed in their matrix are prepared by annealing them with sodium metal and they are combined with NiCo2O4 spheres by a simple hydro-thermal treatment. Structures and electrochemical performances of resulted samples are examined with X-ray diffraction, Raman scattering spectra, X-ray photoelectron spectroscopy, infrared spectroscopy, electron microscopy, gas physisorption, cyclic voltammetry and electrochemical impedance spectra, respectively. The largest specific capacitance of resulted composites is measured about 920 F g−1 at 1 A g−1, which is about 3.7 times larger than that of pure carbon spheres and 2.8 times larger than that of pure NiCo2O4 spheres. The formation of multilayered graphene in the matrix of carbon spheres not only increases the high specific capacitance based on electric double layers, but also makes metal oxides combined with them display greatly increased pseudo-capacitance. The electric and ionic conductivity of resulted composites with various weight ratios of NiCo2O4 and carbon spheres are respectively investigated and their effects on their electrochemical performances are also discussed.

A novel approach to produce monodisperse hollow pure silica spheres

In this work, we report an efficient method to produce pure hollow silica spheres (HSS) using phenyltrimethoxysilane (PTMS) compound. The production of HSS was carried out via hydrolysis of PTMS in the aqueous media and followed by a condensation reaction to form silica spheres with phenyl groups. The product was then calcined to remove phenyl groups and obtain pure silica spheres with >95% fine structure. The chemical nature of pure silica was confirmed by Fourier transforms infrared spectroscopy. The calcined HSS were stable beyond the temperature of 900 °C as confirmed by thermal gravimetric analysis (TGA). The calcined spheres preserved their spherical appearance and hollow core as shown by SEM and TEM micrographs. Interestingly, the average size of the spheres was reduced significantly after calcination from 760 to 510 nm, confirming further the removal of phenyl groups. The calcined HSS offered much higher surface area (As) when analysed by BET; As for calcined product was ∼406 and mere ∼4.8 m2/g for uncalcined HSS. Finally, drug release study of cisplatin/HSS showed over 45% of steady cumulative release for 72 h. The prepared HSS can be dispersed in water opening the possibility of many novel bio/non-bio applications.

Surface-plasmon-enhanced ultraviolet emission of Au-decorated ZnO structures for gas sensing and photocatalytic devices.

Pure and Au-decorated sub-micrometer ZnO spheres were successfully grown on glass substrates by simple chemical bath deposition and photoreduction methods. The analysis of scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images, energy-dispersive X-ray spectroscopy (EDS), UV–vis absorption, and photoluminescence (PL) spectra results were used to verify the incorporation of plasmonic Au nanoparticles (NPs) on the ZnO film. Time-resolved photoluminescence (TRPL) spectra indicated that a surface plasmonic effect exists with a fast rate of charge transfer from Au nanoparticles to the sub-micrometer ZnO sphere, which suggested the strong possibility of the use of the material for the design of efficient catalytic devices. The NO2 sensing ability of as-deposited ZnO films was investigated with different gas concentrations at an optimized sensing temperature of 120 °C. Surface decoration of plasmonic Au nanoparticles provided an enhanced sensitivity (141 times) with improved response (τRes = 9 s) and recovery time (τRec = 39 s). The enhanced gas sensing performance and photocatalytic degradation processes are suggested to be attributed to not only the surface plasmon resonance effect, but also due to a Schottky barrier between plasmonic Au and ZnO structures.