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At least 865 records · Page 48
All sourcesNASA NTRSDOE OSTI
DOE OSTI2017

Surface nanostructuring in the carbon–silicon(100) system upon microwave plasma treatment

The study is concerned with the physical and chemical processes and the mechanisms of the effect of plasma preparation of a surface on the systematic features of condensation and surface phase transformations during the formation of Si–C mask domains on p-Si(100) crystals by the deposition of submonolayer C coatings in the microwave plasma of low-pressure ethanol vapors. It is shown that, at short durations of the deposition of carbon onto silicon wafers with a natural-oxide coating at a temperature of 100°C, the formation of domains is observed. The lateral dimensions of the domains lie in the range from 10–15 to 200 nm, and the heights of ridges produced by the plasma chemical etching of silicon through the mask domain coatings vary in the range from 40 to 80 nm.

36 MATERIALS SCIENCE↗
DOE OSTI2024

Tomography of entangling two-qubit logic operations in exchange-coupled donor electron spin qubits

Scalable quantum processors require high-fidelity universal quantum logic operations in a manufacturable physical platform. Donors in silicon provide atomic size, excellent quantum coherence and compatibility with standard semiconductor processing, but no entanglement between donor-bound electron spins has been demonstrated to date. Here we present the experimental demonstration and tomography of universal one- and two-qubit gates in a system of two weakly exchange-coupled electrons, bound to single phosphorus donors introduced in silicon by ion implantation. We observe that the exchange interaction has no effect on the qubit coherence. We quantify the fidelity of the quantum operations using gate set tomography (GST), and we use the universal gate set to create entangled Bell states of the electrons spins, with fidelity 91.3 ± 3.0%, and concurrence 0.87 ± 0.05. These results form the necessary basis for scaling up donor-based quantum computers.

42 ENGINEERING↗
DOE OSTI2016

Thermal aging effect of vanadyl acetylacetonate precursor for deposition of VO{sub 2} thin films with thermochromic properties

Highlights: • 7 day aged VO(acac){sub 2} sol shows enhanced adhesivity on the SiO{sub 2} compared with non-aged sol. • The aging process has significantly affected the morphologies of VO{sub 2} films. • From the FT-IR spectra, thermal aging process provides the deformation of precursor. • The metal insulator transition (MIT) efficiency (ΔT{sub at2000} {sub nm}) reached a maximum value of 51% at 7 day aging. • Thermal aging process could shorten the aging time of sol solution. - Abstract: Thermochromic properties of vanadium dioxide (VO{sub 2}) have been studied extensively due to their IR reflection applications in energy smart windows. In this paper, we studied the optical switching property of VO{sub 2} thin film, depending on the thermal aging time of the vanadyl acetylacetonate (VO(acac){sub 2}) precursor. We found the alteration of the IR spectra of the precursor by tuning the aging time as well as heat treatments of the precursor. An aging effect of vanadium precursor directly affects the morphologies, optical switching property and crystallinity of VO{sub 2} films. The optimum condition was achieved at the 7 day aging time with metal insulator transition (MIT) efficiency of 50%.

36 MATERIALS SCIENCE↗
DOE OSTI2011

A tetrahedron beam computed tomography benchtop system with a multiple pixel field emission x-ray tube

Purpose: To demonstrate the feasibility of Tetrahedron Beam Computed Tomography (TBCT) using a carbon nanotube (CNT) multiple pixel field emission x-ray (MPFEX) tube. Methods: A multiple pixel x-ray source facilitates the creation of novel x-ray imaging modalities. In a previous publication, the authors proposed a Tetrahedron Beam Computed Tomography (TBCT) imaging system which comprises a linear source array and a linear detector array that are orthogonal to each other. TBCT is expected to reduce scatter compared with Cone Beam Computed Tomography (CBCT) and to have better detector performance. Therefore, it may produce improved image quality for image guided radiotherapy. In this study, a TBCT benchtop system has been developed with an MPFEX tube. The tube has 75 CNT cold cathodes, which generate 75 x-ray focal spots on an elongated anode, and has 4 mm pixel spacing. An in-house-developed, 5-row CT detector array using silicon photodiodes and CdWO{sub 4} scintillators was employed in the system. Hardware and software were developed for tube control and detector data acquisition. The raw data were preprocessed for beam hardening and detector response linearity and were reconstructed with an FDK-based image reconstruction algorithm. Results: The focal spots were measured at about 1 x 2 mm{sup 2} using a star phantom. Each cathode generates around 3 mA cathode current with 2190 V gate voltage. The benchtop system is able to perform TBCT scans with a prolonged scanning time. Images of a commercial CT phantom were successfully acquired. Conclusions: A prototype system was developed, and preliminary phantom images were successfully acquired. MPFEX is a promising x-ray source for TBCT. Further improvement of tube output is needed in order for it to be used in clinical TBCT systems.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2018

Microstructural Evolution and Mechanical Behavior of Lead-Free Silicon Brass Manufactured by Low-Pressure Die Casting

Low-pressure die casting (LPDC) has been widely used to process aluminum and magnesium alloys; however, it has yet to be applied to manufacture brass alloys. This study investigates the microstructural evolution and mechanical behavior of a lead-free CuZnSiAl silicon brass via a variable-controlling approach on the basis of a faucet casting by LPDC. The manufactured silicon brass castings are predominantly composed of bcc β-CuZn(Si, Al) and minor fcc α-Cu(Zn, Si) solid solutions. The silicon brass castings also predominantly exhibit short rod-like or granular α phases, which distinctly differ from the acicular α morphology obtained by conventional gravity casting. The manufactured silicon brass castings which contain finer β grains and short rod-like or granular α phase exhibit superior mechanical properties. Their optimal mechanical properties—elongation of 15.0%, yield strength of 359.8 MPa, and ultimate tensile strength of 598.9 MPa—are far superior to those of the typical lead brass HPb59-1. The results obtained in this study provide insight into the manufacture and design of lead-free silicon brass castings by LDPC.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Tutorial on forming through-silicon vias

Through-silicon vias (TSVs) are a critical technology for three-dimensional integrated circuit technology. These through-substrate interconnects allow electronic devices to be stacked vertically for a broad range of applications and performance improvements such as increased bandwidth, reduced signal delay, improved power management, and smaller form-factors. There are many interdependent processing steps involved in the successful integration of TSVs. This article provides a tutorial style review of the following semiconductor fabrication process steps that are commonly used in forming TSVs: deep etching of silicon to form the via, thin film deposition to provide insulation, barrier, and seed layers, electroplating of copper for the conductive metal, and wafer thinning to reveal the TSVs. Recent work in copper electrochemical deposition is highlighted, analyzing the effect of accelerator and suppressor additives in the electrolyte to enable void-free bottom-up filling from a conformally lined seed metal.

42 ENGINEERING↗
DOE OSTI2022

Degradation of Edge-Defined Film-Fed Silicon Glass–Glass Modules on Florida Rooftop After 22 Years

Thin silicon (< 100 μm) adoption can provide significantly lower cost. Kerfless technologies provide thin wafers while preventing material from being wasted. Understanding how this family of processing influences module reliability is important. A set of four edge-defined film-fed growth (EFG) silicon modules from a ten-module system in Florida is measured after 22 years of exposure. Power loss rates of 0.58–0.78% year -1 are measured for three modules, while a rate of 1.32% is measured for a module with severe delamination and corrosion. Short-circuit current degrades between 10.7% and 13.1% for all modules. Further, the losses are primarily optical and recombination based; however, series and shunt resistance effects play a non-negligible role. Pre-existing recombination losses exist but are exacerbated via degradation. Optical losses in short-circuit current are due in part to encapsulant yellowing. Electroluminescence (EL) images display the effects of processing on bulk quality by clearly showing lines of alternating brightness along the wafer length. To the authors’ knowledge, this is the first article displaying suns–V OC data, effective lifetime versus excess carrier density data, and module EL images for EFG silicon-based modules.

36 MATERIALS SCIENCE↗
DOE OSTI2014

Controllable synthesis of hollow mesoporous silica spheres and application as support of nano-gold

Hollow silica spheres with mesoporous structure were synthesized by sol–gel/emulsion method. In the process, the surfactant, cetyltrimethylammonium bromide (CTAB) was used to stabilize the oil droplet and also used as structure direct agent. The diameter of the hollow silica spheres, ranging from 895 nm to 157 nm, can be controlled by changing the ratio of ethanol to water and the concentration of the surfactant as well. The shell thickness of the spheres decreased when the ratio of ethanol to water decreased. The proposed mechanism of the formation of silica spheres could elucidate the experimental results well. Furthermore, the resultant hollow mesoporous silica spheres were then employed as support of nano-gold which was used to catalyze the isomerization reaction of propylene oxide to produce allyl alcohol. - Graphical abstract: It is the schematic mechanism for the formation of hollow mesoporous silica spheres. - Highlights: • The formation mechanism of the hollow spheres is proposed. • The isomerization of propylene oxide can be catalyzed by the nano-gold/SiO{sub 2}. • The hollow silica spheres can be prepared controllably.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2014

Structural, optical and waveguiding properties improvement of SiO{sub 2}/TiO{sub 2} Bragg reflectors processed by the sol–gel method under the effect of Ni-doped TiO{sub 2} and annealing duration

Highlights: • The formation of anatase phase only, whatever are Ni content and annealing duration. • Transmission and PL spectra redshifted with Ni content and annealing duration. • PL lowering with Ni content is due to the recombination rate of electron–hole reduction. • Annealing duration increases the recombination rate and then the PL intensity rises. • Increasing Ni content improves waveguiding properties and then two TE modes appear. - Abstract: We investigated the nickel doped TiO{sub 2} layer and annealing duration effects on SiO{sub 2}/TiO{sub 2} Bragg reflectors. The films crystallize in pure anatase phase whatever is the Ni content and the annealing duration. In UV–vis-NIR analyses, variations of width, position and transmission coefficient of the stop-band were observed. The PL spectra red-shifted when the Ni content and annealing duration increased. As the annealing duration increases, an additional sharp emission peak appears around 867 nm, indicating a reduced number of defects. As Ni content increased, the M-lines spectroscopy shows two transverse electric polarization guided modes TE{sub 0} and TE{sub 1}, which indicates a decreased refractive index and an increased film thickness.

36 MATERIALS SCIENCE↗
DOE OSTI2014

Trivalent chromium removal from aqueous solutions by a sol–gel synthesized silica adsorbent functionalized with sulphonic acid groups

Highlights: • Corpuscular sulphonic acid-functionalized silica holds improved uptake of chromium. • Mesopores on adsorbent facilitate (CH{sub 3}COO){sub 2}Cr{sup +} ion uptake on sulphonate sites. • Formation of chromium acetate sulphonate complex proposed from XPS results. • Fixed bed chromium uptake results suggest potential industrial use. - Abstract: A high capacity hybrid silica adsorbent was synthesized via sol–gel processing with sulphonic acid groups as trivalent chromium complex ions chelators from aqueous solutions. The synthesis included co-condensation of tetraethoxysilane (TEOS) with 3-(mercaptopropyl)trimethoxysilane (MPS), and oxidation of thiol to sulphonic acid groups. Chromium uptake kinetic, batch and fixed-bed experiments were performed to assess the removal of this metal from aqueous solutions. {sup 13}C, {sup 29}Si CPMAS NMR, FTIR, XPS were used to characterize the adsorbent structure and the nature of chromium complexes on the adsorbent surface. Chromium maximum uptake was obtained at pH 3 (72.8 mg/g). Elemental analysis results showed ligand density of 1.48 mmol sulphonic groups/g. About 407 mL of Cr(III) solution (311 mg/L) were treated to breakthrough point reaching ≤0.06 mg/L at the effluent. These results comply with USEPA regulation for chromium concentration in drinking water (≤0.1 mg/L). The adsorbent shows potential to be used in chromium separations to the industrial level.

36 MATERIALS SCIENCE↗
DOE OSTI2010

Improved growth of GaN layers on ultra thin silicon nitride/Si (1 1 1) by RF-MBE

High-quality GaN epilayers were grown on Si (1 1 1) substrates by molecular beam epitaxy using a new growth process sequence which involved a substrate nitridation at low temperatures, annealing at high temperatures, followed by nitridation at high temperatures, deposition of a low-temperature buffer layer, and a high-temperature overgrowth. The material quality of the GaN films was also investigated as a function of nitridation time and temperature. Crystallinity and surface roughness of GaN was found to improve when the Si substrate was treated under the new growth process sequence. Micro-Raman and photoluminescence (PL) measurement results indicate that the GaN film grown by the new process sequence has less tensile stress and optically good. The surface and interface structures of an ultra thin silicon nitride film grown on the Si surface are investigated by core-level photoelectron spectroscopy and it clearly indicates that the quality of silicon nitride notably affects the properties of GaN growth.

36 MATERIALS SCIENCE↗
DOE OSTI2010

Reactive solid-state dewetting of Cu-Ni films on silicon

The behavior of a 50 nm Cu-Ni alloy film on Si in a process of reactive solid-state dewetting is presented. The films were annealed at a range of temperatures (300-700 deg. C) in 1%H{sub 2} 99%N{sub 2} reducing atmosphere. The resulting alloy and silicide particles formed by film dewetting and film reaction with the substrate were distinguished by selective wet etching and examined by scanning electron microscopy and spectroscopy. After potassium hydroxide etch, regions that etch slower than silicon substrate have distribution statistics similar to the alloy and silicide particles prior to their removal, indicating strong coupling between mass transport across the interface and along the surface.

36 MATERIALS SCIENCE↗
DOE OSTI2014

Ta{sub 2}O{sub 5}-based high-K dielectric thin films from solution processed at low temperatures

Highlights: • Ta{sub 2}O{sub 5}–Al{sub 2}O{sub 3}–SiO{sub 2} (Ta:Al:Si = 8:1:1 atomic ratio) and Ta{sub 2}O{sub 5} films were processed from solutions. • The XRD-amorphous films, heated at or below 400 °C, are smooth (RMS < 0.5 nm). • The dielectric permittivity of the single- and mixed-oxide films heated at 400 °C is 27 and 22, respectively. • The current–voltage characteristics of the mixed-oxide films reveal the Poole–Frenkel behaviour. - Abstract: Ta{sub 2}O{sub 5}-based thin films were prepared by chemical solution deposition at temperatures not exceeding 400 °C. The aim of the work was to investigate the properties of high-K dielectric films of the ternary composition Ta{sub 2}O{sub 5}–Al{sub 2}O{sub 3}–SiO{sub 2} with the Ta:Al:Si = 8:1:1 atomic ratio. Pure Ta{sub 2}O{sub 5} samples were also prepared. All thin films were amorphous, and had smooth and flat surfaces with the average roughness of below 0.5 nm. The mixed oxide samples heated between 300 °C and 400 °C showed little difference in the dielectric permittivity with the values ranging from about 19 to 22. The Ta{sub 2}O{sub 5} film heated at 400 °C exhibited the highest permittivity of about 27. The current–voltage measurements revealed considerably improved characteristics of the Ta{sub 2}O{sub 5}–Al{sub 2}O{sub 3}–SiO{sub 2} samples within the investigated heating temperature range, with a significant overall decrease of the leakage currents in contrast to that of the pure Ta{sub 2}O{sub 5} thin films.

36 MATERIALS SCIENCE↗
DOE OSTI2022

Array of Graphene Variable Capacitors on 100 mm Silicon Wafers for Vibration-Based Applications

Highly flexible, electrically conductive freestanding graphene membranes hold great promise for vibration-based applications. This study focuses on their integration into mainstream semiconductor manufacturing methods. We designed a two-mask lithography process that creates an array of freestanding graphene-based variable capacitors on 100 mm silicon wafers. The first mask forms long trenches terminated by square wells featuring cone-shaped tips at their centers. The second mask fabricates metal traces from each tip to its contact pad along the trench and a second contact pad opposite the square well. A graphene membrane is then suspended over the square well to form a variable capacitor. The same capacitor structures were also built on 5 mm by 5 mm bare dies containing an integrated circuit underneath. We used atomic force microscopy, optical microscopy, and capacitance measurements in time to characterize the samples.

36 MATERIALS SCIENCE↗
DOE OSTI2012

Magnetically separable {gamma}-Fe{sub 2}O{sub 3}-SiO{sub 2}-Ce-doped TiO{sub 2} core-shell nanocomposites: Fabrication and visible-light-driven photocatalytic activity

Novel visible-light-induced {gamma}-Fe{sub 2}O{sub 3}-SiO{sub 2}-Ce-doped-TiO{sub 2} core-shell nanocomposite photocatalysts capable of magnetic separation have been synthesized by a facile sol-gel and after-annealing process. The as-obtained core-shell nanocomposite is composed of a central {gamma}-Fe{sub 2}O{sub 3} core with a strong response to external fields, an interlayer of SiO{sub 2}, and an outer layer of Ce-doped TiO{sub 2} nanocrystals. UV-vis spectra analysis indicates that Ce doping in the compound results in a red-shift of the absorption edge, thus offering increased visible light absorption. We show that such a {gamma}-Fe{sub 2}O{sub 3}-SiO{sub 2}-Ce-doped-TiO{sub 2} core-shell nanocomposite with appreciated Ce doping amount exhibits much higher visible-light photocatalytic activity than bare TiO{sub 2} and undoped {gamma}-Fe{sub 2}O{sub 3}-SiO{sub 2}-TiO{sub 2} core-shell nanocomposite toward the degradation of rhodamine B (RhB). Moreover, the {gamma}-Fe{sub 2}O{sub 3}-SiO{sub 2}-Ce-doped-TiO{sub 2} core-shell nanocomposite photocatalysts could be easily separated and reused from the treated water under application of an external magnetic field. - Graphical abstract: Novel {gamma}-Fe{sub 2}O{sub 3}-SiO{sub 2}-Ce-doped-TiO{sub 2} core/shell nanocomposite photocatalysts with enhanced photocatalytic activity and fast magnetic separability were prepared. Highlights: Black-Right-Pointing-Pointer Novel {gamma}-Fe{sub 2}O{sub 3}-SiO{sub 2}-Ce-doped TiO{sub 2} core/shell composite photocatalysts were prepared. Black-Right-Pointing-Pointer The resulting core/shell composite show high visible light photocatalytic activity. Black-Right-Pointing-Pointer The nanocomposite photocatalysts can be easily recycled with excellent durability.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2012

Stabilization of the high coercivity {epsilon}-Fe{sub 2}O{sub 3} phase in the CeO{sub 2}-Fe{sub 2}O{sub 3}/SiO{sub 2} nanocomposites

We have investigated the processes leading to the formation of the Fe{sub 2}O{sub 3} and CeO{sub 2} nanoparticles in the SiO{sub 2} matrix in order to stabilize the {epsilon}-Fe{sub 2}O{sub 3} as the major phase. The samples with two different concentrations of the Fe were prepared by sol-gel method, subsequently annealed at different temperatures up to 1100 Degree-Sign C, and characterized by the Moessbauer spectroscopy, Transmission Electron Microscopy (TEM), Powder X-ray Diffraction (PXRD), Energy Dispersive X-ray analysis (EDX) and magnetic measurements. The evolution of the different Fe{sub 2}O{sub 3} phases under various conditions of preparation was investigated, starting with the preferential appearance of the {gamma}-Fe{sub 2}O{sub 3} phase for the sample with low Fe concentration and low annealing temperature and stabilization of the major {epsilon}-Fe{sub 2}O{sub 3} phase for high Fe concentration and high annealing temperature, coexisting with the most stable {alpha}-Fe{sub 2}O{sub 3} phase. A continuous increase of the particle size of the CeO{sub 2} nanocrystals with increasing annealing temperature was also observed. - Graphical abstract: The graphical abstract displays the most important results of our work. The significant change of the phase composition due to the variation of preparation conditions is demonstrated. As a result, significant change of the magnetic properties from superparamagnetic {gamma}-Fe{sub 2}O{sub 3} phase with negligible coercivity to the high coercivity {epsilon}-Fe{sub 2}O{sub 3} phase has been observed. Highlights: Black-Right-Pointing-Pointer Research of the stabilization of the high coercivity {epsilon}-Fe{sub 2}O{sub 3} in CeO{sub 2}-Fe{sub 2}O{sub 3}/SiO{sub 2}. Black-Right-Pointing-Pointer Samples with two different concentrations of Fe and three annealing temperatures. Black-Right-Pointing-Pointer Phase transition {gamma}{yields}{epsilon}{yields}({beta}){yields}{alpha} with increasing annealing temperature and particle size. Black-Right-Pointing-Pointer Elimination of the superparamagnetic phases in samples with higher content of Fe. Black-Right-Pointing-Pointer Best conditions for high coercivity {epsilon}-Fe{sub 2}O{sub 3}-higher Fe content and T{sub A}=1100 Degree-Sign C.

36 MATERIALS SCIENCE↗
DOE OSTI2011

Wear testing of friction stir spot welding tools for joining of DP 980 Steel

Friction stir spot welding has been shown to be a viable method of joining ultra high strength steel (UHSS), both in terms of joint strength and process cycle time. However, the cost of tooling must be reasonable in order for this method to be adopted as an industrial process. Several tooling materials have been evaluated in prior studies, including silicon nitride and polycrystalline cubic boron nitride (PCBN). Recently a new tool alloy has been developed, where a blend of PCBN and tungsten rhenium (W-Re) was used in order to improve the toughness of the tool. Wear testing results are presented for two of these alloys: one with a composition of 60% PCBN and 40% W-Re (designated as Q60), and one with 70% PCBN and 30% W-Re (designated at Q70). The sheet material used for all wear testing was DP 980. Tool profiles were measured periodically during the testing process in order to show the progression of wear as a function of the number of spots produced. Lap shear testing was done each time a tool profile was taken in order to show the relationship between tool wear and joint strength. For the welding parameters chosen for this study the Q70 tool provided the best combination of wear resistance and joint strength.

Friction Stir↗
DOE OSTI2014

Photocatalytic hydrogen production using visible-light-responsive Ta{sub 3}N{sub 5} photocatalyst supported on monodisperse spherical SiO{sub 2} particulates

Graphical abstract: A simple and effective sol–gel process followed by nitridation in an NH{sub 3} flow has been developed to deposit Ta{sub 3}N{sub 5} semiconductor photocatalyst layers onto monodisperse spherical SiO{sub 2} particles. The obtained Ta{sub 3}N{sub 5}/SiO{sub 2} particles maintain an original spherical morphology of SiO{sub 2} and a sub-micrometer size with a narrow size distribution and without aggregation. The presence of SiO{sub 2} support shows at least no detrimental effects on photocatalytic activity, but tunes the secondary particle size to control dispersibility of the photocatalyst in the solution. - Highlights: • Fine nanoparticles of Ta{sub 3}N{sub 5} were immobilized on the surfaces of SiO{sub 2} giving SiO{sub 2}@Ta{sub 3}N{sub 5} core–shell spheres successfully produced H{sub 2} from methanol solution under visible light. • The presence of support (SiO{sub 2}) ensures the dispersion of the particulate in solution maintaining high photocatalytic activity of Ta{sub 3}N{sub 5}. • The obtained supported photocatalyst gives uniform size distribution and control the degree of dispersibility in the solution, which may control nature of light absorption and reflection of the photoreactor. - Abstract: Fine nanoparticles of Ta{sub 3}N{sub 5} (10–20 nm) were synthesized on the surfaces of SiO{sub 2} spheres with a diameter of ∼550 nm. A sol–gel method was used to modify the surface of SiO{sub 2} with Ta{sub 2}O{sub 5} from TaCl{sub 5} dissolved in ethanol in the presence of citric acid and polyethylene glycol. The resulting oxide composites were treated in an NH{sub 3} flow at 1123 K to form core–shell structured Ta{sub 3}N{sub 5}/SiO{sub 2} sub-microspheres. The obtained samples were characterized using powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectra (EDX), transmission electron microscopy (TEM), and photocatalytic activity measurements for H{sub 2} evolution from an aqueous methanol solution. The XRD results demonstrate the expected sequential formation of Ta{sub 2}O{sub 5} layers, followed by Ta{sub 3}N{sub 5} after nitridation on the Ta{sub 2}O{sub 5}/SiO{sub 2} composite. SEM and TEM observations indicate that the obtained Ta{sub 3}N{sub 5}/SiO{sub 2} sub-microspheres have a uniform size distribution with high crystallinity and an obvious core–shell structure. The presence of support maintained the intrinsic photocatalytic activity of Ta{sub 3}N{sub 5} nanoparticles, but it did drastically improve the dispersion of the photocatalysts in the solution. This study proposes the use of an inert support in photocatalytic reactors to improve ease of handling the powder photocatalyst for gas-phase photocatalysis and the suspension of the solution, controlling nature of light harvesting and degree of scattering of the photoreactor.

36 MATERIALS SCIENCE↗