Rutile Nanoparticles Research Articles

Manufacturing Titanium Dioxide (Anatase and Rutile) Nanoparticles on the Surface of Reduced Graphene Oxide

Manufacturing Titanium Dioxide (Anatase and Rutile) Nanoparticles on the Surface of Reduced Graphene Oxide

Preparation and characterization of rutile TiO2 nanoparticles by HCl-water volatilization-assisted precipitation method

TiO2 nanoparticles were prepared by HCl-water volatilization-assisted precipitation method. Results indicated that the single anatase and mixed phase TiO2 containing rutile and anatase can be fabricated at the short HCl-water volatilization time of one and eight days calcined between 150 °C and 250 °C possessing spherical morphology. The elongated HCl-water volatilization time significantly influenced the phase transformation and morphology of TiO2 nanoparticles. The single rutile TiO2 was obtained at the calcination temperature of 200 °C when the HCl-water volatilization time was 5 months (150 days, atmospheric environment), possessing bamboo leaf-like morphology rather than spherical morphology. The degradation efficiency of methyl orange (MO) using rutile TiO2 calcined at 200 °C reached 87 % and 49.1 % after 2 h of ultraviolet and visible light irradiation respectively, being better than that of the low temperature-synthesized anatase TiO2, high temperature-synthesized rutile TiO2 and commercial Degussa P25.

Ag/GO/TiO2 nanocomposites: the role of the interfacial charge transfer for application in photocatalysis

TiO2 semiconductor nanoparticles (NPs) in the anatase phase have presented limitations of application in photocatalysis, mainly due to the fast recombination of photoexcited electrons. The combination with other nanoparticles/nanostructures has been shown to be a promising solution for increasing photocatalytic efficiency. In this work, titanium dioxide (TiO2) nanoparticles in different crystalline phases were prepared through a rapid microwave-assisted synthesis and modified by silver nanoparticles (Ag) and graphene oxide (GO). The samples were characterized by x-ray diffraction, transmission electron microscopy, energy dispersive x-ray spectroscopy, infrared spectroscopy and gas adsorption. Crystalline anatase NPs were obtained in basic conditions (pH = 8) while in acidic conditions (pH = 1), single-crystalline rutile NPs were formed. Different previous drying methods: oven and freeze-drying used led to a differentiation in crystallographic phases obtained. Anatase TiO2 and anatase-rutile mixture NPs calcined at 400 °C showed properties as high specific surface area, crystallinity and reduced electron–hole recombination which contributed to an enhanced photocatalytic activity, when compared to the Degussa P25 photoactivity. The effect of silver nanoparticles and GO addition to TiO2 nanopowder was evaluated for photocatalysis activity. An improvement in the methylene blue and rhodamine B dyes photodegradation was observed for both anatase and rutile TiO2 nanocomposites. We noted that anatase TiO2 nanoparticles degraded 53% of rhodamine B, and when functionalized with GO, the photodegradation increased to 69%. Comparatively, the addition of silver nanoparticles to anatase TiO2 increased the dye degradation to 97% in 180 min. Hence, we revel that in the TiO2 nanocomposites, silver nanoparticles showed better interfacial charge transfer than GO, contributing more effectively to the dye photodegradation process.

High Throughput Synthesis and Characterization of Multi-Metallic PGM-Free Aerogels for Catalyzing the Oxygen Evolution Reaction

Electrochemical energy conversion and storage technologies are at the heart of the societal pursuit towards circular economy, greenhouse gas emission-free fuel and sustainable energy future. The oxygen evolution reaction (OER) plays a central role in many of these electrochemical technologies, such as electrolyzers and metal-air batteries. The sluggish kinetics of the 4-electron oxidation of water to O2 and the resulting large overpotential limit the efficiency of these devices. The low abundance, prohibitive cost, and moderate stability of state-of-the-art OER catalysts, iridium- and ruthenium-based materials (i.e., IrO2 and RuO2) are obstacles against the cost-effective implementation of electrolysis technologies.1-3 To address these concerns and take the advantage of the intriguing properties and rich chemistry of nanoporous materials,4-7 we have developed a high throughput synthesis route for multi-metallic PGM-free aerogels for catalyzing the OER. The synthesis route is capable of producing 100 samples per batch using the High-Throughput Research Facility at Argonne National Laboratory. The effect of electrocatalyst composition (metal ion ratio) as well as the nature of the metal centers on the OER electrocatalytic activity have been evaluated.AcknowledgementsThis work was supported by the U.S. Department of Energy, Advanced Research Projects Agency Energy (ARPA-E) under the DIFFERENTIATE program. This work was authored in part by Argonne National Laboratory, a U.S. Department of Energy (DOE) Office of Science laboratory operated for DOE by UChicago Argonne, LLC under contract no. DE-AC02-06CH11357.References Katsounaros, Ioannis, Serhiy Cherevko, Aleksandar R. Zeradjanin, and Karl JJ Mayrhofer. "Oxygen electrochemistry as a cornerstone for sustainable energy conversion." Angewandte Chemie International Edition53, no. 1 (2014): 102-121.Lee, Youngmin, Jin Suntivich, Kevin J. May, Erin E. Perry, and Yang Shao-Horn. "Synthesis and activities of rutile IrO2 and RuO2 nanoparticles for oxygen evolution in acid and alkaline solutions." The journal of physical chemistry letters3, no. 3 (2012): 399-404.Cherevko, S. et al. Oxygen and hydrogen evolution reactions on Ru, RuO2, Ir, and IrO2 thin film electrodes in acidic and alkaline electrolytes: A comparative study on activity and stability. Today 262, 170–180 (2016).Nahar, Lamia, Ahmed A. Farghaly, Richard J. Alan Esteves, and Indika U. Arachchige. "Shape controlled synthesis of Au/Ag/Pd nanoalloys and their oxidation-induced self-assembly into electrocatalytically active aerogel monoliths." Chemistry of Materials29, no. 18 (2017): 7704-7715.Farghaly, Ahmed A., Rezaul K. Khan, and Maryanne M. Collinson. "Biofouling-resistant platinum bimetallic alloys." ACS applied materials & interfaces10, no. 25 (2018): 21103-21112.Khan, Rezaul K., Ahmed A. Farghaly, Tiago A. Silva, Dexian Ye, and Maryanne M. Collinson. "Gold-Nanoparticle-Decorated Titanium Nitride Electrodes Prepared by Glancing-Angle Deposition for Sensing Applications." ACS Applied Nano Materials2, no. 3 (2019): 1562-1569.Farghaly, Ahmed A., Mai Lam, Christopher J. Freeman, Badharinadh Uppalapati, and Maryanne M. Collinson. "Potentiometric measurements in biofouling solutions: comparison of nanoporous gold to planar gold." Journal of The Electrochemical Society163, no. 4 (2015): H3083.

Machine Learning Driven Discovery and Optimization of Multi-Component Oxygen Evolution Reaction Catalysts

Electrochemical energy conversion and storage technologies are in the heart of the societal pursuit towards circular economy, greenhouse gas emission-free fuel and sustainable energy future. Oxygen evolution reaction (OER) plays a central role in many of these electrochemical technologies such as electrolyzers and metal-air batteries. However, the sluggish kinetics of 4-electron water oxidation to O2, the resulting large overpotential and severe energy loss limit the development of energy efficient devices. The low-abundance, prohibitive cost, and moderate stability of state-of-the-art OER catalysts, iridium- and ruthenium-based materials i.e. IrO2 and RuO2, also limit the cost effective implementation of electrolyzers.1-3 This presentation will describe our research to address these concerns, taking advantage of the intriguing properties and rich chemistry of nanoporous materials, the demonstrated capability of machine learning (ML)-guided materials discovery, and the high OER electrocatalytic activity of perovskites especially in alkaline media.4-10 We will describe our work in simulating over 8,000 perovskites across a variety of cell sizes, space groups, and compositions using density functional theory (DFT). By mining this simulation data, we found that experimentally-known perovskites have low energy above the thermodynamic convex hull. Then, using efficient search algorithms, deep learning-based models, and DFT calculations, the space of perovskite oxides is explored to produce novel compositions with tailored electronic descriptors. Promising compositions designed for high activity and stability are then selected for high throughput automated synthesis using the High-Throughput Research Facility at Argonne National Laboratory.AcknowledgementsThis work was supported by the U.S. Department of Energy, Advanced Research Projects Agency-Energy (ARPA-E) under the DIFFERENTIATE program. This work was authored in part by Argonne National Laboratory, a U.S. Department of Energy (DOE) Office of Science laboratory operated for DOE by UChicago Argonne, LLC under contract no. DE-AC02-06CH11357.References Katsounaros, Ioannis, Serhiy Cherevko, Aleksandar R. Zeradjanin, and Karl JJ Mayrhofer. "Oxygen electrochemistry as a cornerstone for sustainable energy conversion." Angewandte Chemie International Edition53, no. 1 (2014): 102-121.Lee, Youngmin, Jin Suntivich, Kevin J. May, Erin E. Perry, and Yang Shao-Horn. "Synthesis and activities of rutile IrO2 and RuO2 nanoparticles for oxygen evolution in acid and alkaline solutions." The journal of physical chemistry letters3, no. 3 (2012): 399-404.Cherevko, S. et al. Oxygen and hydrogen evolution reactions on Ru, RuO2, Ir, and IrO2 thin film electrodes in acidic and alkaline electrolytes: A comparative study on activity and stability. Today 262, 170–180 (2016).Nahar, Lamia, Ahmed A. Farghaly, Richard J. Alan Esteves, and Indika U. Arachchige. "Shape controlled synthesis of Au/Ag/Pd nanoalloys and their oxidation-induced self-assembly into electrocatalytically active aerogel monoliths." Chemistry of Materials29, no. 18 (2017): 7704-7715.Farghaly, Ahmed A., Rezaul K. Khan, and Maryanne M. Collinson. "Biofouling-resistant platinum bimetallic alloys." ACS applied materials & interfaces10, no. 25 (2018): 21103-21112.Khan, Rezaul K., Ahmed A. Farghaly, Tiago A. Silva, Dexian Ye, and Maryanne M. Collinson. "Gold-Nanoparticle-Decorated Titanium Nitride Electrodes Prepared by Glancing-Angle Deposition for Sensing Applications." ACS Applied Nano Materials2, no. 3 (2019): 1562-1569.Farghaly, Ahmed A., Mai Lam, Christopher J. Freeman, Badharinadh Uppalapati, and Maryanne M. Collinson. "Potentiometric measurements in biofouling solutions: comparison of nanoporous gold to planar gold." Journal of The Electrochemical Society163, no. 4 (2015): H3083.Suntivich, Jin, Kevin J. May, Hubert A. Gasteiger, John B. Goodenough, and Yang Shao-Horn. "A perovskite oxide optimized for oxygen evolution catalysis from molecular orbital principles." Science334, no. 6061 (2011): 1383-1385.Hwang, Jonathan, Zhenxing Feng, Nenian Charles, Xiao Renshaw Wang, Dongkyu Lee, Kelsey A. Stoerzinger, Sokseiha Muy et al. "Tuning perovskite oxides by strain: electronic structure, properties, and functions in (electro) catalysis and ferroelectricity." Materials Today31 (2019): 100-118.Gómez-Bombarelli, Rafael, Jennifer N. Wei, David Duvenaud, José Miguel Hernández-Lobato, Benjamín Sánchez-Lengeling, Dennis Sheberla, Jorge Aguilera-Iparraguirre, Timothy D. Hirzel, Ryan P. Adams, and Alán Aspuru-Guzik. "Automatic chemical design using a data-driven continuous representation of molecules." ACS central science4, no. 2 (2018): 268-276.

Anatase and Rutile TiO2 Nanoparticles Lead Effective Bone Damage in Young Rat Model via the IGF-1 Signaling Pathway.

PurposeTo evaluate the effects of anatase and rutile TiO2 nanoparticles (NPs) on the growth and development of bones in young rats and explore their possible mechanisms.MethodsThree-week-old male rats were orally administered anatase TiO2 NPs and rutile TiO2 NPs for 28 days. The indicators of rat growth and development, liver function, bone metabolism, and insulin-like growth factor-1 (IGF-1) levels were evaluated. Micro-computed tomography (micro-CT) and immunohistochemistry were used to evaluate the tibia.ResultsNo significant differences were observed among growth and development indicators in young rats. Significant differences were found in IGF-1 levels, phosphorus levels, and liver function. Micro-CT revealed osteoporosis in the bones. The micro-CT data supported the same result. Bone immunohistochemistry results showed that the expression of osteoprotegerin (OPG) was decreased and the expression of receptor activator of nuclear factor-κB ligand (RANKL) and cathepsin K (CTSK) was increased.ConclusionThis study demonstrated that TiO2 NPs can damage bones via the IGF-1/OPG/RANKL/CTSK pathway in young rats. Furthermore, rutile TiO2 NPs damaged the bones more seriously than anatase TiO2 NPs.

Superior improvement in dynamic response of liquid crystal lens using organic and inorganic nanocomposite

In this study, the response time of a 4 mm-aperture hole-patterned liquid crystal (HLC) lens has been significantly improved with doping of N-benzyl-2-methyl-4-nitroaniline (BNA) and rutile titanium dioxide nanoparticle (TiO2 NP) nanocomposite. The proposed HLC lens provides the focus and defocus times that are 8.5× and 14× faster than the pristine HLC lens, respectively. Meanwhile, the focus and defocus times of the proposed HLC lens reach the order of millisecond. Result shows that the synergistic effect of BNA and TiO2 NP induces a 78% decrement in the viscosity of pristine LC mixture that significantly shortens the focus and defocus times of HLC lens. The remarkable decrement in viscosity is mainly attributed to spontaneous polarization electric fields from the permanent dipole moments of the additives. Besides, the strengthened electric field surrounding TiO2 NP assists in decreasing the focus time of HLC lens. The focus and defocus times of HLC lens are related to the wavefront (or phase profile) bending speed. The time-dependent phase profiles of the HLC lenses with various viscosities are calculated. This result shows the decrease in wavefront bending time is not simply proportional to viscosity decrement. Furthermore, the proposed HLC lens emerges a larger tunable focus capability within smaller voltage interval than the pristine HLC lens.

One-step fabrication of a new outstanding rutile TiO2 nanoparticles/anthracite adsorbent: Modeling and physicochemical interpretations for malachite green removal

In this study, a facile method was developed to synthesize a new composite via the impregnation of rutile (TiO2) nanoparticles (Rt) into H2O2–modified anthracite (MAn). This new rutile(TiO2)/modified anthracite (Rt/MAn) adsorbent was characterized and employed as an outstanding and cost–effective material to remove malachite green (MG) dye at 25–55 °C. This adsorbent displayed the highest removal efficiency (96.2 %) as compared to its individual components MAn (49.8 %) and Rt (71.4 %) at pH 8.0. The experimental adsorption of MG onto Rt/MAn at equilibrium were satisfactorily fitted to the Freundlich equation and a multilayer statistical physics model at all tested temperatures. The physicochemical parameters (steric and energetic) related to a multilayer adsorption were calculated and interpreted to understand the adsorption mechanism. The theoretical number of adsorbed MG dye molecules per functional group (n) varied from 0.94 to 1.60 indicating a multi-docking adsorption mechanism. The adsorption capacity of MG at saturation (Qsat) increased from 513 to 740 mg/g at 25 and 55 °C and was primarily caused by the density of Rt/MAn functional groups (i.e., the DM parameter). MG adsorption energy with Rt/MAn varied from 13.87 to 29. 96 kJ/mol and was governed by physical interactions. The tested adsorbent was easily reactivated by the dye desorption and reused up to five cycles where it retained>80 % of MG adsorption capacity even after the 5th adsorption–desorption cycle. These results demonstrated that Rt/MAn is an effective adsorbent to remove MG, thus offering outstanding adsorption capacities largely beyond the current state of the art (up to 740 mg/g) and its application could be extended for the adsorption of other organic pollutants from wastewaters.

Natural Rubber-TiO2 Nanocomposite Film for Triboelectric Nanogenerator Application.

In this research, natural rubber (NR)-TiO2 nanocomposites were developed for triboelectric nanogenerator (TENG) application to harvest mechanical energy into electrical energy. Rutile TiO2 nanoparticles were used as fillers in NR material to improve dielectric properties so as to enhance the energy conversion performance of the NR composite TENG. The effect of filler concentration on TENG performance of the NR-TiO2 composites was investigated. In addition, ball-milling method was employed to reduce the agglomeration of TiO2 nanoparticles in order to improve their dispersion in the NR film. It was found that the TENG performance was significantly enhanced due to the increased dielectric constant of the NR-TiO2 composite films fabricated from the ball-milled TiO2. The TENG, fabricated from the NR-TiO2 composite using 24 h ball-milled TiO2 at 0.5%wt, delivered the highest power density of 237 mW/m2, which was almost four times higher than that of pristine NR TENG. Furthermore, the applications of the fabricated NR-TiO2 TENG as a power source to operate portable electronics devices were also demonstrated.

Unraveling the Lattice Matching Effect in Surface Phase Junctions for Interfacial Charge Separation

Exquisite control over the interface structure is highly desired for the successful fabrication of a semiconductor heterojunction, which has been confirmed to effectively promote charge separation and transfer. However, the influences of the interface microstructure in the heterojunction on the charge separation and transfer efficiency are still unclear. Herein, taking the TiO2 heterophase junction (A/R) between anatase and rutile phases and the TiO2 homophase junction (Rs/R) between large rutile rodlike particles and small rutile nanoparticles (∼20 nm) as a prototypical model, it is found that the lattice match at the interface is a key factor determining the charge separation and transfer efficiency and the photocatalytic activity. As compared with A/R, the atomically smooth interface with a highly matched lattice in Rs/R leads to a less-defective and abrupt interface and provides a smooth interfacial charge separation and transfer path, leading to improved charge separation and transfer efficiency and a great enhancement in photocatalytic activity. This study provides a novel insight into optimizing the heterojunction structure by designing a highly matched lattice interface between two components.

Tuning the Chemical Properties of Co-Ti3 C2 Tx MXene Materials for Catalytic CO2 Reduction.

MXenes, a novel family of 2D materials, are energy materials that have gained considerable attention, particularly for their catalytic applications in emerging areas such as CO2 and N2 hydrogenation. Herein, for the first time, it is shown that the surface reducibility of Ti3 C2 Tx MXene can be tuned by N doping, which induces a change in the catalytic properties of supported Co nanoparticles. Pristine Co-Ti3 C2 Tx MXene favors CO production during CO2 hydrogenation, whereas CH4 production is favored when the MXene is subjected to simple N doping. X-ray photoelectron spectroscopy and transmission electron microscopy (TEM) reveal that surface rutile TiO2 nanoparticles appear on the Ti3 C2 Tx support upon N doping, which interact strongly with the supported Co nanoparticles. This interaction alters the reducibility of the supported Co nanoparticles at the interface with the TiO2 nanoparticles, shifting the product selectivity from CO to CH4 . This study successfully showcases a practical strategy, based on surface chemistry modulation of 2D MXenes, for regulating product distribution in CO2 hydrogenation.

Sol-gel synthesized rutile TiO2 nanoparticles loaded with cardamom essential oil: Enhanced antibacterial activity

Nanoparticles have been recognized as a promising alternative to overcome problems associated with antibiotic-resistant bacterial strains. In the current study, the combination of TiO2 nanoparticles with cardamom essential oil (CEO) was assessed for its antibacterial effects. First, TiO2 nanoparticles were synthesized via sol-gel route and subjected to various physico-chemical characterizations; structural using both X-ray diffraction and Raman spectroscopy, morphological by scanning electron microscopy and elemental analysis by X-ray photoelectron spectroscopy. The synthesized nanoparticles were, then, loaded with natural CEO to form the conjugate CEO@TiO2. The effectiveness of the conjugate CEO@TiO2 was assessed against a standard test strain as well as against two clinical isolates using ultraviolet–visible spectrophotometry measurements. The results demonstrate that CEO@TiO2 conjugates exhibit potent antibacterial activity against all the tested bacteria than CEO or TiO2 nanoparticles alone. An attempt to explain the mechanism of action of the devised antibacterial agent was undertaken based on confocal microscopy observations. Overall, this proof-of-concept antibacterial system may have important implications for the development of numerous therapeutic, environmental and food industry applications.

Synchrotron Radiation Spectroscopy and Transmission Electron Microscopy Techniques to Evaluate TiO2 NPs Incorporation, Speciation, and Impact on Root Cells Ultrastructure of Pisum sativum L. Plants.

Biosolids (Bs) for use in agriculture are an important way for introducing and transferring TiO2 nanoparticles (NPs) to plants and food chain. Roots of Pisum sativum L. plants grown in Bs-amended soils spiked with TiO2 800 mg/kg as rutile NPs, anatase NPs, mixture of both NPs and submicron particles (SMPs) were investigated by Transmission Electron Microscopy (TEM), synchrotron radiation based micro X-ray Fluorescence and micro X-ray Absorption Near-Edge Structure (µXRF/µXANES) and Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). TEM analysis showed damages in cells ultrastructure of all treated samples, although a more evident effect was observed with single anatase or rutile NPs treatments. Micro-XRF and TEM evidenced the presence of nano and SMPs mainly in the cortex cells near the rhizodermis. Micro-XRF/micro-XANES analysis revealed anatase, rutile, and ilmenite as the main TiO2 polymorphs in the original soil and Bs, and the preferential anatase uptake by the roots. For all treatments Ti concentration in the roots increased by 38–56%, however plants translocation factor (TF) increased mostly with NPs treatment (261–315%) and less with SMPs (about 85%), with respect to control. In addition, all samples showed a limited transfer of TiO2 to the shoots (very low TF value). These findings evidenced a potential toxicity of TiO2 NPs present in Bs and accumulating in soil, suggesting the necessity of appropriate regulations for the occurrence of NPs in Bs used in agriculture.

Post-synthesis plasma processing and activation of TiO2 photocatalyst for the removal of synthetic dyes from industrial wastewater

In this study, TiO2 nanopowders were prepared by combining the surfactant assisted sol–gel method with microwave plasma calcination. Plasma calcination was performed just for 20–30 min for reducing the calcination time and ensuring the energy efficient synthesis of photocatalyst. The mixed anatase–rutile phased TiO2 nanoparticles were obtained under these synthesis conditions. The band gap energy of the photocatalyst decreased by 40% on microwave plasma calcination. The surfactants were found to be ineffective on phase transformations of synthesized TiO2. FTIR analysis confirmed the absorption of O–Ti–O band stretching between 415 and 420 cm−1. The hydroxyl bands (OH) were observed to be less stretched after plasma calcination. The conventionally calcined HA–Ti, NA–Ti and MS–Ti samples showed band gap energies of 5.09 eV, 4.88 eV and 5.06 eV, respectively. The band gap energy of plasma calcined MTHA–Ti, MTNNA–Ti and MTMS–Ti samples was calculated about 4.92 eV, 3.11 eV and 4.96 eV, respectively. The combined effect of photocatalyst, plasma reactive species and UV radiations promoted the degradation efficiency of the methylene blue dye. Under DC plasma jet exposure, the maximum degradation efficiency of 95% was achieved after 30 min of plasma exposure time. The catalyst retained about 93–95% degradation efficiency after five cycles of dye degradation.

Fabrication of Carbon Nanofibers Decorated with Various Kinds of Metal Oxides for Battery Applications

Carbon nanofibers decorated with various metal oxide nanoparticles were fabricated by combining an electrospinning technique of bicomponent polymer mixture and a sol-gel reaction and subsequent carbonization process. Electrospun polymer nanofibers consisting of polyacrylonitrile (PAN) and poly(vinyl pyrrolidone) (PVP) with controllable diameters were fabricated with PAN/PVP core/shell types via phase-separation due to the immiscibility between two polymers. The electrospun nanofibers served as supporting materials with binding sites of PVP to incorporate titanium oxide precursor. Subsequently, the carbonization of the fibers led to the formation of carbon nanofibers@TiO2 for energy application, in which rutile TiO2 nanoparticles were decorated on the surface of carbon nanofiber. Especially, this TiO2 decorated carbon nanofiber electrode exhibited excellent electrochemical property in lithium-ion batteries (≈600 mA h g−1 at C/5 rate for 100 cycles). Furthermore, the carbon nanofibers were also successfully modified with other metal oxides, including NiO, SnO2, and ZrO2 nanoparticles, in a similar manner.

Synergistic effect of anatase/rutile TiO2 with exfoliated Ti3C2TR MXene multilayers composite for enhanced CO2 photoreduction via dry and bi-reforming of methane under UV–visible light

MXene-based materials are favorable as cocatalyst for photocatalytic reduction of CO2 owing to their distinctive two-dimensional (2D) layered structure, large surface area, electrical conductivity and incredible chemical stability. Well-designed anatase TiO2 anchored Ti3C2/TiO2R composite was synthesized through ultrasonic approach, whereas controlled etching method was employed for in-situ growth of rutile TiO2 NPs. The TiO2 (rutile) nanoparticles were distributed onto the Ti3C2 MXene nanosheets, whereas, the increase in etching time from 24 to 96 h caused increased in the quantity of TiO2 embedded over Ti3C2 surface to produce Ti3C2/TiO2R. The resulting TiO2A/Ti3C2/TiO2R MXene composite was tested through different reforming systems which include CO2 reduction with H2O, dry reforming of methane (DRM) and bi-reforming of methane (BRM). Using CO2-water, the composite exhibited 85 and 18 μmol g−1 h−1 for CO and CH4 evolution, respectively, when photo-reduced with H2O. Using DRM process, CO and H2 were the main products with yield 47.8 and 13.8 µmol g−1 h−1, respectively. Using BRM, performance of composite was increased by 9.53 folds higher than using DRM process. The BRM process showed high efficiency and selectivity for hydrogen rich syngas production due to efficient oxidation process in the presence of water with yield 38.25 and 52.5 µmol g−1 h−1, respectively. These findings imply that TiO2A/ Ti3C2/TiO2R nanocomposite has the capability as a cocatalyst for high-performance photocatalytic material. Moreover, TiO2A coupled with Ti3C2/TiO2R showed excellent cycling stability without deactivation after three cycles and can be a potential structured material for other energy applications.

SORPTION PROPERTIES OF RUTILE PHASE TiO2 NANOPARTICLES

There are many scientific studies on phenol adsorption. Sorption of phenol in the presence of activated carbon, graphite oxide and other adsorbents is very common. This article is the first to study the sorption properties of TiO2nanoparticles with a rutile phase; TiO2 nanoparticles with a rutile phase were synthesized by the sol-gel method and used as an adsorbent. Later the process of adsorption of a 1 mgL-1 phenol solution in the presence of rutile TiO2 nanoparticles was studied. The adsorption process lasted 2 hours at a temperature of 25°C.Although the rutile TiO2 phase is a very good photocatalyst it has been shown to be a weak adsorbent. Nano crystalline TiO2 particles of the rutile phase were characterized by powder X-ray diffraction (XRD).The course of adsorption was studied on the device "Varian Cary 50". Based on the curves plotted on the “Varian Cary 50” it was determined that adsorption was incomplete. At the end of the process judging by the graph we can say that the amount of phenol in the solution decreased but phenol still remained which indicates incomplete adsorption. Mathematical modeling of the process has been developed using both logistic and exponential methods. Keywords: nano-TiO2, phenol, adsorption, XRD, TEM.

A rapid and dual-mode visualization of latent and bloody fingermarks using Cr- and Sb-codoped titanium dioxide nanoparticles

In forensic science, the demand for the discovery and extraction of latent fingermarks at crime scenes in a fast and convenient way is still urgent. Herein, a rutile Cr- and Sb-codoped TiO2 nanoparticle was synthesized via homogeneous precipitation and was characterized by scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, Raman spectroscopy, and X-ray fluorescence. Subsequently, the as-prepared nanoparticle was used to visualize latent fingermarks using a powder dusting method and to enhance the visualization of bloody fingermarks using a small particle reagent method on porous, semiporous, and nonporous substrates. Notably, the anti-ultraviolet property of this yellow nanoparticle was investigated. This intriguing property contributed to the detection of latent fingermarks on strong-fluorescence or multicolored surfaces in a negative-image manner. Moreover, two potential interaction mechanisms were proposed between hemoglobin and surfactants in bloody fingermark enhancement. This work showed that this rutile TiO2 nanoparticle doped with Cr and Sb is a versatile eikonogen for the rapid visualization of latent and bloody fingermarks and has high sensitivity, selectivity, contrast as well as wide applicability compared with traditional developing methods.

Ratiometric Sensing and Discrimination of Rutile and Anatase TiO2 Nanoparticles by a Quinoline-Benzimidazole Conjugate

A quinoline-benzimidazole conjugate 1 has been synthesized as a potential probe to discriminate the TiO2 anatase and rutile nanoparticles by fluorimetry. Probe 1 exhibits selective TiO2 sensing through a photoinduced electron transfer process (PET) and the ratiometric sensing response by intramolecular charge transfer (ICT) mechanism. The binding ratio and the association constants were also calculated. The limit of detection of TiO2 nanoparticles by probe 1 was upto micro molar concentrations.

Quantum-chemical studies of rutile nanoparticles toxicity II. Comparison of B3LYP and PM6 data

Abstract The relation between copper atomic charges and metal-ligand interaction energies obtained by PM6 and DFT-B3LYP methods for cytotoxicity prediction of model rutile nanoparticles [Ti40O124H81]7–, [Ti7O28H26]2–, [Ti2O10H10]2–, [Ti7O30H30]2– and their Cu(II) complexes is investigated. Except for Mulliken charges, very good statistical parameters were obtained for the linear relation between the results obtained by both methods if standard accuracy of quantum-chemical calculations is achieved.