TiO2 Nanocatalysts Research Articles

Biowaste‐Mediated Synthesis of CeO₂–TiO₂ Nanoparticles: An Efficient Recoverable Nanocatalyst for the Solvent‐Free Synthesis of Antipyrine Derivatives and Their Biological Evaluation

AbstractA facile, efficient, and environmentally friendly protocol for the solvent‐free synthesis of antipyrine‐ linked quinoline derivatives catalyzed by CeO2–TiO2 nanocatalyst under ultrasonication is developed. Antipyrine derivatives are involved in various synthetic processes and exhibit valuable biological activities, such as antibacterial, anti‐inflammatory, antioxidant, and anticancer properties. Biowaste‐ derived CeO2–TiO2 nanoparticles have been synthesized using outer covering calyx leaves extract of Physalis peruviana fruits and utilized for the construction of biologically important antipyrine derivatives by the multicomponent reaction in short reaction time with excellent yield. The nanocatalyst was characterized by FT‐IR, powder X‐ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and electron dispersion spectroscopy (EDS). The functionalized nanoparticles show excellent reusability without any significant loss in catalytic activity. The hot filtering experiment shows that there is no noticeable leaching or boomerang effect and that the catalysis is heterogeneous in nature. All synthesized compounds underwent screening for antibacterial activity against selected microorganisms, and their antioxidant activity was assessed using DPPH (2,2‐diphenyl‐1‐picrylhydrazyl). Some of the synthesized compounds exhibited promising results in both screenings.

Nitrogen doped TIO2/g-C3N4 nanocatalyst for photodegradation of methylene blue dye

In this study, the ethanol dispersion procedure was implemented to prepare the g-C3N4/N–TiO2 nanocatalyst structure. Sol-gel synthesis is utilized for synthesizing N–TiO2 and g-C3N4 via urea thermal decomposition. Physicochemical properties of produced photocatalysts were revealed using PL imaging, UV–vis DRS, XRD, FTIR, SEM, BET, and TEM. Evaluation of photocatalytic activity of synthetic photocatalysts by exposure to sunlight and degradation of methylene blue (MB) dye. g-C3N4/N–TiO2 NCs showed excellent photocatalytic activity, reaching 96 % MB degradation efficiency in 80 min. g-C3N4 and N–TiO2 doped form a nanocomposite structure that increases photocatalytic activity, affecting charge separation performance and service life. The system also exhibits the ability to collect visible and ultraviolet light. Even after four consecutive cycles, the efficiency of the MB is still above 85 %. Capture experiments showed that the decomposition of MB was mainly caused by h+ and O22− radicals. The results of kinetic investigations indicate that the degradation rate of g-C3N4/N–TiO2 nanocomposites surpasses that of N–TiO2 nanoparticles.

Enhanced Photocatalytic Degradation of Methyl Orange by Metal‐Tio2 Nanoparticles

AbstractIn this study, a series of transition metal‐doped TiO2 was prepared by a simple sol‐solvothermal method. Mix an ethanol solution of tetrabutyl titanate and metal nitrate solution to obtain a homogeneous sol, which is then subjected to solvothermal treatment. After calcination, the metal‐TiO2 naoncomposite was obtained. Selected transition metal precursors, including Cu, Fe, Ag, Cr, Co and Zn, were doped into TiO2 nanocatalysts to assess photocatalytic degradation activities. The results show that 1 mol % Ag−TiO2 photocatalyst has a larger specific surface area, a stable anatase phase and the narrowest forbidden band energy (3.00 eV). In photocatalytic degradation of methyl orange (MO) tests, 1 mol % Ag−TiO2 could reach 100 % decolourisation after 70 min and 75.43 % mineralisation after 90 min. ESR analysis confirmed that Ag doping significantly increased the content of ⋅O2− and ⋅OH for the TiO2 catalyst, which are responsible for the oxidation reactions and consequently degradation of pollutants. The photocatalytic degradation mechanism of MO was also proposed. The TOC analyses confirmed the mineralization of MO. The excellent thermal and chemical stability of 1 mol % Ag−TiO2 has also been demonstrated by thermogravimetric analysis and cycling experiments. Electrochemical tests have also demonstrated the excellent electrochemical properties of 1 mol % Ag−TiO2.

Fe-doped TiO2 nanocrystals as highly efficient catalysts for heterogeneous catalytic transesterification of coconut oil

BackgroundThe impact of Fe doped TiO2 nanocatalyst on the heterogeneous catalytic transesterification reaction of coconut oil into biodiesel has been investigated. MethodsThe nanocatalyst was prepared by sol-gel method using titanium isopropoxide as TiO2 precursor and Fe(NO3)3 as iron (Fe) source. Several conditions of Fe-TiO2 were synthesized, each with Fe concentration of 0.5 %, 1 %, and 1.5 %, and calcined at 500 °C. The nanocatalyst's physical and chemical characteristics including phase crystallinity and morphology were examined. Significant findingsWe found that the biodiesel conversion efficiency increases with the increasing of Fe content in the Fe-TiO2 nanocatalyst and optimum at the Fe concentration of 1.5 % (w/w). The optimal Fe-TiO2 nanocatalyst could yield biodiesel output as high as 30.8 %, under at a relatively low temperature of 60 °C. Furthermore, the presence of the nanocatalyst effectively reduced the free fatty acid content in the biodiesel product by 1.43 %. Moreover, the acidity of the produced biodiesel was exceptionally low, at 0.02 %, primarily attributed to lauric acid. These exceptional performances are believed to be attributed to the enhanced surface chemistry properties of the Fe-TiO2 nanocatalyst. The Fe-TiO2 system is expected to find extensive application in the cost-effective production of biodiesel.

Cu(II)-doped flower-like TiO2 nano-catalyst for enhanced photoconversion of CO2 to CH4

Cu(II)-doped flower-like TiO2 nano-catalyst for enhanced photoconversion of CO2 to CH4

Environmental Assessment of Narmada River Tributary I. E Ganjal River Water and its Photo Chemical Degradation using TiO2 Nanocatalyst

Environmental Assessment of Narmada River Tributary I. E Ganjal River Water and its Photo Chemical Degradation using TiO2 Nanocatalyst

Photocatalytic Activity of Metal- and Non-Metal-Anchored ZnO and TiO2 Nanocatalysts for Advanced Photocatalysis: Comparative Study

This review article provides useful information on TiO2 and ZnO photocatalysts and their derivatives in removing organic contaminants such as dyes, hydrocarbons, pesticides, etc. Also, the reaction mechanisms of TiO2 and ZnO photocatalysts and their derivatives were investigated. In addition, the impact of adding metallic (e.g., Ag, Co, Pt, Pd, Cu, Au, and Ni) and non-metallic (e.g., C, N, O, and S) cocatalysts to their structure on the photodegradation efficiency of organic compounds was thoroughly studied. Moreover, the advantages and disadvantages of various synthesis procedures of ZnO and TiO2 nanocatalysts were discussed and compared. Furthermore, the impact of photocatalyst dosage, photocatalyst structure, contaminant concentration, pH, light intensity and wavelength, temperature, and reaction time on the photodegradation efficiency were studied. According to previous studies, adding metallic and non-metallic cocatalysts to the TiO2 and ZnO structure led to a remarkable enhancement in their stability and reusability. In addition, metallic and non-metallic cocatalysts attached to TiO2 and ZnO demonstrated remarkable photocatalytic efficiency in removing organic contaminants.

Enhanced photodegradation of methylene blue by Zr-doped TiO2:A combined DFT and experimental investigation

The effective mitigation of effluents in water has attracted researchers as a foremost task for addressing environmental concerns. To overcome these concerns, TiO2 (labeled as PCT-1) and Zr-doped TiO2 (labeled as PCT-2) nano catalysts are prepared by an efficient sol–gel protocol and their photocatalytic degradation performance of methylene blue (MB) is investigated. The structural integrity of nanostructures is determined by analytical tools. More than 96 % MB degradation is observed when PCT-2 is subjected to ultraviolet light for 180 min. Nanosized PCT-2 exhibits attractively advanced photocatalytic performance than PCT-1 owing to lower electron–hole pair recombination (3.02 eV) as well as superior photon capture via oxidation by photocatalytic response (confirmed through active species trapping scavenger tests). Furthermore, the results of bandgap are also confirmed by spin-polarized density functional theory (DFT) computations. The findings of this study indicate that band tuning is an attractive photocatalytic system for improving catalytic performance.

The effects of nitrogen-doping on photocatalytic mineralization of TiO2 nanocatalyst against formaldehyde in ambient air

The effects of nitrogen-doping on photocatalytic mineralization of TiO2 nanocatalyst against formaldehyde in ambient air

A Study of Green Synthesis of Nano-TiO2 Catalyst by Gossypium Leaf Extract and Its Nanocatalysis in the Synthesis of Biofuel from Gossypium Seed Oil

Synthesis of TiO2 nanoparticles by aqueous leaf extract of Gossypium (Gossypiumarboretum) leaves on meta titanic acid [TiO(OH)2]. Rutile tetragonal TiO2 nanoparticles were characterized by XRD, SEM and TEM studies and their particle size was calculated, which was below 100 nm. The Obtained TiO2NPs were used as catalysts in the transesterification of Gossypium seed oil, which enhanced the rate of reaction. Thus, it is a very attractive catalyst for biodiesel production from Gossypium seed oil. The effect of the amount of nano-TiO2 catalyst and microwave heating was studied. In this study, the preparation of both catalyst and biodiesel from the parts of the same Gossypium plant and the feasibility of carrying out the microwave-assisted transesterification (green process) of Gossypium seed oil by using biogenic nanoTiO2 catalyst was explored. They improve the efficiency of transesterification. The used catalyst can be recycled by simple filtration and reused without reduction in its activity. It is a green method (affords nontoxic and noncorrosive medium), clean reaction, simple experimental, isolation procedures, gives high yield and the properties of synthesized biodiesel are in good agreement with that of diesel oil. So, it may be used alone or by blending with diesel.

Degradation of textiles dyes and scavenging activity of spherical shape obtained anatase phase of Co–Ni-doped TiO2 nanocatalyst

Degradation of textiles dyes and scavenging activity of spherical shape obtained anatase phase of Co–Ni-doped TiO2 nanocatalyst

The nature of crystal facet effect of TiO2-supported Pd/Pt catalysts on selective hydrogenation of cinnamaldehyde: electron transfer process promoted by interfacial oxygen species.

Supported noble metal nanocatalysts typically exhibit strong crystal plane dependent catalytic behavior, but their working mechanism is still unclear. Herein, using anatase TiO2 with well-exposed crystal facets of {101}, {100} and {001} as a prototype support, Pd- and Pt-based supported TiO2 nanocatalysts (TiO2-Pd and TiO2-Pt) were prepared by chemical reduction with NaBH4 as reducer, and they showed a distinct metal-dependent crystal facet effect in the selective hydrogenation of cinamaldehyde (CAL). For Pd-based nanocatalysts, most Pd species on the {100} plane of TiO2 are present in the oxidized form with positive charges and unexpectedly show higher reactivity than the Pd species in the zero-valence state on the {101} and {001} planes. On the contrary, Pt species on all three crystal planes of TiO2 show zero-valence state, with relatively low conversion, but much better selectivity for hydrogenation of a CO bond than Pd-based catalysts. Well-designed experiments manipulating the stability and type of surface oxygen species confirmed that the essence of the crystal facet effect of the catalyst support actually creates a unique nanoconfined interface at the molecular level to construct a surface p-band intermediate state (PBIS), which provides a new alternative channel for surface electron transfer and consequently accelerates the reaction kinetics.

Photocatalytic Degradation of Gaseous Benzene Using Cu/Fe-Doped TiO2 Nanocatalysts under Visible Light.

Visible-light-enhanced TiO2 nanocatalysts doped with Cu and Fe were synthesized using the sol-gel method to investigate their performance in degrading gaseous benzene. The structure and morphology of mono- and co-doped TiO2 (i.e., Cu/Fe-TiO2, Cu-Fe-TiO2) were characterized using SEM, EDS, XRD, BET, Raman, UV-vis-DRS, and XPS techniques. The results indicated that the presence of Cu/Fe mono- and co-doped TiO2 leads to the formation of an anatase phase similar to pure TiO2. Furthermore, the introduction of Cu/Fe enhanced the presence of lattice defects and increased the specific surface area of TiO2. This enhancement can be attributed to the increase in oxygen vacancies, especially in the case of Cu-Fe-TiO2. Additionally, Cu-Fe-TiO2 showed a higher concentration of surface-bound hydroxyl groups/chemically adsorbed oxygen and a narrower bandgap than pure TiO2. Consequently, Cu-Fe-TiO2 exhibited the highest photocatalytic performance of 658.33 μgC6H6/(g·h), achieving a benzene degradation rate of 88.87%, surpassing that of pure TiO2 (5.09%), Cu-TiO2 (66.92%), and Fe-TiO2 (59.99%). Reusability tests demonstrated that Cu-Fe-TiO2 maintained a high benzene degradation efficiency of 71.4%, even after five experimental cycles, highlighting its exceptional stability and reusability. In summary, the addition of Cu/Fe to TiO2 enhances its ability to degrade gaseous benzene by prolonging the catalyst's lifespan and expanding its photoresponse range to include visible light.

Cleaner Biofuel Production via Process Parametric Optimization of Nonedible Feedstock in a Membrane Reactor Using a Titania-Based Heterogeneous Nanocatalyst: An Aid to Sustainable Energy Development.

Membrane technology has been embraced as a feasible and suitable substitute for conventional time- and energy-intensive biodiesel synthesis processes. It is ecofriendly, easier to run and regulate, and requires less energy than conventional approaches, with excellent stability. Therefore, the present study involved the synthesis and application of a highly reactive and recyclable Titania-based heterogeneous nanocatalyst (TiO2) for biodiesel production from nonedible Azadhiracta indica seed oil via a membrane reactor, since Azadhiracta indica is easily and widely accessible and has a rich oil content (39% w/w). The high free fatty acids content (6.52 mg/g KOH) of the nonedible oil was decreased to less than 1% via two-step esterification. Following the esterification, transesterification was performed using a heterogeneous TiO2 nanocatalyst under optimum conditions, such as a 9:1 methanol-oil molar ratio, 90 °C reaction temperature, 2 wt.% catalyst loading, and an agitation rate of 600 rpm, and the biodiesel yield was optimized through response surface methodology (RSM). Azadhiracta indica seed oil contains 68.98% unsaturated (61.01% oleic acid, 8.97% linoleic acid) and 31.02% saturated fatty acids (15.91% palmitic acid, 15.11% stearic acid). These fatty acids transformed into respective methyl esters, with a total yield up to 95% achieved. The biodiesel was analyzed via advanced characterization techniques like gas chromatography-mass spectrometry (GC-MS), Fourier transform infrared spectroscopy (FT-IR), and nuclear magnetic resonance (NMR), whereas the catalyst was characterized via X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray (EDX), and Fourier transform infrared spectroscopy (FT-IR). Due to its physicochemical properties, Azadirachta indica seed oil is a highly recommended feedstock for biodiesel production. Moreover, it is concluded that the Titania-based heterogeneous nanocatalyst (TiO2) is effective for high-quality liquid fuel synthesis from nonedible Azadirachta indica seed oil in a membrane reactor, which could be an optional green route to cleaner production of bioenergy, eventually leading to sustenance, robustness, and resilience that will aid in developing a holistic framework for integrated waste management.

Catalytic efficiency of encapsulated coupled doped Zn-Ni TiO2 nanocatalyst for the removal of organic pollutants and free radical assay

ABSTRACT In this study, encapsulation of polymer polyvinylpyrrolidone and plant Tinospora cordifolia was done in coupled doped zinc-nickel titanium dioxide (TiO2) nanoparticles (Zn-Ni TDNPs) via using microwave-assisted method with 2.45 GHz operating frequency and power of 700 Watts for about 120 s. The catalytic efficiency of encapsulated TDNPs was analysed through photocatalytic activity against methyl orange (MO) and methylene blue (MB) dyes, which are considered aquatic pollutants released by textiles dyes. Also, these encapsulated TDNPs were installed in scavenging activity to eliminate the free radicals 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. Various physicochemical properties of the encapsulated TDNPs were analysed using different characterisation techniques. The encapsulated TDNPs had a tetragonal crystal lattice structure, with an average particle size ranging from 68 to 83 nm and spheroidal morphology. The bandgap of the encapsulated coupled doped Zn-Ni TDNPs was found to be between 3.48 and 3.55 eV. Under UV radiation, the photocatalytic activity against MO and MB dyes increased with an increase in TDNPs catalyst dosage, and in rare cases, the rate of degradation reached up to 98% for both dyes. Additionally, the encapsulated coupled doped Zn-Ni TDNPs demonstrated antioxidant activity of up to 89% against the DPPH assay.

Solar Chlorine Activation for Efficient Rhodamine B Removal in Strong Basic pH: Processing Conditions, Radicals Probing, and TiO2 Nanocatalyst Effect

In recent years, there has been growing interest in the application of UV/chlorine advanced oxidation processes for wastewater treatment. However, few studies have investigated this process in a strongly basic medium (pH > 10), which is a common characteristic of many industrial effluents. In addition, the use of artificial UV lamps in these processes can be costly. To address these challenges, we investigated the use of solar light (referred to as Solar-L) in the Solar-L/chlorine process for the degradation of Rhodamine B (RhB) in a strongly basic medium (pH 11). We found that separate solar light or chlorination showed no degradation after half an hour, but the Solar-L/chlorine process effectively degraded RhB, with complete removal achieved in only 30 min, using 1000 µM ClO−. The process also resulted in a significant reduction of TOC, i.e., 60% after 120 min and 80% after 240 min. Our results indicate that both •OH/O•− and reactive chlorine species (RCS) were involved in the degradation process, while O3 played no role. The process performance improved with the decreasing initial contaminant concentration and increasing temperature (up to 55 °C). The addition of a TiO2 nanocatalyst to the Solar-L/chlorine system significantly improved the RhB degradation efficiency by more than 30%. It was found that neither adsorption (on TiO2) nor Solar-L/TiO2 photolysis contributed to the dye removal by the Solar-L/chlorine/TiO2 system. Instead, the improvement associated with the Solar-L/chlorine/TiO2 system was related to the involvement of hypochlorite in the photocatalytic reaction at the catalyst surface. A detailed discussion of the effect of TiO2 was carried out based on the physicochemical properties of RhB and TiO2 catalyst with respect to the solution’s pH. In conclusion, this study highlights the potential of solar light as a sustainable and efficient technology for the treatment of polluted water in strong basic media in the presence of chlorine and chlorine/TiO2 as additives. These valuable findings provide a basis for the future research and development of this promising technology for water treatment applications.

Hydrothermally Derived Mg-Doped TiO2 Nanostructures for Enhanced H2 Evolution Using Photo- and Electro-Catalytic Water Splitting

Mg-doped TiO2 nano-structures in different compositions (1, 2.5 and 5%) were successfully synthesized by low-temperature hydrothermal route. X-ray diffraction and electron microscopic studies were used to investigate the crystal structure, surface morphology and particle size of the as-synthesized materials. Raman studies were carried out to elucidate the phase identification and the modes of vibrations to determine the impact of dopant ion on the crystal structures. The band gap was estimated using UV-DRS studies whereas, BET surface area analysis revealed an increase in the surface area of increasing Mg2+ ions concentration in TiO2 nanostructures. Among the synthesized various composition of nano-structures, 5% Mg-doped TiO2 photocatalyst showed maximum hydrogen evolution activity (38.96 mmol gcat−1) in an 8-hour (h) analysis cycle. Moreover, the 2.5% Mg-doped TiO2 nanocatalyst with tafel slopes of 123.5 and 126.7 mV/dec showed strong activity for both HER in 0.5N H2SO4 and 0.1N KOH, with an onset potential of 0.96 V (at 10 mA/cm2) and −1.38 V (at 1 mA/cm2) for HER, respectively. Experimental investigations deduced that the incorporation of Mg2+ ions in the TiO2 resulted in the increase of hydrogen generation catalytic activity of titanium dioxide owing to the synergistic effect provided by the remarkable surface area and the presence of defects introduced by doping.

MXene/Fluoropolymer‐Derived Laser‐Carbonaceous All‐Fibrous Nanohybrid Patch for Soft Wearable Bioelectronics (Adv. Funct. Mater. 21/2023)

Laser-Carbonization In article number 2208894, Jae Y. Park and co-workers, report an electrochemical-electrophysiological multimodal biosensing patch based on MXene/fluoropolymer nanofibers (MFNFs)-derived hierarchical porous TiO2 nanocatalyst interconnected three-dimensional fibrous carbon nanohybrid electrodes. The nanohybrid electrode is produced via a one-step laser carbonaceous thermal oxidation of MFNFs. The nanohybrid modified biosensing patch integrated into textile is demonstrated to be capable of simultaneously and precisely monitoring sweat glucose with pH adjustment and electrocardiogram signals.

Fe2O3-Ag2O/TiO2 Nanocatalyst-Assisted LC-MS/MS-Based Detoxification of Pesticide Residues in Daphnia magna and Algae Mediums

In this work, a simple sensitive validated liquid chromatography mass spectroscopy (LC-MS/MS) analytical method was developed for the determination of Spirodiclofen residues in different aquatic toxic media. The toxic media were those that provide nutrients and help with the growth of different aquatic organisms for their survival and multiplication. The different media were the M4 medium for Daphnia magna and The Organization for Economic Cooperation and Development (OECD TG 201) medium for alga. Fe2O3-Ag2O/TiO2 nanocomposites were prepared by using a precipitation method, which was used as a photo-catalyst for the removal of Spirodiclofen pesticide from aquatic media. The experiment was performed under direct sunlight at a single fortification level (1.0 µg/mL) in M4 and OECD TG 201 media. The optimum catalyst concentration for the complete degradation was found to be 10 mg/L under sunlight. Spirodiclofen residues in water were determined by LC-MS/MS, and the rate constant DT50 (half-life) values were calculated from the obtained data. The results showed that with Fe2O3-Ag2O/TiO2 nanocatalyst, the DT50 (half-life) value was found to be approximately 8 h. These results revealed that iron-oxide- and silver-oxide-incorporated TiO2 nanocomposites were excellent photocatalysts when compared with TiO2, Fe2O3-TiO2, and Ag2O-TiO2 for the decontamination of pesticide residues in aquatic media samples.

Comparative study of TiO2 and palladium doped TiO2 nano catalysts for water purification under solar and ultraviolet irradiation

The photo degradation of Congo red (CR) with TiO2 and TiO2 doped with Pd was investigated. The TiO2 and Pd doped TiO2 nanoparticles were created through solution combustion with glycine as the fuel, and their band gap was determined using UV absorption spectroscopy. All experiments were conducted in natural Sunlight and UV light. Both nanoparticles degraded rapidly at 20 ​ppm dye concentration and 0.1 ​g/1000 ​ml catalyst concentration. It demonstrates that synthesized TiO2 and Pd doped TiO2 nanoparticles can degrade Congo red in an aqueous solution.