Mesoporous Titania Nanoparticles Research Articles

Highly uniform platinum photodeposited hollow mesoporous titania nanoparticles for photocatalytic degradation of phenol

Pt-photodeposited hollow mesoporous titania nanoparticles exhibit excellent phenol degrading photocatalytic efficiency by providing abundant reaction sites, improved mass transport, Pt-enhanced absorption band extension, reduced e− h+ recombination.

Mesoporous CdTe supported SiO2-TiO2 nanocomposite: Structural, optical, and photocatalytic applications

Owing to polluted water remediation, semiconductor nano photocatalysis has been considered a promising methodology. However, low reaction rates and high electron-hole recombination have impeded their large-scale applications. Therefore, heterogeneous nano photocatalysts are required for promoting their functional applications. Here, sol-gel-based mesoporous titania nanoparticles (TNPs) and silica-titania nanocomposite (STNC) are synthesized and supported with CdTe (CdTe/STNC) for photocatalytic applications. Vapor pressure scanning electron microscopy (VPSEM) exhibited the porous and colonial nanostructure of CdTe supported STNC catalyst. The high-resolution transmission electron microscopy (HRTEM) possessed a spherical morphology with particle size 5.6 nm of TNPs, 2.6 nm of STNC, and 2.1 nm of CdTe/STNC. Moreover, the CdTe/STNC catalyst exhibited a large surface area (SBET) ∼ 410 m2/g and pore size distribution ∼ 1.8 nm. The CdTe/STNC exhibited high photocatalytic activity with methylene blue degradation of 95% (k = 0.01 min−1) after 180 min of ultraviolet radiation.

Fabrication of S-scheme TiO2/g-C3N4 nanocomposites for generation of hydrogen gas and removal of fluorescein dye

Herein, an effective S-scheme heterojunctions were fabricated with ultrasonic aspects for effective decomposition of fluorescein dye and evolution of green hydrogen gas. Mesoporous pristine titania nanoparticles with anatase phase structure and 156 m2/g surface area were synthesized by sol-gel mechanism using pluronic solution as templating agent, however, g-C3N4 sheets generated by thermal treatment of urea at 515 °C. The a-synthesized nanocomposites embedded various compositions of g-C3N4 (1−10) wt% were synthesized by ultrasonic pathway. The properties of the specimens were recorded by HRTEM, XRD, DRS, N2-surface area measurement, PL and XPS. The experimental results reveal the noticeably reduction in sample crystallinity and intensity of PL peak with introduction of 8 wt% g-C3N4 supporting the efficient charge carriers separation. The sonicated heterojunction with 8 wt% g-C3N4 is account for decomposition of 94% of fluorescein anionic dye and production of hydrogen gas with rate 4.9 mmolg−1 h−1 which is eleven fold greater than that of pristine TiO2. The strong redox power of this heterojunction is ascribed to step S-scheme mechanism which promote the charge transportation and enhance the separation efficiency of the charge carriers. This charge migration route is established by trapping scavengers and PL experiments. The photocatalytic property of the optimum sample is still with exceptional reactivity for decomposition of anionic dye pollutant and evolution of hydrogen gas after six consecutive cycles.

High electrocatalytic activity of Pt on porous Nb-doped TiO2 nanoparticles prepared by aerosol-assisted self-assembly.

This study explores an aerosol-assisted method to prepare an efficient support for the Pt catalyst of polymer electrolyte membrane fuel cells (PEMFCs). Titania nanoparticles and mesoporous niobium-doped titania nanoparticles were prepared by aerosol-assisted self-assembly using titanium(iv) isopropoxide and niobium(v) ethoxide as the titanium and niobium sources for application as non-carbon supports for the platinum electrocatalyst. The structural characteristics and electrochemical properties of the supports were investigated by transmission electron microscopy, X-ray diffraction, Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, electron paramagnetic resonance, inductively coupled plasma optical emission spectrometry, and dynamic light scattering. The Brunauer–Emmett–Teller method was used to calculate the specific surface areas of the samples, and the pore size distribution was also examined. The results demonstrated that under a radial concentration gradient, the aerosol droplets self-assembled into a spherical shape, and mesoporous supports were obtained after subsequent removal of the surfactant cetyltrimethylammonium bromide by annealing and washing. The hydrothermal technique was then used to deposit platinum on the TiO2-based supports. The electrical conductivity of the non-carbon support was enhanced by the strong metal–support interaction effect between the platinum catalyst particles and the porous niobium-doped TiO2 support. The half-wave potential, electrochemical surface area, mass activity, and specific activity of the obtained Pt/Nb-TiO2 catalyst all surpassed those of commercial Pt/C.

A robust method for the development of mechanically, thermally stable anti-reflective and self-cleaning coatings through in-situ formation of hierarchical raspberry-like mesoporous nanoparticles

A robust formulation was developed to produce anti-reflective and self-cleaning coatings, consisting of hierarchical mesoporous silica, modified mesoporous titania nanoparticles and siloxane resin along with other ingredients. The hierarchical arrangement of nanoparticles by the process of self-assembly along with the polymerization of resin developed hierarchical micro and nanoscale structure on the coated surface because of the in-situ generation of raspberry-like particles during film formation. A systematic study was carried out to investigate the effect of additives on the microstructure, optical property and wettability of the coatings. The optimum composition of the coating has anti-reflective property with maximum transmittance of 99.6% (364 nm) with an absolute increase in transmittance of 5.3% in the wavelength range of 360–600 nm with a contact angle of 140° with water. The addition of Hexamethyldisilazane (HMDS) into the formulation enhanced the hydrophobicity of the coatings by extending the formation of more micro-nano scale structure. Moreover, developed coatings have 5B adhesion, significant humidity resistance, passed the 3H pencil hardness test and are thermally stable up to 250 °C. The developed process is also suitable for low temperature organic substrates, feasible for scale-up production and the stable formulation can be available in a two-pack system.

Insight into the influence of defect sites in mixed phase of mesoporous titania nanoparticles toward photocatalytic degradation of 2‐chlorophenol: Effect of light source

AbstractThe impact of different light irradiation was studied on photocatalytic degradation of 2‐chlorophenol (2‐CP) using mesoporous titania nanoparticles (MTNs) prepared by microwave‐assisted methods. The photoactivity of MTNs was also compared with pretreated commercial TiO2 and Degussa P25 (P25). The reactions were conducted for 2.5 hr under UV‐A, UV‐C, sunlight, and visible light using a batch reactor. The catalysts were characterized by X‐ray powder diffractometer, UV–Vis diffuse reflectance spectroscopy, photoluminescence, Brunauer–Emmett–Teller method, field‐emission scanning electron microscopy, transmission electron microscopy, and X‐ray photoelectron spectroscopy. The characterization results confirmed that MTN consisted a composition of 21% rutile phase and 79% anatase phase with Ti3+ site defects (TSDs) and oxygen vacancies (OVs) in their structures because of their anionic surfactant nature, microwave heating, and high calcination temperature during the catalyst preparation. Besides, the photoactivity of MTN upon degradation of 2‐CP under sunlight has exhibited the best performance with 100% degradation followed by UV‐A, visible light, and UV‐C with degradation of 96, 52, and 39%, respectively. MTNs showed a remarkable performance due to their mixed‐phase crystalline structures as well as the formation of TSDs and OVs, which improved the charge migration, lowered the band gap energy, and reduced the rate of electron–hole recombination, thus succeeded to be activated under a wide range of light responses.

Mesoporous titania nanoparticles as photocatalyst for degradation of 2-chlorophenol

Mesoporous titania nanoparticles (MTN) was successfully prepared by microwave-assisted menthod. The performance of MTN was compared with degussa P25 (commercial TiO2) on photocatalytic degradation of 2-chlorophenol (2-CP). Both catalysts were characterized by XRD, FTIR, UV-Vis DRS and surface area analysis. The characterization data indicated that MTN has higher surface area and lower particle size than P25. The 2-CP was successfully degraded completely under UV light irradiation despite of having a slightly higher band-gap value compared with P25. This study demonstrated that MTN shows a good potential as a photocatalyst.

Rational design of hollow mesoporous titania nanoparticles loaded with curcumin for UV-controlled release and targeted drug delivery

Curcumin (Cur), appeared to provide huge potential in biomedical application. However, its therapeutic efficacy was greatly limited as the result of poor solubility and instability. To address these limitations, we create a new type of hollow mesoporous titania nanoparticle (HMTN) to encapsulate Cur. HMTN was decorated with a layer of hydrophilic polyethylenimine (PEI), which controlled the release rate of Cur inside the pore due to its dendritic structure. Combined with the folic acid (FA) mediated targeting effect, the potential multifunctional Cur loaded titania nanoparticle (Cur-FA-PEI-HMTN) showed excellent biocompatibility and bioavailability, as well as the UV-responsive drug release properties. The operating parameters to prepare hollow structure were studied and the Cur-FA-PEI-HMTN nanosystem had been fully characterized by Brunauer–Emmet–Teller, Fourier transform infrared spectroscopy, transmission electron microscope, thermal gravity analysis, differential thermal analysis, x-ray diffraction, dynamic light scattering and zeta potential. In addition, the hemolytic test, as well as CCK8, flow cytometry, Hoechst 33342 staining experiment, were carried out to confirm the low cytotoxity and high biocompatibility. The confocal microscopy analysis results also revealed the increasing uptake of Cur@FA-PEI-HMTN by MCF-7 cells. The synthesized nanoparticles displayed great potential as drug nanovehicles with high biocompatibility.

Effect of iron loading onto mesoporous titania nanoparticles and its photoactivity

Titania is proven to be one of the best catalysts for various pollutant degradations. However, it can only be activated under UV light. This research was conducted to further enhance the photoactivity of titania under visible light irradiation by doping with iron metal. Different weight loadings of Fe (3, 5, 7 and 10 wt.%) supported on mesoporous titania nanoparticles (MT) were synthesised via a facile in-situ electrochemical method and denoted as 3FMT, 5FMT, 7FMT and 10FMT to degrade 2-chlorophenol (2-CP). These catalysts were characterised by XRD, FTIR and UV-Vis DRS. The photocatalytic activity of 3FMT was the most effective with 98% degradation probably due to its lowest band gap energy. This work showed that the catalyst functioned best with dosage 0.075 g in a solution of pH 5 and a concentration of 10 mg L−1. Therefore, this study showed great enhancement in the photoactivity of the catalysts especially under visible light irradiation by lowering their band gaps.

Effect of microwave power intensity on synthesis of mesoporous titania nanoparticles for degradation of 2,4-dichlorophenol: Photoactivity performance and kinetic studies

In this study, mesoporous titania nanoparticles (MTN) were synthesized via microwave (MW)-assisted method under various heating power (0.12 (MTN1), 0.37 (MTN2) and 0.56 (MTN3) Wg−1). The performance of MTN was investigated on photocatalytic degradation of 2,4-dichlorophenol (2,4-DCP) in aqueous solution using a batch reactor under visible light irradiation. The catalysts were characterized by XRD, UV-Vis DRS, BET and FTIR. The degradation of 2,4-DCP showed that catalyst synthesized at MTN2 was the most effective with 89.43% degradation compared to MTN1 and MTN3 with 82.93% and 86.99%, respectively. This result probably MTN2 has the lowest band gap and highest surface area compared to MTN1 and MTN3. The kinetic studies for degradation 2,4-DCP using MTN2 revealed that the reaction followed pseudo-first order kinetics with reaction rate values (kapp ) decreased as the initial concentration increased that proved the system was preferable at low concentration.

Electrogenerated iron supported on mesoporous titania nanoparticles for the photocatalytic degradation of 2-chlorophenol

In this research, various weight loadings of Fe (3%, 5%, 7%, and 10%) supported on mesoporous titania nanoparticles (MTNs) were prepared using in-situ electrolysis before being characterised using X-ray diffraction, Fourier transform infrared, surface area analysis, UV–vis diffuse reflectance spectroscopy, and X-ray photoelectron spectroscopy. The performance of the Fe–MTN catalysts was investigated under visible light illumination based on the photocatalytic degradation of 2-chlorophenol. Among the catalysts, 3 wt% Fe–MTN demonstrated the highest degradation (99%), followed by 10, 7, and 5 wt% with degradations of 71%, 58%, and 54%, respectively. It has been indicated that the addition of Fe into MTN has enhanced the photocatalytic performance by lowering the catalyst's band gap to improve its efficiency under visible light. The kinetic study has shown that the reaction followed a pseudo-first-order kinetic model and the catalyst remained stable with a slight decrease after five cycles of degradation. Furthermore, the catalyst illustrated a positive performance in photocatalytic degradation of phenolic derivatives.

SYNTHESIS OF MESOPOROUS NANOPARTICLES VIA MICROWAVE-ASSISTED METHOD FOR PHOTOCATALYTIC DEGRADATION OF PHENOL DERIVATIVES

Mesoporous transition metal oxides have gained attention widely since they possess both optical and electronic properties of transition metal oxides especially for photocatalytic degradation application. In this research work, mesoporous titania nanoparticles (MTN) and mesoporous zinc oxide nanoparticles (MZN) were successfully synthesized using microwave (MW)-assisted method to degrade phenol derivatives under visible light irradiation. The microwave sintering effect on the surface of these modified structures was studied to relate with their photocatalytic performance. The characterization results indicated that MW-assisted method was mainly contributed in generating Ti3+ site defects (TSD) and oxygen vacancies (OV) in MTN while for MZN contained only OV as one of the strategies in light-absorption modification for TiO2 and ZnO to enhance their photoactivity. MTN also showed the degradation of 2-chlorophenol was up to 97% while degradation of phenol by MZN was up to 87%.

Ecofriendly, green tea extract directed sol–gel synthesis of nano titania for photocatalytic application

Biomaterial assisted green synthesis of metal oxide nanoparticles plays a vital role as an eco-friendly alternate to chemical templated approach, in enhancing the physico-chemical properties of the solids. Herein, we have reported the synthesis of mesoporous titania nanoparticles by sol–gel method with the assistance of green tea extract (GTE). The synthesized catalysts were characterized using X-ray diffraction (XRD), Fourier transform infrared (FT-IR), Thermo gravimetric (TG), Brunauer-Emmett-Teller (BET), diffused reflectance spectroscopy UV–Visible (DRS-UV), scanning electron microscopy (SEM) and Transmission electron microscopy (TEM) analyses. The resulting nano titania exhibited excellent mesoporosity with increased surface area compared to control nano titania as evidenced from BET analysis. XRD results showed that highly crystalline anatase titania nanoparticles could be derived through controlled hydrolysis. Green tea extract also aided in shifting the optical absorption edge of titania towards the visible light region and enabled nano titania to function as an efficient photocatalyst for the photodegradation of Congo red, a model organic pollutant, under solar irradiation. Green tea extract was proved to be a suitable template for the synthesis of visible light active titania with good crystallite characteristics. Hence, it could be proposed as an environmentally benign alternate to the chemical templates for the sol–gel synthesis of titania nanoparticles.

Hyaluronic acid-capped compact silica-supported mesoporous titania nanoparticles for ligand-directed delivery of doxorubicin

Mesoporous titania nanoparticles (MTN), owing to their high surface area to volume ratio and tunable pore sizes, appear capable of delivering sizable amounts of drug payloads, and hence, show considerable promise as drug delivery candidates in cancer therapy. We designed silica-supported MTN (MTNst) coated with hyaluronic acid (HA) to effectively deliver doxorubicin (DOX) for breast cancer therapy. The HA coating served a dual purpose of stabilizing the payload in the carriers as well as actively targeting the nanodevices to CD44 receptors. The so-formed HA-coated MTNst carrying DOX (HA/DOX-MTNst) had spheroid particles with a considerable drug-loading capacity and showed significantly superior in vitro cytotoxicity against MDA-MB-231 cells as compared to free DOX. HA/DOX-MTNst markedly improved the cellular uptake of DOX in an apparently CD44 receptor-dependent manner, and increased the number of apoptotic cells as compared to free DOX. These nanoplatforms accumulated in large quantities in the tumors of MDA-MB-231 xenograft tumor-bearing mice, where they significantly enhanced the inhibition of tumor growth compared to that observed with free DOX with no signs of acute toxicity. Based on these excellent results, we deduced that HA/DOX-MTNst could be successfully used for targeted breast cancer therapy. Statement of SignificanceThis is the first study to use silica-supported mesoporous titania nanoparticles (MTNst) for doxorubicin (DOX) delivery to treat breast cancer, which exhibited effective and enhanced in vitro and in vivo apoptosis and tumor growth inhibition. Solid silica was used to support the mesoporous TiO2 resulting in MTNst, which efficiently incorporated a high DOX payload. The hyaluronic acid (HA) coating over the MTNst surface served a dual purpose of first, stabilizing DOX inside the MTNst (capping agent), and second, directing the nanoplatform device to CD44 receptors that are highly expressed in MDA-MB-231 cells (targeting ligand). The NPs exhibited highly efficacious in vitro tumor-cell killing and excellent in vivo tumor regression, highlighting the enormous promise of this system for breast cancer therapy.

Polyamino Acid Layer-by-Layer (LbL) Constructed Silica-Supported Mesoporous Titania Nanocarriers for Stimuli-Responsive Delivery of microRNA 708 and Paclitaxel for Combined Chemotherapy.

Cellular Fas-associated protein with death domain-like interleukin-1β-converting enzyme-inhibitory protein (c-FLIP), often strongly expressed in numerous cancers, plays a pivotal role in thwarting apoptosis and inducing chemotherapy resistance in cancer. An integrated approach combining chemotherapy with suppression of c-FLIP levels could prove paramount in the treatment of cancers with c-FLIP overexpression. In this study, we utilized a polymeric layer-by-layer (LbL) assembly of silica-supported mesoporous titania nanoparticles (MTNst) to co-deliver paclitaxel (PTX) and microRNA 708 (miR708) for simultaneous chemotherapy and c-FLIP suppression in colorectal carcinoma. The resulting LbL miR708/PTX-MTNst showed dose-dependent cytotoxicity in HCT-116 and DLD-1 colorectal carcinoma cell lines, which was remarkably superior to that of free PTX or LbL PTX-MTNst. LbL miR708/PTX-MTNst strongly inhibited c-FLIP expression and resulted in increased expression of proapoptotic proteins. In DLD-1 xenograft tumor-bearing mice, the nanoparticles accumulated in the tumor, resulting in remarkable tumor regression, with the PTX and miR708-loaded nanoparticles showing significantly greater inhibitory effects than the free PTX or PTX-loaded nanoparticles. Immunohistochemical analyses of the tumors further confirmed the remarkable apoptotic and antiproliferative effects of the nanoparticles, whereas organ histology reinforced the biocompatibility of the system. Therefore, the LbL miR708/PTX-MTNst system, owing to its ability to deliver both chemotherapeutic drug and inhibitory miRNA to the tumor site, shows great potential to treat colorectal carcinoma in clinical settings.

Fabrication of Mesoporous Titania Nanoparticles with Controlled Porosity and Connectivity for Studying the Photovoltaic Properties in Perovskite Solar Cells

AbstractMesoporous titania (TiO2) nanoparticles (NPs) were synthesized by treating prehydrolyzed titanium precursors with polyethylene glycol (PEG). By varying the amount of PEG, their different physical properties were tuned appropriately in terms of surface area, pore size/volume, and electrical conductivity. By increasing the amount of PEG in TiO2, the surface area and pore volume of mesoporous TiO2 increased, and no direct correlation with the photovoltaic performance of perovskite solar cells was observed. In comparison, the pore size of mesoporous TiO2 first increased greatly before quickly decreasing, and a similar trend was also observed for electrical conductivity. These implied that the interparticle interaction became much stronger with an optimum amount of PEG added to form mesoporous TiO2 NPs. With an optimum molar ratio of PEG/Ti precursor at 0.75, greatly improved conductivity of mesoporous TiO2 NPs with interconnection as compared to that prepared in the absence of PEG, which was used as an electron transport layer, improved the power conversion efficiency of perovskite solar cells by ≈36%. Their greatly reduced photoluminescence after incorporating the perovskite also revealed a difference in the electron‐injection properties from the perovskite into mesoporous TiO2. This strategy highlights a versatile tool to tune mesoporous structures to achieve a cooperative effect for studying photovoltaic properties in perovskite solar cells.

Mesoporous TiO2 Embedded with a Uniform Distribution of CuO Exhibit Enhanced Charge Separation and Photocatalytic Efficiency.

Mixed metal oxide nanoparticles have interesting physical and chemical properties, but synthesizing them with colloidal methods is still challenging and often results in very heterogeneous structures. Here, we describe a simple method to synthesize mesoporous titania nanoparticles implanted with a uniform distribution of copper oxide nanocrystals (CuO@MTs). By calcining a titanium-based metal-organic framework (MIL-125) in the presence of Cu ions, we can trap the Cu in the TiO2 matrix. Removal of the organic ligand creates mesoporosity and limits phase separation so that tiny CuO nanocrystals form in the interstices of the TiO2. The CuO@MTs exhibits superior performance for photocatalytic hydrogen evolution (4760 μmol h-1) that is >90 times larger than pristine titania.

Strategies for introducing titania onto mesostructured silica nanoparticles targeting enhanced photocatalytic activity of visible-light-responsive Ti-MSN catalysts

Titanium-mesostructured silica nanoparticles (Ti-MSN) catalysts which are excellent photocatalytic materials for the environment were prepared by supporting mesostructured silica nanoparticles (MSNs) with titanium species synthesized by three different approaches: microwave and in situ and ex situ electrochemical methods, denoted as Ti-MSN-M, Ti-MSN-I, and Ti-MSN-E, respectively. The physicochemical properties of the catalysts were investigated via XRD, 29Si NMR, N2 adsorption-desorption, FTIR, ESR, and UV-DRS analyses. Characterization results revealed that the introduction of mesoporous titania nanoparticles (MTNs) prepared by the microwave method onto MSNs (Ti-MSN-M) did not significantly affect the silica framework. However, the silica network in the Ti-MSN-I and Ti-MSN-E was rather disrupted, particularly for the former catalyst, due to the desilication accompanied by isomorphous substitution of Ti in the MSN framework to form SiOTi bonds. Ti was also found to be exchanged with the terminal hydroxyl groups of all catalysts to form the SiOTi bonds. The addition of Ti species onto MSNs also increased the number of oxygen vacancies (Vo) and metal defect sites. Photocatalytic testing on the decolorization of Congo red (CR) resulted in the following order: Ti-MSN-I (94%) > Ti-MSN-M (90%) > Ti-MSN-E (34%). The Vo and metal defect sites were responsible in lowering the band gap of catalysts and decreasing the electron–hole recombination, while the great numbers of SiOTi bonds as well as large surface area and pore volume increased the active sites and offered a good surface contact with light to enhance the activity of catalysts. A kinetic study demonstrated that the photodegradation followed the pseudo-first-order Langmuir-Hinshelwood model. Ti-MSN-I and Ti-MSN-M maintained their activities for up to five runs without serious catalyst deactivation, indicating their potential for the degradation of dye in wastewater. Mineralization measurements of CR by TOC and BOD5 analyses after 3 h of contact time were 85.7% and 87.6% using Ti-MSN-M, while 83.7% and 80.3% using Ti-MSN-I, respectively. Optimization by response surface methodology showed that the catalyst dosage, pH, and TiO2 loading were the significant factors in the decolorization of CR. This study demonstrated that these two green technologies; electrochemical and MW have a great potential to be used in synthesis of various advanced materials for greener and more sustainable processes.

Visible-light photoactivity of plasmonic silver supported on mesoporous TiO2 nanoparticles (Ag-MTN) for enhanced degradation of 2-chlorophenol: Limitation of Ag-Ti interaction

Various weight loadings of Ag (1–10 wt.%) were introduced to mesoporous titania nanoparticles (MTN) via a direct in-situ electrochemical method. The catalysts were characterized by XRD, surface area analysis, FTIR, ESR, FESEM-EDX and TEM. Characterization results indicated that the introduction of Ag onto MTN decreased the particles size and band gap of the MTN while increasing the number of oxygen vacancies (OV) and Ti3+ site defects (TSD). The activity performance of Ag-MTN on photodegradation of 2-chlorophenol (2-CP) under visible light irradiation was in the following order: 5wt% Ag-MTN>1wt% Ag-MTN>MTN>10wt% Ag-MTN, with degradation percentages of 97, 88, 80 and 63%, respectively. The synergistic effect between Ag0 and MTN seemed to play an important role in the system. The Ag0 acted as both an electron trap and a plasmonic sensitizer which suppressed the electron-hole recombination, while OV and TSD in the MTN accelerated the production of hydroxyl radicals for enhanced degradation of 2-CP. However, the formation of Ti-O-Ag in 10wt% Ag-MTN was found to decrease the photoactivity due to the decrease in the formation of Ag0, TSD and OV as well as the increase in band gap energy. The photodegradation of 5wt% Ag-MTN followed a pseudo-first-order Langmuir- Hinshelwood model and the catalyst was still stable after five cycles.

Controlled synthesis of mesoporous codoped titania nanoparticles and their photocatalytic activity

The photocatalytic (PC) activity of anatase titania nanoparticles can be improved through codoping with transition metals and nitrogen. In addition, the PC activity can also be improved by creating monodisperse, mesoporous nanoparticles of titania. The question naturally arose as to whether combining these two characteristics would result in further improvement in the PC activity or not. Herein, we describe the synthesis and photocatalytic characteristics of codoped, monodisperse anatase titania. The transition metals tested in the polydisperse and the monodisperse forms were Mn, Co, Ni, and Cu. In each case, it was found that the monodisperse version had a higher PC activity compared to the corresponding polydisperse version.