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TiO2 is the most widely used material in photoelectrocatalytic systems. A key parameter to understand its efficacy in such systems is the band bending in the semiconductor layer. In this regard, knowledge on the band energetics at the semiconductor/current collector interface, especially for a nanosemiconductor electrode, is extremely vital as it will directly impact any charge transfer processes at its interface with the electrolyte. Since direct investigation of interfacial electronic features without compromising its structure is difficult, only seldom are attempts made to study the semiconductor/current collector interface specifically. This work utilizes ultraviolet photoelectron spectroscopy (UPS) to determine the valence band maximum (EVBM) and Fermi level (EF) at different depths in a nano-TiO2/TiN thin-film system reached using an Ar gas-clustered ion beam (GCIB). By combining UPS with GCIB depth profiling, we report an innovative approach for truly mapping the energy band structure across a nanosemiconductor/current collector interface. By coupling it with X-ray photoelectron spectroscopy (XPS), correlations among chemistry, chemical bonding, and electronic properties for the nano-TiO2/TiN interface could also be studied. The effects of TiO2 in situ electrochemical reduction in aqueous electrolytes are also investigated where UPS confirmed a decrease in the semiconductor work function (WF) and an associated increase in n-type Ti3+ centers of nano-TiO2 electrodes post use in a 0.2 M potassium chloride solution. We report the use of UPS to precisely determine the energy band diagrams for a nano-TiO2/TiN thin-film interface and confirm the increase in TiO2 n-type dopant concentrations during electrocatalysis, promoting a much more comprehensive and intuitive understanding of the TiO2 activation mechanism by proton intercalation and therefore further optimizing the design process of efficient photocatalytic materials for solar conversion.

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Plastic waste (PW) has received a lot of attention as a possible additional material for industrial and environmental applications, particularly cement and/or concrete production for a more environmentally and economically sound use of raw materials and energy sources. PW has been investigated as an inert and/or active hydraulic filler for cement and/or concrete by numerous scientists. Plastic garbage is cheap, abundant, and takes long period of time to degrade in the eco-system (soil and water). The main goal of the ongoing research is to offer safety and efficacy by partially substituting nano-plastic waste (NPW), incorporated with nano-titania (NT), for the composition of white cement (WC). Blends are built up by substitution of WC with different ratios of NPW incorporated with fixed ratios of nano-titania (1.0 wt.%). Workability, physical, mechanical and microstructural properties have gone through laboratory and instrumental analysis. The results showed improvement in the compressive strength, density and microstructure due to the effective impact of fillers. Consequently, a decrease in total porosity, whiteness reflection (Ry) and early-rapid expansion. Eventually, the outcomes may reduce the pandemic strength, especially in the external environment, and other epidemics.

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Titanium dioxide nanoparticles (TiO2 NPs) are among the most commonly used nanomaterials and are most likely to end up in soil. Therefore, it is pertinent to study the interaction of TiO2 NPs with soil microorganisms. The present in vitro broth study evaluates the impacts of low-dose treatments (0, 1.0, 5.0, 10.0, 20.0, and 40.0 mg L-1 ) of TiO2 NPs on cell viability, morphology, and plant growth promoting (PGP) traits of rhizobia isolated from mung bean root nodule. Two types of TiO2 NPs, that is, mixture of anatase and rutile, and anatase alone were used in the study. These TiO2 NPs were supplemented in broth along with a multifunctional isolate (Bradyrhizobium sp.) and two reference cultures. The exposure of TiO2 (anatase+rutile) NPs at low concentrations (less than 20.0 mg L-1 ) enhanced the cell growth, and total soluble protein content, besides improving the phosphate solubilization, Indole-3-acetic acid (IAA) production, siderophore, and gibberellic acid production. The TiO2 (anatase) NPs enhanced exopolysaccharide (EPS) production by the test rhizobial cultures. The radical scavenging assay was performed to reveal the mode of action of the nano-TiO2 particles. The study revealed higher reactive oxygen species (ROS) generation by the TiO2 (anatase) NPs as compared with TiO2 (anatase+rutile) NPs. Exposure to TiO2 NPs also altered the morphology of rhizobial cells. The findings suggest that TiO2 NPs could act as promoters of PGP traits of PGP bacteria when applied at appropriate lower doses.

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This work addresses two research topics: the first concerns the specific/sensitive trapping of hydroxyl radicals (•OH), and the second concerns the efficacy of encapsulating natural antioxidants, potentially lengthening their preservation activity. For context, nano-titania was solar-irradiated to produce •OH, which was spectrofluorimetrically assessed, based on the selective aromatic hydroxylation of the non-fluorescent sodium terephthalate to 2-hydroxyterephthalate fluorophore. Fluorescence intensity is proportional to generated •OH. Thus, a simple/rapid indirect method was utilized to assess •OH precisely. Accordingly, novel photoluminescent system is outlined in order to assess the scavenging potentiality of •OH in date seed oil (DSO) in both its pure and encapsulated formulations (ECP-DSO), i.e., when fresh and 5 months after extraction and encapsulation, respectively. With the addition of 80 µg/mL DSO or ECP-DSO, the efficacy of •OH scavenging amounted to 25.12 and 63.39%, which increased to 68.65 and 92.72% when 200 µg/mL DSO or ECP-DSO, respectively, was added. Moreover, the IC50 of DSO and ECP-DSO is 136.6 and 62.1 µg/mL, respectively. Furthermore, DSO and ECP-DSO decreased the kinetics for producing •OH by ≈20 and 40%, respectively, relative to •OH generated in the absence of antioxidant. This demonstrates the benefits of encapsulation on the preservation activity of natural antioxidants, even after five months after extraction, in terms of its interesting activity when compared to synthetic antioxidants. The developed fluorimetric •OH probing upgrades antioxidant medicines, thus paving the way for theoretical/practical insights on mechanistic hydroxyl radical-damaging biology.

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Titanium dioxide nanoparticles (nano-titania/TiO2 NPs) are used in different fields and applications. However, the release of TiO2 NPs into the environment has raised concerns about their biosafety and biosecurity. In light of the evidence that TiO2 NPs could be used to counteract antibiotic resistance, they have been investigated for their antibacterial activity. Studies reported so far indicate a good performance of TiO2 NPs against bacteria, alone or in combination with antibiotics. However, bacteria are able to invoke multiple response mechanisms in an attempt to adapt to TiO2 NPs. Bacterial adaption arises from global changes in metabolic pathways via the modulation of regulatory networks and can be related to single-cell or multicellular communities. This review describes how the impact of TiO2 NPs on bacteria leads to several changes in microorganisms, mainly during long-term exposure, that can evolve towards adaptation and/or increased virulence. Strategies employed by bacteria to cope with TiO2 NPs suggest that their use as an antibacterial agent has still to be extensively investigated from the point of view of the risk of adaptation, to prevent the development of resistance. At the same time, possible effects on increased virulence following bacterial target modifications by TiO2 NPs on cells or tissues have to be considered.

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This study explains the use of a ultrafiltration membrane made of polyvinyl pyrrolidone (PVP) and poly(ether ether sulfone) (PEES)/Nano-titania (n-TiO2) for the separation of organic compounds. The results of the tests for porosity, water content, surface chemistry, membrane morphology, and contact angle demonstrated that the developed membranes have more hydrophilicity than PEES membranes due to the redundant hydrophilic nature of PVP and n-TiO2. The membrane pure water flux, which contains 5 wt% PVP and 1.5 wt% n-TiO2, was 312.76 Lm-2h-1, about three-fold higher than that of pristine membrane (95.71 Lm-2h-1). Employing bovine serum albumin as a model foulant, the fouling resistance of the PEES/PVP/n-TiO2 membrane was examined. According to the analysis of flux recovery ratio and irreversible resistance, modified membranes were less likely to foul, and the PEES/n-TiO2 membrane with 5% PVP addition was recommended as optimal. The fabricated membranes effectively removed more than 95% of various organic compounds such as humic acid, safranin O, egg albumin, pepsin, and trypsin from aqueous solution. Permeability of safranin O and humic acid of PEES/PVP/n-TiO2 membranes was about 118 Lm-2h-1 and 138 Lm-2h-1, respectively.

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Nano-titania (n-TiO2), due to its unique photocatalytic and hydrophobic properties, can be used to prepare self-cleaning cement-based smart building materials. The n-TiO2 degrades organic and inorganic pollutants through its photocatalytic action and convert them into non-toxic byproducts, i.e., improves the air quality. In this review, aspects such as methodologies of n-TiO2 synthesis, approaches for n-TiO2 loading on cementitious materials, photocatalytic properties, self-cleaning mechanism, and application of n-TiO2 in cement-based materials have been overviewed. Further, the n-TiO2 can be used either as coatings or admixtures in pavement blocks, mortars/concrete at zebra crossings, road dividers and linings, and high rise buildings. Moreover, the implications and economic aspects of n-TiO2 usage in cement-based materials revealed that n-TiO2 increases the material cost by ~ 27%, (101 to 128.1$) in comparison to conventional building materials. Furthermore, the low-cost carbonized materials such as biochars have been suggested to be used as support of n-TiO2 to lower the cost and improve the remediation efficiency of photocatalytic concrete.

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The study is aimed to synthesize potent metal oxide based biomimetic nanocomposites to overcome the risk associated with artificial bone tissue engineering. High purity TiO2 nanoparticles are synthesized via hydrothermal route. A biomimetic nanocomposite scaffolds containing chitosan-sodium alginate (4: 4) blended with three different (0.5, 1, and 1.5 wt%) concentrations of hydrothermally synthesized TiO2 nanoparticles are obtained by solvent casting technique. The physico-chemical and thermal degradation properties of as-synthesized TiO2 nanoparticles and their nanocomposite scaffolds are analyzed. In-vitro cytotoxicity and biocompatibility of the prepared TiO2 nanoparticles and nanocomposites are tested against human bladder tumor (UC6) and osteosarcoma (MG-63) cell lines. Antibacterial property is tested against Escherichia coli and Staphylococcus aureus. These studies reveal that TiO2 nanoparticles and polymeric nanocomposites contain good physico-chemical and mechanical properties for enhanced in-vitro biocompatibility suitable for biomedical applications. Biomimetically prepared chitosan-sodium alginate scaffold containing TiO2 nanoparticles (1 wt%) is found to exhibit superior biocompatibility for bone tissue engineering applications.

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Nanoscopic properties of TiO2 augmented with its physicochemical properties and biocompatibility make it a material interest in the biomedical field. Efficient methods to design of such materials require a thorough understanding of associated nano-bio interfaces. In the present study, density functional theory calculations were performed to study the interactions of arginine, cysteine and guanine with a nano-TiO2 cluster. Different configurations were sampled for the adsorption of arginine, cysteine and guanine to probe the nano-bio interface via the interaction of various functional groups present on biomolecules. Adsorption energies for arginine, cysteine and guanine were in a range of -25.0 to -57.6, -12.1 to -29.6 and -45.6 to -58.7 kcal/mol, respectively. From the change in adsorption energies and free energies, interaction of amino acids with carboxylic (COOH), thiol (SH) and amine (NH2) groups while the interaction of the nucleobase via O bonded to C and N of purine ring was found to be essential for thermodynamically stable and energetically favorable states. Density of states analysis also disclosed the prominent interactions of the biomolecules with the nano-TiO2 cluster. Decrease in band gaps on adsorption of the biomolecules was a pertinent phenomenon indicating the strong chemical interactions of the biomolecules with the nanoscopic TiO2 chosen for analysis in this study.

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In this study, three batches of nano-titania functionalized covalent organic frameworks were acquired depending on different solvothermal reaction stages (24 h, 48 h and 72 h), which were named as single roll-up shaped nano-titania functionalized COFs (SSTF-COFs), double roll-up shaped nano-titania functionalized COFs (DSTF-COFs) and clover-shaped nano-titania functionalized covalent organic framework (CSTF-COFs), respectively. After comparing their extraction performances, the more efficient and stable CSTF-COFs were selected as sorbent for the dispersive solid phase extraction (dSPE) of eight target N-nitrosamines in drinking water, followed by the determination with liquid chromatography-tandem quadrupole mass spectrometry (LC-MS/MS). Owing to the introduction of hydroxy groups, CSTF-COFs showed high extraction efficiency for N-nitrosamines with a wide range of polarities through hydrogen bonding interaction, hydrophobic interaction and hydrophilic interaction. Under optimum conditions, the developed method provided relatively low limits of detection (0.13-2.45 ng/L) and satisfactory recoveries (88.6-105.5%), with relative standard deviations (RSDs) less than 8.3%. Therefore, with the assistance of CSTF-COFs, trace levels of N-nitrosamines were quantitatively and sensitively determined in 31 out of 460 bottled drinking water samples in a sensitive and convenient way.

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A novel nano-titania modified covalent organic frameworks (NTM-COFs) has been synthesized and characterized by transmission electron microscopy (TEM) and scanning electron micrographs (SEM). Besides, NTM-COFs, as efficient sorbent, has also been evaluated in the on-line pass-through cleanup procedure prior to the analysis of local anesthetic drugs (lidocaine, bupivacaine and tetracaine) in human plasma by liquid chromatography-tandem quadrupole mass spectrometry (LC-MS/MS). Under optimum conditions, the level of matrix effects can be dramatically reduced by the NTM-COFs based on-line pass-through cleanup procedure, with acceptable recoveries ranging from 88.8% to 103%. Satisfactory trueness and precision of the proposed method were also obtained, with the within- and between-run RSDs less than 7.0% and relative error (REs) less than 12%. The limits of detections (LODs) of lidocaine, bupivacaine and tetracaine were 0.029 µg·L-1, 0.027 µg·L-1 and 0.016 µg·L-1, respectively. The analytical method has been successfully applied for the determination of the plasma concentrations of bupivacaine in five parturients who received an epidural administration of bupivacaine hydrochloride during vaginal delivery. Results demonstrate the applicability of the developed NTM-COFs on-line pass-through cleanup procedure coupled with LC-MS/MS method to clinical studies.

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AIM AND OBJECTIVE: Benzodiazepines and indole fused heterocycles are pharmacologically significant scaffolds. Trivial work on indole fused benzodiazepine compounds is reported in the literature. Hence, it is imperative to explore the synthesis of indole-fused benzodiazepines that may act as a template for biological studies in the future. Hence, in the present work, the synthesis of indole fused benzodiazepine derivatives was undertaken using multi-phase nano-titania as catalyst under microwave irradiation. MATERIALS AND METHODS: MAOS technique was used to carry out the synthesis of spiro-benzo [1,4]diazepine derivatives in the presence of multiphase nano-titania as a catalyst. Nano-titania was prepared by sol-gel method and characterized by XRD, FT-IR, FESEM, EDS and thermogravimetric techniques. The synthesized spiro-benzo [1,4] diazepine derivatives were identified by physical and spectral methods. RESULTS: Synthesized compounds were obtained in excellent yields in a short span of time. The synthesis was also carried out in the presence of conventional catalysts in addition to nano-titania. Among all the catalysts, the best result was obtained with nano-titania. The amount of nano-titania was optimized to be 0.05g giving 93- 95% yield of products. The study of reusability of nano-titania revealed that it could be reused up to four times with a negligible change in efficiency. CONCLUSION: The paper reports an efficient, cost-effective and environmentally benign approach for the synthesis of spiro-benzo [1,4] diazepine derivatives in the presence of multiphase nano-titania catalyst under microwave irradiation.

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To develop a rapid, effective, and accurate method for the simultaneous determination of chloramphenicol, thiamphenicol, and florfenicol in human blood by pass-through cleanup solid-phase extraction combined with liquid chromatography-tandem mass spectrometry (LC-MS/MS), novel nano-titania-coated modified magnetic graphene oxide (TiO2-Mag-GO) is used as the PRiME pass-through cleanup solid-phase extraction sorbent for the cleanup of blood phospholipids. The chromatographic separation was performed on an Eclipse Plus C18 column (100 mm×2.1 mm, 1.8 µm) using 0.08% (v/v) aqueous ammonia solution and acetonitrile having aqueous ammonia (0.08%, v/v) as mobile phases. The tandem mass spectrometer was operated using electrospray ion source (ESI) in the multiple reaction monitoring (MRM) mode. The results showed that the linearities were in the range of 0.1-10.0 µg/L with the determination coefficients (r2) greater than 0.9990 for chloramphenicol, thiamphenicol, and florfenicol. The limits of quantification (LOQs) (S/N>10) in the blood samples were between 0.056 and 0.082 µg/L and the recoveries ranged from 90.0% to 105% at three spiked levels. Precision values expressed as relative standard deviations (RSDs) were in the range of 1.2%-6.6%. The developed method can be used for routine analyses to determine chloramphenicol, thiamphenicol, and florfenicol in clinical studies.

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A novel hydrophilicity nano-titania coating modified magnetic graphene oxide (HTC-Mag-GO) has been synthesized. It has been evaluated in PRiME (process, robustness, improvements, matrix effects, ease of use) pass-through cleanup procedure for human blood prior to analysis of fipronil and its metabolites, i.e., fipronil sulphone, fipronil sulphide and fipronil desulfinyl by liquid chromatography-tandem quadrupole mass spectrometry (LC-MS/MS). Compared with the Oasis PRiME HLB cartridge, HTC-Mag-GO is much more effective for the removal of matrix effect. Furthermore, it is beneficial to protect the chromatographic column and ESI source by the HTC-Mag-GO PRiME pass-through cleanup procedure, resulting from the much cleaner blood samples. Under the optimum conditions, the results show higher cleanup efficiency of HTC-Mag-GO with recoveries in the range of 92.4%-108%. Especially, the HTC-Mag-GO is also evaluated for reuse (20 times) without much sacrifice of the cleanup efficiency. The limits of quantification (LOQs) for fipronil, fipronil sulphone, fipronil sulphide and fipronil desulfinyl are 8.9 ng/L, 7.2 ng/L, 8.0 ng/L and 42 ng/L, respectively. The developed method has also been successfully applied to monitoring fipronil and its metabolites in 120 blood samples, and fipronil sulphone is detected in six samples with concentrations in the range of 12.1 ng/L-106 ng/L. Further, the well validation results and the application to analysis of fipronil and its metabolites in real samples demonstrate the applicability to toxico kinetic studies and clinical studies.

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The combined effects of climate change and chemical contaminants on plant performance are still not well understood. Especially, whether different sexes of dioecious plants respond differently to combined stresses is unknown. In order to study the sex-related responses of European aspen to soil nTiO2 contamination (0, 50, 300 mg kg-1) under elevated temperature (+1.6 °C) and CO2 (730 ppm), we conducted a study in greenhouses. Ti accumulated in roots exposed to nTiO2 (1.1-3.3 and 2.7-21.1 mg kg-1 in 50 and 300 mg kg-1 treatments, respectively). Elevated CO2 had no effects on Ti uptake, while elevated temperature increased it in the 300 mg kg-1 treatment. Males grew taller than females under ambient conditions, but females had greater height and biomass increment under elevated temperature. In all climate treatments, nTiO2 increased leaf phenolics in females by 12-19% and 15-26% at 50 and 300 mg kg-1, respectively. Leaf phenolics decreased under elevated temperature, but increased under elevated CO2 in both sexes. Results suggest that females have better chemical defense against nTiO2 than males under future climate conditions. In the longer run, this may cause changes in the competitive abilities of both sexes, which again may affect sex ratios and genetic variation in nature.

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A number of materials are now available to alleviate the ever-growing bone disruption. However, these are inadequate and inappropriate for addressing issues associated natural process of aging and degeneration of bone due to diseases. This study advances the existing material and offers more privileged and synergistically active remedy for these conditions. Here, they are three different nano-composites prepared such as nano-TiO2 with chitosan (TC), nano-TiO2 with chondroitin 4-sulfate (TG), and nano-TiO2 with chitosan and chondroitin 4-sulfate (TCG), whereas nano-TiO2 act as a control. The prepared nanocomposite was studied for determining its bactericidal and fungicidal activity by using disk diffusion method. In addition, the osteoinductive, free radical forming, and scavenging abilities of the nanocomposite treated MG-63 cell lines were analyzed using gene expression and biochemical analysis respectively. The augmented fungicidal (~16mm) activities of TCG against bone-infecting pathogens can be effectively used in bone transplantation application. The expression of osteoblast-inducing genes in MG-63 cell line and their up-regulation in nanocomposite treatment, especially in TCG, made this material more desirable. The formation of free radicals such as thiobarbituric acid reactive substance and nitric oxide gradually reduced with the treatment of nanocomposites than control and nano-TiO2. Contrarily, it was found that MG-63 along with nanocomposites statistically increases the production of ALP, antioxidant enzymes (super oxide mutase) and total antioxidant activity (ferric reducing antioxidant power) in several folds compare with the control and nano-TiO2. All the results with statistical scale suggest TCG as an effectual and affordable biomaterial in bone regeneration therapy among the prepared samples.

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Antimony is classified as a pollutant of priority importance by USEPA. We have earlier reported the synthesis of nano-titania impregnated epichlorohydrin crosslinked chitosan (TA-Cts-Epi) beads, in a format suitable for large scale applications with high sorption capacity for antimony. To understand the sorption mechanism, and to fine tune the bead composition, the effect of crosslinking density on the swelling and sorption properties of the beads was investigated in detail. Epichlorohydrin effected significant changes in physical and sorption properties of the beads. The antimony sorption capacity of the TA-Cts-Epi beads prepared by crosslinking 0.3g non-crosslinked titania-chitosan beads (TA-Cts-NCL) with 6.4mmol epichlorohydrin was 493µmol/g, while those crosslinked with 0.64mmol showed a capacity of 133µmol/g. Whereas, TA-Cts-NCL beads showed a capacity of 75µmol/g. The increase in uptake capacity with increase in crosslinking demonstrated the active involvement of the epichlorohydrin moieties in antimony binding leading to enhanced sorption. Apart from altering the stability, swelling behaviour and sorption kinetics of the beads, crosslinking significantly increased the uptake of the anionic species via electrostatic interactions. Epichlorohydrin crosslinked chitosan beads prepared without TiO2 also showed similar behaviour. The results demonstrated the involvement of chitosan, TiO2 and epichlorohydrin in sorption.

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Changes in tissue transcriptomes and productivity of Arabidopsis thaliana were investigated during exposure of plants to 2 widely used engineered metal oxide nanoparticles, titanium dioxide (nano-titania) and cerium dioxide (nano-ceria). Microarray analyses confirmed that exposure to either nanoparticle altered the transcriptomes of rosette leaves and roots, with comparatively larger numbers of differentially expressed genes found under nano-titania exposure. Nano-titania induced more differentially expressed genes in rosette leaves, whereas roots had more differentially expressed genes under nano-ceria exposure. MapMan analyses indicated that although nano-titania up-regulated overall metabolism in both tissues, metabolic processes under nano-ceria remained mostly unchanged. Gene enrichment analysis indicated that both nanoparticles mainly enriched ontology groups such as responses to stress (abiotic and biotic), and defense responses (pathogens), and responses to endogenous stimuli (hormones). Nano-titania specifically induced genes associated with photosynthesis, whereas nano-ceria induced expression of genes related to activating transcription factors, most notably those belonging to the ethylene responsive element binding protein family. Interestingly, there were also increased numbers of rosette leaves and plant biomass under nano-ceria exposure, but not under nano-titania. Other transcriptomic responses did not clearly relate to responses observed at the organism level, possibly because of functional and genomic redundancy in Arabidopsis, which may mask expression of morphological changes, despite discernable responses at the transcriptome level. In addition, transcriptomic changes often relate to transgenerational phenotypic development, and hence it may be productive to direct further experimental work to integrate high-throughput genomic results with longer term changes in subsequent generations. Environ Toxicol Chem 2017;36:71-82. Published 2016 Wiley Periodicals Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America.

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The use of nanoparticles in food or pharma requires a molecular-level perceptive of how NPs interact with protein corona once exposed to a physiological environment. In this study, the conformational changes of bovine serum albumin (BSA) were investigated in detail when exposed to different concentration of titanium dioxide nanoparticle by various techniques. To analyze the effects of NPs on proteins, the interaction between bovine serum albumin and titanium dioxide nanoparticles at different concentrations were investigated. The interaction, BSA conformations, kinetics, and adsorption were analyzed by dynamic light scattering, Fourier transform infrared spectroscopy and fluorescence quenching. Dynamic light scattering analysis confirms the interaction with major changes in the size of the protein. Fluorescence quenching analysis confirms the side-on or end-on interaction of 1.1 molecules of serum albumin to titanium dioxide nanoparticles. Further, pseudo-second order kinetics was determined with equilibrium contact time of 20min. The spectroscopic analysis suggests that there is a conformational change both at secondary and tertiary structure levels. A distortion in both α-helix and ß-sheets was observed by Fourier transform infrared (FTIR) spectroscopy. Fluorescence quenching analysis confirms the interaction of a molecule of bovine serum albumin to the single TiO2 nanoparticle. Further, pseudo-second order kinetics was determined with equilibrium contact time of 20min. The data of the present study determines the detailed evaluation of BSA adsorption on TiO2 nanoparticle along with mechanism and adsorption kinetics.

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The adsorption and photocatalytic degradation of gaseous benzene were investigated considering the operating variables and kinetic mechanism using nano-titania agglomerates in an annular fluidized bed photocatalytic reactor (AFBPR) designed. The special adsorption equilibrium constant, adsorption active sites, and apparent reaction rate coefficient of benzene were determined by linear regression analysis at various gas velocities and relative humidities (RH). Based on a series of photocatalytic degradation kinetic equations, the influences of operating variables on degradation efficiency, apparent reaction rate coefficient and half-life were explored. The findings indicated that the operating variables have obviously influenced the adsorption/photocatalytic degradation and corresponding kinetic parameters. In the photocatalytic degradation process, the relationship between photocatalytic degradation efficiency and RH indicated that water molecules have a dual-function which was related to the structure characteristics of benzene. The optimal operating conditions for photocatalytic degradation of gaseous benzene in AFBPR were determined as the fluidization number at 1.9 and RH required related to benzene concentration. This investigation highlights the importance of controlling RH and benzene concentration in order to obtain the desired synergy effect in photocatalytic degradation processes.

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