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This study describes the results of synthesizing MIL-100(Fe) materials by hydrothermal method. The results show that the material has an octahedral structure, with a large BET surface area (1820 m2/g). The synthesized materials were capable of adsorption more than 53 % of NOx gas and over 84 % of acetone vapor by mass. The crystalline structure and octahedral shape of material were not changed after adsorption. The investigation of re-adsorption show that the material retains its adsorption capacity after many uses.

Studying Thelypteridaceae in Phia Oac - Phia Den National Park in Cao Bang province, the authors determined that the family Thelypteridaceae includes 8 genera and 12 species. Compared with previous studies, the number of species belonging to the family Thelypteridaceae has increased by 3 species. In addition, the authors have updated the correct nomenclature name of a number of species in the family Thelypteridaceae. Pronephrium is genus with the largest number of species with 4 species (accounting for 33.3%), there is 1 genus with 2 species and 6 genera with 1 species. Within the scope of this paper, the authors have made statistics on the number of species, the number of genera belonging to the family Thelypteridaceae; describe the identification characteristics, where the standard samples were collected (loc. class.), information on the standard specimens of each species (typus), biology and ecology, and distribution of species in the family Thelypteridaceae is distributed in Phia Oac - Phia Den National Park, Cao Bang province.

The genus Amblovenatum J.P. Roux is a small genus in the Thelypteridaceae. Previously, the genus Amblovenatum was named Amphineuron (Holttum, 1971). In 2007, David Middleton argued for the homonyms between the genus Ampineuron (Thelypteridaceae) and the genus Amphineurion (Apocynaceae). By 2009, the name Amblovenatum was used by J.P. Roux to replace the name Amphineuron. The genus Amblovenatum J.P. Roux has outstanding features in fronds, laminae, pinnae, lobes, segments, veinlets, sori, indusia, sporangia. Species of the genus Amblovanatum are distributed from East Africa to Polynesia; India to Northeast Australia; the remainder in Malesia and the Pacific, especially in New Guinea, and has been reported to be distributed in Vietnam. The study added information and explanations on the genus name change and updated the new name of the genus Amblovenatum. Description the morphological characteristics of the genus Amblovenatum, distribution, ecological biology, type; species description Amblovenatum terminans (Hook.) J.P. Roux includes scientific name, Vietnamese name, distribution, ecology, type, examined specimens.

This study examined140 relevant publications from the last few years (2018-2021). In this study, classification was reviewed depending on the operation's progress. Electrocoagulation (EC), electrooxidation (EO), electroflotation (EF), electrodialysis (ED), and electro-Fenton (EFN) processes have received considerable attention. The type of action (individual or hybrid) for each electrochemical procedure was evaluated, and statistical analysis was performed to compare them as a new manner of reviewing cited papers providing a massive amount of information efficiently to the readers. Individual or hybrid operation progress of the electrochemical techniques is critical issues. Their design, operation, and maintenance costs vary depending on the in-situ conditions, as evidenced by surveyed articles and statistical analyses. This work also examines the variables affecting the elimination efficacy, such as the applied current, reaction time, pH, type of electrolyte, initial pollutant concentration, and energy consumption. In addition, owing to its efficacy in removing toxins, the hybrid activity showed a good percentage among the studies reviewed. The promise of each wastewater treatment technology depends on the type of contamination. In some cases, EO requires additives to oxidise the pollutants. EF and EFN eliminated lightweight organic pollutants. ED has been used to treat saline water. Compared to other methods, EC has been extensively employed to remove a wide variety of contaminants.

The purpose of this study was to examine the application of the mathematical model of drift flux to the experimental results of the effect of cationic trimethyl-ammonium bromide (CTAB)-aided continuous foam flotation harvesting on the lipid content in Chlorella vulgaris microalgae. An experiment was conducted to determine the effect of the operating conditions on the enrichment factor (EF) and percentage recovery efficiency (%RE), where the flow rates at the inlet and bottom outlet remained constant. Data for the binary system (without algae) and ternary system (with algae) in an equal-area foam column show that the EF decreases linearly with increasing initial CTAB concentrations ranging from 30 to 75 mg/L for three levels of the studied air volumetric flow rate range (1-3) L/min. The percentage harvesting efficiency increased with increasing initial CTAB concentration and air volumetric flow rate to 96 % in the binary systems and 94 % in the ternary systems. However, in the foam column with the riser used in the three systems, a lower volume of liquid foam in the upward outlet stream resulted in a lower RE% than that of the column without the riser. The objective function of EF for the system with algae increased when the initial CTAB concentration was increased from 30 to 45 mg/L in the foam column with a riser for all air flow rates, and after 45 mg/L, a sudden drop in the microalgae EF was observed. In the comparison between the foam column with and without the riser for the system with algae, the optimum EF was 145 for the design of the column with the riser and 139 for the column without the riser.

This paper describes a novel process for the synthesis of TiO2 from titanium slag, which is realized via roasting titanium slag with KHSO4, acid leaching and hydrolysis. The results showed that the optimum conditions were a mass ratio of KHSO4 to titanium slag of 6, a temperature of 600 oC for 1,5 hours. Besides, this study investigated the possibility of synthesized TiO2 for photocatalytic degradation of methylene blue.

In this work, the THF/H2O mixture was employed to synthesize the nanostrucuted 5,10,15,20-tetra(3,4,5-trimethoxyphenyl) porphyrin (TTOP) via solvophobic self-assembly. The resultant porphyrin nanomaterial was characterized using photoluminescence (PL), UV-vis spectroscopy, and scanning electron microscopy (SEM). The prepared self-assembled porphyrin was in structures of rod-like, cubic-lik, and particles forms. These porphyrin crystals showed high photocatalytic performance for the degradation of RhB under simulated sunlight irradiation, especially with the porphyrin crystal formed with the water fraction of 80 and 90%.

The failure of the centralized water supply system forced XY community to become more dependent on uncertain and unstable water sources. The results of surveying 50 households showed that 89.18% of total households depended on water collected from rivers, which contributed 58.3% of the total water volume used for the domestic demands. The average water volume consumed was 19.5 liters/person/day (l/p/d), and 86.5% of households used more than one source; 13.5% of households collected water only from rivers, and 45.94% of families had rainwater harvesting (RWH) for their activities (domestic water demand); however, RWH only provided 9.9% of total water consumption. In this study, basic methods were applied to calculate the storage tanks necessary to balance the water deficit created by drought months. Three levels of water demand (14, 20, and 30 l/p/d) can be the best choices for RWH; for a higher demand (40 and 60 l/p/d), small roof area (30-40 m2), and many people (six to seven) per family, RWH might be impractical because of unsuitable rainfall or excessively large storage tanks.

This work aims to modify the copper ferrite with a porphyrin derivatives by a simple method of self-assembly. The resultant porphyrin-modified copper ferrite was utilized as a photocatalyst for the removal of methyl blue dyes (MB) from aqueous solution. The results showed that the porphyrin nanofibers were well-intergrated with the copper ferrite nanoparticles. The porphyrin-modified copper ferrite materials exhibited the high photocatalytic performance toward MB dye with the removal percentage of approximately 100% after 200 minutes of irradiation under simulated light. The catalyst could be facilely separate by using a external magnet and reused.

In this manuscript, biological durability, cytotoxicity and MRI image contrast effect of chitosan modified magnetic nanoparticles were investigated. The result of durability study shows that the asprepared sample with average size of about 30 nm had a high stability under pH conditions in range of from 2 to 12 and at salt concentration in range of from 0 to 300 mM. The cytotoxicity testing indicates that the obtained Fe3O4@CS ferrofluid revealed a low cytotoxicity. After 48 h of test on the line of prostate tumor cells of Sarcoma 180, collected IC50 value was 178.5±22 (μg/ml), 7.5 to 27.9 times less cytotoxicity than that of reported ferromagnetic fluids. MRI data shows that the transverse relaxation rate (r2) of the ferrite nanoparticles was 130.32 (mM−1s−1), 2 and 1.44 times larger than that of the commercial products of Sinerem (AMI-227) and Ferumoxytol products, respectively. Invivo test in rabbit shows that the picture of body parts was clearly observed after the injection of the Fe3O4@CS ferrofluid. With these outstanding properties, this magnetic fluid based on the chitosan modified Fe3O4 nanoparticles had great potential for enhancing the image contrast in image diagnosis by MRI magnetic resonance imaging technique.

In this study, iron benzenedicarboxylate framework/graphene nanoplatelets (MIL-100(Fe)/GNPs) composites have been synthesized. As-prepared composite materials were characterized by XRD, SEM, FTIR techniques, UV-VIS diffuse reflectance.

Porous carbon material is one of the most common and very important for various applications thank to its high surface area and adsorption capability. In this study, mesoporous carbon was prepared by thermal decomposition of copper-based metal-organic framework MOF-199 under inert atmosphere and followed by immersing in diluted HNO3 solution in order to remove metal/metal oxide and activation of the resultant porous carbon. Scanning electron microscopy (SEM) revealed that as-prepared material remained intact octahedral morphology of pre-pyrolysis MOF structure, and product has spongy structure with specific surface area of 375 m2/g as measured using N2 adsorption isotherm (BET), which can be employed as an effective adsorbent.

In this study, iron nanomaterial was synthesized by a reaction between FeCl3 and NaBH4 using microfluidic device as a microreactor which is prepared by photolithography and soft molding processes. Morphology and structure of the as-prepared nanomaterial was characterized by scanning microscope and X-ray diffraction analysis methods. The collected product is zero valent iron material with the morphology is nano-sheet with the thickness is approximatly 50 nm. Hexavalent chromium ion from K2Cr2O7 solution could be removed by the as-prepared iron nanomaterial. The removal of ions Cr(VI) is determined and confirmed by the visible ultraviolet (UV-Vis) absorption spectroscopy which is proportional to the amount of nanomaterial used and is influenced by pH conditions.

The aim of this study was to recover Sc as the main product and Fe as a by-product from Hungarian bauxite residue/red mud (RM) waste material by solvent extraction (SX). Moreover, a new technique was developed for the selective separation of Sc and Fe from real RM leachates. The presence of high Fe content (∼38%) in RM makes it difficult to recover Sc because of the similarity of their physicochemical properties. Pyrometallurgical and hydrometallurgical methods were applied to remove the Fe prior to SX. Two protocols based on organophosphorus compounds (OPCs) were proposed, and the main extractants were evaluated: bis(2-ethylhexyl) phosphoric acid (D2EHPA/P204) and tributyl phosphate (TBP). The results showed that SX using diethyl ether and tri-n-octylamine (N

Photocatalysts comprising 2D carbon nitride-based systems have emerged as a fervently researched topic for addressing the problems of fuel depletion and the environment. However, the photocatalytic activities of pristine g-C3N4 are still mediocre and suffer from issues pertaining to the restrictions in light absorption, charge separation, and carrier-induced surface reactions; however, efforts have been made in the past decades to boost the efficiencies. This review endeavors to present a roadmap to prepare high-performance g-C3N4 photocatalysts by expounding the cutting-edge research on g-C3N4 materials either as a single component or g-C3N4-based composites including current challenges and perspectives on this topical theme. We believe that this review will provide a broader picture and recommendations for the preparation of superior g-C3N4 photocatalysts towards a greener, cleaner, and resilient future.

Knowing the effluent quality of treatment systems in advance to enable the design of treatment systems that comply with environmental standards is a realistic strategy. This study aims to develop machine learning - based predictive models for designing the subsurface constructed wetlands (SCW). Data from the SCW literature during the period of 2009–2020 included 618 sets and 10 features. Five algorithms namely, Random forest, Classification and Regression trees, Support vector machines, K-nearest neighbors, and Cubist were compared to determine an optimal algorithm. All nine input features including the influent concentrations, C:N ratio, hydraulic loading rate, height, aeration, flow type, feeding, and filter type were confirmed as relevant features for the predictive algorithms. The comparative result revealed that Cubist is the best algorithm with the lowest RMSE (7.77 and 21.77 mg.L−1 for NH4–N and COD, respectively) corresponding to 84% of the variance in the effluents explained. The coefficient of determination of the Cubist algorithm obtained for NH4–N and COD prediction from the test data were 0.92 and 0.93, respectively. Five case studies of the application of SCW design were also exercised and verified by the prediction model. Finally, a fully developed Cubist algorithm-based design tool for SCW was proposed.

Abundantly available biomass wastes from agriculture can serve as effective environmental remediation materials. In this study, activated biochar was fabricated from macadamia nutshell (MCN) through carbonization and chemical modification. The resultant biochars were used as adsorbents to remove toxic metal ions such as Cu2+ and Zn2+ from aqueous solutions. The results showed that the activated MCN biochar has a high adsorption capacity for toxic metal ions. When MCN biochar was activated with K2CO3, the adsorption efficiencies for Cu2+ and Zn2+ were 84.02% and 53.42%, respectively. With H3PO4 activation, the Cu2+- and Zn2+-adsorption performances were 95.92% and 67.41%, respectively. H2O2-modified MCN biochar had reasonable Cu2+- and Zn2+-adsorption efficiencies of 79.33% and 64.52%, respectively. The effects of pH, adsorbent concentration and adsorption time on the removal performances of Cu2+ and Zn2+ in aqueous solution were evaluated. The results exhibited that the activated MCN biochar showed quick adsorption ability with an optimal pH of 4 and 4.5 for both Cu2+ and Zn2+, respectively.

This study investigated methyl orange (MO) dye adsorption using three biochars produced from agro-waste and invasive plants; the latter consisted of wattle bark (BA), mimosa (BM), and coffee husks (BC). BC had the lowest specific surface area (2.62 m2/g) compared to BA (393.15 m2/g) and BM (285.53 m2/g). The adsorption efficiency of MO was stable at pH 2–7 (95%–96%), whilst it had reduced stability at pH 7–12. Between 0 and 30 min, MO adsorption efficiency was >82%, and at 120 min, representative adsorption equilibrium had occurred. The maximum adsorption capacity of the biochars was 12.3 mg/g. The underlying adsorption mechanisms of the three biochars were governed by electrostatic adsorption and pore diffusion. There was an abundance of active sites for adsorption in BA and BM, while chemical adsorption appeared to be more vital for BC, as it contained more functional groups on its surface. The highest MO adsorption efficiency occurred with BM. BC was not recommended for MO removal, as it was observed to stain the water when a dose exceeding 5.0 g/L was utilized.

The failure of the centralized water supply system forced XY community to become more dependent on uncertain and unstable water sources. The results of surveying 50 households showed that 89.18% of total households depended on water collected from rivers, which contributed 58.3% of the total water volume used for the domestic demands. The average water volume consumed was 19.5 liters/person/day (l/p/d), and 86.5% of households used more than one source; 13.5% of households collected water only from rivers, and 45.94% of families had rainwater harvesting (RWH) for their activities (domestic water demand); however, RWH only provided 9.9% of total water consumption. In this study, basic methods were applied to calculate the storage tanks necessary to balance the water deficit created by drought months. Three levels of water demand (14, 20, and 30 l/p/d) can be the best choices for RWH; for a higher demand (40 and 60 l/p/d), small roof area (30-40 m

The phenolic compounds from natural plant extracts, which have strong antioxidant properties as inhibitors for browning retardants of fruits, have been extensively investigate in the last few decades. In this study, the polyphenols in Cleistocalyx operculatus (Roxb.), a distinct plant in tropical region, was successfully extracted and determined. The obtained Roxb. extract (CE) as an antioxidant additive was employed in Chitosan/Gum Arabic (CH/GA) edible coating for the fruit preservation. The resultant CE/CH/GA coating revealed the high effectiveness in improving the freshness of banana at ambient storage conditions. The properties of bananas before and after coated by CE/CH/GA were investigated and assessed. The surface structure of banana was examined by using scanning electron microscopy, showed wrinkle and crack structure for uncoated banana and smooth surface for banana coated with CE/CH/GA coating. The freshness of banana treated with CH/GA/CE edible coating could last for 21 days of storage at room conditions. Thus, it is promising for good potential practical application to preserve fruits.

Biomass has been extensively considered a sustainable resource for preparing activated carbon for energy and environmental applications. However, the fabrication of activated carbon from biomass with a high surface area that can be effectively utilized for environmental treatment remains the main drawback. In this study, activated carbon with an ultra-high surface area was fabricated from sawdust by simple, one-step chemical activation. The effects of the activating temperature and time on the surface area of the activated carbon were investigated. The sawdust activated carbon (sAC) that was obtained was characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), FTIR spectroscopy, and Brunauer, Emmett and Teller (BET) surface area measurements. The prepared sAC had a porous structure, which comprised aggregated nanoparticles with diameters ranging from 10 to 20 nm. The sAC exhibited a high and rapid removal efficiency toward Rhodamine B (RhB), with a removal percentage of nearly 100% after 10 min at an RhB concentration of 10 ppm. The effect of the pH solution on RhB removal performance by sawdust-activated carbon toward RhB was also investigated and discussed and showed that the sAC absorbed more than 90% of the RhB in all the pH at room temperature solutions.

Coffee husk, a carbonaceous precursor and common agricultural waste in Vietnam, was utilized to produce activated carbon by hydrothermal carbonization (HTC) with high adsorption capacity for pollutants. The characteristics and adsorption capacity of the hydrochar produced at the first HTC step (180 °C, 6 h) were subjected to further hydrothermal activation (130 °C for 2 h) with a low concentration of potassium hydroxide (ACHC-KOH 1 M), and directly soaked in KOH medium (ACHC-KOH 1:1). The surface area of the activated hydrochar obtained was significantly increased from 33.7 m2/g (raw hydrochar) to 703.9 m2/g for ACHC-KOH 1 M and 743.8 m2/g for ACHC- KOH 1:1, respectively. The maximum methylene blue (MB) adsorption achieved by the activated carbon materials were 357.38, 314.05, and 103.62 mg/g by ACHC-KOH 1 M, ACHC-KOH 1:1, and raw hydrochar, respectively. Adsorption kinetics and isotherms were employed to explain the MB adsorption process. Adsorption data of MB on ACHC-KOH 1 M and ACHC-KOH 1:1 fitted well with Langmuir adsorption isotherm and pseudo-second-order kinetic model. The results show that coffee husk-based activated carbon is a promising sorbent for the removal of MB from aqueous solutions. Compared to other carbonization methods, the HTC method has advantages of using a low temperature and concentration of KOH.

The main aim of this work was to compare six machine learning (ML) - based models to predict the municipal solid waste (MSW) generation from selected residential areas of Vietnam. The input data include eight variables that cover the economy, demography, consumption and waste generation characteristics of the study area. The model simulation results showed that the urban population, average monthly consumption expenditure, and total retail sales were the most influential variables for MSW generation. Among the ML models, the random forest (RF), and k-nearest neighbor (KNN) algorithms show good predictive ability of the training data (80% of the data), with an R2 value > 0.96 and a mean absolute error (MAE) of 121.5–125.0 for the testing data (20% of the data). The developed ML models provided reliable forecasting of the data on MSW generation that will help in the planning, design and implementation of an integrated solid waste management action plan for Vietnam. The limitations of this work may be the heterogeneity of the dataset, such as the lack of data from lower administrative units in the country. In such cases, the predictive ML algorithm can be updated and re-trained in the future when the reliable data is added.

Using photocatalysts to harvest photon energy from sunlight (renewable fuel) is a promising pathway for a wide range of applications, especially for the removal of contaminants from water. Porphyrin and its derivatives are analogs of natural chlorophyll; both compounds have similar structures and photochemical properties. Therefore, various porphyrin derivatives have been extensively studied as effective sensitizers for light energy absorption and as nature-inspired photocatalysts for water treatment. In this study, a simple solvophobic self-assembly protocol is employed to obtain nanostructured porphyrin from monomeric tetrakis-triphenylamine porphyrin (TTPAP) in a mixture of THF/H2O. The porphyrin is assembled into various forms such as rod-like and belt-like microstructures, depending on the water fraction in the THF/H2O mixture. The main driving forces for self-assembly of the TTPAP monomers into nanostructured materials are balanced stacking involving hydrophobic interactions of the periphery and π-π interactions of the porphyrin cores. While both porphyrin microstructures (rod-like and belt-like) show reasonable photocatalytic activity toward rhodamine B (RhB) dye in aqueous media under simulated visible irradiation, the belt-like porphyrin aggregates exhibit better performance than the rod-like counterparts under the same reaction conditions. A possible mechanism for the photocatalytic activity of the TTPAP aggregates in RhB degradation is also presented.

ZnO nanoparticles are nontoxic inorganic oxides that have been extensively used as a supplement for zinc nutrients and antibacterial agents in the food industry, especially in edible coatings to protect food from deterioration by viruses, fungi, and bacteria. In this work, ZnO nanoparticles were fabricated by a hydrothermal method and characterized by scanning electron microscopy and X-ray diffraction. The prepared ZnO nanoparticles exhibited good antibacterial properties against several bacteria, including Staphylococcus aureus, Escherichia coli, and Bacillus subtilis. The ZnO nanoparticles as an antibacterial agent were incorporated into a chitosan/gum arabic (CH/GA) edible coating, and the protective performance for the preservation of bananas was investigated. The obtained CH/GA/ZnO coating significantly improved the quality and shelf life of bananas at a temperature of 35 °C and relative humidity (RH) of 54 %. The banana surface treated with the CH/GA/ZnO coating was relatively smooth with a CH/GA/ZnO film thickness of approximately 50 μm. The utilization of the resultant coating enabled the maintenance of banana quality, including fruit firmness, weight loss, reducing sugar, and titratable acidity, for a remarkably longer period. The banana coated with the CH/GA/ZnO system was demonstrated to maintain freshness for more than 17 d in comparison with the less than 13 d for the control banana at 35 °C and 54 % RH.

The main aim of this study was to synthesize an innovative magnetic CuFe2O4@porphyrin nanofiber hybrid material via one-step re-precipitation self-assembly of freebase-tetracarboxy-porphyrin (TCPP), in the presence of CuFe2O4 nanoparticles. The resultant hybrid materials were thoroughly characterized using scanning electron microscopy, energy-dispersive X-ray mapping, X-ray diffractometry, and Fourier-transform infrared, and UV–vis spectroscopy. Results showed well-integration of CuFe2O4 nanoparticles into TCPP nanofiber network, with the average size of CuFe2O4 being less than 100 nm and diameter and length of TCPP aggregate being approximately 20 nm and several µm, respectively. The as-prepared hybrid material possessed strong magnetic properties with a saturated magnetization value of approximately 25 emu/g. This photocatalyst was highly efficient in the removal of rhodamine B (RhB) dye, with the rate constant reaching 2.1 × 10−2 min−1. This paper describes in detail a plausible photocatalytic mechanism for RhB removal by CuFe2O4@porphyrin nanofiber hybrid material.

This study developed a unique system by combining the novel vertical flow (NVF) using expanded clay (ExC) and free flow surface constructed wetland (FWS) for dormitory sewage purification and reuse. The NVF tank consisted of filter layers of ExC, sandy soil, sand, and gravel. The FWS consisted of sandy soil substrate and was installed after the NVF. Colocasia esculenta and Dracaena sanderiana was planted in NVF and FWS, respectively. The treatment system was operated and tested for more than 21 weeks by increasing the hydraulic loading rate (HLR) from 0.02 m/d to 0.12 m/d. The results demonstrated that effluents in the system changed proportionally to the HLRs, except for nitrate nitrogen. Furthermore, the maximum removal efficiencies for TSS, BOD5, NH4-N, and Tcol were 76 ± 13%, 74 ± 11%, 90 ± 3%, and 59 ± 18% (0.37 ± 0.19 log10MPN/100 mL), respectively. At HLRs of 0.04–0.06 m/d, the treatment system satisfied the limits of agriculture irrigation.

Fe2O3/TiO2 composite has been extensively studied for heavy metals removal and photocatalysis. In photocatalysis, this composite was used for the degradation of organic dye pollutants. Herein, we reported a green approach to fabricate Fe2O3/TiO2 nanoparticles from ilmenite ore. The Fe2O3/rutile was synthesized by one-step reaction of ilmenite at 700 °C in 3 h, the raw Fe2O3/rutile composite was, then, grounded by a ball-milled process in 4 h to obtain nanostructured composite. The obtained Fe2O3/rutile nanoparticles have the diameter of 50–100 nm with the BET surface area of 7 m2 g−1. The adsorption behaviour of the nanostructured Fe2O3/TiO2 composite as adsorbent toward arsenic (particularly, oxidized form of arsenic [As(V)]) was investigated by carrying out batch adsorption. The adsorption isotherm was investigated by using both the Langmuir and Freundlich models. The sorption kinetics of adsorbent toward arsenic adsorption was found to be pseudo-second order. The Fe2O3/TiO2 composite exhibited fast and high adsorption capacity of 47.12 mg g−1 toward arsenic in various solution pHs. The composite was also found to be durable and recyclable for arsenic adsorption. Therefore, this as-prepared Fe2O3/TiO2 composite could be promising and cost-effective adsorbent for effective removal of arsenic contaminant from aqueous environment.

A superhydrophobic and superoleophilic copper mesh was prepared via a simple electrochemical route. Copper substrates were anodized in a 1 mol/L NaOH aqueous solution to produce a rough thin film of Cu(OH) 2 nanoneedle arrays and then the film was reacted with 1H,1H,2H,2H-perfluorooctyltriethoxysilane to form a very thin and stable hydrophobic coating layer. X-ray photoelectron spectroscopy (XPS) data revealed the coordination of silicon atoms with cuprate (CuO) molecules present on the anodized substrate. The water contact angle of the perfluoroalkylsilane-modified nanoneedle surface was approximately 170°. Furthermore, the superhydrophobicity was maintained after wet treatments in aqueous solutions with a wide pH range of 2−14 and after a long storage time of 4 months. This excellent durability and long-term reliability, which was unattainable in comparable samples modified with n -dodecanethiol or n -dodecanoic acid, could be interpreted with the formation of a stable and dense surface modification layer via a condensation reaction between –SiOEt and –CuOH and subsequent polymerization among the ethoxysilane adsorbates. Preliminary studies of the dynamic permeation behaviors of water and non-polar solvents exhibited a potential use of the hybrid copper mesh as a filtering layer for oil and water separation.

Nanostructured copper compounds were grown by electrochemical anodization of copper foil in aqueous NaOH under varying conditions including electrolyte concentration, reaction temperature, current density, and reaction time. Their morphology and atomic composition were investigated by using SEM, TEM, XRD, EDS and XPS. At the conditions ([NaOH] = 1 M, 20 °C, 2 mA cm -2 ), wire-like orthorhombic Cu(OH) 2 nanobundles with an average width of 100 - 300 nm and length of 10 μm were synthesized with the preferential [100] growth direction. Furthermore, when the concentration decreased to 0.5 M NaOH, the 1D nanobundle structure became narrower and longer without any change in compositions or crystalline structure. Side reaction pathways appeared to compete with the 1D nanostructure formation channels: the formation of CuO nanoleaves at 50 °C via the sequential dehydration ofCu(OH) 2 , CuO/Cu 2 O aggregates in 4 M NaOH, and Cu 2 O nanoparticles and CuO nanosheets at lower current density.

Six composite sensors were prepared by casting a solution of different polymers and conductive carbon black nanoparticles on a glass substrate with two comb-shape Au electrodes. The chemoresistive response and background noise level were measured as a function of concentration upon exposure to various breath biomarker compounds: acetic acid, toluene, ethanol, acetone, n -pentane, and isoprene. All sensors exhibited a good linear response with respect to concentration, suggesting a typical volumetric transduction mechanism. Limit-of-detection (LOD) values were determined by an extrapolation of the linear relationship and were found to be in the range of 80 ppb to 240 ppm, demonstrating the potential of highly sensitive detection for the biomarkers. The LOD variation can be roughly interpreted in terms of the difference in boiling temperature of an analyte in a physisorption-based model; the higher boiling temperature results in a lower LOD due to a strong tendency toward condensation. The LOD values were observed to become two or three orders of magnitude smaller by exploiting specific chemical interactions between the polymers used and the analyte.

Porphyrin nanostructures with well-controlled size, shape and functionality can be used for visible-light photocatalysis. In this work, a graphene@porphyrin nanofibre composite was successfully fabricated via arginine-mediated self-assembly of tetrakis (4-carboxyphenyl) porphyrin (TCPP) on graphene nanoplates (GNPs). The formation and crystallisation of the graphene@porphyrin nanofibre composite was fully characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), fourier transform infrared (FTIR), ultraviolet-visible (UV-vis) and fluorescence spectroscopy. The assembled TCPP nanofibers were 50–200 nm in diameter with length in micrometers long, which were densely and uniformly distributed on the surface of graphene. The GNPs@TCPP nanofibers showed enhanced visible-light photocatalytic activity in comparison with free-standing TCPP nanorods for the degradation of Rhodamine B (RhB) and methyl orange (MO). The possible photodegradation mechanism of these dyes by the GNPs@TCPP nanofiber photocatalyst was proposed.

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