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Progress in materials science is associated with the development of nanomaterials in terms of energy-saving, environmentally friendly, and low-cost methods. Since the use of tributyltin compounds in antifouling coatings was banned in 2003, the search for ecofriendly alternatives has been promoted. Foul-release (FR) nanocoatings have been extensively investigated because of their non-stick, ecological, and economic advantages. Such nanocomposite systems are dynamic non-stick surfaces that deter any fouling attachment through physical anti-adhesion terminology. Instead of biocidal solutions, several functional FR nanocomposite coatings have been developed to counter biofouling and biocorrosion with ecological and ecofriendly effects. Selected inorganic nanofillers have been incorporated because of their enhanced interaction at the filler‐polymer interface for nanocomposites. Metallic nanoparticles and their oxides have also been widely explored because of their unique morphological characteristics and size-dependent, self-cleaning properties. In modeling a novel series of FR nanocoatings, two modes of prevention are combined: chemical inertness and physical microfouling repulsion for maritime navigation applications. Long-term durability and self-cleaning performance are among the advantages of developing effective, stable, and ecofriendly modeling alternatives. This review provides a holistic overview of nano-FR research achievements and describes recent advancements in non-stick marine nanocoatings for ship hulls. This review highlights the key issues of nanocomposite structures and their features in improving the biological activity and surface self-cleaning performance of ship hulls. This review may also open new horizons toward futuristic developments in FR nanocomposites for maritime navigations. [ABSTRACT FROM AUTHOR]

The development of inexpensive and effective electrocatalysts for oxygen reduction reaction (ORR) as a substitute for commercial Pt/C catalyst is an important issue in fuel cells. In this paper, we report on novel fabrication of self-supported nitrogen-doped carbon-supported titanium nanofibers (N TiO 2 @C) and carbon-supported titanium (TiO 2 @C) electrocatalysts via a facile electrospinning route. The nitrogen atom integrates physically and homogenously into the entire carbon–titanium structure. We demonstrate the catalytic performance of N TiO 2 @C and TiO 2 @C for ORR under alkaline conditions in comparison with Pt/C catalyst. The N TiO 2 @C catalyst shows excellent ORR reactivity and durability. Interestingly, among all the catalysts used in this ORR, N TiO 2 @C-0.75 exhibits remarkable competitive oxygen reduction activity in terms of current density and onset potential, as well as superior methanol tolerance. Such tolerance attributes to maximizing the diffusion of trigger pulse electrons during catalytic reactions because of enhanced electronic features. Results indicate that our fabrication strategy can provide an opportunity to produce a simple, efficient, cost-effective, and promising ORR electrocatalyst for practical applications in energy conversion and storage technologies. [ABSTRACT FROM AUTHOR]

Highlights: [•] We engineered a simple, micro-object mesosensor based on aluminosilica pellets. [•] Ultra-fast and specific remote visualization and removal of multi-toxic metals were evident. [•] The sensor shows high stability, reproducibility, and versatility over ion detections. [•] Selective removal of Hg2+, Cd2+, and Cu2+ ions from drinking water and blood was evident. [Copyright &y& Elsevier]

Highlights: [•] A hand-operating and easy-to-make synthesis of core double shell nanocarriers was achieved. [•] Selective recognition and removal of target ions from multi-ion mixtures were evident. [•] Ultra-trace monitoring of toxic (Cd2+, Hg2+, Co2+, and Cu2+) ions using a single technique. [•] The sensing systems showed functionality in terms of reversibility, selectivity and stability. [Copyright &y& Elsevier]

Abstract: This study developed a pH-dependent mesosensor for the optical and selective removal of Hg2+ ions from drinking water and physiological fluids. The fine-tuned surface patterning of the mesoscopic solid aluminosilica scaffolding architectures, which was achieved using a dispersible active agent such as a cationic surfactant, resulted in the dense immobilization of addressable diphenylcarbazide chelating agent. These mesosensor responses can be triggered by the target species and can transduce measurable optical signals under synergistic pH conditions, thus enabling the binding of Fe3+ and Hg2+ metals into a hydrophobic chelating pocket to be simulated. Results verified the one-step removal and optical adsorption efficiency of ultra-trace, wide-range (0.001mg dm−3 to 2.0mg dm−3) concentrations of Fe3+ and Hg2+ ions into the interior pore surface coverage of the DPC-modified mesosensor from drinking water. Importantly, the mesosensor can be repeatedly recycled without damaging the unique mesostructures. Furthermore, the hemolysis test of Hg2+ ion toxicity in red blood cells (RBCs) and the counteraction effect of the phosphatidylserine (Ptd-L-Ser) receptor exposure of RBCs were also investigated in a physiological system such as human blood. Results indicated that the strong binding site-metal interaction enabled the remarkably selective removal of Hg2+ ions from physiological fluids. [Copyright &y& Elsevier]

Abstract: With the remarkable progress in the field of gene technology, proteins have gained an important function in the field of disease diagnosis and treatment. Protein bioadsorption has drawn increasing attention partly because of the promising advances for diagnostic assays, sensors, separations, and gene technology. Mesocage alumina has a cage-type structure with high surface area and pore volume, exhibiting superior capabilities for protein adsorption. In this study, we report the size-selective adsorption/removal of virtual proteins having different shapes, sizes, functions, and properties, including insulin, HopPmaL domain, lysozyme, galectin-3, β-lactoglobulin, α-1-antitrypsin, α-amylase, and myosin in aqueous water using mesocage alumina. The mesoporous alumina monoliths have unique morphology and physical properties and enhanced protein adsorption characteristics in terms of sample loading capacity and quantity, thereby ensuring a higher concentration of proteins, interior pore diffusivity, and encapsulation in a short period. Thermodynamic analysis shows that protein adsorption on mesocage alumina monoliths is favorable and spontaneous. Theoretical models have been studied to investigate the major driving forces to achieve the most optimal performance of protein adsorption. The development of ultra- or micrometer-scale morphology composed of mesocage-shaped mesoporous monoliths or alumina network clusters can be effectively used to encapsulate the macromolecules into the interior cage cavities, which can greatly assist in other potentials for biomedical applications. Furthermore, the adsorption of a single protein from mixtures based on size- and shape-selective separation can open up new ways to produce micro-objects that suit a given protein encapsulation design. [Copyright &y& Elsevier]

Abstract: A general design for optical chemical nanosensors is necessary for the development of efficient sensing systems with high flexibility and low capital cost for the controlled recognition of heavy and toxic metals. In the present work, we designed optical chemical nanosensors for the colorimetric recognition and simultaneous removal of Cu(II) and Pd(II) ions. The optical nanosensors were designed by direct immobilization of a synthesized N,N′-disalicylidene-4,5-diamino-6-hydroxy-2-mercaptopyrimidine (DSAHMP) chelate onto hexagonal mesoporous aluminosilica carriers. The natural surfaces and active acid sites of the aluminosilicas strongly induced H-bonding and dispersive interactions with the DSAHMP chelate, leading to the formation of stable sensors without leaching of the chelate during sensing assays of metal ions. No elution of the probe molecules was evident with the addition of Cu(II) and Pd(II) analyte ions during the sensing process. In addition, the structural features of the open-pore, hexagonal mesostructures led to high rates of accessibility and adsorption capacity of the DSAHMP chelate. Within such a tailored nanosensor design, the ability to achieve flexibility in the specific activity of the electron acceptor/donor strength of the chemically responsive DSAHMP molecular probe enabled easy generation and transduction of optical color signals as a response to DSAHMP-Cu(II) or DSAHMP-Pd(II) binding events, even at ultra-trace concentrations (10−9 mol/dm3) of heavy metals. The functional and solid design of the nanosensors offered a simple, one-step sensing procedure for both the quantitate and visual detection of such elements from their sources without the need for sophisticated instruments. Controlled sensing and removal assays significantly enhanced nanosensor functionality in terms of long-term stability, reversibility, and selectivity. The key result in our study is that the design-made nanosensors exhibited significant ion-selectivity toward the target ions in environmental and waste disposal samples. [Copyright &y& Elsevier]

Abstract: This study is an efficient arsenic(V) removal from contaminated waters used as drinking water in adsorption process by zirconium(IV) loaded ligand exchange fibrous adsorbent. The bifunctional fibers contained both phosphonate and sulfonate groups. The bifunctional fiber was synthesised by graft polymerization of chloromethylstyrene onto polyethylene coated polypropylene fiber by means of electron irradiation graft polymerization technique and then desired phosphonate and sulfonate groups were introduced by Arbusov reaction followed by phosphorylation and sulfonation. Arsenic(V) adsorption was clarified in column methods with continuous flow operation in order to assess the arsenic(V) removal capacity in various conditions. The adsorption efficiency was evaluated in several parameters such as competing ions (chloride and sulfate), feed solution acidity, feed flow rate, feed concentration and kinetic performances at high feed flow rate of trace concentration arsenic(V). Arsenic(V) adsorption was not greatly changed when feed solutions pH at 3.0–7.0 and high breakthrough capacity was observed in strong acidic area below pH 2.2. Increasing the flow rate brings a decrease both breakthrough capacity and total adsorption. Trace level of arsenic(V) (0.015 mM) in presence of competing ions was also removed at high flow rate (750 h−1) with high removal efficiency. Therefore, the adsorbent is highly selective to arsenic(V) even in the presence of high concentration competing ions. The adsorbent is reversible and reusable in many cycles without any deterioration in its original performances. Therefore, Zr(IV) loaded ligand exchange adsorbent is to be an effective means to treat arsenic(V) contaminated water efficiently and able to safeguard the human health. [Copyright &y& Elsevier]

Abstract: The toxicity of mercury (Hg) to humans, including damage to the nervous system, is well known. Hg cannot be degraded into non-toxic compounds or other elements. It is released mainly through mining, industries, and fossil fuel combustion. Anthropogenic and natural activities, such as volcanoes, transform elemental Hg (Hg0) into its ionic form [Hg(II)], which bioaccumulates in biota and is biomagnified in the food chain, notably in aquatic environments. This critical report aims to control Hg(II)-ion toxicity through risk assessment, recognition, and removal via high-level waste management. We first discuss successful and up-to-date developments in different techniques, designs and studies that are potentially useful in enhancing the effectiveness of control of Hg(II)-ion toxicity. The key to designing optical nanosensors is to construct chromophore and fluorophore receptors as nanoscale platform scavengers with different functional characteristics (e.g., density, accessibility, and intrinsic mobility), which allow for easy, reliable signaling in continuous monitoring modes. We highlight a technique that depends on the use of engineered mesocage materials that have multidirectional cavities and microsized, particle-like monoliths to control the adsorption/detection of toxic metal ions, especially Hg(II) ions. With regard to proximal sensing, we consider controlled assessment processes that involve the evaluation of intrinsic properties (e.g., signal change, long-term stability, adsorption efficiency, extraordinary sensitivity, selectivity, and reusability). This study provides evidence that miniaturized mesosensor strips can revolutionize consumer and industrial markets with the introduction of ion-sensor strips. [Copyright &y& Elsevier]

Abstract: The polyaniline (PANI) film deposition during the oxidative polymerization of aniline was studied using the quartz crystal microbalance (QCM) technique. PANI was prepared in the presence and absence of PDAs (p-phenylenediamine (PPDA), o-phenylenediamine (OPDA) and m-phenylenediamine (MPDA)). The effect of PDAs concentrations on the PANI films formation were monitored using QCM technique. It was found that PPDA has an acceleration effect, OPDA has no or little effect and MPDA has retardation effect and work as inhibitor for the PANI film formation. The Gr and m′ increases by increasing PPDA concentrations in the same time induction period and reaction time decreases, in the opposite direction MPDA The Gr and m′ decreases by increasing MPDA concentrations and the induction period and reaction time increases, in the case of OPDA there is no measurable effect on the induction period, Gr , m′ and reaction time. UV–vis absorption spectra for the bulk and PANI films deposited onto glass supports were used for justification the data obtained from QCM. The presences of PDAs have no effect on the chemical structure and crystallinity of PANI and were confirmed using FTIR and X-ray. [Copyright &y& Elsevier]

Abstract: In order to control the design functionality of mesocylinder filters for molecular sieving of proteins, we fabricated tight mesocylinder silica nanotube (NT) arrays as promising filter candidates for size-exclusion separation of high-concentration macromolecules, such as insulin (INS), α-amylase (AMY), β-lactoglobulin (β-LG), and myosin (MYO) proteins. In this study, hexagonal mesocylinder structures were fabricated successfully inside anodic alumina membrane (AAM) nanochannels using a variety of cationic and nonionic surfactants as templates. The systematic design of the nanofilters was based on densely patterned polar silane coupling agents (“linkers”) onto the AAM nanochannels, leading to the fabrication of mesocylinder silica arrays with vertical alignment and open surfaces of top-bottom ends inside AAM. Further surface coating of silica NTs hybrid AAM with hydrophobic agents facilitated the production of extremely robust constructed sequences of membranes without the formation of air gaps among NT arrays. The fabricated membranes with impermeable coated layers, robust surfaces, and uniformly multidirectional cylinder pores in nanoscale sizes rapidly separate large quantities of proteins within seconds. Meanwhile, comprehensive factors that affect the performance of the molecular transport, diffusivity, and filtration rate through nanofilter membranes were discussed. The mesocylinder filters of macromolecules show promise for the efficient separation and molecular transport of large molecular weight and size as well as concentrations of proteins. [Copyright &y& Elsevier]

Abstract: Polyaniline (PANI) was prepared using chemical method in the presence and absence of p-phenylenediamine (PPDA) and Ammonium peroxydisulfate (APS) was used as oxidizing agent. The effect of PPDA concentrations on the PANI films formation were monitored using quartz crystal microbalance (QCM) technique. It was found that the presence of PPDA affect the growth rate (Gr ) and the reaction time. As the PPDA concentration increases reaction time decreases and the Gr increases. UV–VIS absorption spectra for the in situ PANI films deposited onto glass supports was used for justification the data obtained from QCM. The presence of PPDA has no effect on the structure and crystallinity of PANI and that confirmed using FTIR and X-ray. [ABSTRACT FROM AUTHOR]

Sustainable materials are urgently desired for treatment of radioactive cesium (Cs) contaminated water to safe-guard the public health. Apart from the synthetic ligand-based materials, the Mangrove charcoal modified adsorbent was fabricated for assessing of Cs removal from waste sample. The raw charcoal was oxidized using nitrification approach and diverse oxygen containing carboxyl, carbonyl and hydroxyl functional groups were introduced. After modification, the adsorbent characteristics were drastically changed as compared to the charcoal during the measurement of FTIR, N 2 adsorption-desorption isotherms and SEM micrographs. The data clarified that charcoal modified adsorbent was exhibited high Cs transport through the inner surface of the adsorbent based on bonding ability. The adsorbent was shown comparatively slow kinetics to Cs ion; however, the adsorption capacity was high as 133.54 mg/g, which was higher than the crown ether based conjugate materials. The adsorption data were followed to the Langmuir adsorption isotherms and the monolayer coverage was possible due to the data presentation. The presence of high amount of Na and K were slightly interfered to the Cs adsorption by the charcoal modified adsorbent, however; the Na and K concentration was 350–600 folds higher than the Cs concentration. Then the proposed adsorbent was selective to Cs for the potential real radioactive Cs contaminated water. The volume reduction was established rather than desorption and reuses advantages. More than 99% volume reduction was measured by burning of Cs adsorbed adsorbent at 500 °C for ensuring the safe storage and disposal of used adsorbent. Therefore, the charcoal modified adsorbent may open the new door to treat the Cs containing wastewater. Image 1 • A cellulosic charcoal modified adsorbent was fabricated for cesium (Cs) removal. • The adsorbent was selectively taken up Cs even in the presence of high-level Na & K. • The Cs adsorption was high as enormous functional groups as expected in adsorbent. • Volume reduction was established rather than desorption and reuses advantages. [ABSTRACT FROM AUTHOR]

Promoting green hydrogen has emerged as a pivotal discourse in the contemporary energy landscape, driven by pressing environmental concerns and the quest for sustainable energy solutions. This paper delves into the multifaceted domain of C -Suite issues about green hydrogen, encompassing both technological advancements and policy considerations. The question of whether green hydrogen is poised to become the focal point of the upcoming energy race is explored through an extensive analysis of its potential as a clean and versatile energy carrier. The transition from conventional fossil fuels to green hydrogen is considered a fundamental shift in energy paradigms, with far-reaching implications for global energy markets. The paper provides a comprehensive overview of state-of-the-art green hydrogen technologies, including fuel cells, photocatalysts, photo electrocatalysts, and hydrogen panels. In tandem with technological advancements, the role of policy and strategy in fostering the development of green hydrogen energy assumes paramount significance. The paper elucidates the critical interplay between government policies, market dynamics, and corporate strategies in shaping the green hydrogen landscape. It delves into policy mechanisms such as subsidies, carbon pricing, and renewable energy mandates, shedding light on their potential to incentivize the production and adoption of green hydrogen. This paper offers a nuanced exploration of C -Suite issues surrounding green hydrogen, painting a comprehensive picture of the technological and policy considerations that underpin its emergence as a transformative energy source. As the global community grapples with the imperatives of climate change mitigation and the pursuit of sustainable energy solutions, understanding these issues becomes imperative for executives, policymakers, and stakeholders alike. [Display omitted] • The latest advancements in photo electrocatalysts and fuel cell technologies are reviewed. • The storage and transportation within the realm of green hydrogen energy were discussed. • Policy and strategy for fostering the development of green energy are proposed. [ABSTRACT FROM AUTHOR]

The monitoring and removal of abundant heavy metals such as Cu ions are considerable global concerns because of their severe impact on the health of humans and other living organisms. To meet this global challenge, we engineered a novel mesoscopic capture protocol for the highly selective removal and visual monitoring of copper (Cu2+) ions from wide-ranging water sources. The capture hierarchy carriers featured three-dimensional, microsized MgO mesoarchitecture rectangular sheet-like mosaics that were randomly built in horizontal and vertical directions, uniformly arranged sheet faces, corners, and edges, smoothly quadrilateral surface coverage for strong Cu2+-to-ligand binding exposure, and multidiffusible pathways. The Cu2+ ion-selectively active captor surface design was engineered through the simple incorporation/encapsulation of a synthetic molecular chelation agent into hierarchical mesoporous MgO rectangular sheet platforms to produce a selective, visual mesoscopic captor (VMC). The nanoscale VMC dressing of MgO rectangular mosaic hierarchy by molecularly electron-enriched chelates with actively double core bindings of azo- and sulfonamide- groups and hydrophobic dodecyl tail showed potential to selectively trap and efficiently remove ultratrace Cu2+-ions with an extreme removal capability of ~233 mg/g from watery solutions, such as drinking water, hospital effluent, and food-processing wastewater at specific pH values. In addition to the Cu2+ ion-selective removal, the VMC design enabled the continuous visual monitoring of ultratrace Cu2+ ions (~3.35 × 10−8 M) as a consequence of strong chelate-to-Cu2+ binding events among all accumulated matrices in water sources. Our experimental recycle protocol provided evidence of reusability and recyclability of VMC (≥10 cycles). With our mesoscopic capture protocol, the VMC can be a promising candidate for the selective decontamination/removal and sensitive detection of hazardous inorganic pollutants from different water sources with indoor or outdoor applications. ga1 • Copper ions removal is of global concern due to its severe impact on human health. • Heterogeneous visual capture protocol was designed to remove Cu(II) ions from water. • The 3D microsized MgO mesoarchitecture was used as the capture design platform. • The VMC showed high efficiency and selectivity removal of Cu with q m of ~233 mg/g. • The VMC provides sensitive/selective captor to treat indoor/outdoor water sources. [ABSTRACT FROM AUTHOR]

With increasing the dye contamination scenes reported around the globe, the highly promising materials are needed to clean up the water to safeguard the human health. In this work, we have investigated the naturally available carbohydrate polymeric biodegradable adsorbent of wheat flour (WF) for the encapsulation of cationic Rhodamine B (RB) dye with high sensitivity and selectivity. The adsorbent was characterized to define the functional groups existing for complexation ability to the RB dye molecules. Adsorption studies were evaluated in batch mode with the function of solution acidity, contact time, initial RB concentration, competing ions existing and reusability with using eluent. The solution acidity was exhibited the key role, and the suitable pH 5.50 was selected based on the high adsorption efficiency and sensitivity nature. Moreover, the adsorption data were highly adjacent with the Langmuir adsorption isotherms model with monolayer coverage. The determined maximum adsorption was 142.26 mg/g, which was comparable with the other forms of adsorbents in the cationic dye adsorption operations. The competing ions were not adversely affected in the RB dye adsorption by the WF adsorbent due to the complexation ability. The WF adsorbent was exhibited the high reusability based on the elution and reuses performances. The adsorbed RB dye elution was evaluated using ethanol and then the WF adsorbent was ready to use for RB dye adsorption after washing with water without significant loss in its functionality. Therefore, the biodegradable natural carbohydrate polymeric WF adsorbent will attract the scientific community as suitable bio-adsorbent for efficient cationic dye removal from contaminated water as well as the production of value-added adsorbent for water treatments for safeguarding the public health. Unlabelled Image • Toxic dye removal was assessed using natural biodegradable polymeric adsorbent. • The adsorbents were exhibited high removal efficiency with immense sensitivity. • The competing ions were not interfered due to specific complexation mechanism. [ABSTRACT FROM AUTHOR]

The complete remediation of extremely toxic elements, such as cadmium, must be achieved to control the various stages in their life cycles, from mining as virgin ore to using them as consumer and industrial end products, and recycling. Considerable progress has been made in monitoring cadmium ions, but sensors or captors that can simultaneously detect and remove toxic metal ions across a wide range of environments are still greatly needed. This article reviews the tools and the strategies for the environmental remediation of cadmium ions, with special emphasis on state-of-the-art colorimetric sensors. Selective colorimetric sensors based on immobilization of hydrophobic or hydrophilic chromophore molecules into nanosized space cavities have significant advantages because of their dual functionality, namely, early warning “detection” and removal of cadmium ions. This review concludes with a thorough evaluation of emerging challenges and future requirements in monitoring, detecting, and removing cadmium ions from environmental matrices. [ABSTRACT FROM AUTHOR]

Abstract: This study aims to develop novel nanocollectors for potential application in cobalt [Co(II)] detection and removal from lithium ion batteries. The optical nanocollectors were fabricated through functional immobilization of 2-nitroso-1-naphthol, bis[N,N-bis(carboxymethyl) aminomethyl]fluorescein, and pyrogallol red chromophore probes into large, open, cage-pored, three-dimensional cubic mesostructures with micrometer-sized monolith particles. The monolithic nanocollectors are stable and easy to use, and they have sensitive detection capabilities for low Co(II) ion concentrations. The construction of these probes into highly ordered pore-based monoliths transform ion sensing and removal systems into smart, stable assemblies and portable laboratory assays. The experiments were conducted to determine the effects of feed solution pH, concentration, and competing ions on the selective detection and removal of Co(II) ions. Solution pH played an important role in the selective removal of Co(II) ions. The nanocollectors were able to detect Co(II) ions selectively despite high concentrations of interfering ions. The unique features of the nanocollectors allow the visual detection, removal, and extraction of ultratrace concentrations of Co(II) ions without preconcentration. The adsorbed Co(II) was eluted/extracted with stripping agents and the nanocollectors were simultaneously regenerated for subsequent removal operations after rinsing with water. The nanocollectors retained their functionality despite several chemical treatments during the removal–extraction–regeneration cycles. Therefore, large-scale pilot studies are recommended to confirm these promising results. [Copyright &y& Elsevier]

Abstract: In this work, polypyrrole samples were synthesized by chemical oxidative polymerization technique with Iron (III) chloride as an oxidant. Thin films of PPy were prepared by spin coating technique. The molecular structure of polypyrrole film was characterized by Fourier transform infrared spectroscopy (FTIR). The optical properties of the PPy films were studied using spectrophotometric measurements of the transmittance and reflectance at normal incidence of light in the wavelength range from 200 to 2500nm. The recorded absorption measurements in the UV–vis region show two well defined absorption bands. The analysis of the spectral behavior of the absorption coefficient (α), in the absorption region revealed two direct transitions. The dispersion parameters were determined and discussed based on the single oscillator model. According to the analysis of dispersion curves, the parameters, namely; dispersion energy (E d ), oscillator energy (E o ), high frequency dielectric constant (ɛ ∞ ) and lattice dielectric constant (ɛ L ) were evaluated. Discussion of the obtained results and their comparison with the previous published data were also given. [Copyright &y& Elsevier]

Abstract: In this work, a poly(o-toluidine) “POT” was synthesized by chemical oxidative polymerization method in aqueous media. High uniform and good adhesion thin films of POT have been successfully deposited by the spin coating technique. The films were characterized by X-ray diffraction (XRD) and Fourier transforms infrared (FTIR) spectroscopy. The XRD pattern of the POT shows the semi-crystalline nature of the films. FTIR studies show the information of functional groups in POT. The optical transmittance and reflectance of POT film was measured in the 200–2500nm wavelength range. The absorption coefficient analysis shows that the optical band gaps of POT film are direct allowed transition band gaps with 1.2 and 2.6eV. Other optical absorption parameters such as extinction molar coefficient, oscillator strength and electric dipole strength were also calculated. The dispersion parameters were determined and discussed based on the single oscillator model. According to the analysis of dispersion curves some important parameters such as dispersion energy (E d ), oscillator energy (E o ), high frequency dielectric constant ( ε ∞) and lattice dielectric constant (ε L ) were also evaluated. Discussion of the obtained results and their comparison with the previous published data were also given. The obtained desirable results of POT thin film can be useful for the optoelectronic applications. [Copyright &y& Elsevier]

Alkali treated tea waste (ATTW) was investigated as a novel alternative cost-effective natural adsorbent to decontaminate the pollutant of chromium (Cr(VI)) in the polluted water with the variation of equilibration time, solution pH, initial Cr(VI) concentration, adsorbent dosage, and temperature with a view to ensuring a safe disposal as well as sustainable management of the discarded bulk quantities of industrial tea leaves wastes. The adsorbent characteristic was confirmed the significant amount of Cr(VI) accumulation onto ATTW surfaces. The adsorption processes were satisfactorily described by pseudo-first order (PFO), pseudo-second order (PSO) and intra-particles diffusion models (IDM) where the PSO model evidently shows a better fitting with the regression coefficient (R 2 = 0.994). Exploration of Langmuir, Freundlich, Flory-Huggins, and Temkin isotherm models were also investigated and the best fitting was observed for the Langmuir model as it was produced the highest regression coefficient value (R 2 = 0.993). The maximum adsorption ability of ATTW according to the Langmuir model was found to be 158.73 mg/g. These results demonstrate that Cr(VI) adsorption was a complex process involving a physicochemical spontaneous monolayer and multiple rate-limiting states, which was predominantly chemical or chemisorption due to ion-exchange or electrostatic attraction/surface complexation formation, film diffusion and intra-particle diffusion. Furthermore, the substrates exhibited an excellent regeneration capacity upon using 0.10 M HNO 3 as eluent and ATTW was reused several cycles without influencing the adsorption performance. The results of this study thus concludes that ATTW could be a promising environmentally friendly and cheap bio-adsorbent for Cr(VI) remediation with profound implications in water and wastewater treatment for a large-scale environmental pollutant clean-up laden with toxic Cr(VI) ions. Unlabelled Image • A natural adsorbent was developed using alkali treated tea waste for pollutant removal. • The developed adsorbent demonstrated high adsorption to clean up wastewater efficiently. • The pollutant removal was predominantly governed by the chemisorption mechanisms. [ABSTRACT FROM AUTHOR]