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In this study, the electrochemical hydrogen storage of bentonite composites containing TiO 2 and Au nanoparticles (NPs) has been investigated by cyclic voltammetry (CV) analysis. TiO 2 NPs were first deposited on the bentonite substrate by reflux technique. Au NPs were then prepared by laser ablation in liquid (LAL) method under different laser irradiation times (6, 12, and 18 min), and utilized in the decoration of bentonite/TiO 2 nanocomposite by physical mixing. X-ray diffraction, transmission electron microscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy, and elemental mapping were carried out in the characterization of the prepared bentonite/TiO 2 /Au nanocomposite. The surface and chemical properties of the acquired nanocomposite were analyzed by Brunauer-Emmett-Teller and Fourier transform infrared spectroscopy, respectively. Electrochemical measurement was performed on stainless steel mesh prefabricated electrodes in 1 M KOH electrolyte solution. The B-T/Au nanocomposite prepared under 12 min laser irradiation displayed the highest hydrogen storage capacity (15 Cg-1). Image 1 • Au nanoparticles were synthesized by LAL. • Bentonite/TiO 2 /Au nanocomposite was fabricated by physical mixing. • Hydrogen storage capacity was attained 15 Cg-1. [ABSTRACT FROM AUTHOR]

The article offers information on decrease in quality and quantity of Iran's groundwater. It also include how Iran's climate varies from arid to semiarid and use of groundwater is three times higher than the global average.

[Display omitted] • Very stable Cu, Ag, Au, Ni, Pd, and Pt nanofluids were synthesized via one step and fast LAL method. • The prepared metallic nanofluids used for photo-thermal conversion for many cycles without losing their performance. • The prepared metallic nanofluids have long life and high thermal stability. • The prepared metallic nanofluids used for solar energy harvesting. Synthesis of pure and stable metallic nanoparticles with a fast, green, and cost-effective method is a challenging topic. Herein, stable nanofluids by the laser ablation in liquids (LAL) are prepared. The prepared nanofluids include Cu, Ag, Au, Ni, Pd, and Pt nanoparticles (having localized surface plasmon resonance (LSPR) property) dispersed in polyethylene glycol (PEG). The average particle and hydrodynamic diameters of ∼ 4.5 nm and ∼ 106 nm for Ag nanoparticles reveal the capping of nanoparticles by PEG which leads to the high stability of the nanofluids. The photo-thermal conversion capability of all the samples is studied. The Ag, Au, and Pd nanofluids show the highest capability in the photo-thermal conversion. For Ag nanofluid, the surface temperature reaches ≅ 52 °C (ΔT ≅ 24 °C) during 60 min sunlight radiation. Moreover, the eligibility of the Ag nanofluid in converting light to heat is examined in different light intensities and various nanoparticle concentrations. For all the synthesized nanofluids, the thermal properties including, stored energy ratio, total stored energy, photo-thermal conversion efficiency, and heat dissipation are calculated and compared. Based on all results, the prepared nanofluids show noticeable eligibilities: simplicity, environmental-friendly, and fast preparation method, no need for stabilizers or hazardous chemicals, thermal durability and stability, and good performance in photo-thermal conversion. [ABSTRACT FROM AUTHOR]

Global reduction of traditional fuel sources such as natural gases, coal, and petroleum has led researchers to seek prominent and beneficial energy conversion devices. Fuel cells are a newfound and upcoming energy generation systems that have progressed rapidly. Fuel cells are popular eco-friendly devices among different energy conversion devices due to their cost-effectiveness and high output. In a fuel cell composed of a cathode, anode, and electrolyte, the electrical energy is produced through chemical reactions. Various fuels such as H 2 , alcohols, especially ethanol and methanol, and formic acid are applied in fuel cells. Large scale application of this technology mainly depends on two aspects, including one is the possibility to produce on a large scale and accessible cost-efficient catalytic materials (anodic and cathodic), and second is the stable and high performing membrane in fuel cells. Among various investigated materials, carbon supports and metal-free carbon materials are widely used in fuel cell devices, which increases their overall electrochemical surface area (ECSA) and performance. Carbon-based materials with high surface area, excellent electrical conductivity, and high porosity is known to be a primary substrate for electrochemical energy storage applications such as batteries, supercapacitors, and fuel cells. Herein, we have reviewed the efficacy of carbon-based materials on electrocatalytic activity, stability, and output performance of different fuel cells. Fuel cells are promising converter energy devices. The high surface area, high porosity, and electrical conductivity of carbon support effectively increase the activity of fuel cells. Herein, we have critically overviewed the information about the role of carbon-based materials for the fuel cells performance and output. [Display omitted] • Carbon-based materials show remarkable potential for fuel cell performance. • Fuel cell application of (metal-free)carbon-based catalysts has been reviewed. • Various carbon materials in different fuel cells are discussed in detail. • The fuel cell's performance in understanding their electrochemical reactions have been studied. • Future research directions and challenges in the field of fuel cells have been discussed. [ABSTRACT FROM AUTHOR]

[Display omitted] • Preparation of TiO 2 /RGO nanocomposite by annealing method at 180 °C. • Employing TiO 2 /RGO nanocomposite toward sensing methanol, ethanol and acetone vapors with different ppm. • Observation an excellent response for ethanol detection even in low gas volume. Reduced graphene oxide and metal oxides derivatives are introduced as relatively benign materials for improving gas sensors' performance as exemplified by the synthesis of TiO 2 /GO nanocomposite via ultrasonication, and then the assembly of RGO adorning TiO 2 nanoparticles (NPs) (TiO 2 /RGO) is accomplished using the thermal annealing method. The characterization of the as-fabricated sample indicated that irregular shaped TiO 2 NPs with size of 26 nm covered the RGO nanosheets. The optical band gap measurement indicated the values of 3.19, 2.1 and 2.5 eV for TiO 2 , GO and TiO 2 /RGO samples, respectively. The ensued nanocomposites are then deployed for the gas sensing response of three common organic vapors of ethanol, methanol, and acetone with concentrations of 20, 40, 60, 80, 100 ppm, at ambient temperature. The TiO 2 /RGO sensor relatively exhibited an excellent response (3–4 times) for ethanol detection. These results indicated that the application of TiO 2 /RGO can help assist in the evolvement of portable gas sensing devices endowed with the capability to detect common place organic vapors. [ABSTRACT FROM AUTHOR]

Pt-nanofluids with localized surface plasmon resonance (LSPR) property were environmentally-friendly prepared using the laser ablation in liquids (LAL) while H 2 O acts as a working fluid. Based on transmission electron microscopy (TEM), the obtained Pt nanoparticles have an average diameter of 6 nm which were strongly surrounded with H 2 O molecules, leading to excellent longtime durability. Moreover, fluorescence spectroscopy and fluorescence microscopy images indicated that the prepared sample has fluorescence property that makes it capable to absorb more light and then, to convert it to heat. The Pt-nanofluids were applied for light to heat conversion. After several continuous heating/cooling cycles, the prepared nanofluids did not lose their efficiency in terms of light to heat conversion. In addition, the potential of the Pt-nanofluids in harvesting solar energy was investigated. The infrared thermographs proved that the upper layer temperature of the Pt-nanofluids reached > 49 °C after 60 min light illumination, under ≅ 0.9 Sun intensity. The obtained results proved that the prepared Pt-nanofluids have outstanding advantages, consist of fast, simple, and green synthesis method, no necessity for dispersant, high thermal-stability, long-time stability, and high performance in photo-thermal conversion. So, the Pt-nanofluids have high capability for practical solar energy utilization. [Display omitted] • Pt-nanofluids were synthesized via one step and fast LAL method. • Pt-nanofluids used for photo-thermal conversion for consecutive cycles without losing its performance. • The prepared Pt-nanofluids have long life and thermal stability. • Pt-nanofluids used for solar energy harvesting. [ABSTRACT FROM AUTHOR]

Polycarbonate (PC)-ZnO films with different percentages of ZnO were prepared by a solution stirring technique and subjected to ultraviolet (UV; λ = 254 nm) irradiation. Structural parameters of the samples and the effects of UV irradiation on the surface properties of the PC and PC-ZnO nanocomposites were evaluated by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), water contact angle (WCA) measurements, and a Vickers microhardness (HV) tester. The XRD patterns of the nanocomposite films were found to show an increase in crystallinity with the increasing ZnO nanoparticles percentage. The WCA was found to be reduced from 90° to 17° after 15 h of UV irradiation, which could be ascribed to the oxidation of the surface of the samples during the irradiation and exposure of the ZnO nanoparticles, a result that is also supported by the obtained XPS data. The microhardness value of the PC-ZnO films including 30 wt.% ZnO enhanced considerably after UV radiation, which can also be attributed to the exposition of the ZnO nanoparticles after photodegradation of the PC superficial layer of the nanocomposite films. [ABSTRACT FROM AUTHOR]

The ever-increasing demand for portable smart devices through an extensive range of military, commercial, industrial, and consumer sectors has faced scientists with various challenges. Electromagnetic (EM) pollution is a critical issue threatening the general function of surrounding electronic systems and human well-being. The graphene family (GF) has been investigated thoroughly during the last decade to satisfy the need for light and cost-effective portable devices and address EM pollution and effective shielding devices from its adverse effects. GF has presented an incredible ability to attenuate the EM pollution and, therefore, be used as an alternative for the conventional metal-based electromagnetic interference (EMI) shielding materials. Due to the importance of this topic and the necessity of finding a practical solution for the real-life application of EMI shielding materials, we report the recent research progress and development status of using GFs as EMI shielding materials in a broad frequency range. This review surveys the shielding effectiveness of graphene as a two-dimensional (2D) structure (freestanding thin film and coating), skeleton, filler in polymers' matrix, and three-dimensional (3D) structure (foam and aerogel). Moreover, the shielding mechanism of the materials is investigated comprehensively. This review will briefly discuss the importance of using graphene as an alternative to the conventional shielding material. In the following sections, the EMI shielding performance of graphene as 2D structure, skeleton, filler, and 3D structure is reviewed, and the influence of their conductivity, thickness, and composition on their shielding characteristics is investigated. Finally, the outlooks and conclusions of the recent research will be discussed. [Display omitted] • The shielding effectiveness of graphene-based materials including, 2D structures (freestanding thin film and coating), 3D structures (foam and aerogel), graphene as a matrix, and graphene as filler in polymers, has been surveyed. • The dominant shielding mechanism of graphene-based materials has been described. • Future challenges of electromagnetic waves shielding have been discussed. [ABSTRACT FROM AUTHOR]

Over the course of a few decades, the concern of environmental damages of fossil fuels, an increase in CO 2 emission and a decrease of hydrogen have been growing more and more. Accordingly, hydrogen production is a crucial issue nowadays. Different polymers are applied to attain the purpose. Among all polymers, biodegradables polymers are the best choices to develop the main aim. Polysaccharides and proteins are biodegradable polymers with unique places and advantages with regards to their ecofriendly properties. There are different techniques to apply and achieve the foremost purpose. It is worthwhile to mention that green and facile methods are always attracting attention in different aspects and fields. The three non-polluting and economical techniques, that is, electrochemical hydrogen evolution reaction (HER), photocatalytic technique, and hydrolysis of hydrides, are reviewed in this paper. This review helps researchers, who are environment supporters, to evaluate and choose the most ecological biopolymers and processes in their work. [Display omitted] • Developments in hydrogen evolution by biopolymer-derived (nano)catalysts have been described. • Summary of synthetic procedures to obtain biopolymer-derived (nano)catalysts. • Future challenges of hydrogen evolution using biopolymer-derived (nano)catalysts have been discussed. [ABSTRACT FROM AUTHOR]

In both developing and industrialized/developed countries, various hazardous/toxic environmental pollutants are entering water bodies from organic and inorganic compounds (heavy metals and specifically dyes). The global population is growing whereas the accessibility of clean, potable and safe drinking water is decreasing, leading to world deterioration in human health and limitation of agricultural and/or economic development. Treatment of water/wastewater (mainly industrial water) via catalytic reduction/degradation of environmental pollutants is extremely critical and is a major concern/issue for public health. Light and/or laser ablation induced photocatalytic processes have attracted much attention during recent years for water treatment due to their good (photo)catalytic efficiencies in the reduction/degradation of organic/inorganic pollutants. Pulsed laser ablation (PLA) is a rather novel catalyst fabrication approach for the generation of nanostructures with special morphologies (nanoparticles (NPs), nanocrystals, nanocomposites, nanowires, etc.) and different compositions (metals, alloys, oxides, core-shell, etc.). Laser ablation in liquid (LAL) is generally considered a quickly growing approach for the synthesis and modification of nanomaterials for practical applications in diverse fields. LAL-synthesized nanomaterials have been identified as attractive nanocatalysts or valuable photocatalysts in (photo)catalytic reduction/degradation reactions. In this review, the laser ablation/irradiation strategies based on LAL are systematically described and the applications of LAL synthesized metal/metal oxide nanocatalysts with highly controlled nanostructures in the degradation/reduction of organic/inorganic water pollutants are highlighted along with their degradation/reduction mechanisms. [Display omitted] [ABSTRACT FROM AUTHOR]

Zinc oxide (ZnO) nanoparticles were grown on graphene oxide (GO) surface via reflux method. Electrophoretic deposition (EPD) process was employed to deposit graphene oxide/zinc oxide (GO/ZnO) nanocomposite on Al plate with 1 mg/ml of GO/ZnO suspension, 30 V and 3 min. X-ray Diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), energy-dispersive X-ray spectrometry (EDX) and elemental mapping (MAP) investigation were used to characterize the samples. The hydrophobic and hydrophilic behavior of samples were obtained by heat treatment and UV irradiation, respectively. Heat treatment and UV-irradiation affect wettability of samples. Moreover, switchable wettability of samples was investigated. The WCA changes from 5° to 137° by heat treatment and vice versa by UV-irradiation. [ABSTRACT FROM AUTHOR]

• Anodic fabrication of 3D PbO 2 electrocatalyst on carbon felt substrate. • ZrO 2− MoO x modified 3D carbon felt/β-PbO 2 anode has more electrochemical active area, OEP and service time compared to carbon felt/β-PbO 2. • Degradation of 98.9% of HCQ after 75 min of reaction under optimal conditions. • The electrochemical behavior of HCQ and the suggestion of its possible degradation pathways. • Biodegradability of pharmaceutical wastewater after 180 min of treatment with modified anode. In this study, a 3D and porous carbon felt/β-PbO 2 anodes has modified by ZrO 2− MoO x nanoparticles to enhance the electrocatalytic degradation of hydroxychloroquine (HCQ). Modification of the anode surface with ZrO 2− MoO x significantly increased the its active surface area (5.71 m2 g−1 vs. 1.63 m2 g−1) and OEP (2.2 V vs. 1.8 V) so that the efficiency of HCQ degradation after 105 min of reaction by CF/β-PbO 2 -ZrO 2− MoO x and CF/β-PbO 2 anodes was 94.2% and 61.2%, respectively. Additionally, in this work, the electrochemical behavior, adsorption activity and E -pH (Pourbaix) response of HCQ at various pH values in the range 1–13 were comprehensively studied by cyclic voltammetry (CV) and differential pulse voltammetry. These studies have led to the proposed mechanism for oxidation pathway of HCQ for the first time. The improved electrocatalytic performance of the CF/β-PbO 2 -ZrO 2− MoO x anode increased the BOD/COD ratio of the pharmaceutical wastewater to more than 0.4 after 180 min, indicating that the treated wastewater is fully biodegradable. [Display omitted] [ABSTRACT FROM AUTHOR]

In this research, a simple, green, and efficient approach is described to produce novel bentonite/Ag nanocomposite wherein the preparation of Ag nanoparticles (Ag NPs) deployed the laser ablation method in air; Ag NPs are deposited on the bentonite via the magnetic stirring method. The structural and morphological characterization of the as-prepared bentonite/Ag nanocomposite (denoted as B/Ag30, 30 min being the laser ablation time) is accomplished using different methods. Additionally, the catalytic assessment of the ensued composite exhibited excellent catalytic reduction/degradation activity for common aqueous pollutants namely methyl orange (MO), congo red (CR) and 4-nitrophenol (4-NP) utilizing NaBH 4 as reductant. Furthermore, the recycling tests displayed the high stability/reusability of B/Ag30 nanocomposite for at least 4 runs with retention of catalytic prowess. [Display omitted] • Application of laser ablation in air medium for the synthesis of Ag nanoparticles. • Ag nanoparticles were loaded on the bentonite substrate via the magnetic stirring method. • Bentonite/Ag nanocomposite degrade methyl orange, congo red and 4-nitrophenol in an aqueous medium with NaBH 4. [ABSTRACT FROM AUTHOR]

[Display omitted] • Facile synthesis of Au NPs on zirconia NPs by laser ablation in liquid (LAL) protocol. • A high-performance strategy for NaBH 4 -mediated degradation of MO and MB in water. • Characterization of ZrO 2 -Au nanocomposite via XRD, FTIR, SEM, EDS, XPS, BET, and MAP analyses. • The ZrO 2 -Au nanocomposite can be reused several times with almost no loss in activity. The continuous development of industrial activities and also changing climate of worldwide lead to increase water pollutants and the eradication of safe water sources. Hence, remediation of wastewater and reduction of water pollutants notably organic dyes have become a serious environmental challenge. Reducing organic pollutants by heterogeneous nanocatalysts can be employed as an efficacious manner to overcome this problem. Accordingly, a nanocomposite catalyst consisting of zirconium oxide or zirconia nanoparticles (ZrO 2 NPs) and gold (Au) NPs were made by means of a straightforward and green route. Au NPs were firstly prepared via laser ablation in liquid (LAL) method and then deposited on the ZrO 2 NPs with the size of 53–88 nm using the magnetic stirring approach. The characterization methods indicated that the ZrO 2 -Au nanocomposite was successfully fabricated. The catalytic performance of ZrO 2 -Au catalyst for the degradation of methylene orange (MO) and methylene blue (MB) was investigated. [ABSTRACT FROM AUTHOR]

Today, the increasing world population has led to increased consumption of fossil fuels for energy production, causing environmental problems. Hydrogen with high energy density can be used as a suitable alternative to fossil fuel sources. Hydrogen atoms can be stored on porous structures by physical interaction. Hence, simple and eco-friendly approaches have been taken to prepare bentonite/Pd nanocomposites for electrochemical hydrogen storage. Laser ablation in the deionized water medium was employed as a physical route for the synthesis of Pd nanoparticles (NPs). Bentonite, a porous substrate with a high surface area of 47 m2/g, was employed for the deposition of Pd NPs via physical mixing. The morphological study of nanocomposite indicated that the spherically shaped Pd NPs with a diameter of 20–27 nm are successfully deposited on the bentonite substrate. The as-prepared nanocomposites were loaded on stainless steel electrode through drop-casting and their hydrogen storage capacity was determined via cyclic voltammetry (CV). The CV measurement of the B/Pdx electrodes (x is laser ablation times of 15, 30, 45, and 60 min) in 1.0 M KOH electrolyte at the scan rate of 100 mV/s at room temperature demonstrated good hydrogen storage capacity (37 C/g) and stability during 200 scans. [Display omitted] • The LAL method was applied as an eco-friendly approach for preparation of Pd NPs. • Pd NPs were deposited on the bentonite via physical mixing. • Electrochemical hydrogen storage performance of B/Pd was evaluated by CV. • Electrochemical hydrogen storage capacity of B/Pd30 was obtained 37 C/g. [ABSTRACT FROM AUTHOR]

Carbon nanoparticles (CNPs) with high porosity and great optical features can be used as a luminescent material. One year later, the same group investigated the NLO properties CNPs and boron-doped CNPs by 532 nm and 1064 nm laser excitations to uncover the underlying physical mechanisms in their NLO response. Hence, a facile approach, laser ablation technique, was employed for carbon nanoparticles (CNPs) synthesis from suspended activated carbon (AC). Morphological properties of the prepared CNPs were studied by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). UV-Vis and fluorescence (FL) spectra were used to optical properties investigation of CNPs. The size distribution of nanoparticles was evaluated using dynamic light scattering (DLS). The nonlinear optical (NLO) coefficients of the synthesized CNPs were determined by the Z-scan method. As a result, strong reverse saturable absorption and self-defocusing effects were observed at the excitation wavelength of 442 nm laser irradiation. These effects were ascribed to the presence of delocalized π-electrons in AC CNPs. To the best of our knowledge, this is the first study investigating the NLO properties of the AC CNPs. [ABSTRACT FROM AUTHOR]

The modification of chemical and physical properties of polypropylene (PP) membrane has been of interest as the creation of hydrophilic surface broadens their potential applications. Herein, we describe the use of laser surface modification methodology to overcome the hydrophobic nature of polypropylene membrane via the deployment of an ArF excimer laser. The modified samples were characterized by means of attenuated total reflectance Fourier transform infrared (ATR-FTIR), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), water contact angle (WCA) measurement, and water flux (WF) test. The results suggest that ArF excimer laser irradiation of PP membrane results in the generation of some polar functional groups and surface morphological changes both of them being effective for enhancing the hydrophilicity of PP membrane. In addition, despite increased hydrophilicity of PP membrane at higher fluences of ArF excimer laser, WF decreases due to the covering of pores by melted PP; being 100 mJ/cm2 under the optimized laser fluence. • ArF excimer laser treatment of polypropylene (PP) membrane was performed. • Modified surface of PP was investigated by XPS and ATR-FTIR spectroscopy. • Water flux improvement was discerned at nearly laser ablation threshold fluence. • Maximum hydrophilicity of polypropylene membrane occurs at higher laser fluence. [ABSTRACT FROM AUTHOR]