Tungsten oxide/graphene hybrid materials are attractive semiconductors for energy‐related applications. Herein, we report an asymmetric supercapacitor (ASC, HRG//m‐WO3 ASC), fabricated from monoclinic tungsten oxide (m‐WO3) nanoplates as a negative electrode and highly reduced graphene oxide (HRG) as a positive electrode material. The supercapacitor performance of the prepared electrodes was evaluated in an aqueous electrolyte (1 m H2SO4) using three‐ and two‐electrode systems. The HRG//m‐WO3 ASC exhibits a maximum specific capacitance of 389 F g−1 at a current density of 0.5 A g−1, with an associated high energy density of 93 Wh kg−1 at a power density of 500 W kg−1 in a wide 1.6 V operating potential window. In addition, the HRG//m‐WO3 ASC displays long‐term cycling stability, maintaining 92 % of the original specific capacitance after 5000 galvanostatic charge–discharge cycles. The m‐WO3 nanoplates were prepared hydrothermally while HRG was synthesized by a modified Hummers method.

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The optoelectrical and magnetic characteristics of naturally existing iron-based nanostructures, especially hematite and magnetite nanoparticles (H-NPs and M-NPs), gained significant research interest in various applications, recently. The main purpose of this Review is to provide an overview of the utilization of H-NPs and M-NPs in various environmental remediation. Iron-based NPs are extensively explored to generate green energy from environmental friendly processes such as water splitting and CO2 conversion to hydrogen and low molecular weight hydrocarbons, respectively. The latter part of the Review provided a critical overview to use H-NPs and M-NPs for the detection and decontamination of inorganic and organic contaminants to counter the environmental pollution and toxicity challenge, which could ensure environmental sustainability and hygiene. Some of the future perspectives are comprehensively presented in the final portion of the script, optimiztically, and it is supported by some relevant literature surveys to predict the possible routes of H-NPs and M-NPs modifications that could enable researchers to use these NPs in more advanced environmental applications. The literature collection and discussion on the critical assessment of reserving the environmental sustainability challenges provided in this Review will be useful not only for experienced researchers but also for novices in the field.

The search for clean, low-cost, and renewable energy sources is one important challenge of modern industrial societies. [1] Hydrogen generated by photochemistry has been identified as a promising energy carrier with high energy density and zero CO 2 emission while being environmentally clean. [2,3] To set up a light-driven and hydrogen based economy an exploration of new materials for eco-friendly, economically viable, stable, and efficient photocatalysts is needed. [4] Noble metals like platinum, iridium, and ruthenium are efficient catalysts for the electrolysis of water, but their scarcity and high-costs limit large-scale technological use. [5] The development of cheap and active catalysts with long-term stability for the hydrogen or oxygen evolution reaction in standard electrolytes is an important goal. A general method to carry out the fluorination of metal oxides with poly(tetrafluoroethylene) (PTFE, Teflon) waste by spark plasma sintering (SPS) on a minute scale with Teflon is reported. The potential of this new approach is highlighted by the following results. i) The tantalum oxyfluorides Ta 3 O 7 F and TaO 2 F are obtained from plastic scrap without using toxic or caustic chemicals for fluorination. ii) Short reaction times (minutes rather than days) reduce the process time the energy costs by almost three orders of magnitude. iii) The oxyfluorides Ta 3 O 7 F and TaO 2 F are produced in gram amounts of nanoparticles. Their synthesis can be upscaled to the kg range with industrial sintering equipment. iv) SPS processing changes the catalytic properties: while conventionally prepared Ta 3 O 7 F and TaO 2 F show little catalytic activity, SPS-prepared Ta 3 O 7 F and TaO 2 F exhibit high activity for photocatalytic oxygen evolution, reaching photoconversion efficiencies up to 24.7% and applied bias to photoconversion values of 0.86%. This study shows that the materials properties are dictated by the processing which poses new challenges to understand and predict the underlying factors.

-Nanotechnology has opened a new horizon of research in various fields including applied physics, chemistry, electronics, optics, robotics, biotechnology and medicine. In the biomedical field, nanomaterials have shown remarkable potential as theranostic agents. Materials which are considered inert are often used in nanomedicine owning to their nontoxic profile. At nanoscale, these inert materials have shown unique properties that differ from bulk and dissolved counterparts. In the case of metals, this unique behavior not only imparts paramount advantages but also confers toxicity due to their unwanted interaction with different cellular processes. In the literature, the toxicity of nanoparticles made from inert materials has been investigated and many of these have revealed toxic potential under specific conditions. The surge to understand underlying mechanism of toxicity has increased and different means have been employed to overcome toxicity problems associated with these agents. In this review, we have focused nanoparticles of three inert metallic materials i.e. gold, silver and iron as these are regarded as biologically inert in the bulk and dissolved form. These materials have gained wider research interest and studies indicating the toxicity of these materials are also emerging. Oxidative stress, physical binding and interference with intracellular signaling are the major role player in nanotoxicity and their predominance is highly dependent upon size, surface coating and administered dose of nanoparticles. Current strategies to overcome toxicity have also been reviewed in the light of recent literature. The authors also suggested that uniform testing standards and well-designed studies are needed to evaluate nanotoxicity of these materials that are otherwise considered as inert.

A field experiment was conducted to study the response of two maize hybrids to external K application under saline field conditions (ECe 5.71-8.91 dS m-1). The data showed that there was an increase in the different growth and yield components with the increase in the external K. The increase was more pronounced when K was applied at the rate of 175 kg ha-1 with respect to control treatment. The enhanced growth and yield of these hybrids under saline conditions might be due to the response of K application, resulting in reduced Na uptake. The results indicated that the hybrids Pioneer 32B33 perform better than Dekalb 979 and economical yield can be obtained when potassium was applied at the rate of 125 kg ha-1.

Energy from renewable resources is central to environmental sustainability. Among the renewables, sunlight-driven fuel synthesis is a sustainable and economical approach to produce vectors such as hydrogen through water splitting. The photocatalytic water splitting is limited by the water oxidation half-reaction, which is kinetically and energetically demanding and entails designer photocatalysts. Such challenges can be addressed by employing alternative oxidation half-reactions. Photoreforming can drive the breakdown of waste plastics and biomass into valuable organic products for the production of H 2 . We provide an overview of photoreforming and its underlying mechanisms that convert waste polymers into H 2 fuels and fine chemicals. This is of paramount importance from two complementary perspectives: (i) green energy harvesting and (ii) environmental sustainability by decomposing waste polymers into valuables. Competitive results for the generation of H 2 fuel without environmental hazards through photoreforming are being generated. The photoreforming process, mechanisms, and critical assessment of the field are scarce. We address such points by focusing on (i) the concept of photoreforming and up-to-date knowledge with key milestones achieved, (ii) uncovering the concepts and challenges in photoreforming, and (iii) the design of photocatalysts with underlying mechanisms and pathways through the use of different polymer wastes as substrates. CONTENTS

A facile and chemical specific method to synthesize highly reduced graphene oxide (HRG) and Pd (HRG@Pd) nanocomposite is presented. The HRG surfaces are tailored with amine groups using 1-aminopyrene (1-AP) as functionalizing molecules. The aromatic rings of 1-AP sit on the basal planes of HRG through π-π interactions, leaving amino groups outwards (similar like self-assembled monolayer on 2D substrates). The amino groups provide the chemically specific binding sites to the Pd nucleation which subsequently grow into nanoparticles. HRG@Pd nanocomposite demonstrated both uniform distribution of Pd nanoparticles on HRG surface as well as excellent physical stability and dispersibility. The surface functionalization was confirmed using, ultraviolet-visible (UV-Vis), Fourier transform infra-red and Raman spectroscopy. The size and distribution of Pd nanoparticles on the HRG and crystallinity were confirmed using high-resolution transmission electron microscopy and powder X-ray diffraction and X-ray photoelectron spectroscopy. The catalytic efficiency of highly reduced graphene oxide-pyrene-palladium nanocomposite (HRG-Py-Pd) is tested towards the Suzuki coupling reactions of various aryl halides. The kinetics of the catalytic reaction (Suzuki coupling) using HRG-Py-Pd nanocomposite was monitored using gas chromatography (GC). The highly reduced graphene oxide (HRG) with its exceptional physicochemical properties is among extensively studied materials in the world 1,2. It is the strongest, thinnest and stiffest material with several remarkable properties, including high thermal and electric conductivities and large theoretical specific surface area 3,4. These unique properties have attracted the vigil eye of researchers in both scientific (academics) and engineering communities (industrial applications) 5. Currently, several methods have been applied to obtain bulk quantities of defect free graphene, which are mainly classified into the bottom-up and top-down approaches 6,7. The most popular methods under the bottom-up approaches include chemical vapor deposition (CVD), chemical conversion, and arc discharge 8,9. Whereas, the top-down approach involve, the sequential oxidation and reduction of graphite. These chemical methods (top-down approaches), offer excellent opportunities for the production of large quantities of graphene like materials, which is best known as highly reduced graphene oxide (HRG) 10,11. The recent advancement in the synthesis of homogeneously dispersed graphene using different reduction and functionalization techniques, have led to the development of various graphene based hybrid materials, such as graphene-inorganic nanoparticles (NPs) based nanocomposites 12,13. The hybridization of inorganic NPs with graphene further enhance the properties and broaden the applications ranging from the medical to the energy