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Many materials with varied characteristics have been used for water purification and separation applications. Recently discovered graphene oxide (GO), a two-dimensional derivative of graphene has been considered as a promising membrane material for water purification due to its excellent hydrophilicity, high water permeability, and excellent ionic/molecular separation properties. This review is focussed on the possible versatile applicability of GO membranes. It is also known that selective reduction of GO results in membranes with a pore size of $0.35 nm, ideally suited for desalination applications. This article presents the applicability of graphene-based membranes for multiple separation applications. This is indeed the first review article outlining a comparison of GO and r-GO membranes and discussing the suitability for applications based on the porosity of the membranes.

Innovative applications based on two-dimensional solids require cost-effective fabrication processes resulting in large areas of high quality materials. Chemical vapour deposition is among the most promising methods to fulfill these requirements. However, for 2D materials prepared in this way it is generally assumed that they are of inferior quality in comparison to the exfoliated 2D materials commonly used in basic research. In this work we challenge this assumption and aim to quantify the differences in quality for the prototypical transition metal dichalcogenide MoS2. To this end single layers of MoS2 prepared by different techniques (exfoliation, grown by different chemical vapour deposition methods, transfer techniques and as vertical heterostructure with graphene) are studied by Raman and photoluminescence spectroscopy, complemented by atomic force microscopy. We demonstrate that as-prepared MoS2, directly grown on SiO2, differs from exfoliated MoS2 in terms of higher photoluminescence, lower electron concentration and increased strain. As soon as a water film is intercalated (e.g. by transfer) underneath the grown MoS2, in particular the (opto)electronic properties become practically identical to those of exfoliated MoS2. A comparison of the two most common precursors shows that the growth with MoO3 causes greater strain and/or defect density deviations than growth with ammonium heptamolybdate. As part of a heterostructure directly grown MoS2 interacts much stronger with the substrate and in this case an intercalated water film does not lead to the complete decoupling, which is typical for exfoliation or transfer. Our work shows that the supposedly poorer quality of grown 2D transition metal dichalcogenides is indeed a misconception.

with diverse functional properties makes a fabric suitable for smart textiles, which can be well suited for numerous potential applications including protective clothing, health monitoring, wearable motion sensing, sports clothing, personal entertainment, and the Internet of Things. [1,2] Due to these revolutionary prospective applications, in recent times the interest in multifunctional wearable smart textiles has been increasing remarkably. [3] However, the existing smart textile manufacturing technology involves the processing of separately manufactured conductive threads with some complicated and timeconsuming steps like sewing, knitting, weaving, and embroidery. [4] Besides, fabrication of high electroconductive multifunctional fabric with good washing durability by maintaining a facile fabrication method is very challenging. Having extraordinarily high electrical, thermal, mechanical, hydrophobic, and many other significant properties, graphene and its derivatives (graphene oxide, GO and reduced graphene oxide, RGO) [5] have already demonstrated immense capability to be adsorbed (by covalent and hydrogen bond) onto fabrics and fabricated into smart textiles. [2,3,6] Presence of oxygenbearing (negative) functional groups (hydroxyl, carboxyl, and Graphene derivatives have the capability of forming chemical bonding with fabrics and show the potential to be used in smart textiles. However, the challenge is to fabricate highly conductive multifunctional fabric with good washing durability. Herein, reduced graphene oxide (RGO) and silver (Ag)/copper (Cu) nanoparticles (NPs)-coated durable electroconductive silk fabric is fabricated by facile dip and dry method using 3-glycidyloxypropyl trimethoxy silane as coupling agent (CA). Results show that RGO and NPs-coated fabrics not only demonstrate low surface resistance but also excellent electrothermal property, UV shielding, enhanced thermal stability, and outstanding hydrophobicity consistently in the following order: pure silk < silk-RGO < silk-CARGO < silk-CARGO -Ag < silk-CARGO -Cu. The addition of CA and NPs is found to have a significant impact on performance and washing durability. Cu incorporated samples (silk-CARGO -Cu) show a very low value of surface resistance (3.15 kΩ sq −1) and even after washing 20 times, the resistance (6.76 kΩ sq −1) is observed to be lower than unwashed non-Cu incorporated samples. Moreover, silk-CARGO -Cu also has the highest UV resistance, Joule heating, hydrophobicity, and thermal stability among all samples, which makes it well suited for numerous potential applications including protective clothing, health monitoring, motion sensing, and sports clothing.

This paper describes the development of a thermal transformation process to recycle waste toner powder in a sustainable and environmentally friendly manner. The process leverages high-temperature reactions and the morphology and chemical composition of waste toner powder, mainly the iron oxide and carbon content, by utilizing the gases evolved during the thermal transformation as an in situ source of carbon to convert the waste toner powder into 98% pure iron. A temperature of 1550 °C was employed in the present study to ensure the complete transformation of waste toner powder to iron and also because of its practical relevance to operating conditions encountered in metal manufacturing and processing industries. The process delivers an iron recovery of 81.6%. X-ray diffraction, scanning electron microscopy–energy-dispersive spectroscopy, and inductively coupled plasma optical emission spectroscopy analyses were employed to confirm the composition of the metallic product. GC–MS analysis was utilized to monitor gaseous aromatic compounds during the thermal degradation studies of the waste toner powder, and none were detected above 1200 °C. In addition, this paper presents a comprehensive characterization of the waste toner powder and resultant products using various analytical techniques, a kinetic study of the thermal decomposition of waste toner powder, and a pelletization technique to overcome its material handling hazards.

There is a pressing need for the introduction of highly efficient and cost-effective energy storage systems to meet worldwide burgeoning energy demand. Key to these systems is the development of sustainable, higher capacity, electrode materials. Carbonaceous materials have demonstrated the most success as negative electrode materials for alkali-ion batteries, and the development of novel methods to produce these materials more sustainably will enable the production of next-generation alkali-ion batteries with reduced environmental impact. This study demonstrates that activated carbon derived from end-of-life printer plastics can act as high capacity anode materials for sodium-ion batteries. These carbons exhibited superior rate capability and delivered capacities as high as 190 mAh/g at 3 mA/g after 25 cycles. They were able to retain up to 100% of their second discharge capacity after 100 cycles at 20 mA/g. In-depth ex situ analysis of the electrodes, using a combination of techniques such as solid state nuclear magnetic resonance and X-ray diffraction is also presented to shed light on the sodium storage mechanism, a topic still being vigorously investigated in the scientific community. This work provides an excellent example of repurposing waste for sustainable energy storage applications.

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