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MXene is a growing class of two-dimensional layered material that has been showed promising application in various energy storage and conversion technologies, due to its unique electrical, mechanical, surface and electrocatalytic properties. One of the promising applications of MXene is, its definite role as durable catalyst support material, for fuel cell anodic/cathodic reactions. Very recently, MXene supported catalysts have been identified as potential and stable support for various Pt and non-Pt metals designed for cathodic oxygen reduction reaction and it has been proved as excellent material to enhance the oxygen reduction kinetics. This had motivated the researchers to explore MXene as catalyst support for anodic methanol/ethanol oxidation reactions. In this review, recent developments in experimental and theoretical research on MXene-based electrocatalysts for the methanol/ethanol oxidation reactions are examined and overviewed. After careful examination of the available literature, we presume that MXene supported electrocatalyst showed enhanced methanol/ethanol oxidation kinetics and therefore believed to have tremendous opportunities as durable catalyst support for alcohol fuel cells. However, researchers also consider several limitations and challenges that must be addressed for efficient application of MXenes as catalyst supports. Therefore, current research on MXenes with respect to the methanol/ethanol oxidation are discussed, with a focus on synthesis strategies, oxidation kinetics, and factors responsible for enhancing the electrocatalytic performance. Several strategies for the further development of efficient and durable MXene supported catalysts are also proposed.

Pt based catalysts represent the state-of-the-art electrocatalyst for electrochemical cathodic oxygen reduction reaction of proton exchange membrane fuel cells. Among Pt based electrocatalysts, Pt-transition metal catalysts have been the most successful in terms of activity. However, the poor structural and chemical stability of Pt-alloy catalysts are challenges. Alternatively, alloying Pt with rare earth metals is considered as one of the effective ways to discover active and durable electrocatalysts for the ORR. The advantages of alloying with rare earth metals bring a substantial change in the electronic properties and their negative alloying energy or enthalpy of formation of alloys provides special driving force to resist against dissolution. Synthesis of Pt-rare earth alloys by a solution phase route is challenging. To date there have been only physical metallurgical methods which help to synthesize them successfully in the form of an alloy, where as traditional wet chemical synthesis methods results rare earth turns into metal oxide/hydroxide. This article reviews several studies put forward to synthesize Pt-rare earth alloy/oxide catalysts by various physical metallurgical methods and solution-based synthesis protocols and their effect on the improvement of ORR activity.

Rational, low cost, stable and more realistic synthesis of electrocatalysts comprising of earth abundant metals alterative to platinum-based catalysts is highly required for fuel cells. In this work, we demonstrate 2D nanosheet catalyst from metal organic frame works with zinc and 2-amino thiazole as organic ligand in presence of cobalt metal ions. The special bonding configurations of zinc with 2-amino thiazole ligand resulted in formation of 2D ZnxCo1-x(C3H4N2S) and the pyrolysis of 2D ZnxCo1-x(C3H4N2S) resulted in Co@NSC electrocatalyst. The electrochemical oxygen reduction reaction analysis of the Co@NSC catalyst reveals excellent activity with the half-wave potential of 0.88 V, similar to the commercial Pt/C catalyst. Moreover, Co@NSC catalyst also show the ultra-low HO2− formation bellow

Quercetin-3-O-α-l-rhamnopyranosyl(1→2)-O-α-l-rhamnopyranoside (QDR) was isolated from the remaining underground parts of Curcuma longa after harvesting the medicinal parts, and the antioxidant activities in vitro and lifespan-extending effect of QDR were elucidated using the Caenorhabditis elegans model system. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging effect of QDR showed similar potent activities in comparison with vitamin C. QDR also showed strong superoxide quenching activities as measured by the riboflavin- and xanthine-originated superoxide quenching activities. QDR demonstrated potent lifespan extension of worms under normal culture condition. Subsequently, the protective effect of QDR on the stress conditions such as thermal and oxidative stresses was determined. In the case of heat stress, QDR-treated worms exhibited enhanced survival rate, as compared to control worms. In addition, QDR-fed worms lived longer than control worms under oxidative stress induced by paraquat. To verify the possible mechanism of QDR-mediated increased lifespan and stress resistance of worms, we investigated whether QDR might alter superoxide dismutase (SOD) activity and intracellular reactive oxygen species (ROS) levels. Our results showed that QDR was able to elevate SOD activity of worms and reduce intracellular ROS accumulation in a dose-dependent manner.

An analysis of fouling material and the effects of chemical cleaning were examined for a reverse osmosis (RO) membrane, which was used for the treatment of wastewater from a rolling mill process in the steel industry. The bulk foulant accumulated in the membrane module consisted mainly of CaSO 4 ·2H 2 O, and the organic contaminants were contained at a very low level. The test pieces obtained from the exhausted RO membrane module (spiral-wound type) were used to examine chemical cleaning with the following solutions: acid and alkaline solutions with EDTA added, 50% methanol, and 10% ethyleneglycol monobutyrate (EGMB). Although a major component of the fouling material was calcium salt, the acid or alkaline solution containing EDTA did not promote the effective recovery of the water flux. On the other hand, cleaning with 50% methanol or 10% EGME solution increased the water flux significantly. The atomic force microscopy images of the membrane surface indicated that relatively large particles accumulated at the surface of the fouled membranes, and the large particles remained even after acid or alkaline cleaning. In the case of EGMB cleaning after alkaline cleaning, large particles did not remain, and uniform and fine particles were observed. The results that calcium salt, a major fouling material, was not removed effectively with the acid and alkaline solution may be due to trace organic materials in the fouling layer that act as a binder for inorganic fouling materials.

Phosphate removal is important to control eutrophication and an ion exchange process is one of several treatment processes for this purpose. Hydrotalcite compounds (HTALs) are useful as adsorbents for phosphate removal because of their ion exchange properties. In this study, the adsorption properties of a granular synthetic HTAL for phosphate and the method of regeneration of the granular HTAL were examined. The adsorption isotherm of the granular HTAL was approximated by a modified Langmuir type, and the maximum adsorption capacity was 47.3 mg P g(-1), which corresponded to the content of HTAL in the granular one. Phosphate adsorbed on the HTAL was effectively desorbed with alkaline NaCl solutions and the HTAL was regenerated with 25 w/v% MgCl(2) solution. The regenerated HTAL could be reused repeatedly for the phosphate removal. Phosphate in the exhausted desorption solution was recovered as a precipitate of calcium phosphate by addition of CaCl(2), and the residual exhausted desorption solution could be also reused after supplying NaOH. The results suggest the possibility of an effective system for phosphate removal and recovery, which includes the following processes: adsorption, desorption, recovery of phosphate, and regeneration of the HTAL and the desorption solution.

Varying amounts of exfoliated graphene oxide (GO) are systematically incorporated into nanoscale polyacrylonitrile (PAN) fibers via an electrospinning method. Subsequent treatment of the PAN–GO composite nanofibers under a moderate temperature and high pressure leads to the formation of membrane sheets with enhanced mechanical properties. scanning electron microscope, Fourier transform infrared spectroscopy, and contact angle measurements confirm the successful incorporation of the GO into the PAN nanofiber membranes whose diameter, porosity, and pore size are notably influenced by the amount of the GO content. These composite membranes also exhibit a gradual reduction in the water contact angle as a function of the hydrophilic GO content, resulting in a beneficial property for water purification. In addition, the proper integration of GO into the PAN nanofibers improves the protein rejection rate and water flux during the filtration process, which indicates the possibility of utilizing these types of composite membranes in water treatment systems. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45858.