Ruthenium anchored on carbon nanotube electrocatalyst for hydrogen production with enhanced Faradaic efficiency

Developing efficient and stable electrocatalysts is crucial for the electrochemical production of pure and clean hydrogen. For practical applications, an economical and facile method of producing catalysts for the hydrogen evolution reaction (HER) is essential. Here, we report ruthenium (Ru) nanoparticles uniformly deposited on multi-walled carbon nanotubes (MWCNTs) as an efficient HER catalyst. The catalyst exhibits the small overpotentials of 13 and 17 mV at a current density of 10 mA cm(-2) in 0.5M aq. H2SO4 and 1.0M aq. KOH, respectively, surpassing the commercial Pt/C (16 mV and 33 mV). Moreover, the catalyst has excellent stability in both media, showing almost "zeroloss" during cycling. In a real device, the catalyst produces 15.4% more hydrogen per power consumed, and shows a higher Faradaic efficiency (92.28%) than the benchmark Pt/C (85.97%). Density functional theory calculations suggest that Ru-C bonding is the most plausible active site for the HER

Activation of PERK Signaling Attenuates Aβ-Mediated ER Stress

Alzheimer's disease (AD) is characterized by the deposition of aggregated beta-amyloid (Aβ), which triggers a cellular stress response called the unfolded protein response (UPR). The UPR signaling pathway is a cellular defense system for dealing with the accumulation of misfolded proteins but switches to apoptosis when endoplasmic reticulum (ER) stress is prolonged. ER stress is involved in neurodegenerative diseases including AD, but the molecular mechanisms of ER stress-mediated Aβ neurotoxicity still remain unknown. Here, we show that treatment of Aβ triggers the UPR in the SK-N-SH human neuroblastoma cells. Aβ mediated UPR pathway accompanies the activation of protective pathways such as Grp78/Bip and PERK-eIF2α pathway, as well as the apoptotic pathways of the UPR such as CHOP and caspase-4. Knockdown of PERK enhances Aβ neurotoxicity through reducing the activation of eIF2α and Grp8/Bip in neurons. Salubrinal, an activator of the eIF2α pathway, significantly increased the Grp78/Bip ER chaperone resulted in attenuating caspase-4 dependent apoptosis in Aβ treated neurons. These results indicate that PERK-eIF2α pathway is a potential target for therapeutic applications in neurodegenerative diseases including AD

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School of Energy and Chemical Engineering (Energy Engineering)clos

Edge???Functionalized Graphene Nanoplatelets as Metal???Free Electrocatalysts for Dye???Sensitized Solar Cells

A scalable and low???cost production of graphene nanoplatelets (GnPs) is one of the most important challenges for their commercialization. A simple mechanochemical reaction has been developed and applied to prepare various edge???functionalized GnPs (EFGnPs). EFGnPs can be produced in a simple and ecofriendly manner by ball milling of graphite with target substances (X = nonmetals, halogens, semimetals, or metalloids). The unique feature of this method is its use of kinetic energy, which can generate active carbon species by unzipping of graphitic C???C bonds in dry conditions (no solvent). The active carbon species efficiently pick up X substance(s), leading to the formation of graphitic C???X bonds along the broken edges and the delamination of graphitic layers into EFGnPs. Unlike graphene oxide (GO) and reduced GO (rGO), the preparation of EFGnPs does not involve toxic chemicals, such as corrosive acids and toxic reducing agents. Furthermore, the prepared EFGnPs preserve high crystallinity in the basal area due to their edge???selective functionalization. Considering the available edge X groups that can be selectively employed, the potential applications of EFGnPs are unlimited. In this context, the synthesis, characterizations, and applications of EFGnPs, specifically, as metal???free carbon???based electrocatalysts for dye???sensitized solar cells (DSSCs) in both cobalt and iodine electrolytes are reviewed

Electrochemical Catalysts for Green Hydrogen Energy

Developing clean and renewable energy resources has become one of the world's most important challenges, given the double burden of energy scarcity and environmental pollution. For sustainable energy conversion and storage, efficient electrocatalysts play a pivotal role in important energy-related reactions, including oxygen reduction, oxygen evolution, and hydrogen evolution. To satisfy practical requirements, the catalysts need to demonstrate high performance, durability, and acceptable cost. These are primary considerations when designing and preparing various new electrocatalysts. Among the research programs being actively conducted around the world, some promising recent results suggest strong potential alternatives to current expensive noble metal-based catalysts. This review summarizes recent technical advances in the preparation of efficient electrocatalysts

Enhancing the Photocatalytic Activity of TiO2 Catalysts

To address energy and environmental problems, innumerable titanium dioxide (TiO2)-based photocatalysts have been reported over the last four decades. TiO2 has attracted immense interest because it is low-cost, abundant, and photoresponsive. Sunlight-driven fuel production is one of the ideal photocatalytic approaches in terms of economics and the environment. However, performance issues with TiO2 photocatalysts remain, including insufficient charge separation due to the rapid recombination of photogenerated charge carriers, and poor utilization of light, because of the material's wide bandgap. To be economically efficient, TiO2 photocatalysts responsive to visible light are essential. Many researchers have investigated effective modification methods for this purpose. Numerous studies have focused on enhancing photocatalytic activity by modifying TiO2. Methods include combining TiO2 with noble metals, incorporating metals or nonmetals, and introducing vacancies by chemical and physical methods. In addition, many studies have also been conducted to comprehensively determine the underlying reaction mechanisms, and thus guide future research directions. This Review aims to understand the basic principles of photolysis, to summarize recent research trends, to envision future research directions, and to help the development of a new type of TiO2-based photocatalysts for enhanced solar energy conversion efficiency

Desalted Salicornia europaea powder and its active constituent, trans-ferulic acid, exert anti-obesity effects by suppressing adipogenic-related factors

Context: Salicornia europaea (Amaranthaceae) (SE) has been shown to reduce obesity, but it remains a problem as a food supplement because of its high salt content (25–35% NaCl). Objectives: This study investigated the anti-obesity effects and mechanism of action of desalted SE powder (DSP). Materials and methods: Sprague–Dawley rats (n = 50) were divided into a normal control group (NC), a high-fat diet (HFD)-induced obesity control group (HFD), and HFD groups co-administered DSP (250 and 500 mg/kg) or Garcinia cambogia (Clusiaceae) extract (GE, 200 mg/kg, standard control) orally each day for 12 weeks. Results: The body weight was significantly reduced by co-administration of DSP (596.51 ± 19.84 kg, 4.60% and 562.08 ± 9.74 kg, 10.10%, respectively) and GE (576.00 ± 11.29 kg, 7.88%) relative to the HFD group (625.25 ± 14.02 kg) and was accompanied by reduced abdominal fat mass, and serum lipid levels, with no effects on feed intake. To find the underlying mechanism of the anti-obesity effects, trans-ferulic acid (TFA) was identified as the main ingredient and investigated with regard to whether it attenuated adipogenesity in 3T3L-1 cells. DSP-derived TFA suppressed adipocyte differentiation and accumulation of intracellular lipids. TFA also down-regulated the adipogenesis-related gene expression of sterol regulatory element-binding protein 1, peroxisome proliferator-activated receptor γ, CCAAT/enhancer binding protein-α and fatty acid synthase. Conclusions: These findings suggest that DSP may be considered for use as a food supplement intent of controlling obesity through its antiobesity and antiadipogenic properties