Nitrogen and Sulfur Doped Porous Carbon Sheet with Trace Amount of Iron as Efficient Polysulfide Conversion Catalyst for High Loading Lithium-Sulfur Batteries.

The major challenges in enhancing the cycle life of lithium-sulfur (Li-S) batteries are polysulfide (PS) shuttling and sluggish reaction kinetics (S to LiS, LiS to S). To alleviate the above issues, the use of heteroatom-doped carbon as a cathode host matrix is a low-cost and efficient approach, as it works as a dual-functional framework for PS anchoring as well as an electrocatalyst for faster redox kinetics. Here, the dual role of heteroatom-doped carbon sheets (CS) in the chemisorption of LiS and catalysis of its faster conversion to LiS is established.

Hydroxide Ion Conduction through Viologen-Based Covalent Organic Frameworks (vCOFs): An Approach toward the Advancement.

Alkaline fuel cells rely on the movement of hydroxide anions (OH) for their operation, yet these anions face challenges in efficient conduction due to their limited diffusion coefficient and substantial mass compared to proton (H) transport. Within the covalent organic framework structure, ordered channels offer a promising solution for the OH ion transport. Herein, we synthesized a cationic covalent organic framework (vTAPA) via the solvothermal-assisted Zincke reaction.

Solvent-Free, One-Pot Synthesis of Tungsten Semi-Carbide for Stable and Self-Hydrating Short-Side-Chain-Based Polymer Electrolyte Membrane for Low-Humidity Hydrogen Fuel Cells.

Polymer electrolyte membranes (PEMs) that promote fast and selective ionic transport at low relative humidity (RH) are of high demand for energy conversion devices, particularly in hydrogen fuel cells. Herein, we report a facile and solvent free synthesis of tungsten semi-carbide (WC@NC) and its incorporation onto short side chain (SSC)-based membrane matrix to facilitate water holding and water-assisted humidification generated by the reaction of crossover gas molecules. In the present study, the influence of WC@NC on the membrane matrix is widely investigated through its microstructure, physicochemical properties, proton conductivity, and fuel cell performance.

Electrochemical nitrogen fixation on single metal atom catalysts.

The electrochemical reduction of nitrogen (eNRR) offers a promising alternative to the Haber-Bosch (H-B) process for producing ammonia under moderate conditions. However, the inertness of dinitrogen and the competing hydrogen evolution reaction pose significant challenges for eNRR. Thus, developing more efficient electrocatalysts requires a deeper understanding of the underlying mechanistic reactions and electrocatalytic activity.

Anion Exchange Membranes for Alkaline Polymer Electrolyte Fuel Cells-A Concise Review.

Solid anion exchange membrane (AEM) electrolytes are an essential commodity considering their importance as separators in alkaline polymer electrolyte fuel cells (APEFC). Mechanical and thermal stability are distinguished by polymer matrix characteristics, whereas anion exchange capacity, transport number, and conductivities are governed by the anionic group. The physico-chemical stability is regulated mostly by the polymer matrix and, to a lesser extent, the cationic head framework.

A new silicon oxycarbide based gas diffusion layer for zinc-air batteries.

Rational material designs play a vital role in the gas diffusion layer (GDL) by increasing the oxygen diffusion rate and, consequently, facilitating a longer cycle life for metal-air batteries. In this work, a new porous conductive ceramic membrane has been developed as a cathodic GDL for zinc-air battery (ZAB). The bilayered structure with a thickness of 390 μm and an open porosity of 55% is derived from a preceramic precursor with the help of the freeze tape casting technique.

Electrochemical deposition of three-dimensional platinum nanoflowers for high-performance polymer electrolyte fuel cells.

In the present work, the three-dimensional ultra-fine platinum nanoflowers are directly deposited on carbon-coated gas diffusion layer electrode (C-GDL) by a single-step electrodeposition method towards the application of polymer electrolyte fuel cells. The surface morphology, particle size distribution, crystallinity, and chemical oxidation state of platinum nanoflowers are examined using various techniques. The morphological features of the Pt nanostructures are highly influenced by the difference in current density.

Structurally Modulated Graphitic Carbon Nanofiber and Heteroatom (N,F) Engineering toward Metal-Free ORR Electrocatalysts for Polymer Electrolyte Membrane Fuel Cells.

The present study designates the heteroatom (N,F)-doped various graphitic carbon nanofibers (GNFs) viz. GNF-linear segmented platelets, antlers, herringbone type, and their structural deformations from pristine fiber with many open-edge active centers as metal-free, cost-effective electrocatalysts for oxygen reduction reaction (ORR) in polymer electrolyte membrane fuel cells (PEMFCs). Introduction of heteroatoms to GNF frameworks enlarges the lattice spacing between graphene platelets and leads to structural modulation.

Fluorine-enriched mesoporous carbon as efficient oxygen reduction catalyst: understanding the defects in porous matrix and fuel cell applications.

Herein, fluorine enrichment in mesoporous carbon (F-MC) was explored to introduce maximum charge polarization in the porous matrix, which is beneficial for the preferential orientation of O molecules and their subsequent reduction. doping of F to porous carbon derived from phloroglucinol-formaldehyde resin using Pluronic F-127 as a structure-directing agent is standardized. The optimized F-MC catalyst exhibited excellent electrocatalytic activity towards the oxygen reduction reaction (ORR) in alkaline media (0.

Carbon Nanocomposite Membrane Electrolytes for Direct Methanol Fuel Cells-A Concise Review.

A membrane electrolyte that restricts the methanol cross-over while retaining proton conductivity is essential for better electrochemical selectivity in direct methanol fuel cells (DMFCs). Extensive research carried out to explore numerous blends and composites for application as polymer electrolyte membranes (PEMs) revealed promising electrochemical selectivity in DMFCs of carbon nanomaterial-based polymer composites. The present review covers important literature on different carbon nanomaterial-based PEMs reported during the last decade.

A Convenient Synthesis Route for CoO Hollow Microspheres and Their Application as a High Performing Anode in Li-Ion Batteries.

A new, rapid, and cost-effective method for synthesizing hollow microspheres (HMSs) of cobalt oxide (CoO) using the phloroglucinol-formaldehyde gel route is reported here. Further, the synthesized hollow CoO microspheres were investigated as an anode material for Li-ion batteries. The CoO hollow spheres exhibited excellent electrochemical performance and cycling stability, for example, a capacity of 915 mA h g was obtained at 1 C rate over 350 cycles.

Development of high-performance supercapacitor electrode derived from sugar industry spent wash waste.

This study aims at developing supercapacitor materials from sugar and distillery industry wastes, thereby mediating waste disposal problem through reuse. In a two-step process, biomethanated spent wash (BMSW) was acid treated to produce solid waste sludge and waste water with significantly reduced total organic carbon (TOC) and biological oxygen demand (BOD) content. Further, waste sludge was directly calcined in presence of activating agent ZnCl in inert atmosphere resulting in high surface area (730-900mg) carbon of unique hexagonal morphology.

Cumulative effect of transition metals on nitrogen and fluorine co-doped graphite nanofibers: an efficient and highly durable non-precious metal catalyst for the oxygen reduction reaction.

Nitrogen and fluorine co-doped graphite nanofibers (N/F-GNF) and their cumulative effect with Fe and Co have been developed as an alternative non-precious metal catalyst for efficient oxygen reduction reaction (ORR) in acidic media. The synergistic effect between the doped hetero atoms and the co-ordinated Fe and Co towards ORR activity and durability of the catalyst is deeply investigated. A high ORR onset potential comparable with commercial Pt/C catalyst is observed with the Fe-Co/NF-GNF catalyst, which indicates that this catalyst is a potential alternative to Pt/C.

Carbon-supported Pd-Co as cathode catalyst for APEMFCs and validation by DFT.

Carbon supported PdCo catalysts in varying atomic ratios of Pd to Co, namely 1 : 1, 2 : 1 and 3 : 1, were prepared. The oxygen reduction reaction (ORR) was studied on commercial carbon-supported Pd and carbon-supported PdCo nanocatalysts in aqueous 0.1 M KOH solution with and without methanol.

Durable electrocatalytic-activity of Pt-Au/C cathode in PEMFCs.

Longevity remains as one of the central issues in the successful commercialization of polymer electrolyte membrane fuel cells (PEMFCs) and primarily hinges on the durability of the cathode. Incorporation of gold (Au) to platinum (Pt) is known to ameliorate both the electrocatalytic activity and stability of cathode in relation to pristine Pt-cathodes that are currently being used in PEMFCs. In this study, an accelerated stress test (AST) is conducted to simulate prolonged fuel-cell operating conditions by potential cycling the carbon-supported Pt-Au (Pt-Au/C) cathode.