Heat treatment effect on the microstructure and corrosion behavior of 316L stainless steel fabricated by selective laser melting for proton exchange membrane fuel cells

The fate and role of in situ formed carbon in polymer-derived ceramics

In this article, influence of anodization parameters on the formation of tubes, tube dimensions, formation mechanism, properties of TiO2 nanotubes (TNT), and their applications in biomedical field are reviewed. The fabrication of TNT of a different shape such as pore size, length, and wall thickness by varying anodization parameters including electrolytes, pH, voltage, electrolyte bath temperature, and current density is examined and discussed. The crystallographic nature of the nanotube obtained by various methods has also been discussed. Finally, the article concludes by examining the key properties including the corrosion aspect and various applications in biomedical field in depth.

/pdf/a-review-on-tio2-nanotubes-influence-of-anodization-39iksw61lf.pdf

A Review on TiO2 Nanotubes: Influence of Anodization Parameters, Formation Mechanism, Properties, Corrosion Behavior, and Biomedical Applications

Nitrate enrichment, which is mainly caused by the over-utilization of fertilisers and industrial sewage discharge, is a major global engineering challenge because of its negative influence on the environment and human health. To solve this serious problem, many technologies, such as the activated sludge method, reverse osmosis, ion exchange, adsorption, and electrodialysis, have been developed to reduce the nitrate levels in water bodies. However, the applications of these traditional techniques are limited by several drawbacks, such as a long sludge retention time, slow kinetics, and undesirable by-products. From an environmental perspective, the most promising nitrate reduction technology is enabled to convert nitrate into benign N2, and features low cost, high efficiency, and environmental friendliness. Recently, electrocatalytic nitrate reduction has been proven by satisfactory research achievements to be one of the most promising methods among these technologies. This review provides a comprehensive account of nitrate reduction using electrocatalysis methods. The fundamentals of electrocatalytic nitrate reduction, including the reaction mechanisms, reactor design principles, product detection methods, and performance evaluation methods, have been systematically summarised. A detailed introduction to electrocatalytic nitrate reduction on transition metals, especially noble metals and alloys, Cu-based electrocatalysts, and Fe-based electrocatalysts is provided, as they are essential for the accurate reporting of experimental results. The current challenges and potential opportunities in this field, including the innovation of material design systems, value-added product yields, and challenges for products beyond N2 and large-scale sewage treatment, are highlighted.

Electrocatalytic reduction of nitrate - a step towards a sustainable nitrogen cycle.

Titanium (Ti) plays a predominant role as the material of choice in orthopaedic and dental implants. Despite the majority of Ti implants having long-term success, premature failure due to unsuccessful osseointegration leading to aseptic loosening is still too common. Recently, surface topography modification and biological/non-biological coatings have been integrated into orthopaedic/dental implants in order to mimic the surrounding biological environment as well as reduce the inflammation/infection that may occur. In this review, we summarize the impact of various Ti coatings on cell behaviour both in vivo and in vitro. First, we focus on the Ti surface properties and their effects on osteogenesis and then on bacterial adhesion and viability. We conclude from the current literature that surface modification of Ti implants can be generated that offer both osteoinductive and antimicrobial properties.

/pdf/impact-of-surface-topography-and-coating-on-osteogenesis-and-5edwyuz20k.pdf

Impact of surface topography and coating on osteogenesis and bacterial attachment on titanium implants.

Hydrogen has the potential to promote the development of new, innovative and environmentally friendly solutions for future demands which would help for the smooth energy transition from fossil fuels. Though hydrogen has a high potential to replace fossil fuels, the challenges associated with the hydrogen value chain are in the production, storage, transportation and distribution stages.
 Electrolysis of water in PEM based system is a single step green hydrogen production process while integrated with renewable energy resources. However, this energy-intensive process makes the hydrogen production cost high and it is pave way for adopting the grey hydrogen or blue hydrogen production route as an intermediate stage for the transition from fossil fuel to hydrogen fuel economy. In this context PEM based Electrochemical Methanol Reformer (ECMR) technology has unique advantages such as low electrical energy consumption than water electrolysis and it can be easily integrated with renewable energy sources. Further, it can be operated at near ambient temperature and doesn’t require any hydrogen purification system, unlike a chemical reformer. Currently, PEM based water electrolyzer is producing pressurized hydrogen, which will eliminate the need for an external hydrogen compressor for its storage. Further, the influence of operating parameters on the operation of PEM water electrolyser under pressurised conditions is studied in the literature. However, this aspect of the study is not well studied and not much literature is available on PEM based ECMR systems. The present work, it is aimed to systematically study the effect of various operating parameters on the performance of ECMR under pressurised operation conditions and the obtained results are discussed. It shows the operation of ECMR under pressurised condition are promising and it will eliminate the need for an external H2 compressor system for hydrogen storage like PEM based water electrolyzer.
 
 Keywords: Hydrogen, PEM based Electrochemical reformer, pressurised hydrogen 


Influence of Operating Parametres on PEM Based Ecmr for Hydrogen Production in Pressurised Condition

Electrochromism refers to the persistent and reversible change in color by applying an electric field. The phenomenon involves the insertion and extraction of electrons and ions within the active material. There is a keen interest in electrochromic (EC) materials, since they exhibit a wide range of potential applications. In recent years, transition-metal oxides have been widely investigated as EC materials due to their low power requirement, high coloration efficiency, and memory effect under an open-circuit condition. Nickel oxide (NiO), a p-type wide band gap semiconductor, exhibits attractive features such as a high color contrast ratio, good chemical stability, cost-effectiveness, and good compatibility with the cathodically coloring tungsten oxide. NiO thin films have been fabricated by various methods, but these are not cost-effective, scalable, or suitable for flexible applications. With the increasing demand for flexible and soft EC devices, it is essential to find routes to fabricate NiO thin films at lower temperatures. In this work, a NiO/Ni(OH)2-based thin EC layer on fluorine-doped tin oxide-coated glass is developed via an electroless nickel (EN) deposition route, followed by room-temperature electrochemical oxidation. The deposition time is optimized to control the film thickness. The EC performance is investigated in an aqueous alkaline electrolyte (1 M KOH) by means of cyclic voltammetry, chronoamperometry, and transmittance measurements. Both the as-deposited and annealed films, after electrochemical oxidation, exhibit excellent EC properties with an optical modulation of approximately 64% (at 550 nm) and good response times of approximately 3 s (coloration) and 14 s (bleaching). A 2 × 2 display obtained by patterning the EN deposition is also demonstrated as part of this work.

https://pubs.acs.org/doi/pdf/10.1021/acsomega.2c04859

Lakshman Neelakantan

Papers

Influence of Operating Parametres on PEM Based Ecmr for Hydrogen Production in Pressurised Condition

Electrochromic Displays via the Room-Temperature Electrochemical Oxidation of Nickel