Hydrogen energy, economy and storage: Review and recommendation

A review on the current progress of metal hydrides material for solid-state hydrogen storage applications

Review of hydrogen storage techniques for on board vehicle applications

Materials, technological status, and fundamentals of PEM fuel cells – A review

Hydrogen is a promising alternative energy carrier that can potentially facilitate the transition from fossil fuels to sources of clean energy because of its prominent advantages such as high energy density (142 MJ kg(-1); ref. 1), great variety of potential sources (for example water, biomass, organic matter), light weight, and low environmental impact (water is the sole combustion product). However, there remains a challenge to produce a material capable of simultaneously optimizing two conflicting criteria--absorbing hydrogen strongly enough to form a stable thermodynamic state, but weakly enough to release it on-demand with a small temperature rise. Many materials under development, including metal-organic frameworks, nanoporous polymers, and other carbon-based materials, physisorb only a small amount of hydrogen (typically 1-2 wt%) at room temperature. Metal hydrides were traditionally thought to be unsuitable materials because of their high bond formation enthalpies (for example MgH(2) has a ΔHf~75 kJ mol(-1)), thus requiring unacceptably high release temperatures resulting in low energy efficiency. However, recent theoretical calculations and metal-catalysed thin-film studies have shown that microstructuring of these materials can enhance the kinetics by decreasing diffusion path lengths for hydrogen and decreasing the required thickness of the poorly permeable hydride layer that forms during absorption. Here, we report the synthesis of an air-stable composite material that consists of metallic Mg nanocrystals (NCs) in a gas-barrier polymer matrix that enables both the storage of a high density of hydrogen (up to 6 wt% of Mg, 4 wt% for the composite) and rapid kinetics (loading in <30 min at 200 °C). Moreover, nanostructuring of the Mg provides rapid storage kinetics without using expensive heavy-metal catalysts.

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Air-stable magnesium nanocomposites provide rapid and high-capacity hydrogen storage without using heavy-metal catalysts

a b s t r a c t Many recent studies have highlighted the possibility to tailor the physical and chemical properties of porphyrin at the molecular level to design novel catalysts, sensors and devices with applications in electronics, opto-electronics, etc. In the present work we study the electronic properties of 2H-Tetraphenylporphyrin (2H-TPP) on iron (Fe) and iron silicide (Fe3Si) onto Si (1 0 0) substrate using X-ray and Ultraviolet photoelectron spectroscopy (XPS & UPS). The results revealed that the iron atom is coordinated by TPP molecules at Fe/Si system. XPS results provide evidence of the iron coordination with TPP molecules. The UPS analysis show the fine structure in the electronic spectra related to HOMO states below the Fermi level.

Conformational adaptation of 2H-Tetraphenylporphyrin at Fe/Si(1 0 0) interface during metalation

Radiation damage and the product formation chemistry in Polymethyl methacrylate (PMMA) due to γ-irradiation have been studied by SEM, XRD, FTIR, and UV-Vis spectroscopy. Co-60 gamma source with a dose rate of 1.707 kGy/hr has been used for irradiation to a total 570 kGy dose. No significant changes in morphology upon such irradiation. Crystallinity decreases at a lower dose and then increases for a higher dose. Crosslinking dominates at lower doses, and chain scission overwhelms at higher doses in the irradiated polymer. Two isosbestic points are formed, and the absorption maxima shift towards a higher wavelength. The optical bandgap energy decreases with the addition of radiation dose. A new FTIR peak at 1638 cm-1 appeared, suggesting the formation of an unsaturation center in the irradiated polymer. Up to a dose of 409 kGy, FTIR absorption peak intensity increases and decreases with further irradiation.

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Spectroscopic Investigations of Optical Bandgap and Search for Reaction Mechanism Chemistry Due to γ-Rays Irradiated PMMA Polymer

Reversible hydrogen storage in MgH2 under specified conditions is a possible way for the positive reception of hydrogen economy, in which the developments of cheap and highly efficient catalysts are the major challenge, still now. Herein, MgH2 − x wt% MM (x = 0, 10, 20, 30) nanomaterials are prepared via ball milling method and has been evaluated for the hydrogen storage performance, which are characterized by XRD, SEM and DTA/DSC. The hydrogen absorption properties of nanomaterials are measured by pressure composition isotherm, and analysis show that the MgH2 − 30 wt% MM nanomaterials have the maximum hydrogen absorption capacity (~ 3.27 wt% at 300 °C) than MgH2. The activation energy of nanomaterials is remarkably changed by the introduction of MM as additives in MgH2.

Catalytic effect on hydrogen de/absorption properties of MgH2 - x wt% MM (x = 0, 10, 20, 30) nanomaterials.

Numerous specialists and academics have backed the improved physicochemical characteristics of metal substrate (Ag, Au) based composite nanoparticles for a number of applications, including pharmaceuticals, optoelectronics, and environmental impact. Insights of Ag and Au NPs-based nanomaterials will be discussed, as well as important production, physicochemical, and biotechnological characteristics. The plasmon capacities of Ag and Au NPs, along with their customisable form, scale, and surface modification could be described by specified geometries and constituent contents. It was revealed that interaction dynamics of Ag and Au implanted nanomaterials with dopants/defects ratios seem to be more effective in stimulating pathogens by interrupting biochemical reactions. As a result, we focus on defect science in Ag and Au-based nanoscale materials, taking into account surface morphology, ionic packing, and chemical phase assessment. This chapter will cover the important optical, geometrical, and physicochemical features of Ag and Au nanomaterials, and their pharmacological significance.

https://www.mdpi.com/2073-4352/12/5/589/pdf?version=1650793713

Chhagan Lal

Papers

Conformational adaptation of 2H-Tetraphenylporphyrin at Fe/Si(1 0 0) interface during metalation

Spectroscopic Investigations of Optical Bandgap and Search for Reaction Mechanism Chemistry Due to γ-Rays Irradiated PMMA Polymer

Catalytic effect on hydrogen de/absorption properties of MgH2 - x wt% MM (x = 0, 10, 20, 30) nanomaterials.

Enhanced Plasmon Based Ag and Au Nanosystems and Their Improved Biomedical Impacts

Effect of PdCl2 catalyst on the hydrogenation properties and sorption kinetics of Mg