Preface to the Special Issue on Hydrogen Production, Storage, Application, and Sensing.

This issue focuses on the multifaceted nature of hydrogen, exploring the latest research, advancements, and applications in this rapidly evolving field. Topics covered include hydrogen production methods, advancements in storage technologies, diverse applications, and the significance of hydrogen sensing for monitoring its environmental impact.

Identification of Suitable Mesh Size of Commercial Stainless-Steel for Electrochemical Oxygen Evolution Reaction.

The study examines the oxygen evolution reaction (OER) electrocatalytic efficiency of various stainless-steel mesh (SSM) sizes in electrolytic cells. Stainless steel is chosen due to its widespread availability and stability, making it an economically viable option. The primary objective of this investigation is to determine the optimal stainless-steel mesh size among those currently widely available on the market.

Advanced High-Energy All-Solid-State Hybrid Supercapacitor with Nickel-Cobalt-Layered Double Hydroxide Nanoflowers Supported on Jute Stick-Derived Activated Carbon Nanosheets.

Developing efficient, lightweight, and durable all-solid-state supercapacitors is crucial for future energy storage systems. The study focuses on optimizing electrode materials to achieve high capacitance and stability. This study introduces a novel two-step pyrolysis process to synthesize activated carbon nanosheets from jute sticks (JAC), resulting in an optimized JAC-2 material with a high yield (≈24%) and specific surface area (≈2600 m g).

Electrochemical Reduction of CO to C1 and C2 Liquid Products on Copper-Decorated Nitrogen-Doped Carbon Nanosheets.

Due to the significant rise in atmospheric carbon dioxide (CO) concentration and its detrimental environmental effects, the electrochemical CO conversion to valuable liquid products has received great interest. In this work, the copper-melamine complex was used to synthesize copper-based electrocatalysts comprising copper nanoparticles decorating thin layers of nitrogen-doped carbon nanosheets (Cu/NC). The as-prepared electrocatalysts were characterized by XRD, SEM, EDX, and TEM and investigated in the electrochemical CO reduction reaction (ECORR) to useful liquid products.

Steam Catalytic Cracking of n-Dodecane to Light Olefins over Phosphorous- and Metal-Modified Nanozeolite Y.

Nanozeolite Y was synthesized without a template and modified with phosphorous (P) and metals. P was introduced via impregnation with different weight loadings (0.5, 1, and 2 wt %), while ion exchange was developed to introduce zirconium (Zr) and cobalt (Co).

Acidity modifications of nanozeolite-Y for enhanced selectivity to olefins from the steam catalytic cracking of dodecane.

Nanozeolite-Y was synthesized in the absence of a templating agent with several modification methods. The parent nanozeolite-Y was prepared with different sodium (Na) contents and crystallization conditions. Then, the parent nanozeolite-Y was modified by ion exchange, calcination, and steam treatment.

Recent Progress in Carbonaceous and Redox-Active Nanoarchitectures for Hybrid Supercapacitors: Performance Evaluation, Challenges, and Future Prospects.

Due to advancements in technology, the energy demand is becoming more intense with time. The rapid fossil fuels consumption and environmental concerns triggered intensive research for alternative renewable energy resources, including sunlight and wind. Yet, due to their time-dependent operations, significant electric energy storage systems are required to store substantial energy.

Experimental and Theoretical Study on the Interchange between Zr and Ti within the MIL-125-NH Metal Cluster.

This study aims to investigate the effect of replacing Ti with Zr in the SBU of MIL-125-NH . We were able to replace Ti with Zr in the mixed metal synthesis of MIL-125-NH , for the first time. After experimentally confirming the consistency in their framework structure and comparing their morphology, we related the femtosecond light dynamics with photocatalytic CO visible light conversion yield of the different variants in order to establish the composition-function relation in MIL-125 vis a vis CO reduction.

Mixed Dimensional Nanostructure (UiO-66-Decorated MWCNT) as a Nanofiller in Mixed-Matrix Membranes for Enhanced CO /CH Separation.

Mixed-matrix membranes (MMMs) with combination of two distinct dimensional nanofillers (such as 1D-3D, 2D-3D, or 3D-3D, etc.) have drawn special attention for gas separation applications due to their concerted effects on gas permeation and mechanical properties. An amine-functionalized 1D multiwalled carbon nanotube (NH -MWCNT) with exceptional mechanical strength and rapid gas transport was crosslinked with an amine-functionalized 3D metal-organic framework (UiO-66-NH ) with high CO affinity in a Schiff base reaction.

Trends and Prospects in UiO-66 Metal-Organic Framework for CO Capture, Separation, and Conversion.

Among thousands of known metal-organic frameworks (MOFs), the University of Oslo's MOF (UiO-66) exhibits unique structure topology, chemical and thermal stability, and intriguing tunable properties, that have gained incredible research interest. This paper summarizes the structural advancement of UiO-66 and its role in CO capture, separation, and transformation into chemicals. The first part of the review summarizes the fast-growing literature related to the CO capture reported by UiO-66 during the past ten years.

The validity of laser diffraction system to reproduce hydrometer results for grain size analysis in geotechnical applications.

The grain size analysis plays a significant role in any geotechnical study. The grain size analysis, by means of sieving, is usually used for coarse material of particle size > 75 μm. For the fine material; the sedimentation methods are frequently adopted (e.

Fabrication and Characterization of Transparent and Scratch-Proof Yttrium/Sialon Thin Films.

Transparent and amorphous yttrium (Y)/Sialon thin films were successfully fabricated using pulsed laser deposition (PLD). The thin films were fabricated in three steps. First, Y/Sialon target was synthesized using spark plasma sintering technique at 1500 °C in an inert atmosphere.

Highly Efficient Permeation and Separation of Gases with Metal-Organic Frameworks Confined in Polymeric Nanochannels.

This work demonstrates the confinement of porous metal-organic framework (HKUST-1) on the surface and walls of track-etched nanochannel in polyethylene terephthalate (np-PET) membrane using a liquid-phase epitaxy (LPE) technique. The composite membrane (HKUST-1/np-PET) exhibits defect-free MOF growth continuity, strong attachment of MOF to the support, and a high degree of flexibility. The high flexibility and the strong confinement of the MOF in composite membrane results from (i) the flexible np-PET support, (ii) coordination attachment between HKUST-1 and the support, and (iii) the growth of HKUST-1 crystal in nanoconfined geometries.

An Ultrasensitive and Selective Metal-Organic Framework Chemosensor for Palladium Detection in Water.

A new europium-based metal-organic framework, termed KFUPM-3, was constructed using an allyloxy-functionalized linker. As a result of coordinative interactions between the allyloxy moieties and Pd, highly selective changes in both the absorption and emission spectra of KFUPM-3 were observed. Accordingly, KFUPM-3 was demonstrated to have an ultrasensitive Pd detection limit (44 ppb), regenerative properties without loss in performance, detection of palladium in different oxidation states and in the presence of other competitor metal ions, and fully functional sensing capabilities over a wide pH range.

Electrocatalytic CO₂ Reduction: From Homogeneous Catalysts to Heterogeneous-Based Reticular Chemistry.

CO₂, emitted mainly from fossil fuel combustion, is one of the major greenhouse gases. CO₂ could be converted into more valuable chemical feedstocks including CO, HCOOH, HCHO, CH₃OH, or CH₄. To reduce CO₂, catalysts were designed and their unique characteristics were utilized based on types of reaction processes, including catalytic hydrogenation, complex metal hydrides, photocatalysis, biological reduction, and electrochemical reduction.

Interconnected Hollow Cobalt Phosphide Grown on Carbon Nanotubes for Hydrogen Evolution Reaction.

Transition-metal phosphides are deemed as potential alternative to platinum for large-scale and sustainable electrocatalytic hydrogen production from water. In this study, facile preparation of interconnected hollow cobalt monophosphide (CoP) supported on carbon nanotubes is demonstrated and evaluated as a low-cost electrocatalyst for hydrogen evolution reaction. Hexamethylenetetramine is used as a structure-directing agent to guide the formation of interconnected cobalt oxide, which further grows into interconnected hollow CoP.

Indium Tin Oxide Nanoparticle-modified Glassy Carbon Electrode for Electrochemical Sulfide Detection in Alcoholic Medium.

An electrochemical sensor based on an indium tin oxide nanoparticle (ITONP)-modified glassy carbon electrode (ITONP/GCE) was developed for the detection of sulfides in alcoholic medium. The ITONP/GCE was prepared by simply dropping the aqueous solution of ITONP on the GCE surface and then drying at 40°C. The homogeneous distribution of ITONP on the GCE surfaces was confirmed by recording the camera photographs and field emission scanning electron microscopic images.

Tuning the Interplay between Selectivity and Permeability of ZIF-7 Mixed Matrix Membranes.

Nanoparticles of zeolitic imidazolate framework-7 (nZIF-7) were blended with poly(ether imide) (PEI) to fabricate a new mixed-matrix membrane (nZIF-7/PEI). nZIF-7 was chosen in order to demonstrate the power of postsynthetic modification (PSM) by linker exchange of benzimidazolate to benzotriazolate for tuning the permeability and selectivity properties of a resulting membrane (PSM-nZIF-7/PEI). These two new membranes were subjected to constant volume, variable pressure gas permeation measurements (H, N, O, CH, CO, CH, and CH), in which unique gas separation behavior was observed when compared to the pure PEI membrane.

Sonochemical-driven ultrafast facile synthesis of SnO nanoparticles: Growth mechanism structural electrical and hydrogen gas sensing properties.

Synthesis of SnO nanoparticles have been successfully accomplished moderately at lower temperature by facile, rapid, efficient and mild ultrasonic irradiation method. The as-grown SnO nanoparticles are investigated by various characterization techniques in terms of structural, optical, electrical and gas sensing properties. XRD investigation has shown that the SnO nanoparticles materials exhibit single rutile crystal phase with high crystallinity.

Sonochemical Assisted Solvothermal Synthesis of Gallium Oxynitride Nanosheets and their Solar-Driven Photoelectrochemical Water-Splitting Applications.

Gallium oxynitride (GaON) nanosheets for photoelectrochemical (PEC) analysis are synthesized via direct solvothermal approach. Their FE-SEM revealed nanosheets morphology of GaON prepared at a reaction time of 24 hours at 180 °C. The elemental composition and mapping of Ga, O and N are carried out through electron dispersive X-ray spectroscopy (EDX).

Fluorescein-N-Methylimidazole Conjugate as Cu(2+) Sensor in Mixed Aqueous Media Through Electron Transfer.

A new highly selective, chromogenic, and fluorogenic Cu(2+) chemosensor, fluorescein-N-methylimidazole conjugate 1, and another fluorescein-N-imidazole conjugate 2 were synthesized and investigated by UV-visible and fluorescence spectroscopy. The sensing of Cu(2+) quenches the emission band of 1 at λmax = 525 nm, with an association constant (K a = 1.0 x 10(7) M(-1)) and a stoichiometry of 1:1 in a buffered H2O: MeOH solution (4:1, pH = 7.

Enhanced photoelectrochemical and photocatalytic activity of WO3-surface modified TiO2 thin film.

Development of nanostructured photocatalysts for harnessing solar energy in energy-efficient and environmentally benign way remains an important area of research. Pure and WO3-surface modified thin films of TiO2 were prepared by magnetron sputtering on indium tin oxide glass, and photoelectrochemical and photocatalytic activities of these films were studied. TiO2 particles were <50 nm, while deposited WO3 particles were <20 nm in size.

Enhanced photoactivity on Ag/Ag3PO4 composites by plasmonic effect.

The work presented here deals with the photoreduction in metallic silver nanoparticles onto the surface of Ag(3)PO(4) and resulting photocatalytic activity enhancement toward degradation of dye molecules, namely Rhodamine B (Rh. B) as a model compound, from aqueous solution under UV or visible light irradiation. Our results clearly indicated that the photoactivity of Ag(3)PO(4) was significantly enhanced by depositing an optimum amount of silver nanoparticles, even though the adsorption kinetics rate and capacity decreased after the silver nanoparticles agglomerate extensively.

Pulsed laser-induced photocatalytic reduction of greenhouse gas CO2 into methanol: A value-added hydrocarbon product over SiC.

CO(2) was converted into value-added hydrocarbons (methanol) by laser-induced photocatalytic reduction of CO(2) over commercially available silicon-carbide (SiC) granules as catalyst. The conversion of CO(2) was carried out in a glass reactor having quartz window and equipped with stirring system and was provided with continuous CO(2) flow at ambient conditions. Laser radiations of 355 nm, which were generated by third harmonics of Nd:YAG laser (1060 nm) were applied as an excitation source.

BiOCl-assisted photodegradation of Rhodamine B under white light and monochromatic green pulsed laser irradiation.

BiOCl-assisted photodegradation of Rhodamine B (Rh. B) molecules was investigated by using white light and green pulsed laser as sources of irradiation in the visible region for the first time. The dependences of removal efficiencies on catalyst dosage, incident pulsed laser energy were investigated and discussed.