Search Results (4,923)

Hexagonal ZnO nanowires were grown using the PLD/VLS technique on a SAW sensor active area for hydrogen sensing. The influence of different carbon and nitrogen surface contaminant concentrations on sensor output was investigated for three active area cases: a few weeks’ exposure to free ambient air contamination, 3 h at 600 °C thermal desorption of carbon, and (room temperature) plasma-activated nitrogen and carbon contamination. Correlations between sensing performance and contamination element concentration were established. To understand the adsorption versus absorption mechanisms, similar studies were further performed on circular ZnO nanowires morphology, which have a different surface-area-to-volume ratio. Comparative results show that, while a 20% carbon surface contamination variation generates a variation of 3–5% in nanostructure hydrogen sorption, nitrogen surface contamination influence depends on nanostructure morphology. Thus, in our comparative studies, for the case of a nanowire hexagonal cross-section a 12% nitrogen surface contamination variation generates a 5–7% increase in hydrogen adsorption and also an increase of 6–8% in hydrogen absorption. Consequently, the catalytic effect of nitrogen could enlarge the linear response of nanowire-based (SAW) sensors over a wider hydrogen concentration range. Full article

An electrochemical reactions coupled multi-physics model is developed and applied to elucidate overall performance and thermal stress distributed in solid oxide electrolysis cells (SOECs) with graded fuel electrodes. Extending the conventional fuel electrode, the effects of various graded parameters are investigated and discussed in terms of porosity, pore size, and material composition, with the goal of identifying characteristics of the hydrogen production rate and maximum thermal stress. The results show that the application of the graded parameters is able to optimize the gas distribution and to improve reaction kinetics, avoiding local overheating. The generated hydrogen molar fraction is enhanced by 15.6% while the maximum thermal stress is decreased by 5.0% if the graded parameters are applied, while changing the material composition may increase the thermal stress under the same circumstances. These explorations elucidate the complex role of the graded fuel electrodes on the electrolysis and thermomechanical properties of SOECs. Full article

As one of the key processes of photosynthesis, carbon fixation and reduction is one of the most important biochemical reactions on planet Earth. Yet, reducing oxidized carbon elements through directly harnessing solar energy by using water-soluble, simple enzymes continues to be challenging. Here, CO₂ and bicarbonate were found to be transformed into methanol by fluorescent protein mRuby by using light as the single energy input. The binding of substrates to mRuby chromophore was supported by crystallography and light spectrometry. Gas chromatography showed the generation of methanol in mRuby-bicarbonate aqueous solution upon sunlight illumination. Atomic-resolution serial structures of mRuby showed snapshots of the step-by-step reduction of bicarbonate and CO₂. The amino, imino, or carboxylate group of residues near the chromophore was within hydrogen bonding distances of the substrates, respectively. A decrease in fluorescence was observed upon binding of bicarbonate, and the energy liberated from fluorescence was presumably utilized for methanol production. This research represents an exciting example of sunlight-driven photobiocatalysis by water-soluble small proteins. The new, green, and sustainable mechanisms uncovered here indicated great promises to harness solar energy straightforwardly, for, i.e., fuel production and green chemistry. Full article

Graphyne, a hypothetical carbon allotrope comprising sp and sp² hybridized carbon atoms, has garnered significant attention for its potential applications in next-generation technologies. Unlike graphene, graphyne’s distinctive acetylenic linkages endow it with a tunable electronic structure, directional charge transport, and superior mechanical flexibility. This review delves into the structural variety, theoretical underpinnings, and burgeoning experimental endeavors associated with various graphyne allotropes, including α-, β-, γ-, and 6,6,12-graphyne. It examines synthesis methods, structural and electronic characteristics, and the material’s prospective roles in diverse fields, such as nanoelectronics, transistors, hydrogen storage, and desalination. Additionally, it highlights the use of computational modeling techniques—density functional theory (DFT), GW approximation, and nonequilibrium Green’s function (NEGF)—to anticipate and validate properties without fully scalable experimental data. Despite substantial theoretical progress, the practical implementation of graphyne-based devices faces several challenges. By critically assessing current research and identifying strategic directions, this review underscores graphyne’s potential to revolutionize advanced materials science. Full article

The sustainable valorization of lignocellulosic biomass into high-value platform chemicals presents a crucial pathway for reducing reliance on fossil resources. Gamma (γ)-valerolactone (GVL) has gained recognition as a versatile bio-derived compound with broad applications in renewable energy systems and green chemical synthesis. While conventional GVL production strategies from carbohydrate biomass typically depend on noble metal catalysts paired with high-pressure hydrogen gas, these approaches face substantial technical barriers including catalyst costs, hydrogen storage requirements, and operational safety concerns in large-scale applications. This work develops an innovative catalytic system utilizing earth-abundant iron for in situ hydrogen generation through water splitting, integrated with Raney Ni as the hydrogenation catalyst. The designed two-stage process enables direct conversion of cellulose—first through acid hydrolysis to levulinic acid (LA) followed by catalytic hydrogenation to GVL without intermediate purification. Through systematic parameter optimization, a remarkable 61.9% overall GVL yield from cellulose feedstock was achieved. Furthermore, the methodology’s versatility was demonstrated through wheat straw conversion experiments, yielding 24.6% GVL. This integrated methodology explores a technically feasible pathway for direct cellulose-to-GVL conversion utilizing abundant water as the hydrogen source, effectively overcoming the critical limitations associated with conventional hydrogenation technologies regarding hydrogen infrastructure and process safety. Full article

In recent years, dielectric films with a high energy-storage capacity have attracted significant attention due to their wide applications in the fields of renewable energy, electronic devices, and power systems. Their fundamental principle relies on the polarization and depolarization processes of dielectric materials under external electric fields to store and release electrical energy, featuring a high power density and high charge–discharge efficiency. In this study, sodium bismuth titanate (NBT) micro-flakes synthesized via a molten salt method were treated with hydrogen peroxide and subsequently blended with a polyvinylidene fluoride (PVDF) matrix. An oriented tape-casting process was utilized to fabricate a dielectric thin film with enhanced energy storage capacity under a weakened electric field. Experimental results demonstrated that the introduction of modified NBT micro-flakes facilitated the interfacial interactions between the ceramic fillers and polymer matrix. Additionally, chemical interactions between surface hydroxyl groups and fluorine atoms within PVDF promoted the phase transition from the α to the β phase. Consequently, the energy storage density of PVDF-NBT composite increased from 2.8 J cm⁻³ to 6.1 J cm⁻³, representing a 110% enhancement. This design strategy provides novel insights for material innovation and interfacial engineering, showcasing promising potential for next-generation power systems. Full article

Reactive oxygen species (ROS) generated by cold atmospheric plasma (CAP) cause irreversible damage to cancer cell DNA, RNA, mitochondria, and antioxidant defense systems, leading to apoptosis. Plasma-induced disruption of the antioxidant defense system of cancer cells by cystine uptake via xC⁻ antiporter has been widely studied, while folate uptake by cancer cells via high expression of hSLC19A1, which generates Nicotinamide Adenine Dinucleotide Phosphate (NADPH) via one-carbon metabolism, is also an important component of the antioxidant defense mechanism of cancer cells. Disrupting folate transport in cancer cells is an important potential pathway for synergizing with pemetrexed (PMX) to induce apoptosis in cancer cells, which is of great research value. In this paper, classical molecular dynamics simulations were employed to study the effect of plasma oxidation of hSLC19A1 on the uptake of 5-Methyltetrahydrofolate (5-MTHF), which is the predominant dietary and circulatory folate, and the antifolate chemotherapeutic agent PMX by cancer cells. The results showed that the channel radius of hSLC19A1 for transporting 5MTHF after oxidation became narrower and the conformation tended to be closed, which was unfavorable for the transport of 5-MTHF; hydrogen bonding and hydrophobic interactions between hSLC19A1 and 5-MTHF decreased, the predicted docking affinity decreased, and the binding energy decreased from −28.023 kcal/mol to −16.866 kcal/mol, while that with PMX was stable around −28 kcal/mol, suggesting that the oxidative modification reduced the binding capacity of hSLC19A1 and 5-MTHF while barely affecting the transport of PMX, which contributed to weakening the antioxidant defense system of cancer cells and synergizing with PMX to induce apoptosis in cancer cells. Our simulations provide theoretical insights for CAP-induced apoptosis in cancer cells at the microscopic level and help promote the further development of cold atmospheric plasma in the field of cancer therapy. Full article

Green hydrogen (GH₂) is expected to play an important role in future energy systems in their fight against climate change. This study, after briefly recalling how GH₂ is produced and the main steps throughout its life cycle, analyses its current development, environmental and social impacts, and a series of case studies from selected literature showing its main applications as fuel in transportation and electricity sectors, as a heat producer in high energy intensive industries and residential and commercial buildings, and as an industrial feedstock for the production of other chemical products. The results show that the use of GH₂ in the three main areas of application has the potential of contributing to the decarbonization goals, although its generation of non-negligible impacts in other environmental categories requires attention. However, the integration of circular economy (CE) principles is important for the mitigation of these impacts. In social terms, the complexity of the value chain of GH₂ generates social impacts well beyond countries where GH₂ is produced and used. This aspect makes the GH₂ value chain complex and difficult to trace, somewhat undermining its renewability claims as well as its expected localness that the CE model is centred around. Full article

A new class of spiro[1,2,4]triazolo[1,5-c]quinazoline derivatives is presented as promising modulators of diacylglycerol kinase α (DGK-α), a target implicated in cancer, neurological disorders, and immune dysfunction. Through structure-based computational design using the CB-Dock2 platform with human DGK-α (PDB ID: 6IIE), 40 novel compounds were systematically evaluated along with established inhibitors (ritanserin, R59022, R59949, BMS502, and (5Z,2E)-CU-3) across five distinct binding pockets. Several compounds demonstrated binding profiles at the level of or surpassing the reference compounds. The physicochemical analysis revealed balanced drug-like properties with favorable molecular weights (252–412 g/mol) and appropriate three-dimensionality. The toxicological assessment indicated reassuring safety profiles with predicted LD₅₀ values of 1000–2000 mg/kg and minimal hepatotoxicity, carcinogenicity, and mutagenicity potential. Notably, compound 33 (adamantyl-substituted) emerged as exceptionally promising, exhibiting strong binding affinity, moderate solubility, and selective CYP inhibition patterns that minimize drug–drug interaction risks. Detailed molecular interaction mapping identified critical binding determinants, including strategic hydrogen bonding with TRP151, GLU166, and ARG126. The multidimensional evaluation identified compounds 13, 18, 33, and 40 as particularly promising candidates that balance potent target engagement with favorable pharmaceutical profiles, establishing this scaffold as a valuable platform for developing next-generation therapeutics targeting DGK-α -mediated signaling pathways. Full article

In this study, a novel mechanical fluid–structure interaction (FSI) model is developed to analyze and discuss high-pressure hydrogen flow in a quick coupler under various operating conditions. The transient-state behavior is investigated with respect to different temperatures, hydrogen pressures, and O-ring thicknesses, which directly affect the compression and deformation of the seal. High-pressure hydrogen flow, which may lead to seal damage or failure, is of growing concern due to the increasing use of hydrogen in refueling stations, a sector expected to play a key role in the future of clean energy infrastructure. This study aims to introduce a coupled multiphysics approach by integrating the Finite Element Method (FEM) for solid mechanics with the Finite Volume Method (FVM) for hydrogen flow modeling. The coupling model shows nonlinear interactions between flowing hydrogen and the deformable polymer seal. The results of this work are expected to enhance both the design and performance of high-pressure hydrogen quick couplers, especially for applications in next-generation hydrogen refueling stations, where durability, sealing efficiency and safety are critical. Full article

The transition to sustainable energy systems necessitates the development of cleaner fuel alternatives for compression ignition (CI) engines, which continue to play a vital role in transportation and power generation. This study explores the potential of hybrid fuel blends comprising biofuels, hydrogen, ammonia, and synthetic fuels to enhance engine performance while minimizing environmental impact. By reviewing recent advancements, the paper analyzes the combustion characteristics, emissions behavior, and feasibility of various fuel combinations. Biofuel–hydrogen blends improve flame speed and reduce carbon emissions, while ammonia offers zero-carbon combustion when paired with more reactive fuels, like biodiesel or hydrogen. Synthetic fuels, particularly those derived from renewable sources, provide high-quality combustion with low particulate emissions. Hybridization strategies leverage the strengths of each component fuel, resulting in synergistic effects that enhance thermal efficiency, reduce greenhouse gas emissions, and support the continued use of CI engines in a carbon-constrained future. The findings indicate that with proper optimization of fuel formulations and engine technologies, hybrid fuels can play a key role in achieving sustainability goals and reducing fossil fuel dependency. Full article

This study evaluates the feasibility of repurposing produced water—an abundant byproduct of hydrocarbon extraction—for green hydrogen production in Wyoming, USA. Analysis of geospatial distribution and production volumes reveals that there are over 1 billion barrels of produced water annually from key basins, with a general total of dissolved solids (TDS) ranging from 35,000 to 150,000 ppm, though Wyoming’s sources are often at the lower end of this spectrum. Optimal locations for hydrogen production hubs have been identified, particularly in high-yield areas like the Powder River Basin, where the top 2% of fields contribute over 80% of the state’s produced water. Detailed water-quality analysis indicates that virtually all of the examined sources exceed direct electrolyzer feed requirements (e.g., <2000 ppm TDS, <0.1 ppm Fe/Mn for target PEM systems), necessitating pre-treatment. A review of advanced treatment technologies highlights viable solutions, with estimated desalination and purification costs ranging from USD 0.11 to USD 1.01 per barrel, potentially constituting 2–6% of the levelized cost of hydrogen (LCOH). Furthermore, Wyoming’s substantial renewable-energy potential (3000–4000 GWh/year from wind and solar) could sustainably power electrolysis, theoretically yielding approximately 0.055–0.073 million metric tons (MMT) of green hydrogen annually (assuming 55 kWh/kg H₂), a volume constrained more by energy availability than water supply. A preliminary economic analysis underscores that, while water treatment (2–6% LCOH) and transportation (potentially > 10% LCOH) are notable, electricity pricing (50–70% LCOH) and electrolyzer CAPEX (20–40% LCOH) are dominant cost factors. While leveraging produced water could reduce freshwater consumption and enhance hydrogen production sustainability, further research is required to optimize treatment processes and assess economic viability under real-world conditions. This study emphasizes the need for integrated approaches combining water treatment, renewable energy, and policy incentives to advance a circular economy model for hydrogen production. Full article

The industrial sector’s increasing electricity demand (direct and indirect), driven by the electrification of processes and the production of green hydrogen, poses significant challenges for achieving decarbonisation goals. While switching to renewable electricity and offsetting emissions appears straightforward, the gap between current generation capacities and projected demand remains substantial. This article analyses survey data from the Energy Efficiency Index of German Industry (EEI), revealing that manufacturing companies aim to reduce 22.1% of their 2019 emissions by 2025 and 27.3% by 2030, primarily through on-site measures. However, given the slow pace of renewable capacity expansion and the increasing electrification across sectors, it becomes evident that the envisaged green electricity share of 80% by 2030 will require far more capacity than currently planned. To address this challenge, the article introduces a decarbonisability factor to better assess on-site versus off-site measures, highlighting the need for a strategic sequencing of efficiency and renewable generation. To support decision-makers, the article calls for improved data collection and periodic reassessment to account for changing geopolitical and economic conditions. Full article

Electrocatalytic nitrate reduction to ammonia (ENRA) presents a promising strategy for simultaneous environmental remediation and sustainable ammonia synthesis. In this work, a Cu–Co bimetallic catalyst supported on functionalized reduced graphene oxide (RGO) was systematically designed to achieve efficient and selective ammonia production. Surface oxygen functional groups on graphene oxide (GO) were optimized through alkaline hydrothermal treatments, enhancing the anchoring capacity for metal active sites. Characterization indicated the successful formation of uniform Cu–Co bimetallic heterointerfaces comprising metallic and oxide phases, which significantly improved catalyst stability and performance. Among the studied compositions, Cu₆Co₄/RGO exhibited superior catalytic activity, achieving a remarkable ammonia selectivity of 99.86% and a Faradaic efficiency of 96.54% at −0.6 V (vs. RHE). Long-term electrocatalysis demonstrated excellent durability, with over 90% Faradaic efficiency maintained for ammonia production after 20 h of operation. In situ FTIR analysis revealed that introducing Co effectively promoted water dissociation, facilitating hydrogen generation (*H) and accelerating the transformation of nitrate intermediates. This work offers valuable mechanistic insights and paves the way for the design of highly efficient bimetallic electrocatalysts for nitrate reduction and ammonia electrosynthesis. Full article

Governments need to evaluate technologies generating electricity from different sources; levelised cost of energy (LCOE) is a widely used metric. However, LCOE is weak at comparing disparate technologies, especially where they have different operational lifespans. The discrepancy is demonstrated using UK government data to examine a range of technologies, namely combined cycle generation (natural gas and hydrogen), sustainable renewable technologies along with independent data describing nuclear power and tidal range schemes. Three methods of analysis were used: LCOE, the internal rate of return (IRR), and a novel analysis. A new metric, the sustained cost of energy (SCOE), negates some of the LCOE shortcomings such as the application of discounting. SCOE examines a fixed period of continuous generation, using the lowest common length of operating life of the technologies analysed. It appears to be a useful metric, especially when interpreted with IRR. The analyses produce broadly similar ordering of technologies, but the longer-lasting systems with high initial costings perform better in SCOE. Subsidies, carbon tax, or credit schemes are essential government incentives if net zero emissions targets are to be met without overly burdening consumers with rapidly growing electricity rates. Full article