This study proposes a detailed numerical investigation on an innovative hybrid solar system combining horizontally aligned tracking coupled evacuated tube collectors and bifacial photovoltaic panels with thermal storage tank for domestic hot-water and electricity co-generation. The novelty lies in its portable compatibility, reduced land use, lower operational costs, and use of a joint-axis solar tracker, as well as maximizes solar exposure for photovoltaic panels and solar water heaters compared to dual independent stationary systems. A dynamic, climate-responsive simulation model is developed using mass and energy balance equations, solved with a fourth-order Runge–Kutta method to simulate performance of the integrated photovoltaic-solar water heating system from energy, exergy, and environ-economic viability perspective. The daily, monthly, and yearly performance is also investigated in terms of photovoltaic power output, thermal power, land-use efficiency (LUE), energy efficiency, net exergy efficiency, and levelized cost of thermal and electrical energies. The findings showed a considerable increase in the electrical and thermal energy production of 24.10%–33.60% when using the tracked hybrid photovoltaic-water heating system compared to the fixed dual independent stationary system. Moreover, the hybrid tracked system increased the LUE from 322.7 to 758.9 kWh/m2/yr, representing a 135.2% improvement. The cost of electricity also decreased from 0.0601 to 0.0403 $/kWh,ele and the cost of heat reduced from 0.0298 to $0.021 $/kWh,heat as well as minimized the CO₂ emissions by 39.50 t. The suggested hybrid solar system enhances the technical and economic efficiency of hot water and electricity co-generation and can be used as a sustainable alternative in residential sustainable buildings.

Adsorption cooling systems (ACSs) are a promising alternative to vapor-compression chillers. However, for low-GWP refrigerant/activated-carbon pairs operating at high pressure, kinetic data are limited, which hampers cycle modeling, performance prediction, and material selection. This study investigated the adsorption kinetics of HFC32 (difluoromethane) on six palm-derived activated carbons with increasing pore size and volume and assessed their four-bed adsorption chiller performance via dynamic modeling. Transient uptake curves were measured using a high-precision thermogravimetric analyzer (TGA) at 30–90 °C and pressures up to 3 MPa and interpreted using a Fickian diffusion (FD) model coupled with the Darken and Arrhenius corrections. The apparent Fickian diffusivity decreased sharply with surface coverage and declined with increasing pore volume. In contrast, the Darken-corrected intrinsic diffusivity increased with pore size, suggesting that the slower apparent uptake in larger-pore samples was mainly due to molecular crowding at high loadings rather than reduced migration mobility. The Arrhenius analysis further showed that the activation energy increased with pore size, while remaining modest (7.50–10.43 kJ mol–1). These equilibrium and kinetic parameters were embedded into a validated four-bed dynamic model to map COP and SCP. Simulation results showed that increased pore volume systematically enhances COP, whereas kinetic variations mainly shift the cycle time that maximizes SCP. At a driving temperature of 90 °C, the best-performing palm-derived carbon achieves COP approaching 0.51 and peak SCP of 160 kg–1 under favorable condenser/evaporator condition. Overall, this study provides high-pressure kinetic data and applies system-level dynamic simulations, offering insights for the design of activated-carbon-based adsorption cooling systems using low-GWP refrigerants.

Adsorption cooling is a sustainable technology for providing thermal comfort in terms of energy use and environment-friendly refrigerant/adsorbent pairs. Driven primarily by waste-heat or solar heat, it can reduce reliance on conventional electrically powered vapor-compression systems while maintaining effective cooling performance. This study examines low-grade-heat adsorption cooling cycles using CO2 paired with three activated carbons: Maxsorb III (Parent MAX), H2-treated Maxsorb III (H-MAX), and KOH-activated H2-treated Maxsorb III (Ox-MAX). Adsorption equilibrium data are measured with a magnetic suspension mass measurement unit over 10 to 90 °C and 0 to 5 MPa. The results are well represented by modified Dubinin–Astakhov and Tóth isotherm models. Based on the Tóth fit, the maximum CO2 uptake reaches 4.39, 3.81, and 3.19 g g−1 for Parent MAX, H-MAX, and Ox-MAX, respectively. The isosteric heat of adsorption (Qst), obtained from the Clausius–Clapeyron relation, decreases with increasing surface loading, while uptake-dependent enthalpy and entropy trends suggest strong CO2-surface interactions after activation. A thermodynamic cycle is illustrated using a pressure-temperature-uptake (P-T-W) diagram, and ideal-cycle performance is evaluated with a time-independent model. At 15 °C evaporation, 30 °C adsorption, and 90 °C desorption, specific cooling capacities are found 61.36, 56.27, and 45.82 kJ kg−1, with corresponding COPs of 0.146, 0.153, and 0.135 for the studied pairs. These metrics guide the optimization of efficient adsorption cooling systems.

This study investigated the adsorption kinetics of difluoromethane (R32) on mangrove-derived activated carbon (MAC) over 30-90 degrees C and 0-3000 kPa using a thermogravimetric (TGA) setup. To capture the transient uptake and investigate the equilibrium pressure effects on adsorption kinetics, a dual pseudo-first-order (dual-PFO) model was adopted, in which total uptake is expressed as the sum of two branches with distinct rate constants (k1, k2); their contributions to total uptake are characterized by the fractional capacity alpha. The model fitted all the experiments with high accuracy (average R2 = 0.9976). Parameter analysis showed that alpha and k1 decrease as the equilibrium pressure increases, whereas k2 is nearly pressure-invariant. Applying the dual-PFO model to literature datasets (Maxsorb III/R32 and MAC/CO2), alpha, k1 and k2 exhibited the same pressure dependence trend as MAC/R32. Comparison of fitted parameters across three working pairs together with pore-structure differences between MAC and Maxsorb III indicates a mesopore-associated fast branch and a micropore-controlled slow branch. Parameters (alpha, k1, k2) were regressed as functions of pressure and temperature, yielding a global correlation formula that reproduces representative curves with high accuracy. Embedding the correlation in a dynamic two-bed R32/MAC adsorption cooling model yielded a coefficient of performance (COP) of 0.173 and a cooling power (CP) of 1.47 kW under representative conditions (Tevap = 10 degrees C, Tcond = 30 degrees C, Tdes = 75 degrees C), suggesting that MAC/R32 is a promising working pair and that the dual-PFO kinetics can facilitate system-level performance evaluation under the examined conditions.

The widespread presence of fluoroquinolone antibiotics (such as ciprofloxacin, CIP) in aquatic environments poses a serious threat to ecosystems and human health. Therefore, it is urgent to explore adsorbents with superior CIP removal performance and cost-effectiveness. Hence, this study employed KOH activation to convert pinecone biomass into low-cost, environmentally friendly porous carbon, which was further modified with three metal dopants (Fe, Mg, and Mn). Metal incorporation markedly enhanced porosity (up to 1530.44 m(2) g(-1)) and introduced uniformly dispersed metal-O active sites. The optimized pore size (similar to 2.1 nm) was approximately twice the molecular dimension of CIP, favoring rapid diffusion and efficient adsorption. Among these, Fe-doped porous carbon (Fe-PC) exhibited the highest CIP adsorption capacity (468.4 mg g(-1)), outperforming most reported biochar-based adsorbents. Kinetic and isotherm analyses indicated that CIP adsorption followed monolayer chemisorption behavior. FT-IR, XPS, zeta potential analyses, and DFT calculations identified Fe-O coordination sites as the dominant adsorption centers, synergistic with pi-pi interactions, electrostatic attraction, and pore filling. DFT further revealed the shortest Fe-O_CIP coordination distance (1.87 & Aring;), pronounced interfacial charge redistribution in the Fe-PC/CIP complex, and the lowest adsorption energy (-4.52 eV) compared with pristine PC, confirming enhanced chemisorptive adsorption on Fe-PC. Moreover, Fe-PC exhibited good pH adaptability, ionic stability, and reusability, indicating potential applicability in complex aqueous environments. Cost analysis revealed the competitive cost of Fe-PC (27.47 $ kg(-1)) with commercial activated carbon. This study provides mechanistic insights and scalable strategies for designing metal-modified biochar for efficient antibiotic removal.

Japan faces a critical juncture in its energy transition as it works to achieve its carbon neutrality goals by 2050. The debate between focusing on electrification or hydrogen (H2) technologies or adopting a synergistic approach for the future energy system is a critical aspect of policy and research discussion. This study explores the opportunities, challenges, and potential synergies of electrification and hydrogen in Japan's future energy landscape. It provides quantitative analysis of energy demand, cost implications, emission reduction potential, and economic impacts under three different scenarios: Business-as-Usual (BAU), High Electrification (HE), and a Hydrogen Economy (H2E). The findings suggest that while electrification is the most cost-effective approach for reducing emissions and improving energy efficiency, hydrogen is indispensable for hard-to-electrify sectors. A balanced pathway that integrates both strategies offers the most feasible and sustainable transition to a carbon-neutral Japan by 2050.

Hydrofluoroolefins (HFOs) represent a critical breakthrough in refrigeration, offering ultra-low global warming potential (GWP) and zero ozone depletion potential (ODP). However, optimizing heat transfer efficiency in copper-based systems remains essential for maximizing the performance. Although surface topology is recognized as critical, the fundamental molecular mechanisms governing condensation kinetics of refrigerants on nano-roughened copper surfaces remain unexplored, limiting rational design of next-generation cooling systems. This work employs molecular dynamics (MD) simulations to elucidate how nanoscale surface roughness modulates HFO-1132a condensation within copper microchannels. By systematically changing roughness on both channel walls, we decouple the contributions of surface topology to molecular interactions, collision dynamics, and phase transitions. Results demonstrate that rough surfaces substantially enhance copper-refrigerant interactions, promoting accelerated molecular adsorption and rapid liquid film formation. Though roughened surfaces produce more nucleation spots for initial condensation, the smooth surface enables uniform molecular scattering, effective droplet coalescence, and compact liquid film formation. Based on the quantitative criterion: at low supersaturation (sp = 0.671) at T = 300.15 K, the condensation time increases, but becomes faster at high supersaturation (sp = 0.946) at T = 280.15 K; the condensing temperature chosen as T = 286.15 K. These findings provide unprecedented molecular-scale understanding of HFO condensation on engineered surfaces, with direct implications for designing high-performance, thermally optimized copper components. This framework establishes a generalizable approach for developing energy-efficient, climate-neutral cooling technologies essential for both residential and industrial applications.

A strategy to overcome sluggish hydrogenation/dehydrogenation of magnesium is demonstrated by creating magnesium-graphene interphase boundaries via high-pressure torsion (HPT). HPT reduces the grain size of pure magnesium from similar to 1 mm to similar to 850 nm, with 70% of grain boundaries having high misorientation angles. Graphene addition leads to even finer grain sizes of 10-500 nm with a bimodal morphology. The magnesiumgraphene composites exhibit superior kinetics at 623 K while maintaining high air resistance. Kinetic modeling reveals that the rate-controlling mechanism transits from interfacial reaction in coarse-grained magnesium to atomic diffusion in magnesium-graphene nanocomposites. Kissinger analysis shows that the activation energy for hydrogen desorption remains unchanged at 145 +/- 2 kJ/mol, regardless of the presence of grain or interphase boundaries. However, the frequency factor (number of successful attempts to overcome the activation energy) increases with the generation of interfaces, which serve as sites for hydrogen diffusion and heterogeneous metal/hydride nucleation. These findings highlight the impact of interphase boundary engineering via severe plastic deformation for enhancing the kinetics and air resistance of hydrogen storage materials.

Adsorption cooling effectively utilizes low-grade heat; however, it is limited by transport at the adsorption bed level and the relatively low uptake of conventional adsorbents such as silica gel (SG). Computational fluid dynamics (CFD) serves as an essential tool for visualizing and quantifying the intricate heat and mass transport within adsorption bed design. Nonetheless, the majority of previous CFD studies have focused on single processes, employed simplified bed geometry, and concentrated solely on traditional adsorbents. In this context, a 2D, cycle-resolved CFD model has been developed to simulate the complete four-stage sequence of adsorption, preheating, desorption, and cooling for an entire adsorption bed. The model incorporates a validated userdefined function programmed in the C language. This study represents the first cycle-resolved CFD comparison of MOF-303 and SG performed within the same computational domain under identical geometry and boundary conditions. Under identical boundary conditions, MOF-303 delivers a working-capacity swing approximately 1.8 times larger than that of SG, roughly 0.09 versus 0.0498 kg.kg - 1 . Increasing the heat transfer coefficient improved the performance up to a threshold of approximately 700 W.m - 2 .K -1 , beyond which internal diffusion dominated. Heating water temperature is the most influential parameter: at 90 degrees C, MOF-303 attains a specific cooling power of approximately 241 W.kg -1 . Cycle time analysis indicates a trade-off: shorter half-cycles result in approximately 254 W.kg -1 , whereas longer half-cycles enhance regeneration and increase the uptake swing to approximately 0.142 kg.kg -1 for MOF-303. The developed cycle resolved model clarifies when and why MOF-303 outperforms SG and identifies the operating windows for compact, low-grade heat-driven ACS.

Biomass-derived porous carbons are attractive for CO2 capture and supercapacitive energy storage because of their low cost and tunable porosity. Hierarchical porous carbons were synthesized from pinecone biomass via template-free KOH activation. The activation temperature and KOH/precursor ratio were systematically varied to tune the ultramicroporosity (<0.7 nm), specific surface area, and micropore-to-mesopore ratio of the samples. At 298 K and 1 bar, the optimized carbon exhibited a CO2 uptake of 3.83 mmol g(-1), a CO2/N-2 selectivity of 11, and excellent regenerability. As supercapacitor electrodes, they delivered a specific capacitance of 266.08 F g(-1) at 0.5 A g(-1), an energy density of 25.3 Wh kg(-1), a power density of 1600 W kg(-1), and 95.02 % capacitance retention after 10,000 charge/discharge cycles, surpassing the performance of typical porous carbons. Structure-performance analysis indicated that CO2 adsorption was governed by ultramicroporosity rather than the total surface area, whereas the rate capability depended on a well-connected micro/mesopore network. A web-like ("spider-web") architecture formed during activation provides continuous mass transfer pathways and lowers charge-transfer resistance, enabling simultaneous enhancement of CO2 capture and capacitive performance. This approach offers a scalable route to multifunctional porous carbons and a mechanistic basis for porosity-optimized design.

The current research explores the utilization of a novel continuous non-catalytic microwave reactor for the conversion of waste cooking oil (WCO) to biodiesel. The process follows the principles of green chemistry by converting WCO into clean fuel under a catalyst-free, energy-efficient approach. By applying the subcritical microwave-assisted technique optimized via response surface methodology, a maximum biodiesel yield of 97.89 +/- 0.02 % was observed within 12 min. The cost of production was estimated to be $0.45/L, demonstrating its high potential for commercial-scale application. Kinetic and thermodynamic studies identified pseudo-first-order model, endergonic and nonspontaneous character of the process, respectively. The energy consumption for the overall process was 105 kWh, which demonstrated a low energy requirement, thus confirming the sustainability of the suggested method. Thus, the implementation of the microwave-assisted, non-catalytic, continuous biodiesel production process is an encouraging area of process intensification with a cost-effective route to offset price fluctuations of transportation fuels. The method can be considered for large scale biodiesel production; however, its industrial implementation would demand cautious consideration of pressure management and plant safety.

Layered double hydroxides (LDHs) are promising pseudocapacitive materials but suffer from poor conductivity, nanosheet restacking, and weak electrode-substrate coupling. Herein, a ZIF-67-assisted precursor conversion strategy is developed to construct hydrangea-like NiCoMn-LDH nanosheets on nickel foam through a two-step in situ growth and hydrothermal reconstruction. Nickel foam provides a conductive scaffold, while ZIF-67 acts as both a sacrificial template and a local Co source, enabling confined reconstruction of ternary LDH nanosheets into interconnected porous architecture. Benefiting from this integrated structural and compositional regulation, the optimized NCM-LDH/NF-0.5 electrode delivers 2258 F g−1 at 1 A g−1 and retains 83.2% of its capacitance after 5000 cycles. The assembled asymmetric supercapacitor maintains 81.6% capacitance retention after 5000 cycles. DFT calculations reveal interfacial charge redistribution, enhanced electronic states near the Fermi level, and favorable OH− adsorption, consistent with reduced charge-transfer resistance.

Metallic bipolar plates (BPPs) are crucial for advancing proton exchange membrane fuel cells (PEMFCs) because they dictate the stack durability, efficiency, and cost. Although stainless steel, aluminum, and titanium have been widely studied, their intrinsic trade-offs in terms of corrosion resistance, conductivity, and manufacturability remain major barriers to commercialization. This review provides a comparative framework that unifies disparate performance metrics, enabling the direct evaluation of the cost–durability–scalability balance across different metallic substrates. Particular emphasis is placed on surface engineering strategies, including carbon-based layers, nitrides/carbides, conductive polymers, and emerging MXene or high-entropy alloy coatings, which suppress interfacial contact resistance and enhance defect tolerance. Beyond short-term tests, this review systematically dissects long-term degradation mechanisms under realistic PEMFC conditions, such as humidity cycling, start–stop transients, and contaminant exposure, which are often overlooked in previous surveys. By linking material selection, coating design, and aging pathways, this study outlines critical research gaps and proposes future directions centered on scalable manufacturing, sustainable modification, and durability metrics (ΔICR@1000 h, Δjcorr@1000 h). These insights aim to guide the rational development of next-generation metallic BPPs that reconcile performance with industrial feasibility.

ABSTRACT Activated carbon (AC) materials, characterized by their high surface area, diverse pore structure, and excellent electrical conductivity, have proven to be highly efficient and versatile options for applications in electrochemical energy storage. This investigation explores the most recent advancements in the synthesis and application of AC materials and their use in novel hydrogen storage and supercapacitor solutions. Carbon‐based electrodes demonstrate outstanding electrochemical performance in supercapacitors, characterized by their high capacitance, rapid charge‐discharge cycles, and long life span. Through surface modifications and the incorporation of metal nanoparticles, AC materials exhibit notable adsorption potential for hydrogen storage, demonstrating enhanced hydrogen absorption properties. Maximizing the performance of AC electrodes requires a critical examination of the interplay between pore size distribution, surface kinetics, and material processing. This analysis provides a detailed and comprehensive examination of the current challenges and prospective strategies for improving the energy storage and hydrogen storage capabilities of AC materials, focusing on their structural and chemical characteristics. The findings underscore the promise of AC materials as viable and sustainable options in the transition to clean energy technologies.

Reducing atmospheric CO2 requires low cost and energy efficient adsorbents, yet porous carbons are still often designed primarily based on BET surface area. Here, pinecone-derived porous carbons were synthesized via metal-assisted activation to tailor ultramicropore structure and surface chemistry. The optimized Mn-600-700 sample shows a CO2 uptake of 4.18 mmol g-1 at 298.15 K, with high CO2/N2 selectivity of 13.56 at 1 bar and a moderate adsorption heat of 21.28 kJ mol-1, together with initial adsorption-desorption regenerability. Correlation analysis reveals that CO2 uptake is governed mainly by ultramicropores rather than total surface area, indicating a confinement-controlled mechanism relevant to low pressure capture. Dual-site Langmuir fitting and DFT calculations based on an idealized metal-O-modified graphene model further suggest that polarized metal-carbon interfacial sites enhance surface polarization and CO2 affinity without inducing strong chemisorption, thereby preserving reversibility. In contrast, electrochemical charge storage depends more on ion-accessible micropores and mesopore-assisted transport. This work clarifies the distinct pore-structure requirements for CO2 capture and capacitive storage and provides a practical strategy for designing sustainable biomass-derived carbons.

This study advances a sustainable pressurized-CO2 activation route that transforms waste Bangladeshi jute sticks into ultrapure (> 99

The equiatomic refractory high-entropy alloy TiZrHfNbTa was processed by high-pressure torsion (HPT) to investigate the effect of nanostructuring and defect engineering on thermal and electrical transport properties. Severe plastic deformation (SPD) via the HPT treatment induces substantial accumulation of dislocations, grain refinement to the nanometer level (average: 40 nm), and partial transformation from the BCC phase to the ω phase. While hardness increases to a steady state with processing, the specific heat capacity exhibits a non-monotonic behavior: it decreases at low strains due to the suppression of low-frequency vibrational modes by dislocations, then partially recovers at high strains due to anharmonic vibrations at newly formed high-angle grain boundaries. Thermal conductivity decreases at low strains but shows a slight recovery at high strains, whereas electrical conductivity decreases monotonically to a steady state without recovery. Analysis using the Wiedemann-Franz law reveals that the electronic contribution dominates thermal transport, while the phononic contribution (limited by the scattering of phonons on defects) is only 11 to 23%, depending on the degree of straining. The contrasting evolution of thermal and electrical conductivity is ascribed to the transition from dislocation-dominated vibrations at low strains to grain boundary-dominated vibrations at high strains, which affects phonons and electrons with different efficiencies.

A metal-organic framework (MOF) is a crystalline material that exhibits distinctive physical and chemical properties due to the coordination between metal ions and organic ligands. These properties, including a high surface area, adjustable porosity, and the ability to easily modify the chemical composition, collectively render MOFs advantageous for adsorption and separation applications. Introducing polar groups and bimetallic components into the MOF structure could significantly enhance CO2 adsorption performance. This article investigated the impact of integrating these two approaches on CO2 capture. Three Lewis acid metal ions (Al3+, Fe3+, and Cu2+) were doped into MOFs, specifically UiO-66 and UiO-66-NH2. A range of characterization techniques were employed to facilitate comparison and verification of the results, including N2 adsorption, powder X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray photoelectron spectroscopy, and thermogravimetric analysis. This study then evaluated CO2 adsorption at varying temperatures. The findings indicated that the Fe3+-doped samples exhibited the best performance irrespective of the presence of amino groups. Notably, the higher the concentration of metal dopants in UiO-66, the greater the adsorption capacity. UiO-66(Zr1 Fe1) exhibited the highest CO2 adsorption capacity of 2.22 mmol per gram of the modified MOF. In contrast, modified UiO-66-NH2 exhibited the opposite trend, where the lower the metal doping level, the higher the adsorption capacity. UiO-66-NH2(Zr5 Fe1) exhibited the highest adsorption capacity of 3.5 mmol/g.