Energy Dilemma Research Articles

Highly enhanced electro-catalytic behavior of an amide functionalized Cu(II) coordination polymer on OER at large current densities

Extensive utilization of fossil fuels has led to their swift exhaustion, causing an escalating energy dilemma and significant environmental apprehensions. This situation has spurred advancement of sustainable energy conversion systems. Electrochemical water splitting is viewed as a capable method for generating hydrogen and oxygen intended for diverse electrochemical energy apparatus. A proficient, multifunctional electro-catalyst capable of facilitating both OERs) and HERs is of paramount importance. In this work, we report Cu-MOF electro-catalyst synthesized via the solvothermal route engaging OER activity using nickel foam (NF) in a 1 M KOH solution. Several analytical techniques were used to investigate the electro-catalysts BET, PXRD, FTIR and oxidation states. The water-splitting evaluation of the LOCOM-1 demonstrated exceptional oxygen activity concerning OER (oxygen evolution reaction), showcasing to extent a current density of 10 mAcm−2 a reduced of 286 mV over potential. Additionally, it exhibited a diminished onset potential of 1.37 V attributable towards a decreased Tafel slope of 44.50 mVdec−1, and a proton couple electron transfer (PCET) channel that is stable over an extended period of time (1000 cycles of cyclic voltammetry and 40 h of chronoamperometry). Therefore, this current endeavour might offer a new prospect or pathway for exploring the OER (Oxygen Evolution Reaction).

Energy harvesting properties for potassium-sodium niobate piezoceramics through synergistic effect of phase structure and texturing engineering

In order to address the energy dilemma and meet environmental protection requirements, it is an urgent need to develop lead-free piezoelectric energy harvesters (PEHs). However, the low output power density has seriously hindered the application of lead-free piezoceramics as high efficiency energy harvesters. To solve above question, the combination of phase structure regulation and texturing technique in the K0.5Na0.5NbO3-xBi0.5Na0.5ZrO3-0.5%wtBiFeO3 (KNN-xBNZ) ceramics was adopted in this work. Because of both the Rhombohedral-Orthorhombic-Tetragonal (R-O-T) multiphases coexistence and texturing engineering, an ultrahigh piezoelectric activity quality factor d33×g33 ∼ 18324 × 10−15 m2 N−1 was achieved in the textured KNN-0.05BNZ (T-KNN-0.05BNZ) ceramics, which is about third times higher than that of random KNN-0.05BNZ (R-KNN-0.05BNZ) (d33×g33 ∼ 6672 × 10−15 m2 N−1) ones. A high output power of ∼0.32 mW was also obtained in the T-KNN-0.05BNZ ceramics by cantilever beam-based energy harvester devices under the resonance frequency of 75 Hz and matched RL of 1.2 MΩ, suggesting that the T-KNN-0.05BNZ ceramics have a great potential for application in the PEHs devices. This result also reveals that the combination of phase structure regulation and texturing technique is an effective way to achieved a high energy harvesting performances.

A comparative analysis of intelligent energy modelling approaches for a grid-tied PVT system application

Renewable energy resources are a long-term answer to the current chronic energy dilemma. Solar photovoltaic (PV) systems are the most often used form of a practical solution for power supply and energy management in buildings. A PV-thermal (PVT) system is essential to lowering the demand for grid energy by capturing electrical and thermal energy from sunlight, optimising energy usage and encouraging sustainable energy practices. The most significant difficulty faced by developing countries, such as South Africa, is a lack of power supply to meet demand while limiting grid overload. An alternative source of energy is a critical component. This research compares two intelligent energy modelling methodologies: optimal control scheme-based open loop and model predictive control (MPC) in a PVT application. The primary goal of the modelling is to limit the electricity required from the grid while stressing the system’s energy efficiency and cost-effectiveness. The open loop approach uses mathematical optimisation techniques to establish the best control strategy for the PVT system. The ideal set-points for various system parameters are found by presenting the problem as an optimisation task to reduce grid power usage. The optimal control technique delivers a global optimisation solution based on the system dynamics and constraints. The MPC technique employs a predictive control technique of the PVT system to create optimal control actions in a receding horizon manner. The MPC algorithm anticipates future system behaviour and generates control actions that minimise grid power drawn by iteratively solving an optimisation problem at each time step. This robust online control scheme enables real-time modifications and responses to system disruptions that effectively and dynamically coordinate system behaviour.

Quantitative simulation and validation of energy carbon emission efficiency changes in Chinese urban agglomerations

In the context of the global energy dilemma, enhancing energy efficiency has inevitably become a pivotal strategy for mitigating energy waste and promoting sustainable development. Urban agglomerations, as growth poles leading high-quality regional economic development, play a significant role in this process. Within these urban agglomerations, the aggregation of various factors and the substitution of energy resources substantially influence the energy carbon emission efficiency (ECEE) of surrounding cities during their development and maturation phases. This study initially employs a three-stage Data Envelopment Analysis (DEA) to quantitatively analyze the ECEE values of 19 urban agglomerations from 2006 to 2020. It then establishes a methodology for calculating the joint intensity (JI) and joint threshold (JT) of ECEE within these urban agglomerations. Finally, a validation process is executed using MATLAB simulation and verification methodology to fit and authenticate the evolutionary patterns of ECEE in Chinese urban agglomerations. The primary objective of this research is to model the evolution of ECEE, thereby exploring the sustainable development pathways for urban agglomerations in China. The research findings indicate that: (1) The results from the three-stage DEA demonstrate that, after removing the influences of external environmental factors and random errors, the comprehensive technical efficiency (TE) of energy carbon emissions for the 19 urban agglomerations in China experienced a wave-like increase, rising from 0.410 to 0.506 between 2006 and 2020. (2) The calculation results of the constructed JI model indicate that the JT values of ECEE for national-level, regional-level, and local-level urban agglomerations are 1006.92, 226.60, and 160.14, respectively. The national-level urban agglomerations have significantly higher JT values and JI than the other two levels of urban agglomerations. (3) The results of the Matlab simulation verification show that 16 urban agglomerations fit well with the wave-like ascending evolutionary pattern. However, four urban agglomerations exhibit an opposite fitting effect due to the influence of their pillar industries or the small number of cities within these accumulations, making them unrepresentative. Consequently, the evolutionary curve of ECEE in Chinese urban agglomerations generally exhibits a wave-like upward trend over time.

Assessing the energy system's greenhouse emissions via the health of Smart Territories and Cities

The aim of this paper is to understand how the main drivers of air pollution and greenhouse emissions impact public health in a Smart Territory — meaning a technologically integrated city or neighborhood — as well as how to design an optimized energy system model beyond only data by including the holistic experience of its people through phenomenology and ethics. We understand that a Territory and a City is a complex system where mathematical tool modeling known as Design of Experiment (DOE) and its optimization solutions are required to establish causality and identify the variables that have a broader impact on public health so that mortality rates due to air pollution are reduced. DOE's statistical branch is a novel methodology when applied to energy systems and the design of Smart Territories and Cities. Because of it, we have been able to demonstrate how energy emissions, capacity and Levelized Cost of Energy (LCOE) affect the mortality rate and create the foundations for building fully decarbonised energy systems enhanced by mathematical solutions. However, the Cartesian approach of extrapolating from models which align themselves with economic growth alone will not solve the energy dilemma. In fact, the current energy transition project is based on outdated archetypes that lead to scary futures. To course-correct the problematic energy model of a Smart Territory, phenomenologists and creative imagination need to be cultivated and put into action together with mathematical modeling, leading to vectors of positive change and adaptation. Only then might the energy models designed to be reproducible could became ethically virtuous and therefore accepted by the Territory's co-dwellers within the chain of causalities.

Fracture behavior of 3D-printed thermoplastics—A dilemma of fracture toughness versus fracture energy

The Material Extrusion (ME) technique in 3D printing facilitates the production of thermoplastic materials with diverse cellular or lattice-like infill geometries, enabling the creation of lightweight, high-performance materials. This study investigates the influence of infill geometry and relative density on the fracture behavior of 3D-printed thermoplastics produced through ME. Polylactic acid (PLA) is used as the model material, with unit cell geometries-square, triangle, and Kagome-and relative densities ranging from 0.4 to 0.8 explored. Tensile tests are first conducted to determine in-plane elastic moduli in two orthogonal directions, accounting for unit cell anisotropy. These results are employed in effective fracture energy calculations. Compact tension fracture tests follow, quantitatively characterize crack growth characteristics in both directions. In both tests, digital image correlation method is used to measure full field strain distributions. Three significant findings emerge. First, there is a power scaling relationship between Elastic Modulus and relative density across all unit cells, with Kagome exhibiting the highest correlation constant. Triangle and Kagome unit cells show negligible orthotropic responses in perpendicular directions for varying relative densities. Second, the relationship between nondimensional fracture toughness and relative density follows a similar scaling law, with minor variations depending on unit cell type. The correlation factor slightly dependens on unit cell geometry but remains around 3 across the the examined relative density range. Third, considering the dissipation of inelastic fracture energy, both triangle and Kagome unit cell geometries demonstrate an order of magnitude higher effective fracture energy (i.e., crack growth resistance) compared to the square unit cell. This is associated with toughening mechanisms such as crack deflection and bifurcation. These findings highlight the disparity between fracture toughness and effective fracture energy in assessing the fracture resistance of 3D-printed thermoplastics, clearly demonstrating that fracture toughness alone is insufficient for a comprehensive assessment. The proposed scaling laws provide predictive insights into the fracture toughness of polymeric materials produced via the ME method.

Construction of multi-functional S-Vacancy-Zn3In2S6/Bi-MOF S-scheme heterojunction containing interfacial chemical bonds for the efficient photocatalytic production of H2O2 and excellent photocatalytic degradation of OTC and TC

Designing outstanding S-scheme heterojunction photocatalysts for eliminating pharmaceutical pollution and energy dilemmas is an effective strategy for tackling the issue of global environmental pollution. Herein, the Zn3In2S6/Bi-MOF S-scheme heterojunction was prepared through a facile in-situ hydrothermal method. The Bi-S bonds were introduced into the interface of an S-vacancy-containing Zn3In2S6/Bi-MOF S-scheme heterojunction, which profoundly boosts migration and separation of photogenerated carriers as the highway for electron transfer. The practical significance of Zn3In2S6/Bi-MOF composites for environmental pollution control was assessed using oxytetracycline (OTC) and tetracycline (TC) as representative pharmaceutical pollutants. Simultaneously, the production performance of H2O2 as a new energy carrier was also evaluated to determine the multi-functionality of the Zn3In2S6/Bi-MOF composite. The H2O2 production rate of optimal proportion photocatalyst reaches 3689.94 μmol/g/h without using the sacrificial agent. In addition, it exhibited a photocatalytic degradation of OTC and TC efficiency of 88.1 % and 65.2 % within 60 min, respectively. The Zn3In2S6/Bi-MOF photocatalytic not only exhibits excellent cyclic stability but also has exceptional anti-interference properties-systematic elucidation of the effects of catalyst dosage, pH, and co-existing substances. The efficient photocatalytic production of H2O2 and the degradation of OTC/TC through Bi-S bonds and VS-modificatory S-scheme charge transfer offer valuable new perspectives for designing photocatalysts.

The study of solid flame model of diffusion jet flame for the ammonia and propane mixed gas under the inclined ceiling

In order to solve the environmental pollution and energy dilemma, the ammonia has been considered as a new fuel and a carbon-free hydrogen carrier, which can be blended into the traditional hydrocarbon fuels. In this study, the evolution of flame emissivity, view factor and radiative heat flux have been investigated under different mass flow rates of ammonia and propane, and inclined angle of ceiling. A radiation prediction model of ammonia-propane mixed gas jet flame under inclined ceiling with different inclined angles has been developed. This prediction model can accurately describe the flame morphology and simplify the calculations, and consider the influence of mixing ratio on combustion reaction. The experimental results indicated that the flame emissivity, view factor, and radiative heat flux decrease with the increase of ammonia concentration. The prediction error of the traditional model will be enlarged with the increase in the inclined angle of ceiling. The modified model added the undersurface of ceiling jet flame, which reduces the prediction error from 25 % to 14 %. These prediction models are helpful in predicting the thermal radiation of jet flame under inclined ceiling.

Targeting SDG7: Identifying heterogeneous energy dilemmas for socially disadvantaged groups in India using machine learning

To achieve Sustainable Development Goal (SDG) 7, prioritizing the socially disadvantaged segments of the population is imperative, given their inherent susceptibility to heightened risks of energy exclusion. However, a comprehensive understanding of the diverse energy challenges faced by households with socio-economic disparities remains elusive. This article thus addresses this gap by examining three widely acknowledged categories of marginalized households in India: racial inferiority, income poverty, and gender inequality. It notably pioneers the quantification of an umbrella pattern of energy deprivation within the SDG7 framework, encompassing energy unaffordability, energy unreliability, energy inaccessibility, and energy inequality. To do so, leveraging the latest household survey dataset and employing least squares estimates, we preliminarily capture that these three disadvantaged groups encounter significant energy barriers in the pursuit of SDG7 achievement. Given respectively selected models based on Least Absolute Shrinkage and Selection Operator (LASSO) approach, the gradient boosting model (GBM), another state-of-the-art machine learning technique, is subsequently adopted to verify feature significance and rank its importance in determining diverse energy deprivation faced by each group. The results reveal that the disadvantaged caste groups and those experiencing greater gender inequality encounter the greatest impediments to their right to reliable energy access. In comparison, energy unaffordability poses a paramount challenge for low-income households. These findings enable policymakers to design straightforward interventions that address a spectrum of socio-economic disparities, thereby fostering an just energy transition grounded in data-driven evidence.

2D/2D Bi2WO6/C3N5 S-scheme heterojunction for highly selective production of CH4 by photocatalytic CO2 reduction under visible light

Photocatalytic CO2 reduction is a practical solution to the energy dilemma and environmental damage caused by greenhouse gases, and it is very important to explore high-efficiency photocatalysts. In this study, a novel Bi2WO6/C3N5 step(S)-scheme heterojunction was successfully constructed and applied for CO2 photoreduction. The 2D/2D structure showed excellent photocatalytic properties, with methane production reaching 1.976 μmol·g−1·h−1 and selectivity reaching 100 % under 5 hours of visible light irradiation. The result indicates that combining Bi2WO6 and C3N5 can promote interfacial charge separation and maintain the optimal reducing ability of photogenerated electrons. Based on experimental and theoretical calculations, we characterized the reaction mechanism and heterojunction formation mechanism. This study offers a novel approach to improve the selectivity and photocatalytic efficiency of CO2 reduction products.

Investigation of ZnO@CdS nanocomposite with amplified photocatalytic H2 production under visible light irradiation

Researchers are trying to develop an efficient solar-powered catalytic water splitting system to solve the energy dilemma and generate green hydrogen. In this study, ZnO@CdS nano-heterostructures were synthesized using sol-gel and co-precipitation techniques. The pristine ZnO, CdS, and their heterostructures were characterized through various characterization tools such as XRD, SAED, XPS, FTIR, EDX, SEM, FE-TEM, UV–vis, Mott-Schottky, GCG, EIS, and PL, to know the crystal structure, chemical state, elemental composition, morphology, band gap, scheme mechanism, hydrogen production and charge transfer resistance characteristics of the samples, respectively. The SEM, FE-TEM, confirm that CdS NPs are well decorated on hexagonal ZnO rods. The efficient H2 production of 587.86 μmolg−1 h−1 were measured for the optimized sample which is 3.91 times greater than pure ZnO rods and 3.22 times than CdS NPs. Strong photo-cyclic stability test was carried out for 20 h in four cycles while, PL spectroscopy confirms the suppressed charge recombination. All of the above characterization prove that (ZC-20) optimized sample, has a potential to be used as an efficient and stable photocatalyst for H2 production via photocatalytic water splitting.

Synergistic Advancements in Battery-Grade Energy Storage: AgCoS@MXene@AC Hybrid Electrode Material as an Enhanced Electrocatalyst for Oxygen Reduction Reaction

The extreme usage of fossil fuels and the rising conservation deterioration have made developing clean, renewable energy essential. Among the most promising methods for addressing the world’s energy dilemma are electrochemical energy storage devices (EES); batteries and supercapacitors (SCs) are two typical components in this class. Supercapacitors are incredibly impressive since they can store energy remarkably in seconds. In this work, we present a highly effective electrode material (AgCoS@MXene) for supercapattery device application that is produced hydrothermally. We examined the morphology and crystallinity of the synthesized materials using SEM and XRD studies. The synthesized compounds were subjected to a thorough electrochemical performance study employing a three-electrode configuration in a 1 M KOH electrolyte. AgCoS@MXene demonstrated an exceptional Qs of 943.22 C g−1 at a current density of 2.0 A g−1. We formed a supercapattery device (AgCoS@MXene//AC) with AgCoS@MXene as the positive electrode and activated carbon (AC) as the negative electrode. The supercapattery device was demonstrated to have a high specific capacity of 315.22 C g−1, a power density of 1275 W kg−1, and an energy density of 35.94 Wh kg−1. In addition, 5000 charging and discharging cycles were used to assess the device’s long-term longevity. The findings indicated that the device preserved nearly 82% of its initial capacity. Besides, the hybrid electrode is used for the electrocatalytic activity for the oxygen reduction reaction. These promising findings imply that AgCoS@MXene is a beneficial electrode material for upcoming energy storage devices to enhance the electrocatalytic activity for the oxygen reduction reaction.

Development and assessment of an integrated wind energy system for green steelmaking based on electric arc furnace route

Optimizing energy structure is important for coping with the increasing environmental problems in iron and steel industry. Wind energy is one of typical zero-carbon, inexhaustible, and accessible energy source for alleviating energy dilemma. In this paper, the electric arc furnace steelmaking processes integrated with wind energy system (EAF-WES) is developed. The input-output data of 1214 and 1536 heats with 30 % and 50 % hot metal ratio are traced and collected. Life cycle assessment and techno-economic analysis of EAF route integrated with traditional energy system (EAF-TES) and EAF-WES are further researched and compared from perspectives of life cycle carbon footprint (LCCF), production cost, wind energy price (WEP), carbon efficiency, carbon reduction benefit (CRB), and carbon tax. The results indicate that EAF-WES enjoys lower LCCF but higher production cost and carbon efficiency than EAF-TES. Considering the price fluctuations, the optimal EAF steelmaking pattern with lowest production cost under different extent of WEP and carbon tax is suggested. When the electricity price is 0.043 and 0.046 $/kWh, the CRB is balanced. It is concluded that EAF-WES is a low-carbon, high-productive, environmentally friendly, and economical route. This research is expected to supply a technical idea for energy conservation and emission reduction in future steel production.

Design and fabrication of a heat pipe and thermoelectric cooler-based food delivery box for vehicles

In recent years, there has been a notable surge in interest regarding the application of heat pipe and thermoelectric cooling technologies to recuperate waste heat, conserve energy, and augment thermal efficiency across diverse commercial and engineering domains. Particularly within the realm of food delivery services reliant on online ordering systems for the conveyance of freshly prepared meals from restaurants to consumers, sustaining the quality of food during transit poses a significant challenge due to heat dissipation from food containers over extended transportation distances. Consequently, maintaining optimal food temperature or beverage warmth in online orders becomes a pressing concern. This investigation's primary goal was to design and construct a portable heating-cooling chamber that would maintain food temperature during transportation. This technological endeavor offers a viable solution to contemporary energy dilemmas by leveraging electricity and waste energy from vehicles to furnish efficient cooling and heating mechanisms. The heating aspect of the chamber is facilitated by a meticulously developed heat pipe system that utilizes deionized water as the working fluid. Experimental results reveal that a 75 % filling ratio engenders optimal heat pipe performance across varying input power levels. The proposed design amalgamates a heating and cooling chamber, integrates a thermosyphon heat pipe within the exhaust gas trajectory to recuperate dissipated heat, and harnesses the vehicle battery to power a thermoelectric cooler. Experimental results substantiate the efficacy of the thermosyphon heat pipe in elevating the heating chamber's temperature to 48 °C within a span of 25 min, while concurrently, the thermoelectric cooler achieves the desired cooling chamber temperature of 5 °C within a mere 8 min.

Investigating the influence of copper benzene-1,2-dicarboxylate (Cu-BDC) and benzene-1,3,5-tricarboxylate ligands (Cu-BTC) on the electrochemical capacity of hybrid supercapacitors

The elevated energy demand and crises have rooted the urge to develop advanced electrode materials that can overcome the energy dilemma present all over the globe. Metal-organic frameworks (MOFs) have emerged as promising electrode materials in recent times due to their better electrochemical properties. Herein the metal ligand synergy produced in MOFs is observed for the same metal center (Cu) with different ligands i.e., benzene-1,3,5-tricarboxylate (1,3,5-BTC) and benzene-1,2-dicarboxylate (1,2-BDC). The hybrid device of the best performing MOF (Cu-1,3,5-BTC//AC) reveals the energy and power density of 88.32 Wh kg−1 and 680 W kg−1, respectively. Even at the highest current density of 15 A/g, the device retained the Es of 21.25 Wh kg−1 and Ps of 12,750 W kg−1. Furthermore, the semi-empirical approach was utilized for the evaluation of capacitive and diffusive contributions.

Two 2D layered Co-modified Anderson-type polyoxometalate-based highly efficient photocatalysts for CO2 reduction

The design of efficient and low-price photocatalysts is an effective way to relieve excessive carbon dioxide emissions and energy dilemma. Polyoxometalates are ideal materials due to their adjustable structures and semiconductor-like properties. Limited by their light absorption capacity, it is a feasible way to construct inorganic-organic composite polyoxometalate-based photocatalysts. Here, two efficient Anderson-type polyoxometalate-based photocatalysts, (C10H9N2)·{[Co(H2O)2]·[H6CrMo6O24]}·4H2O (1), {[Co(H2O)3]·[Co(DAPSC)]2·[H6CrMo6O24]2}·11H2O (2) [2,6-diacetylpyridine bis(semicarbazone), abbr. DAPSC], were prepared by hydrothermal synthesis method. The structural analysis indicates that compounds 1 and 2 share similarities: {CrMo6} units were linked by cobalt ions to form two-dimensional (2D) frameworks. The addition of Co ions provided catalytic active center for the catalyst, compounds 1 and 2 exhibited promising yield into CO, as high as 3061.6 μmol g−1·h−1 and 9309.8 μmol g−1·h−1, respectively. Due to their excellent properties, Anderson-type POMs can be used as the basic units of photocatalysts. At the same time, four cycling tests prove the stability of compound 2 under a long reaction time.

Analysis of biodiesel and fatty acids using state-of-the-art methods from non-edible plants seed oil; Nicotiana tobaccum and Olea ferruginia

The long-term socioeconomic and environmental alternative to fossil fuels is biodiesel. Current biodiesel manufacturing research has developed competitive, sustainable methods. The study validates and explains biodiesel benefits while increasing output. Physicochemical characterizations, gas chromatography-mass spectrometry (GCMS), Fourier transform infrared (FTIR), elemental analysis (EA), inductively coupled plasma atomic emission (ICP-OES), and nuclear magnetic resonance (NMR) are studied. In this study, we discovered two inedible plant seeds, specifically Olea ferruginea (OF) and Nicotiana tobaccum (NT), which exhibited significant oil contents of 30–49% by weight; both seeds had minimal amounts of free fatty acids contents of 1.1% and 0.9%, and biodiesel yield 96.4–97.9% after an optimization process, i.e., methanol/ oil ratio (6:1), KOH concentration (0.32), temperature (65 °C), stirring rate (700 rpm), and time (60 mins). A comprehensive analysis was performed to investigate and contrast the physical, chemical, and compositional attributes of the FAMEs with those of mineral diesel. Gas chromatography determined biodiesel's chemical composition and detected various fatty acid methyl esters (FAMEs) i.e. palmitic (9.7–14.0), stearic (1.8–3.2), oleic (25.5–47.2), linoleic (8.5–32.2), α-Linolenic (3.6–1.1), arachidic (2.4–0.8), and gondoic acid was (48.5–0.5%), respectively. In novel biodiesel characterization, NMR spectroscopy defines and assigns sample chemical structures to identify and quantify unsaturated long-chain alkyl esters. NMR spectroscopic biodiesel methanol quantification is an alternative to official methods. 1H NMR revealed the molecular hydrogen nuclei. This study examines all biodiesel purity and transesterification performance parameters. Producing cost-effective and optimal biodiesel requires the intent of these properties. Inedible seeds can be cultivated in infertile terrain to improve biodiesel production and solve the energy dilemma.

Solar Energy Potential in Pakistan: A Review

Solar Energy Potential in Pakistan: A Review

Succinic acid modified chitosan hydrogel mediates in-situ bioenergetic remodeling of neural cells for neuronal differentiation and spinal cord injury repair

A primary challenge in spinal cord injury repair is the presence of an energy deficit, exacerbated by the injury itself, thereby intensifying the dilemma of insufficient energy. Hence, we posit a hypothesis suggesting that the adoption of a direct energy-supply material strategy has the potential to enhance in situ cellular energy levels, facilitating the acceleration of neuronal differentiation and axonal elongation. We successfully designed a degradable bioenergetic hydrogel by introducing succinic acid (SA), a key intermediate in tricarboxylic acid (TCA) cycle, into chitosan (CS) as an energy-active unit, which was released in a sustained degradation-mediated fashion once implanted. The degraded energy-active units, after being internalized, increased bioenergetic levels via oxidative phosphorylation (OXPHOS) by facilitating TCA flux, thereby contributing to a at least 1.5-fold increase in the expression levels of neuronal differentiation-related markers in vitro, as well as the enhanced spinal cord injury repair and functional recovery in vivo. Further mechanism analysis demonstrated that the upregulation of the bioenergetic basis had the potential to induce neuronal differentiation through the AMP-activated protein kinase-mammalian target of rapamycin (AMPK-mTOR) axis. Additionally, the adenosine triphosphate (ATP) itself acted as a signaling molecule via the P2X7 receptor, leading to the upregulation of intracellular calcium ion-MAPK signal cascades, ultimately promoting neuronal differentiation. Overall, these findings have the potential to significantly alter our understanding of cell metabolism and energy homeostasis, transforming them from passive observers to critical factors in guiding nerve regeneration, and may have implications for future design of bioenergetic-active materials.

Theoretical study of CO2 hydrogenation to methanol on modified Au/In2O3 catalysts: Effects of hydrogen spillover and activation energy prediction for hydrogen transfer

With the increasing attention in environmental issues caused by CO2 emissions, methanol conversion by CO2 hydrogenation is an effective strategy to solve this existing energy dilemma. The rationale behind hydrogen spillover on methanol synthesis is unraveled via density functional theory (DFT) calculations in this work, furthermore, the activation energy of hydrogen transfer process as affected by spillover is also summarized in a general paradigm for facilitating the understanding of hydrogenation characteristics. The results demonstrate that the spillover strategy significantly facilitates the hydrogenation reaction by supplying available hydrogen adatoms. This effect is particularly pronounced during the stage when OH is formed directly at the substrate site and combines with H to produce H2O, leading to a substantial reduction in activation energy from the initial 3.74 eV to 0.78 eV. In addition, a comprehensive predictive model for the kinetic characteristics of hydrogen spillover process is established based on the machine learning algorithm and SISSO guidance. By employing the combined approach of SISSO and neural network, we have achieved a stable prediction performance for activation energy with R2 = 0.99 and RMSE = 0.07 eV. The variable of ChgFSAu is identified as the most representative factor in describing the activation energy, demonstrating a correlation coefficient of -0.60. The extended multidimensional expression of DistAu further highlights its close connection to activation energy, achieving an RMSE value of 0.41 eV. To sum up, this work elucidates the possible thoughts of catalyst design with spillover effect and gives reference for the description screening towards the chemical reactions similar to hydrogen spillover.