Sustainable Energy & Fuels最新文献

The oxygen reduction reaction (ORR) is central to clean energy technologies such as metal–air batteries, but its sluggish kinetics typically rely on precious metal catalysts. Herein, a sulfur-functionalized cobalt–nitrogen–carbon catalyst (S@Co–N–C) was successfully synthesized via a thiourea-assisted pyrolysis strategy using a two-dimensional (2D) zeolitic imidazolate framework (ZIF) as the precursor. Experimental characterization revealed that S-doping effectively modulated electronic structures of Co–N₄ sites, significantly enhancing the intrinsic ORR activity of the Co–N–C material. In 0.1 M KOH, S@Co–N–C exhibited a half-wave potential (E_1/2) of 0.895 V (vs. RHE), surpassing that of commercial Pt/C (20 wt%; 0.870 V vs. RHE). Density functional theory (DFT) calculations confirmed that the introduction of S atoms optimized the d-band center of Co sites and reduced the *OH desorption energy barrier, thereby accelerating ORR kinetics. Furthermore, a Zn–air battery assembled with S@Co–N–C delivered a peak power density of 210 mW cm⁻², outperforming the Pt/C + RuO₂ benchmark (140 mW cm⁻²). S@Co–N–C also demonstrated superior stability for both the ORR and Zn–air battery compared to the control sample Co–N–C and commercial benchmark. This study provides new insights into the design of non-precious metal ORR catalysts with high stability and elucidates the critical role of S-doping in M–N–C materials.

This study proposes a new approach for reducing CO₂ emissions from industrial processes and contributing to sustainable environmental development. The primary focus is on post-processing emitted CO₂ and constructing a coupled catalytic reaction system for CO₂ conversion. This coupled reaction system consists of three reactors: the 1st reactor for the methanation of CO₂, the 2nd reactor for the dry reforming of CH₄ (DRM), and the 3rd reactor for solid carbon capture. The constructed system enabled the continuous production of synthesis gas (H₂ + CO) even at a higher gas flow rate of 2 L min⁻¹ while recovering >30% of the introduced CO₂ as solid carbon. Furthermore, in this system, we have demonstrated that the quantity of H₂ lower than the stoichiometric ratio of the methanation reaction (H₂/CO₂ = 4.0) is advantageous for system operation. Significantly improved DRM and carbon capture performance were achieved under these conditions. The obtained results indicate the potential of this system in the efficient treatment of CO₂ from industrial emissions using a lower stoichiometric ratio of H₂, which has significant implications for environmental conservation and energy reduction. Additionally, the thermodynamic evaluation indicated that reducing the amount of supplied H₂ should have a beneficial impact on the exergy efficiency of the reaction system. The captured carbon has elongated fiber-like morphology with potential utilization as a functional material. We expect that the coupled reaction system designed in this study can serve as an innovative technology, contributing towards realizing a carbon-neutral society.

Rechargeable iron-ion (Fe-ion) batteries are gaining attention due to their unique characteristics, including earth abundance, cost-effectiveness, eco-friendly nature, and high electrochemical performance. However, capacity degradation during cycling hinders their effective use. To investigate the material's degradation in rechargeable Fe-ion batteries, two different coin cells are fabricated utilizing mild steel (MS) and ZnO-coated mild steel (ZnO@MS) as anodes. In both cases, V₂O₅ is used as the cathode, along with a non-aqueous electrolyte. Cyclic voltammetry and galvanostatic charge–discharge analyses are conducted at different cycling stages, viz. 20, 40, 60, and 80 cycles, for determining the electrochemical performance of these anode-based coin cell batteries. The coin cells are dismantled after cycling, and the post-cycled electrodes are subjected to ex situ scanning electron microscopy, X-ray diffraction, and X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) measurements to probe the structural and chemical degradation mechanisms of the electrode materials. The results from the XANES and EXAFS measurements provide critical insights into the evolution of the electronic structure and local atomic environment, revealing degradation trends correlated with the cycling performance. The comparison between the MS and ZnO@MS anodes highlights the protective role of ZnO coating in mitigating degradation. In both cases, the V₂O₅ cathode exhibits significant transformation after cycling, possibly due to changes in the oxidation states due to the insertion of Fe ions in the cathode. Thus, these findings offer a deeper understanding of the stability of materials in Fe-ion batteries and anode modification possibilities, which are crucial for developing durable, cost-effective energy storage systems.

Pressure swing adsorption (PSA) is widely used for hydrogen purification from steam methane reforming (SMR) off-gases, but its design and optimization require extensive equilibrium adsorption data. These data are typically obtained from static experiments, which are often costly, time-consuming, and inefficient. This study presents a machine learning-based approach to predict the adsorption capacities of two types of silica gels (SG1 and SG2) for key gas components (CO₂, CH₄, CO, and H₂) in the SMR process, aiming to significantly reduce experimental costs and enhance data acquisition efficiency. Five widely used machine learning models were investigated, including decision tree (DT), random forest (RF), extreme gradient boosting (XGBoost), support vector machine (SVM), and deep neural network (DNN). To improve model performance, hyperparameters were optimized using the Optuna framework, combined with five-fold cross-validation. All five models demonstrated excellent predictive accuracy, with coefficients of determination (R²) exceeding 0.99. Among them, the DNN model outperformed the others, achieving an R² value of 0.999. To validate the model predictions, three temperature-dependent adsorption isotherm models (single-site Langmuir, single-site Langmuir–Freundlich and dual-site Langmuir) were employed to fit the experimental data. The dual-site Langmuir model provided the best fit for CO₂ and CH₄, while the single-site Langmuir–Freundlich model was most suitable for CO and H₂. The adsorption capacities predicted by the DNN model showed strong agreement with those from the optimal isotherm models for all four gases. Furthermore, the DNN model was used to predict CO₂ adsorption capacities under extrapolated temperature and pressure conditions. The DNN predictions closely matched those from the dual-site Langmuir model and were consistent with experimental measurements. These results confirm that the DNN approach can effectively replace conventional static experiments for accurately and efficiently generating equilibrium adsorption data.

The photocatalytic dissociation of hydroiodic acid (HI) utilizing halide perovskites offers an environmentally benign and economically viable approach for hydrogen production under ambient temperature conditions. With lead-halide perovskites showing encouraging efficacy in the domain of photocatalytic hydrogen generation, this work focused on developing a lead-free Bi-based hybrid perovskite, specifically MA₃Bi₂I₉ (MABI), which was successfully synthesized in a heterostructure configuration, wherein the MABI perovskite was in situ grown around amorphous MoS₂. This research underscores that for heterostructures made of amorphous MoS₂ and MABI, the doping of phosphorus not only modified the energy levels but it also altered the crucial bandgap values of amorphous MoS₂. The shifted energy levels of MoS₂ relative to MABI resulted in unique energy band arrangements for the three composites. A transition of the heterojunction from type I to type II was observed with the phosphorus-doped MoS₂-containing composites. Among all three composites, P50_MoS₂/MABI possessed advantageous band alignment, facilitating the most efficient photogenerated charge separation and transport. Under optimal reaction parameters, a hydrogen evolution rate of 1176 µmol g⁻¹ h⁻¹ can be attained for P50_MoS₂/MABI composites.

Alkaline anion exchange membrane water electrolyzers (AEMWEs) are a promising technology for hydrogen production from renewable energy sources. However, their performance is far lower than that of proton exchange membrane water electrolyzers and traditional alkaline water electrolyzers. Here, we demonstrate that chiral catalysts embedded in the porous transport layer (PTL) can enhance AEMWE performance. The chiral CoO_x-based PTL achieves a current density of 8.21 A cm⁻² at 2.0 V in AEMWEs, which is higher than that of the achiral meso-CoO_x-PTL (5.42 A cm⁻²). The chiral CoO_x-PTL provides additional active sites and facilitates interfacial charge transfer between the catalyst and electrolyte, thereby increasing the current density during electrocatalysis. Electrochemical analysis and measurement of H₂O₂ byproduct concentration confirmed that the chiral CoO_x-PTL suppresses H₂O₂ formation even after surface reconstruction, supporting the persistence of the spin polarization. Extending this strategy to bimetallic systems, the chiral NiFe-based PTL achieves a remarkable current density of 11.5 A cm⁻² at 2.0 V and exceptional operational stability, maintaining 1 A cm⁻² for over 1000 hours in 1 M KOH. These results demonstrate the potential of spin-engineered catalysts for advancing AEMWEs toward industrial-scale hydrogen production.

Extensive research efforts in past few decades have identified thousands of nanoparticles for various potential applications. However, only a few have found relevance in real-world industrial applications. A key question that continues to challenge material researchers is “what truly defines the foundation for designing nanomaterials that can meet all the critical criteria for industrial applications”? This tutorial review begins by highlighting the strategic significance of both metallic and non-metallic components in semiconductor nanomaterial systems. It emphasizes that the intelligent integration of these components can markedly develop the functional properties of semiconductor nanoparticles (NPs). Such synergistic development makes these materials highly attractive for a wide range of industrial applications. Cu–Se synergy mitigates Cu toxicity and yields a low band gap semiconductor with complementary electronic properties of Cu and Se, positioning CuSe as a promising candidate for next-generation solar energy conversion and healthcare technologies. This review emphasizes the crucial role of nanostructures (NSs) design in influencing the photogenerated electron–hole pair's dynamics, detailing various strategies employed to fabricate diverse 0D–3D CuSe NSs. CuSe NSs are also reviewed for their multifunctional solar energy conversion applications, including photocatalysis and photovoltaic cells. Extending beyond solar energy, the promising potential of CuSe NSs in energy storage systems and biomedical applications showcases their versatility and wide-ranging applicability. With a consolidated overview of the findings, the current challenges and future perspectives for harnessing the full potential of CuSe NSs, as advanced multifunctional energy materials, are discussed. Eventually, potential future industrial applications are discussed followed by a summary and outlook.

This study describes the synthesis of high-performance cauliflower-like NiMoP nanosphere electrocatalysts on a titanium mesh via a scalable pulse electrodeposition technique. The optimized cauliflower-like NiMoP demonstrates remarkable activity for the hydrogen evolution reaction in alkaline seawater, requiring only 50.3 mV overpotential to drive 10 mA cm⁻² and exhibiting exceptional durability, with only 0.5% current degradation over 24 hours. This superior performance is attributed to a unique combination of an amorphous structure, a high-surface-area morphology, and synergistic electronic effects among the Ni, Mo, and P components. This work not only presents a top-tier catalyst but also validates pulse electrodeposition as a powerful strategy for engineering catalyst architecture and electronic properties, opening a promising pathway for scalable and efficient hydrogen generation directly from saline environments.

In this paper, we propose a magnet-assisted chaotic pendulum low-frequency piezoelectric energy harvester (MCP-PEH) for wave energy, designed to supply power to ocean wireless sensing equipment. The chaotic pendulum consists of a double pendulum. The main pendulum converts external excitation into internal mechanical swing, while the internal pendulum uses a rotating multistage mass to achieve frequency conversion. This design enables a better output response in the low-frequency ocean environment. The magnet-assisted mechanism allows the harvester to achieve an effective output at 0.4 Hz, reducing the starting frequency and achieving low-frequency broadband performance. Additionally, the electrical signal generated by the bottom piezoelectric sheet can be used to monitor the wave frequency. Theoretical analysis and prototype experiments are conducted to identify the main variables affecting the device, thereby proving its feasibility. Under the optimal load, the magnet-assisted mechanism increases the overall output power by 46.7%, enabling the device to generate 6.57 mW of power. Water tank experiments and energy supply analysis of the sensor further demonstrate the device's practicality and feasibility for powering ocean wireless sensing equipment.

Anaerobic fungi, primarily found in the digestive tracts of herbivores, possess remarkable capabilities to degrade lignocellulosic biomass, positioning them as pivotal contributors to sustainable biofuel production. This review explores the enzymatic arsenal of these fungi, which includes cellulases, hemicellulases, and cellulosomes comprising glycoside hydrolases (GHs), carbohydrate esterases (CEs), polysaccharide lyases (PLs), and carbohydrate-binding modules (CBMs), emphasizing their superior efficiency in breaking down recalcitrant plant materials compared to other microorganisms. We highlight their potential in bioenergy applications, such as enhancing biomethane production through synergistic interactions with methanogens. Furthermore, the review underscores the unique characteristics of anaerobic fungi, including hydrogenosome-driven metabolism, their adaptation to diverse anaerobic environments, and their role in reducing the environmental impact of biofuel production. While challenges in cultivation, genetic engineering, and large-scale application persist, advancing research into these microorganisms could unlock innovative solutions for lignocellulosic biomass utilization, paving the way for a greener energy future. This review sheds light on their untapped biotechnological potential and offers a roadmap for addressing existing barriers to their application.