Advanced Energy and Sustainability Research最新文献

In this review, the transformative role of polymer nanocomposites in hydrogen production from challenging water sources is explored. Their catalytic efficiency and unique properties are highlighted, making them vital for overcoming complexities in hydrogen generation. Polymer nanocomposites demonstrate exceptional adaptability to various water compositions, including wastewater and saline water, enhancing efficiency, stability, and compatibility. In this review, the significance of these nanomaterials in the sustainable energy landscape is underscored, showcasing their ability to outperform conventional methods. Key breakthroughs in catalytic efficiency and adaptability are emphasized, illustrating their crucial role in clean hydrogen production. Looking forward, in this review, potential applications of polymer nanocomposites in diverse fields, from industrial processes to energy sector advancements, are identified. This synthesis of findings not only enhances the understanding but also sets the stage for the widespread adoption of polymer nanocomposites in meeting the global demand for sustainable hydrogen production.

Aqueous processing of lithium (ion) battery cathodes based on Ni-rich layered oxides like LiNi_0.83Co_0.12Mn_0.05O₂ (NCM) can reduce costs, increase sustainability, and pave the way for F-free, e.g., biopolymeric binders, however, the degradation of water-sensitive Ni-rich NCM remains a challenge. Besides strategies like NCM coatings and processing additives, customized binders can be performance-decisive via impacting both, electrode processing aspects (paste viscosity, particle dispersibility, etc.) and chemical interactions with NCM surface, though, a distinction between these two impacting factors is difficult given their mutual influences. For this reason, a bifunctional binder system is chosen in this work, i.e., highly viscous xanthan and low viscous pullulan, both polysaccharides known from the food industry, which realize constant viscosity and processing, finally enabling systematic investigation of binder modifications (here pullulan) with various side groups. In fact, while the rate performance remains constant, suggesting a similar composite network with comparable electronic and ionic conductivities, the modified binders affect the NCM||graphite cycle life, where a higher substitution degree of carboxymethylated pullulan can even compete with N-methyl-2-pyrrolidone/polyvinylidene difluoride state-of-the-art system at conventional upper charge voltage (4.2 V); while at 4.5 V water-reasoned NCM damages get obvious, as seen by enhanced electrode cross-talk via transition metal deposition on anode.

Research on high-surface-area supports and synergic promoters has been made, however, there is still much room for improvement on the catalytic-particles morphology and interaction with the support. A first approach for designing nanoplate supports to improve CDM catalysts was made. Amorphous aluminosilicates nanoplates (a-AS.np) with an average particle size of 23.4 nm and an average height of 2.8 nm, and α-Ni(OH)₂ nanoplates (Ni.np) with an average particle size of 23.2 nm and an average thickness of 8.4 nm, were successfully synthesized, using a two-dimensional reactor in amphiphilic phases (TRAP). Nickel loaded in a-AS materials with different morphologies and promotion effects of lantana (La³⁺) & chromium (Cr³⁺) species were studied. La-Cr promoted a-AS support showed an average increase of 13% on H₂ yield in severe conditions due to improved crystallization of Ni particles on mesoporous support and the electron promotion of La to Ni species. Furthermore, we evaluate the Ni.np as novel morphology support for La³⁺ & copper (Cu²⁺) species in the methane decomposition reaction. La-Cu Ni.np showed outstanding performance and stability, a max H₂ yield of 15.9% (at 700 °C), and more than 400 min of H₂ generation (at 550 °C) compared to its a-AS support counterparts.

Reducing indium consumption in transparent conductive oxide (TCO) layers is crucial for mass production of silicon heterojunction (SHJ) solar cells. In this contribution, optical simulation-assisted design and optimization of SHJ solar cells featuring MoO_x hole collectors with ultra-thin TCO layers is performed. Firstly, bifacial SHJ solar cells with MoO_x as the hole transport layer (HTL) and three types of n-contact as electron transport layer (ETL) are fabricated with 50 nm thick ITO on both sides. It is found that bilayer (nc-Si:H/a-Si:H) and trilayer (nc-SiO_x:H/nc-Si:H/a-Si:H) as n-contacts performed electronically and optically better than monolayer (a-Si:H) in bifacial SHJ cells, respectively. Then, as suggested by optical simulations, the same stack of tungsten-doped indium oxide (IWO) and optimized MgF₂ layers are applied on both sides of front/back-contacted SHJ solar cells. Devices endowed with 10 nm thick IWO and bilayer n-contact exhibit a certified efficiency of 21.66% and 20.66% when measured from MoO_x and n-contact side, respectively. Specifically, when illuminating from the MoO_x side, the short-circuit current density and the fill factor remain well above 40 mA cm⁻² and 77%, respectively. Compared to standard front/rear TCO thicknesses (75 nm/150 nm) deployed in monofacial SHJ solar cells, this represents over 90% TCO reduction. As for bifacial cells featuring 50 nm thick IWO layers, a champion device with a bilayer n-contact as ETL is obtained, which exhibits certified conversion efficiency of 23.25% and 22.75% when characterized from the MoO_x side and the n-layer side, respectively, with a bifaciality factor of 0.98. In general, by utilizing a n-type bilayer stack, bifaciality factor is above 0.96 and it can be further enhanced up to 0.99 by switching to a n-type trilayer stack. Again, compared to the aforementioned standard front/rear TCO thicknesses, this translates to a TCO reduction of more than 67%.

The stability of catalyst layers and membranes in proton exchange membrane water electrolysis (PEMWE) cells represents an ongoing challenge, compounded by the dissolution of components and migration of elements within the catalyst-coated membrane (CCM). Conventional microscopy methods often struggle to efficiently evaluate large cross-sections of PEMWE membranes, which is essential for representative analysis of technical scale CCMs. Herein, synchrotron radiation-based X-Ray fluorescence microscopy is exploited to analyze the stability of CCMs with around 1 μm resolution and a field of view of ≈200 × 75 μm². Three application scenarios are investigated: 1) migration of catalyst elements, 2) dissolution of components, and 3) contaminated water supply containing $��{�\text{Fe}�}^{�2�+�}�$ ions. XRF is performed at three different X-Ray energies (11.7, 11.4, and 11.0 keV), revealing the local elemental composition, including Pt, Ir, Ti, and Fe, under different stressing conditions. Notable observations include the distribution of Ir across the membrane and in the cathode catalyst layer, localization of Pt within the membrane, accumulation of Ti in the cathode catalyst layer, and minimal presence of Fe. XRF has been demonstrated to be a powerful analytical tool for accurate and high throughput imaging of catalyst degradation in PEMWE scenarios, particularly of technical scale devices.

A metal–organic framework (MOF) quasi-solid-state Mg²⁺-ion conductor is prepared with a conductivity of 0.6 × 10⁻⁴ S cm⁻¹ already at room temperature. Mg-MOF-74 acts as host for MgX₂ (X = Cl⁻, Br⁻, BF₄⁻) dissolved in propylene carbonate, leading to dry free-flowing powders with liquid electrolyte exhibiting low activation energy of 0.2 eV with Arrhenius-type behavior (233–333 K). Different halides and pseudohalides reveal an influence of the anions on ionic conductivity, activation energy, and chemical stability. High transference numbers 0.45–0.80 for Mg²⁺ ions are recorded, being among the highest reported with small and low-cost halides. Against magnesium, an insulating solid electrolyte interface layer forms that prevents a steady-state and full-MOF decomposition, as shown by powder X-ray diffraction, FTIR, and Raman spectroscopy. Comparison with pure propylene carbonate shows that the electrolyte is enhanced by MOF addition. Computational studies using density functional theory (DFT) calculations of complexes in solution indicate correlations between the activation energy for Mg²⁺ migration through the MOF and the Gibbs energy needed to form charged Mg compounds in solution. Furthermore, DFT calculations of complexes within the MOF pore reveal variations in binding energy and charge transfer correlating with experimental transference numbers. Altogether, the high potential of MOFs for quasi-solid-state electrolytes with multivalent cations stability issues are illuminated.

Understanding the recombination lifetime of charge carriers ($��{\tau }_c�$) is essential for the diverse applications of photovoltaic materials, such as perovskites. The study on the inorganic perovskite, CsPbBr₃, reveals recombination dynamics exceeding 1 ms below 200 K and $��{\tau }_c�$ approaching 100 μs at room temperature. Utilizing time-resolved microwave-detected photoconductivity decay in conjunction with injection dependence, it is found that $��{\tau }_c�$ is dominated by impurity charge trapping. The observed injection dependence is well corroborated by modeling of the trap mechanism. The ultralong decay time is also consistent with photoconductivity measurements with a continuous-wave excitation at powers corresponding to around 1 Sun irradiation. While charge-carrier trapping may, in theory, impose limitations on the photovoltaic efficiency of single-cell devices, it can also contribute to increased efficiency in tandem cells and find applications in photodetection, photocatalysis, and quantum information storage.

The effect of the preparation method of the mixture catalyst/polymer on the linear low-density polyethylene (LLDPE) pyrolysis is studied by comparing the results obtained when the polymer and the catalyst (Hβ or HZSM-5) are extruded or simply mixed in powder form. By improving the polymer/catalyst contact through extrusion, the polymer degradation took place at lower temperature. The effect of extrusion is more pronounced with Hβ compared to HZSM-5 owing to the highest external surface of Hβ. While the yields of gas/liquid/coke do not differ with the preparation method when HZSM-5 is used as catalyst, more significant amount of liquid phase and high production of paraffins are observed when Hβ/LLDPE mixture is extruded, according to random scission pathway reactions. The subsequent reactions are limited by the size of the pore, which impede hydrogenation reactions, producing high molecular weight molecules. Regardless of zeolite type, the micropores of the zeolite are more affected by deactivation by coke when extrusion method is used, this effect being much more important for HZSM-5. This result is a consequence of a polymer pre-degradation during the extrusion process in which the first cracks of the polymer at low temperature and the first pore blockages can be generated.

The Haber–Bosch process is a cornerstone in the field of ammonia production and represents a decisive advance in industrial chemistry. This method, developed in the early 20th century, revolutionizes agriculture and enables the mass production of fertilizers. As the world strives for sustainable energy and environmental protection, alternative methods such as the photo/photoelectrocatalytic nitrogen reduction reaction (NRR) are gaining momentum. By using sunlight, electricity, or a combination of both, these approaches promise sustainable ammonia production with renewable energy sources and innovative materials. Researchers are trying to understand the underlying principles, mechanisms, and advances of these methods to overcome the challenges and optimize their effectiveness. This research is a step toward sustainable energy and agriculture, and offers a greener and more efficient way forward. This review looks at advances in sustainable ammonia production, particularly through photo- and photoelectrocatalytic NRRs. It examines the hurdles in implementing these methods and provides an overview of the fundamentals of nitrogen fixation and a comparison of current mechanisms. In addition, thermodynamic, theoretical, and computational studies of these processes are summarized. Various photocatalysts and photoelectrocatalysts used for ammonia production are also presented.

Electrocatalytic water splitting through the electrolyzer is the most promising strategy for hydrogen production. Recently, water electrolysis is mainly based on high-purity freshwater, which not only consumes a large number of freshwater resources but also improves the overall cost due to the extra water purification system. Hence, direct electrolysis of seawater is more desirable for large-scale hydrogen generation. As is known, the dominant rate-determining step of overall water splitting is the anodic oxygen evolution reaction (OER), which involves four-electron transfer and owns a much larger overpotential than cathodic hydrogen evolution reaction. The large challenge for the design of OER catalysts in the seawater media is the competition reaction between OER and chloride oxidation reaction, which greatly influences energy efficiency. Hence, except for the activity and stability, selectivity is another key point for seawater splitting. Herein, after a brief introduction of two half reactions for water splitting, the latest metal hydr(oxide) electrocatalysts with different crystalline structures are summarized according to the previous reports. Moreover, the advantages and disadvantages of three common water electrolyzers are compared. Finally, the perspectives of seawater electrolysis for hydrogen production are outlined for practical applications.