Green Energy & Environment最新文献

Implementing a new energy-saving electrochemical synthesis system with high commercial value is a strategy of the sustainable development for upgrading the bulk chemicals preparation technology in the future. Here, we report a multiple redox-mediated linear paired electrolysis system, combining the hydrogen peroxide mediated cathode process with the I₂ mediated anode process, and realize the conversion of furfural to furoic acid in both side of the divided flow cell simultaneously. By reasonably controlling the cathode potential, the undesired water splitting reaction and furfural reduction side reactions are avoided. Under the galvanostatic electrolysis, the two-mediated electrode processes have good compatibility, which reduce the energy consumption by about 22% while improving the electronic efficiency by about 125%. This system provides a green electrochemical synthesis route with commercial prospects.

Solid polymer electrolyte (SPE) shows great potential for all-solid-state batteries because of the inherent safety and flexibility; however, the unfavourable Li⁺ deposition and large thickness hamper its development and application. Herein, a laminar MXene functional layer‒thin SPE layer‒cathode integration (MXene-PEO-LFP) is designed and fabricated. The MXene functional layer formed by stacking rigid MXene nanosheets imparts higher compressive strength relative to PEO electrolyte layer. And the abundant negatively-charged groups on MXene functional layer effectively repel anions and attract cations to adjust the charge distribution behavior at electrolyte–anode interface. Furthermore, the functional layer with rich lithiophilic groups and outstanding electronic conductivity results in low Li nucleation overpotential and nucleation energy barrier. In consequence, the cell assembled with MXene-PEO-LFP, where the PEO electrolyte layer is only 12 μm, much thinner than most solid electrolytes, exhibits uniform, dendrite-free Li⁺ deposition and excellent cycling stability. High capacity (142.8 mAh g⁻¹), stable operation of 140 cycles (capacity decay per cycle, 0.065%), and low polarization potential (0.5 C) are obtained in this Li|MXene-PEO-LFP cell, which is superior to most PEO-based electrolytes under identical condition. This integrated design may provide a strategy for the large-scale application of thin polymer electrolytes in all-solid-state battery.

Improving the reversibility of anionic redox and inhibiting irreversible oxygen evolution are the main challenges in the application of high reversible capacity Li-rich Mn-based cathode materials. A facile synchronous lithiation strategy combining the advantages of yttrium doping and LiYO₂ surface coating is proposed. Yttrium doping effectively suppresses the oxygen evolution during the delithiation process by increasing the energy barrier of oxygen evolution reaction through strong Y–O bond energy. LiYO₂ nanocoating has the function of structural constraint and protection, that protecting the lattice oxygen exposed to the surface, thus avoiding irreversible oxidation. As an Li⁺ conductor, LiYO₂ nanocoating can provide a fast Li⁺ transfer channel, which enables the sample to have excellent rate performance. The synergistic effect of Y doping and nano-LiYO₂ coating integration suppresses the oxygen release from the surface, accelerates the diffusion of Li⁺ from electrolyte to electrode and decreases the interfacial side reactions, enabling the lithium ion batteries to obtain good electrochemical performance. The lithium-ion full cell employing the Y-1 sample (cathode) and commercial graphite (anode) exhibit an excellent specific energy density of 442.9 Wh kg⁻¹ at a current density of 0.1C, with very stable safety performance, which can be used in a wide temperature range (60 to −15 °C) stable operation. This result illustrates a new integration strategy for advanced cathode materials to achieve high specific energy density.

Carbon-based metal-free nanomaterials are promising alternatives to precious metals as electrocatalysts of key energy storage and conversion technologies. Of paramount significance are the establishment of design principles by understanding the catalytic mechanisms and identifying the active sites. Distinct from sp²-conjugated graphene and carbon nanotube, fullerene possesses unique characteristics that are growingly being discovered and exploited by the electrocatalysis community. For instance, the well-defined atomic and molecular structures, the good electron affinity to tune the electronic structures of other substances, the intermolecular self-assembly into superlattices, and the on-demand chemical modification have endowed fullerene with incomparable advantages as electrocatalysts that are otherwise not applicable to other carbon materials. As increasing studies are being reported on this intriguing topic, it is necessary to provide a state-of-the-art overview of the recent progress. This review takes such an initiative by summarizing the promises and challenges in the electrocatalytic applications of fullerene and its derivatives. The content is structured according to the composition and structure of fullerene, including intact fullerene (e.g., fullerene composite and superlattices) and fullerene derivatives (e.g., doped, endohedral, and disintegrated fullerene). The synthesis, characterization, catalytic mechanisms, and deficiencies of these fullerene-based materials are explicitly elaborated. We conclude it by sharing our perspectives on the key aspects that future efforts shall consider.

The exploitation of electrocatalysts with high activity and durability for HER is desirable for future energy systems, but it is still a challenge. NMPs have attracted increasing attentions, but the preparation process often needs toxic regents or dangerous reaction conditions. Herein, we develop a general green method to fabricate metal-rich NMPs anchored on NPG through pyrolyzing DNA cross-linked complexes. The obtained Ru₂P-NPG exhibits an ultrasmall overpotential of 7 mV at 10 mA cm⁻² and ultralow Tafel slope of 33 mV dec⁻¹ in 1.0 mol L⁻¹ KOH, even better than that of commercial Pt/C. In addition, Ru₂P-NPG also shows low overpotentials of 29 and 78 mV in 0.5 mol L⁻¹ H₂SO₄ and 1.0 mol L⁻¹ PBS, respectively. The superior activity can be attributed to the ultrafine dispersion of Ru₂P nanoparticles for more accessible sites, more defects formed for abundant active sites, the two-dimensional plane structure for accelerated electron transfer and mass transport, as well as the regulation of electron distribution of the catalyst. Moreover, the synthetic method can also be applied to prepare other metal-rich noble metal phosphides (Pd₃P-NPG and Rh₂P-NPG), which also exhibits high activity for HER. This work provides an effective strategy for designing NMP-based electrocatalysts.

Superwetting materials have drawn unprecedented attention in the treatment of oily wastewater due to their preferable anti-fouling property and selective oil/water separation. However, it is still a challenge to fabricate multifunctional and environmentally friendly materials, which can be stably applied to purify the actual complicated wastewater. Here, a Ag/α-Fe₂O₃ heterostructure anchored copper mesh was intentionally synthesized using a facile two-step hydrothermal method. The resultant mesh with superhydrophilicity and underwater superoleophobicity was capable of separating various oil/water mixtures with superior separation efficiency and high permeation flux driven by gravity. Benefiting from the joint effects of the smaller band gap of Ag/α-Fe₂O₃ heterojunction, inherent antibacterial capacity of α-Fe₂O₃ and Ag nanoparticles, favorable conductive substrate, as well as the hierarchical structure with superwettability, such mesh presented remarkably enhanced degradation capability toward organic dyes under visible light irradiation and antibacterial activity against both Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) compared with the pure α-Fe₂O₃ coated mesh. Impressively, the mesh exhibited bifunctional water purification performance, in which organic dyes were eliminated simultaneously from water during oil/water separation in one filtration process. More importantly, this mesh behaved exceptional chemical resistance, mechanical stability and long-term reusability. Therefore, this material with multifunctional integration may hold promising potential for steady water purification in practice.

Membrane technologies are becoming increasingly versatile and helpful today for sustainable development. Machine Learning (ML), an essential branch of artificial intelligence (AI), has substantially impacted the research and development norm of new materials for energy and environment. This review provides an overview and perspectives on ML methodologies and their applications in membrane design and discovery. A brief overview of membrane technologies is first provided with the current bottlenecks and potential solutions. Through an applications-based perspective of AI-aided membrane design and discovery, we further show how ML strategies are applied to the membrane discovery cycle (including membrane material design, membrane application, membrane process design, and knowledge extraction), in various membrane systems, ranging from gas, liquid, and fuel cell separation membranes. Furthermore, the best practices of integrating ML methods and specific application targets in membrane design and discovery are presented with an ideal paradigm proposed. The challenges to be addressed and prospects of AI applications in membrane discovery are also highlighted in the end.