Advanced Sensor and Energy Materials最新文献

Metal organic frameworks derived M-N-C catalysts have been discovered as promising alternatives to Pt-based catalysts in oxygen reduction reaction (ORR). However, the dominated micropores in their porous structures strongly restrain the mass transfer and lead to insufficient utilization of active sites. Here, we proposed a dual-template strategy to improve the catalytic performance of ZIF-8 derived M-N-C catalysts. Both the silica and sodium chloride templates created mesopores, which may intensified the mass transfer. Moreover, the molten sodium chloride connected the individual ZIF-8 crystals form highly graphitized carbon structure which had better stability and conductivity. The as-synthesized (FeCo)HPNC@NaCl catalyst exhibited similar ORR activity to commercial Pt/C under acidic conditions with half-wave potential of 0.808 V. The catalyst expressed high stability with 12 mV decrease of half-wave potential after 5000 cycles and 80% remained activity after 100000 s operation. Moreover, we tested the catalyst in fuel cell for practical application, achieving a high peak power density of 427 mW cm⁻².

Photo-induced selective shortening strategy was developed to synthesize Au nanorods (NRs) with different aspect ratios, and in situ observation of photo-induced shortening of single Au nanorod was realized, which is helpful for understanding the relationship between SPR decay and geometric nanostructure. The as-synthesized plasmonic Pd–Au NRs exhibit efficient formic acid dehydrogenation. Very impressively, the interfacial interaction between plasmonic bimetallic nanostructures and adsorbed molecules (HCOOH) was explored in situ at the single-particle level. Significant photoluminescence (PL) quenching of Pd–Au NRs was observed when HCOOH contacted the catalyst, confirming the charge transfer between Pd–Au NRs and HCOOH molecules. Finally, we shed light on the catalytic mechanism of plasmon-induced HCOOH dehydrogenation by coupling single-particle PL measurement with finite difference time domain (FDTD) and density functional theory (DFT) calculations.

Recently, ammonium-ion (NH₄⁺) storage is in a booming stage in aqueous energy storage systems due to its multitudinous merits. To seek suitable electrode materials with excellent NH₄⁺-storage is still in the exploratory stage and full of challenge. Herein, an inorganic-polymer hybrid, poly(3,4-ethylenedioxithiophene) (PEDOT) intercalated hydrated vanadium oxide (VOH), named as VOH/PEDOT, is developed to tune the structure of VOH for boosting NH₄⁺ storage. By the intercalation of PEDOT, the interlayer space of VOH is increased from 11.5 Å to 14.2 Å, which notably facilitates the rapid transport of electrons and charges between layers and improves the electrochemical properties for NH₄⁺ storage. The achieved performances are much better than progressive NH₄⁺ hosting materials. In addition, the concentration of polyvinyl alcohol/ammonium chloride (PVA/NH₄Cl) electrolyte exerts a great impact on the NH₄⁺ storage in VOH/PEDOT. The VOH/PEDOT electrode delivers specific capacitance of 327 F g⁻¹ in 1 M PVA/NH₄Cl electrolyte at −0.2–1 V. Furthermore, the quasi-solid-state VOH/PEDOT//active carbon hybrid supercapacitor (QSS VOH/PEDOT//AC HSC) device is assembled for NH₄⁺ storage, and it exhibits the capacitance of 328 mF cm⁻² at 1 mA cm⁻². The energy density of QSS VOH/PEDOT//AC NH₄⁺-HSC can reach 2.9 Wh m⁻² (2.6 mWh cm⁻³, 10.4 Wh kg⁻¹) at 1 W m⁻² (0.9 mWh cm⁻³, 35.7 W kg⁻¹). This work not only proves that the PEDOT intercalation can boost the NH₄⁺ storage capacity of vanadium oxides, but also provides a novel direction for the development of NH₄⁺ storage materials.

Electrochemical energy storage and conversion toward sustainable carbon neutrality cycle is of great interest in today's society. In this perspective, we highlight the interconversion between carbon dioxide and formic acid by means of electrocatalytic CO₂ reduction reaction (CO₂RR) and formic acid oxidation reaction (FAOR) as an effective way to achieve that goal. In line with the distinctive catalytic nature of Pd to reversibly drive both FAOR and CO₂RR, we first illustrate the intimate mechanistic relation between these two reversed reactions over Pd surfaces. Next, recent advances in developing Pd-based bifunctional catalysts and relevant optimization strategies are briefly summarized, including geometric structure engineering with preferential facet exposure, construction of crystallographic ordering intermetallic, electronic structure manipulation through metal or metalloid doping to fine tune the binding strength for active and poisoning intermediates. At the end, our viewpoints on the design principles at both microscopic and macroscopic scales are offered toward an efficient CO₂ and HCOOH interconversion loop.

The high energy consumption and production of undesired oxygen greatly restrict the wide adoption of water electrolysis for hydrogen production. In a paper recently published in Nature Catalysis, Wang and coworkers rationally introduce aldehydes for oxidation at anode to replace oxygen evolution reaction, which can produce hydrogen and value-added products at low potential, realizing efficient bipolar hydrogen production with high-purity. Moreover, these aldehydes are biomass-derived and contribute to sustainable hydrogen production.

Hybrid redox flow batteries (RFBs) are a special type of RFBs that involve depositing reactions on negative electrodes. The available volume in negative electrodes for cell stacks limits the totally energy-storing capability of these batteries. This paper introduces the first fully flowable Ce–metal flow battery operated with a semisolid, flowable anolyte. Using the semisolid fuel cell concept, we incorporate the sustainable and deposit-abundant features of non-Li-based batteries into the structure of RFBs to develop a fully flowable RFB system. Solid suspension electrodes of hydrophilic carbon particles deposited by earth-abundant metals with redox activity are investigated as alternatives to the redox-active molecules employed in typical RFBs to decouple the power delivery capability from the energy storage capacity in fully flowable RFBs. While being charged, earth-abundant redox-active metal (Cu, Pb or Zn) is electrodeposited on the carbon particle suspension, which is dissolved in the sequent discharging process. On the basis of the proposed contact-charge-transfer mechanism, the electrical contact to the solid suspension electrode is fed by the redox-inert hydrophobic current collector that restrains direct metal deposition on their surfaces due to the hydrophobicity.

Solid-state lithium metal batteries (LMBs) have become a potential component, as they provide a considerable safety upgrade by eliminating flammable organic solvents. Solid polymer electrolytes (SPEs) are also a promising candidate, owing to their non-toxicity, low-manufacturing cost, and comparatively soft nature that allows the development of a seamless interface with the electrodes. Polymerization-induced phase separation (PIPS) controls the connectivity of phase-separated structures and domain size, enabling the co-continuous nanostructures’ formation. Researchers of a study published in Nature envisioned that outstanding mechanical and ionic properties could be realized, provided ionic conducting materials form a 3D interconnected phase inside a mechanically strong elastomer matrix via PIPS.

Rational design of high-efficient and low-cost catalysts as alternatives to Pt-based catalysts toward the oxygen reduction reaction (ORR) is extremely desirable but challenging. In this work, Fe@NCNT is firstly synthesized via the one-pot pyrolysis method, then Fe-N_X active species are in-situ created on the prepared Fe@NCNT by a feasible “plasma inducing” strategy to synthesize the resulting catalyst (Fe@NCNT-P) for ORR. The morphology of Fe@NCNT-P is perfectly inherited by the derived carbon precursor, resulting in the core-shell structure of carbon-coated Fe and a mesoporous dominant nanostructure with a high specific surface area of 536 m² g⁻¹. The resultant Fe@NCNT-P catalyst exhibits remarkable ORR activity and durability, as well as outstanding performance in assembled zinc-air battery (ZAB) test with a peak power density of 240 mW cm⁻². This work not only reports a novel and robust ORR catalyst, but also proposes a simple and effective strategy to improve the ORR electrocatalytic performance.