Recent Advances in the Comprehension and Regulation of Lattice Oxygen Oxidation Mechanism in Oxygen Evolution Reaction

Water electrolysis,a process for producing green hydrogen from renewable energy,plays a crucial role in the transition toward a sustainable energy landscape and the realization of the hydrogen economy.Oxygen evolution reaction(OER)is a critical step in water electrolysis and is often limited by its slow kinetics.Two main mechanisms,namely the adsorbate evolution mechanism(AEM)and lattice oxygen oxidation mechanism(LOM),are commonly considered in the context of OER.However,designing efficient catalysts based on either the AEM or the LOM remains a topic of debate,and there is no consensus on whether activity and stability are directly related to a certain mechanism.Considering the above,we discuss the characteristics,advantages,and disadvantages of AEM and LOM.Additionally,we provide insights on leveraging the LOM to develop highly active and stable OER catalysts in future.For instance,it is essential to accurately differentiate between reversible and irreversible lattice oxygen redox reactions to elucidate the LOM.Furthermore,we discuss strategies for effectively activating lattice oxygen to achieve controllable steady-state exchange between lattice oxygen and an electrolyte(OH^(-)or H_(2)O).Additionally,we discuss the use of in situ characterization techniques and theoretical calculations as promising avenues for further elucidating the LOM.

Cobalt nanoparticles encapsulated in nitrogen-doped carbon for room-temperature selective hydrogenation of nitroarenes

Here,we report cobalt nanoparticles encapsulated in nitrogen‐doped carbon(Co@NC)that exhibit excellent catalytic activity and chemoselectivity for room‐temperature hydrogenation of nitroarenes.Co@NC was synthesized by pyrolyzing a mixture of a cobalt salt,an inexpensive organic molecule,and carbon nitride.Using the Co@NC catalyst,a turnover frequency of^12.3 h?1 and selectivity for 4‐aminophenol of>99.9%were achieved for hydrogenation of 4‐nitrophenol at room temperature and 10 bar H2 pressure.The excellent catalytic performance can be attributed to the cooperative effect of hydrogen activation by electron‐deficient Co nanoparticles and energetically preferred adsorption of the nitro group of nitroarenes to electron‐rich N‐doped carbon.In addition,there is electron transfer from the Co nanoparticles to N‐doped carbon,which further enhances the functionality of the metal center and carbon support.The catalyst also exhibits stable recycling performance and high activity for nitroaromatics with various substituents.

Tandem Co–O dual sites on halloysite with promoted reaction kinetics for sulfur reduction

Facilitating sulfur reduction reaction(SRR)is a promising pathway to tackle the polysulfide shuttle effect and enhance the electrochemical performance of lithium-sulfur(Li-S)batteries.Catalysts with a solo active site can reduce a reaction barrier of a certain transition-intermediate,but the linear scaling relationship between multi-intermediates still obstructs overall SRR.Herein,we construct tandem Co–O dual sites with accelerating SRR kinetics by loading highly dispersed cobalt sulfide clusters on halloysite.This catalyst features Co with upshifted d-orbital and O with downshifted p-orbital,which cooperatively adsorb long-chain polysulfide and dissociate an S–S bond,thus achieving both optimal adsorption–desorption strength and reduced conversion energy barrier of multi-intermediates in SRR.The Li-S coin batteries using the electrocatalyst endows a high specific capacity of 1224.3 m Ah g^(-1)at 0.2 C after 200cycles,and enhances cycling stability with a low-capacity decay rate of 0.03%per cycle at 1 C after1000 cycles.Moreover,the strategy of the tandem Co–O dual sites is further verified in a practical Li-S pouch battery that realizes 1014.1 m Ah g^(-1)for 100 cycles,which opens up a novel avenue for designing electrocatalysts to accelerate multi-step reactions.

Liquid-FEP-based U-tube triboelectric nanogenerator for harvesting water-wave energy

Harvesting ambient mechanical energy is a key technology for realizing self-powered electronics. With advantages of stability and durabilid, a liquid-solid-based triboelectric nanogenerator （TENG） has recently drawn much attention. However, the impacts of liquid properties on the TENG performance and the related working principle are still unclear. We assembled herein a U-tube TENG based on the liquid-solid mode and applied 11 liquids to study the effects of liquid properties on the TENG output performance. The results confirmed that the key factors influencing the output are polarity, dielectric constant, and affinity to fluorinated ethylene propylene （FEP）. Among the 11 liquids, the pure water-based U-tube TENG exhibited the best output with an open-circuit voltage （Voc） of 81.7 V and a short-circuit current （Isc） of 0.26 μA for the shaking mode （0.5 Hz）, which can further increase to 93.0 V and 0.48 μA, respectively, for the horizontal shifting mode （1.25 Hz）. The U-tube TENG can be utilized as a self-powered concentration sensor （component concentration or metal ion concentration） for an aqueous solution with an accuracy higher than 92%. Finally, an upgraded sandwich-like water-FEP U-tube TENG was applied to harvest water-wave energy, showing a high output with Voc of 350 V, Isc of 1.75 μA, and power density of 2.04 W/m3. We successfully lighted up 60 LEDs and powered a temperature-humidity meter. Given its high output performance, the water-FEP U-tube TENG is a very promising approach for harvesting water-wave energy for self-powered electronics.

Engineering interfacial band bending over bismuth vanadate/carbon nitride by work function regulation for efficient solar-driven water splitting

Nature-inspired artificial Z-scheme photocatalyst offers great promise in solar overall water splitting,but its rational design,construction and interfacial charge transfer mechanism remain ambiguous.Here,we design an approach of engineering interfacial band bending via work function regulation,which realizes directional charge transfer at interface and affords direct Z-scheme pathway.Taking BiVO_(4)as prototype,its oxygen vacancy concentration is reduced by slowing down the crystallization rate,thereby changing the work function from smaller to larger than that of polymeric carbon nitride(PCN).Consequently,the photoinduced charge transfer pathway of BiVO_(4)/PCN is switched from type-Ⅱto Z-scheme as evidenced by synchronous illuminated X-ray photoelectron spectroscopy(XPS)and femtosecond transient absorption spectroscopy.Specifically,the direct Z-scheme BiVO_(4)/PCN shows superior photocatalytic performance in water splitting.This work provides deep insights and guidelines to constructing heterojunction photocatalysts for solar utilization.

论世卿礼议之争端——以何休、郑玄与《五经异义》为中心

针对“世卿”礼议之争,公羊家主张“讥世卿”,认为卿大夫任重,当选贤任重,爵位不得继承,不过面对东周以降世卿之现实情况,何休又将选贤与世位结合起来,使“世位”亦浸渍尊贤色彩;《左氏》说、许慎等亦认可“讥世卿”之说,并进一步细化为“世禄不世位”,即卿大夫子孙仅可袭其禄采,不可袭其爵位,郑玄亦同其说,不过又强调有变例,即若有大功德,亦得世卿,以体现尊贤之意。相较而言,许慎、郑玄诸儒当认为周礼本为世禄制,而以世卿为变例;而何休则以“世卿”为周制,“世禄”当为孔子新制,且又变“世位”为“附庸”,如此尊尊与贤贤并重,亦体现孔子改制之义。由此亦体现出东汉时今古文经学之争背后蕴含着对于治统赓续的深刻理解。