Search

Developing highly efficient and durable electrocatalysts toward oxygen evolution reaction (OER) is an urgent demand to produce clean hydrogen energy. In this study, a series of medium‐entropy metal sulfides (MEMS) of (NiFeCoX)3S4 (where X = Mn, Cr, Zn) are synthesized by a facile one‐pot solvothermal strategy using molecular precursors. Benefiting from the multiple‐metal synergistic effect and the low crystallinity, these MEMS show significantly enhanced electrocatalytic OER activity compared with the binary‐metal (NiFe)3S4 and ternary‐metal (NiFeCo)3S4 counterparts. Especially, (NiFeCoMn)3S4 delivers a low overpotential of 289 mV at 10 mA cm−2, a decent Tafel slope of 75.6 mV dec−1 and robust catalytic stability in alkaline medium, outperforming the costly IrO2 benchmark electrocatalyst and the majority of the reported metal sulfide‐based electrocatalysts until now. These MEMS with facile synthesis and excellent electrocatalytic performance bring a great opportunity to design desirable electrocatalysts for practical application. [ABSTRACT FROM AUTHOR]

Finding a low-cost, efficient, and stabilized catalyst to accelerate the sluggish oxygen evolution reaction (OER) process, which hinders the production of clean hydrogen energy, is a frontier issue. Here, we synthesized a three-dimensional heterostructure NiSe2 nanoparticle @ FeSe2 microrod (FeSe2/NiSe2) electrocatalyst using a facile one-step hydrothermal method. Compared to single-phase NiSe2 and FeSe2 catalysts, this heterostructured catalyst exhibits an improved OER performance in alkaline electrolyte, that is, a low overpotential of 316 mV and a Tafel slope of 137 mV dec−1 at a current density of 20 mA cm−2 with a long-term durability. Benefitting from a large electrochemical active surface area provided by the specific heterostructure and the modulation of electronic structure at the heterointerface, the OER kinetics of the as-prepared FeSe2/NiSe2 is accelerated. This work may provide a new insight to fabricate a low-cost and efficient heterostructure electrocatalyst for oxygen evolution reaction.Graphical Abstract: Finding a low-cost, efficient, and stabilized catalyst to accelerate the sluggish oxygen evolution reaction (OER) process, which hinders the production of clean hydrogen energy, is a frontier issue. Here, we synthesized a three-dimensional heterostructure NiSe2 nanoparticle @ FeSe2 microrod (FeSe2/NiSe2) electrocatalyst using a facile one-step hydrothermal method. Compared to single-phase NiSe2 and FeSe2 catalysts, this heterostructured catalyst exhibits an improved OER performance in alkaline electrolyte, that is, a low overpotential of 316 mV and a Tafel slope of 137 mV dec−1 at a current density of 20 mA cm−2 with a long-term durability. Benefitting from a large electrochemical active surface area provided by the specific heterostructure and the modulation of electronic structure at the heterointerface, the OER kinetics of the as-prepared FeSe2/NiSe2 is accelerated. This work may provide a new insight to fabricate a low-cost and efficient heterostructure electrocatalyst for oxygen evolution reaction. [ABSTRACT FROM AUTHOR]

Zinc tungstate (ZnWO 4 ) shows great promise as an anode material for lithium-ion batteries (LIBs) owing to its reversible multi-electron redox reactions and high theoretical capacity. Nevertheless, the low conductivity and big strain during cycling can lead to the inferior electrochemical properties of the ZnWO 4 anode, hindering its practical application. Herein, we report a novel composite with ZnWO 4 /ZnO porous nanoplates in-situ constructed on reduced graphene oxide (rGO) by a metal-organic framework template strategy. The nanoplates with good porosity are composed of nanoparticles and nanorods, providing a short Li + -diffusion distance and plentiful Li + storage active sites. The introduction of rGO can accelerate charge transfer and reinforce structural stability. As a result of these advantages, the ZnWO 4 /ZnO/rGO composite as LIBs anode delivers a high reversible capacity of 811 mAh g after 100 cycles at 200 mA g -1 , excellent rate capability (437 mAh g at 5000 mA g -1 ), and good long cycling stability (485 mAh g after 500 cycles at 2000 mA g -1 ). Notably, the rate capability of the composite far precedes the previously reported ZnWO 4 -based anodes. This work provides an efficient approach for designing and fabricating advanced metal tungstate-based anodes for high-performance LIBs., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Transition-metal oxides as anodes for lithium-ion batteries (LIBs) have attracted enormous interest because of their high theoretical capacity, low cost, and high reserve abundance. Unfortunately, they commonly suffer from poor electronic and ionic conductivity and relatively large volume expansion during discharge/charge processes, thereby triggering inferior cyclic performance and rate capability. Herein, a molybdenum-zinc bimetal oxide-based composite structure (Zn 2 Mo 3 O 8 /ZnO/rGO) with rectangular Zn 2 Mo 3 O 8 /ZnO nanosheets uniformly dispersed on reduced graphene oxide (rGO) has been prepared by using a simple and controllable cyanometallic framework template method. The Zn 2 Mo 3 O 8 /ZnO rectangular nanosheets with desirable porous features are composed of nanocrystalline subunits, facilitating the exposure of abundant active sites and providing sufficient contact with the electrolyte. Benefiting from the composition and structural merits as well as the induced synergistic effects, the Zn 2 Mo 3 O 8 /ZnO/rGO composite as LIB anodes delivers superior electrochemical properties, including high reversible capacity (960 mA h g -1 after 100 cycles at 200 mA g -1 ), outstanding rate performance (417 mA h g -1 at 10,000 mA g -1 ), and admirable long-term cyclic stability (862 mA h g -1 after 400 cycles at 1000 mA g -1 ). The mechanism of lithium storage and the formation of SEI film are systematically elucidated. This work provides an effective strategy for synthesizing promising Mo-cluster compound-based anodes for high-performance LIBs.