Oxygen‐modulated metal nitride clusters with moderate binding ability to insoluble Li₂S_x for reversible polysulfide electrocatalysis

Abstract

Multiphase sulfur redox reactions with advanced homogeneous and heterogeneous electrochemical processes in lithium–sulfur (Li–S) batteries possess sluggish kinetics. The slow kinetics leads to significant capacity decay during charge/discharge processes. Therefore, electrocatalysts with adequate sulfur‐redox properties are required to accelerate reversible polysulfide conversion in cathodes. In this study, we have fabricated an oxygen‐modulated metal nitride cluster (C‐MoNx‐O) that has a moderate binding ability to the insoluble Li2Sx for reversible polysulfide electrocatalysis. A Li–S battery equipped with C‐MoNx‐O electrocatalyst displayed a high discharge capacity of 875 mAh g−1 at 0.5 C. The capacity decay rate of each cycle was only 0.10% after 280 cycles, which is much lower than the control groups (C‐MoOx: 0.16%; C‐MoNx: 0.21%). Kinetic studies and theoretical calculations suggest that C‐MoNx‐O electrocatalyst presents a moderate binding ability to the insoluble Li2S2 and Li2S when compared to the C‐MoOx and C‐MoNx surfaces. Thus, the C‐MoNx‐O can effectively immobilize and reversibly catalyze the solid–solid conversion of Li2S2–Li2S during charge–discharge cycling, thus promoting reaction kinetics and eliminating the shuttle effect. This study to design oxygen‐doped metal nitrides provides innovative structures and reversible solid–solid conversions to overcome the sluggish redox chemistry of polysulfides.

Designing bifunctional catalysts for urea electrolysis: progress and perspectives

“…For real applications, the stability of catalysts plays a critical role. 213 In real wastewater, there will be diverse inorganic and organic pollutants that may influence the urea electrolysis efficiency by impairing the stability of catalysts. [214][215][216] Several studies have conducted real urine electrolysis, and the experimental results suggest that catalysts work worse in alkalized urine solution than in pure alkalized urea solution, 66,[217][218][219] though the reason remains unclear.…”

Tungsten Carbide‐Based Materials for Electrocatalytic Water Splitting: A Review

“…Finally, benefiting from the abundant mesopores and nanosized Mo 2 C/Mo 2 N heterojunctions, the Mobased mesoporous electrocatalyst showed superior hydrogen evolution activity and stability to Pt/C in alkaline condition. [188] Cheng et al [189] [190] described a new type of 2D nano-channeled molybdenum compounds (2D-MoN x ) via the 2D organic-polyoxometalate superstructure for accelerating interfacial polysulfide catalysis toward high-performance lithium-sulfur batteries was reported. The 2D-MoN x shows well-interlinked nano-channels, which increase the reactive interface and contact surface with polysulfides.…”

“…Finally, benefiting from the abundant mesopores and nanosized Mo 2 C/Mo 2 N heterojunctions, the Mo‐based mesoporous electrocatalyst showed superior hydrogen evolution activity and stability to Pt/C in alkaline condition [188] . Cheng et al [189] fabricated an oxygen‐modulated metal nitride cluster (C−MoN x ‐O) that has a moderate binding ability to the insoluble Li 2 S x for reversible polysulfide electrocatalysis. A Li−S battery equipped with C−MoN x ‐O electrocatalyst displayed a high discharge capacity of 875 mAh g −1 .…”

Tunable Structured Metal Oxides for Biocatalytic Therapeutics

“…Compared with carbon‐based materials or polymeric materials, metal oxides exhibit more tunable physicochemical performances, like adjustable surface energy and optical properties, which could further facilitate the regulation of catalytic activities in different practical applications. [ 3,262,263 ] Although research on metal oxide‐based biocatalysts has developed rapidly, latent challenges and serious technological problems still need to be solved, considering further exploration of metal oxide‐based biocatalysts for ROS regulation. It is believed that the following challenges and future perspectives should be considered to offer cutting‐edge and multidisciplinary instruction for the future design of ROS‐catalytic metal oxides, thus stimulating their widespread utilization in broad therapeutic applications ( Figure ).…”