Jianqiu Deng

Strategic modulation of the electronic structure and surface chemistry of electrocatalysts is crucial for achieving highly efficient and cost-effective bifunctional catalysts for water splitting. This study demonstrated the strategic incorporation of redox-active elements (vanadium (V) and iron (Fe)) to optimize the catalytic interface of mixed-valence cobalt-based nanowires (Co_5.47N and CoP), which enhanced their hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) catalytic activity. Experimental and theoretical analyses revealed that the dual-cation doping increased the surface area and optimized the electronic structure of the nanowires, which promoted rapid water dissociation, favoured hydrogen adsorption kinetics, and stabilized the oxygen intermediates. Consequently, the V,Fe-Co_5.47N and V,Fe-CoP nanowire electrocatalysts achieved low overpotentials of 55/251 and 63/265 mV for HER/OER at 10 mA cm⁻² in 1 M KOH electrolyte, respectively, outperforming their pristine and single-cation-doped counterparts. The alkaline overall water-splitting devices assembled based on these bifunctional catalysts required an overall voltage of only 1.64 V and 1.66 V at 100 mA cm⁻² and also demonstrated excellent durability. This work provides valuable insights into enhancing transition metal-based catalysts through the incorporation of redox-active elements for efficient water splitting.

One pot annealing is employed to synthesize N-doped trimetallic selenides. The trisellenide that consist of Ni ₃ Se ₂ , Co _0.85 Se, and MoSe ₂ is used as higher performance trifunctional electrode material for supercapacitor, hydrogen and oxygen evolution reactions.

Antimony-based materials possess high theoretical capacities and suitable potential, which could be promising anode materials for sodium-ion batteries (SIB). However, poor stabilities and sluggish kinetics are drawbacks. Building heterojunction is an ideal method to solve these issues. Its unique structure develops internal electric fields spontaneously to boost the charge transport and relieve stress. Nevertheless, the controllable preparation of face-to-face (2D) heterojunctions is still hard-pressed. Herein, [ ]–[ ] nanoheterojunctions, which consist of two-dimensional [ ]–[ ] nanoblades attached to a one-dimensional Te nanorod, are fabricated through a two-step solvothermal method. Among that, the density of nanoblades is adjustable through the engineering feed ratio. When employed as anodes for SIBs, [ ]–[ ] nanoheterojunctions display a reversible capacity of 463.2[ ]mAh[ ]g[ ] at 100[ ]mA[ ]g[ ]. Even a capacity of 305.5[ ]mAh[ ]g[ ] remains after 1000 cycles under a high current of 1.5[ ]A[ ]g[ ]. Moreover, the density functional theory (DFT) calculations also identify the high conductivity of heterojunction. This work offers an effective way to design the structures and properties of heterojunctions, further expanding their application range.

In recent years, the remarkable energy density of high-nickel ternary materials has captured considerable attention. Nevertheless, the high-nickel ternary cathode material encounters several challenges, including cationic mixing, microcrack formation, poor cycling capability, and limited thermal stability. Coating, as a viable approach, proves to be effective in enhancing the material properties. In this study, the LiNi_0.8Co_0.1Mn_0.1O₂ (NCM811) sample underwent a dry grinding process, followed by Y₂O₃ coating and subsequent sintering at varying temperatures. The microstructure, morphology, and electrochemical properties of the materials were meticulously examined, and the underlying mechanism of coating modification was meticulously explored. The outcomes demonstrate the attainment of dual coating and doping effects through Y₂O₃ modification. Y₂O₃ coating mitigates the direct interaction between the NCM811 surface and the electrolyte, thereby inhibiting undesired side reactions at the interface. Moreover, the Y element infiltrates the crystal structure, imparting stability at elevated sintering temperatures. Remarkably, the Y₂O₃-coated cathode materials exhibit significantly enhanced cycling stability, discharge capacity, and rate performance. These findings can provide novel insights that can be harnessed to improve the energy density cathode material of NCM811.