Enhanced interfacial compatibility of FeS@N,S-C anode with ester-based electrolyte enables stable sodium-ion full cells

The development of sodium-ion full cells is seriously suppressed by the incompatibility between electrodes and electrolytes. Most representatively, high-voltage ester-based electrolytes required by the cathodes present poor interfacial compatibility with the anodes due to unstable solid electrode interphase(SEI). Herein, Fe S@N,S-C(spindle-like Fe S nanoparticles individually encapsulated in N,S-doped carbon) with excellent structural stability is synthesized as a potential sodium anode material. It exhibits exceptional interfacial stability in ester-based electrolyte(1 M NaClO_(4) in ethylene carbonate/propylene carbonate with 5% fluoroethylene carbonate) with long-cycling lifespan(294 days) in Na|Fe S@N,S-C coin cell and remarkable cyclability in pouch cell(capacity retention of 82.2% after 170 cycles at 0.2 A g^(-1)).DFT calculation reveals that N,S-doping on electrode surface could drive strong repulsion to solvated Na_(2) and preferential adsorption to ClO_(4)^(-) anion, guiding the anion-rich inner Helmholtz plane.Consequently, a robust SEI with rich inorganic species(NaCl and Na_(2)O) through the whole depth stabilizes the electrode–electrolyte interface and protects its integrity. This work brings new insight into the role of electrode’s surface properties in interfacial compatibility that can guide the design of more versatile electrodes for advanced rechargeable metal-ion batteries.

Pd/N-doped carbon dots@dendritic mesoporous silica nanospheres:A highly efficient catalyst for the hydrogenation of 4-nitrophenol

Highly dispersed Pd/N-doped carbon dots(Pd/NCDs)were successfully immobilized in the mesoporous channels of amino-functionalized dendritic mesoporous silica nanospheres(NMS).The synthesized Pd/NCDs@NMS catalyst exhibits outstanding performance in the catalytic reduction of 4-nitrophenol(4-NP),achieving a turnover frequency of 1461.8 mol·molPd^(-1)·h^(-1),with the conversion rate remaining above 80%after 11 cycles.Experiments and density functional theory calculations reveal that the NCDs significantly affect the electronic structure of Pd nanoparticles,leading to changes in the energy barriers for the adsorption of 4-NP at the Pd sites and the conversion of 4-NP reaction intermediates,which is a key factor contributing to the catalytic performance.This study offers a new strategy for synthesizing carbon-dot-modified metal-based catalysts.

A novel P-doped and NCDs loaded g-C_(3)N_(4) with enhanced charges separation for photocatalytic hydrogen evolution

Graphite carbon nitride(g-C_(3)N_(4)) is a promising non-metal photocatalyst for photocatalytic hydrogen production, but its performance is still limited due to sluggish charges separation and low utilization of light.In this work, P-doped and N-doped carbon dots(NCDs) supported g-C_(3)N_(4)were successfully prepared via hydrothermal and polymerization reactions. The sub-bandgap formed by P-doping enhances the utilization of visible light, and the high electron density of P sites is conducive to the trapping of holes. NCDs also improve light utilization and, more importantly, act as electron acceptors and transporters to promote electron transport. The built-in electric field formed by the synergy of P-doping and NCDs-loading greatly promotes the separation of charges. The PCN/NCDs showed a significantly improved hydrogen evolution activity of 3731 μmol h^(-1)g^(-1), which was 6.7 times that of pure carbon nitride(560 μmol h^(-1)g^(-1)). This strategy may be generalized to the design of g-C_(3)N_(4)-based photocatalysts, facilitating the separation of charges for enhanced catalytic activity.