Silicon (Si), due to its high theoretical capacity and abundant resources, has emerged as a potential anode material for lithium-ion batteries(LIBs). However, it suffers from intrinsic capacity decay and rapid degradation, coupled with huge volume expansion that leads to unstable growth of solid electrolyte interface (SEI). Here, we present a straightforward method to construct YS-Si/SiO2-Ti@C materials with yolk-shell (YS) structure by reducing titanium silicalite-1 (TS-1) with magnesium and altering depositing carbon sequence. Besides, the intermediate space which can effectively accommodate the expansion of internal silicon nanoparticles. TiO2 structural units anchored in the silica alleviate stress-strain in the Si nanoparticles to enhance the cycling stability. The obtained YS-Si/SiO2-Ti@C composites anode exhibits exceptional reversible capacity and cycling stability compared to YS-Si/SiO2@C (without TiO2) and commercial Si electrodes. Notably, the YS-Si/SiO2-Ti@C composite anode achieves a high specific capacity (1290 mAh g-1 after 200 cycles at 0.8 A g-1) and a stable SEI film. Specially, the YS-Si/SiO2-Ti@C electrode delivers impressive capacity of 1590, 1521, 1222, 646 mAh g−1 at 0.8, 2, 4, and 8 A g-1, respectively. This study paves an avenue for addressing challenge of drastic volume change in silicon during lithiation/delithiation process to improve cycling stability of LIBs.

Electrocatalytic CO2 reduction reaction (CO2RR) in acidic media is a promising approach to overcome the unavoidable formation of carbonates in alkaline or neutral electrolytes. However, the proton-rich environment near the catalyst surface favors hydrogen evolution reactions (HER), leading to lower energy efficiency of the desired products, especially in industrial-level current densities. Here, quaternary ammonium cationic surfactant (cetyltrimethylammonium bromide (CTAB)) was introduced into acidic electrolyte to modulate the interfacial microenvironment, which greatly enhanced CO2 electroreduction to formic acid (HCOOH) at the Bi/C nanoparticles electrode. Using a Bi/C nanoparticles electrode with CTAB added, constant production of formic acid was enabled with a cathodic energy efficiency of > 40% and maximum FEHCOOH (FE = Faradaic efficiency) of 86.2% at −400 mA·cm−2 over 24 h. Combined with in-situ attenuated total reflection Fourier transform infrared spectroscopy, the concentration of *OCHO intermediates significantly increased after CTAB modification, confirming that the hydrophobic interface microenvironment formed by dynamic adsorption of positively charged long alkyl chains on Bi/C nanoparticle electrodes inhibited HER and improved the selectivity of CO2RR to HCOOH.
The chlorine evolution reaction (CER) is a crucial step in the production of chlorine gas and active chlorine by chlor-alkali electrolysis. Currently, the endeavor to fabricate electrodes capable of yielding high current density at minimal overpotential remains a central challenge in advancing the realm of chlorine evolution reactions. Here, we grow TiO2 and RuO2 on MXene@carbon cloth (CC) through the favorable affinity and induced deposition effect between the surface functional groups of MXene and the metal. A self-supported electrode (RuTiO2/MXene@CC) with strong binding at the electrocatalyst–support interface and weak adhesion at electrocatalyst–bubble interface is constructed. The RuTiO2/MXene@CC can reduce the electron density of RuO2 by regulating the electron redistribution at the heterogeneous interface, thus enhancing the adsorption of Cl−. RuTiO2/MXene@CC could achieve a high current density of 1000 mA·cm−2 at a small overpotential of 220 mV, superior to commercial dimensionally stable anodes (DSA). This study provides a new strategy for constructing efficient CER catalysts at high current density.
For the pursuit of high energy supercapacitors, the development of high performance pseudocapacitance or battery-type negative electrode material is urgently needed to make up for the capacity shortage of commercial electric double layer capacitor (EDLC) type materials. Herein, a porous and defect-rich FexBi2−xS3 solid solution structure is firstly constructed by employing Fe-doped Bi2O2CO3 porous nanosheets as a precursor, which presents dramatically increased energy storage performance than Bi2S3 and FeS2 phase. For the optimized FexBi2−xS3 solid solution (FeBiS-60%), the Fe solute is free and random dispersed in Bi2S3 framework, which can effectively modulate the electronic structure of Bi element and introduce rich-defect due to the existence of Fe(II). Meanwhile, the FeBiS-60%, constructed by pore nanosheets that are assembled by self-supported basic nanorod units, presents rich mesoporous channels for fast mass transfer and abundant active sites for promoting capacity performance. Therefore, a high capacitance of 832.8 F·g−1 at a current density of 1 A·g−1 is achieved by the FeBiS-60% electrode. Furthermore, a fabricated Ni3S2@Co3S4 (NCS)//FeBiS-60% hybrid supercapacitor device delivers an outstanding energy density of 85.33 Wh·kg−1 at the power density of 0.799 kW·kg−1, and ultra-long lifespan of remaining 86.7% initial capacitance after 8700 cycles.
Solar-light-driven CO2 reduction CO to CH4 and C2H6 is a complex process involving multiple elementary reactions and energy barriers. Therefore, achieving high CH4 activity and selectivity remains a significant challenge. Here, we integrate bifunctional Cu2O and Cu-MOF (MOF = metal-organic framework) core–shell co-catalysts (Cu2O@Cu-MOF) with semiconductor TiO2. Experiments and theoretical calculations demonstrate that Cu2O (Cu+ facilitates charge separation) and Cu-MOF (Cu2+ improves the CO2 adsorption and activation) in the core–shell structure have a synergistic effect on photocatalytic CO2 reduction, reducing the formation barrier of the key intermediate *COOH and *CHO. The photocatalyst exhibits high CH4 yield (366.0 μmol·g−1·h−1), efficient electron transfer (3283 μmol·g−1·h−1) and hydrocarbon selectivity (95.5%), which represents the highest activity of Cu-MOF-based catalysts in photocatalytic CO2 reduction reaction. This work provides a strategy for designing efficient photocatalysts from the perspective of precise regulation of components.
The main problem faced by ethanol oxidation reaction (EOR) includes low activity, poor selectivity, and durability. In the study, we found that polysulfide modified on the surface of PtCu intermetallic (IM)/C can simultaneously enrich hydroxyl and ethanol, which could effectively improve the catalytic activity, CO2 selectivity, and durability of catalyst. The mass activity and the specific activity of the product in 1 M KOH electrolyte reached 17.83 A·mgPt−1 and 24.67 mA·cm−2. The CO2 selectivity of polysulfide modified product achieved 93.5%, which was 30 folds higher than Pt/C. In addition, the catalyst showed high catalytic stability. The mechanism study demonstrates that the surface modified polysulfide could significantly boost the enrichment effect of ethanol and hydroxyl species, accelerating C–C bond cleavage and CO oxidation.
Dual atom catalysts (DACs), are promising electrocatalysts for oxygen reduction reaction (ORR) on account of the potential dual-atom active sites for the optimized adsorption of catalytic intermediates and the lower reaction energy barriers. Herein, spatial confinement strategy to fabricate DACs with well-defined Fe, Co dual-atom active site is proposed by implanting zeolitic imidazolate frameworks inside the pores of highly porous carbon nanospheres (Fe/Co-SAs-Nx-PCNSs). The atomically dispersed dual-atom active sites facilitate the adsorption/desorption of intermediates. Furthermore, the spatial confinement effect protects metal atoms aggregating. Benefiting from the rich accessible dual-atom active sites and boosted mass transport, we achieve remarkable ORR performance with half-wave potential up to 0.91 and 0.8 V (vs. reversible hydrogen electrode (RHE)), and long-term stability up to 10 h in both alkaline and acidic electrolytes. The remarkably enhanced ORR catalytic property of our as-developed DACs is in the rank of excellence for 1%. The as-developed rechargeable Zn-air battery (ZAB) with Fe/Co-SAs-Nx-PCNSs air cathode delivers ultrahigh power density of 216 mW·cm−2, outstanding specific capacity of 813 mAh·g−1, and promising cycling operation durability over 160 h. The flexible Zn-air battery also exhibits excellent specific capacity, cycling stability, and flexibility performance. This work opens up a new pathway for the multiscale design of efficient electrocatalysts with atomically dispersed multiple active sites.
At present, Ru dopants mainly enhance electrocatalytic performance by inducing strain, vacancy, local electron difference, and synergy. Surprisingly, this work innovatively proposes that trace Ru atoms induce dual-reconstruction of phosphide by regulating the electronic configuration and proportion of Co–P/Co–O species, and ultimately activate superb electrocatalytic performance. Specifically, Ru-CoFeP@C/nickel foam (NF) is reconstructed to generate hydrophilic Co(OH)2 nanosheets during the hydrogen evolution reaction (HER) process, further accelerating the alkaline HER kinetics of phosphide. And the as-formed CoOOH during the oxygen evolution reaction (OER) process directly accelerates the oxygen overflow efficiency. As expected, the overpotential at 100 mA·cm−2 (η100) values of the reconstructed Ru-CoFeP@C/NF are 0.104 and 0.257 V for HER and OER, which are greatly lower than that of Pt/C-NF and RuO2-NF benchmarks, respectively. This work provides guidance for the construction of high-performance catalysts for HER and OER dual reconstruction. This work provides a new idea for the optimization of catalyst structure and electrocatalytic performance.
Constructing 2D/2D face-to-face heterojunctions is believed to be an effective strategy to enhance photocatalytic performance due to the enlarged contact interface and increased surface active sites. Herein, 2D porous NiCo oxyphosphide (NiCoOP) was synthesized for the first time and coupled with graphitic carbon nitride (g-C3N4) nanosheets to form 2D/2D heterojunctions via an in-situ phosphating method. The optimal 4 wt.% 2D/2D NiCoOP/g-C3N4 (OPCN) photocatalyst achieves a hydrogen evolution rate of 1.4 mmol·h−1·g−1, which is 33 times higher than that of pure g-C3N4. The greatly improved photocatalytic performance of the composite photocatalysts could be attributed to the formation of interfacial surface bonding states and sufficient charge transfer channels for accelerating carrier separation and transfer and the porous structure of NiCoOP nanosheets with abundant surface active sites for promoting surface reactions. Amazingly, the 2D/2D OPCN composite photocatalysts also exhibit superior stability during photocatalytic reactions. This study not only designs new noble-metal-free NiCoOP/g-C3N4 composite photocatalysts but also provides a new sight in fabricating face-to-face 2D/2D heterojunctions for their application in energy conversion areas.
Zinc ion hybrid supercapacitors (ZHS) have received much attention due to the enhanced potential window range and high specific capacity. However, the appropriate positive materials with high electrochemical performance are still a challenge. Herein, NH4+ and glycerate anions pre-inserted Mo glycerate (N-MoG) spheres are synthesized and serve as the template to form NH4+ intercalated Ni3S2/Ni3O2(OH)4@MoS2 core–shell nanoflower (N-NiMo-OS) in-situ grown on nickel foam (NF) (N-NiMo-OS/NF) by sulfurization treatment. Compared with the product using traditional MoG as a template, N-NiMo-OS/NF inheriting a larger core structure from N-MoG delivers enhanced space for ions transport and volume expansion during the energy storage process, together with the synergistic effects of multi-components and the heterostructure, the as-prepared N-NiMo-OS/NF nanoflower exhibits excellent performance for the battery-type hybrid supercapacitors (BHS) and ZHS devices. Notably, the ZHS device delivers superior electrochemical performance to the BHS device, such as a higher specific capacity of 327.5 mAh·g−1 at 1 A·g−1, a preeminent energy density of 610.6 Wh·kg−1 at 1710 W·kg−1, and long cycle life. The in-situ Raman, ex-situ X-ray photoelectron spectroscopy (XPS), and theoretical calculation demonstrate the extra Zn2+ insertion/extraction storage mechanism provides enhanced electrochemical performance for ZHS device. Therefore, the dual-ion pre-inserted strategy can be extended for other advanced electrode materials in energy storage fields.