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 FE_HCOOH (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 Fe_xBi_2−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 Fe_xBi_2−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·mg_Pt⁻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-N_x-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-N_x-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.

Developing corrosion resistance bifunctional electrocatalysts with high activity and stability toward both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), especially electrolysis in seawater, is of prime significance but still pressingly challenging. Herein, in-situ introduced PtO_x on the derivative amorphous NiO_n is prepared via heat treatment of Ni ZIF-L nanosheets on nickel foam under low temperature (PtO_x-NiO_n/NF). The synthesized PtO_x-NiO_n/NF possesses suprahydrophilic and aerophilic surface, and then in favor of intimate contact between the electrode and electrolyte and release of the generated gas bubbles during the electrocatalysis. As a result, the in-situ PtO_x-NiO_n/NF electrode presents outstanding bifunctional activity, which only requires extremely low overpotentials of 32 and 240 mV to reach a current density of 10 mA·cm^–2 for HER and OER, respectively, which exceeds most of the electrocatalysts previously developed and even suppresses commercial Pt/C and RuO₂ electrodes. As for two-electrode cell organized by PtO_x-NiO_n/NF, the voltages down to 1.57 and 1.58 V are necessary to drive 10 mA·cm^–2 with remarkable durability in 1 M KOH and alkaline seawater, respectively, along with remarkable stability. Moreover, a low cell voltage of 1.88 V is needed to achieve 1,000 mA·cm^–2 toward water-splitting under industrial conditions. This study provides a new idea for designing in-situ amorphous metal oxide bifunctional electrocatalyst with strong Pt–support interaction for overall water splitting.