It is significant to develop highly efficient electrocatalysts for energy conversion systems. Interface engineering is one of the most feasible approaches to effectively enhance the electrocatalytic activity. Herein, the density functional theory (DFT) calculations predict that the potential barriers of Fe sites at the interface of FeP–CoP heterostructures are lower than that of Fe sites in FeP nanoparticles (NPs), Co sites in CoP NPs, or Co sites in heterostructures. Motivated by the DFT calculation results, FeP–CoP heterostructures have been designed and synthesized by a metal–organic frameworks (MOFs) confined-phosphorization method. The FeP–CoP exhibits the lowest overpotential of 230 mV at the current density of 10 mA·cm⁻² for oxygen evolution reaction (OER), compared with FeP (470 mV) and CoP (340 mV), which outperforms most of transition metal-based catalysts. The Tafel analysis of FeP–CoP heterostructures shows an improved reaction kinetic pathway with the smallest slope of 90.3 mV·dec⁻¹, as compared to the Tafel slopes of FeP NPs (137 mV·dec⁻¹) and CoP NPs (114 mV·dec⁻¹). And the FeP–CoP shows extraordinary long-term stability over 24 h. The excellent activity and long-term stability of FeP–CoP derive from the synergistic effect between FeP and CoP.

The shuttle effect of lithium polysulfides (LiPSs) in lithium-sulfur batteries (LSBs) has been hampered their commercialization. Metal oxides as separator modifications can suppress the shuttle effect. Since there is no direct electron transport between metal oxides and LiPSs, absorbed LiPSs should be diffused from the surface of metal oxides to the carbon matrix to go through redox reactions. If diffusivity of LiPSs from metal oxides surface to carbon substrate is poor, it would hinder the redox reactions of LiPSs. Nevertheless, researchers tend to focus on the adsorption and overlook the diffusion of LiPSs. Herein, same morphology and different crystal phase of TiO₂ nanosheets grown on carbon nanotubes (CNTs@TiO₂-bronze and CNTs@TiO₂-anatase) have been designed via a simple approach. Compared with CNTs and CNTs@TiO₂-anatase composites, the battery with CNTs@TiO₂-bronze modified separator delivers higher specific capacities and stronger cycling stability, especially at high current rates (~ 472 mAh·g^-1 at 2.0 C after 1, 000 cycles). Adsorption tests, density functional theory calculations and electrochemical performance evaluations indicate that suitable diffusion and adsorption for LiPSs on the CNTs@TiO₂-B surface can effectively capture LiPSs and promote the redox reaction, leading to the superior cycling performances.

Alkali-water electrolyzers and hydroxide exchange membrane fuel cells are emerging as promising technologies to realize hydrogen economy. Developing cost-effective electrode materials with high activities towards corresponding hydrogen evolution (HER) and oxidation (HOR) reactions plays a crucial role in commercial hydrogen production and utilization. Herein, we fabricated a V-doped Ni₃N/Ni heterostructure (V-Ni₃N/Ni) through a controlled nitridation treatment on a V-incorporated nickel hydroxide precursor. The resultant catalyst exhibits comparable catalytic activity and durability to commercial Pt/C in terms of both HER (a low overpotential of 44 mV at the current density of 10 mA·cm^-2) and HOR (a high current density of 1.54 mA·cm^-2 at 0.1 V versus reversible hydrogen electrode) under alkaline conditions. The superior activity of V-Ni₃N/Ni grown on different substrates further implies its intrinsic performance. Density functional theory (DFT) calculations reveal that the coupled metallic Ni and doped V can promote the water adsorption, accelerate the Volmer step of alkaline HER, as well as optimize the adsorption and desorption of hydrogen intermediate (H^*) to reach a balanced ΔG_H* value.

Electrochemical CO₂ reduction reaction (CO₂RR) is an attractive pathway for closing the anthropogenic carbon cycle and storing intermittent renewable energy by converting CO₂ to valuable chemicals and fuels. The production of highly reduced carbon compounds beyond CO and formate, such as hydrocarbon and oxygenate products with higher energy density, is particularly desirable for practical applications. However, the productivity towards highly reduced chemicals is typically limited by high overpotential and poor selectivity due to the multiple electron-proton transfer steps. Tandem catalysis, which is extensively utilized by nature for producing biological macromolecules with multiple enzymes via coupled reaction steps, represents a promising strategy for enhancing the CO₂RR performance. Improving the efficiency of CO₂RR via tandem catalysis has recently emerged as an exciting research frontier and achieved significant advances. Here we describe the general principles and also considerations for designing tandem catalysis for CO₂RR. Recent advances in constructing tandem catalysts, mainly including bimetallic alloy nanostructures, bimetallic heterostructures, bimetallic core-shell nanostructures, bimetallic mixture catalysts, metal-metal organic framework (MOF) and metal-metallic complexes, metal-nonmetal hybrid nanomaterials and copper-free hybrid nanomaterials for boosting the CO₂RR performance are systematically summarized. The study of tandem catalysis for CO₂RR is still at the early stage, and future research challenges and opportunities are also discussed.