Transition metal nitride/carbide (TMN/C) have been actively explored as low-cost hydrogen evolution reaction (HER) electrocatalysts owing to their Pt-like physical and chemical properties. Unfortunately, pure TMN/C suffers from strong hydrogen adsorption and lacks active centers for water dissociation. Herein, we developed a switchable WO₃-based in situ gas–solid reaction for preparing sophisticated Fe-N doped WC and Fe-C doped WN nanoarrays. Interestingly, the switch of codoping and phase can be effectively manipulated by regulating the amount of ferrocene. Resultant Fe-C-WN and Fe-N-WC exhibit robust electrocatalytic performance for HER in alkaline and acid electrolytes, respectively. The collective collaboration of morphological, phase and electronic effects are suggested to be responsible for the superior HER activity. The smallest |ΔG_H*| value of Fe-N-WC indicates preferable hydrogen-evolving kinetics on the Fe-N-WC surface for HER under acid condition, while Fe-C-WN is suggested to be beneficial to the adsorption and dissociation of H₂O for HER in alkaline electrolyte.

Electroreduction of greenhouse gas CO₂ into value-added fuels and chemicals provides a promising pathway to address the issues of energy crisis and environmental change. However, the regulations of the selectivity towards C₂ product and the competing hydrogen evolution reaction (HER) are major challenges for CO₂ reduction reaction (CO₂RR). Here, we develop an interface-enhanced strategy by depositing a thin layer of nitrogen-doped graphene (N-G) on a Cu foam surface (Cu-N-G) to selectively promote the ethanol pathway in CO₂RR. Compared to the undetectable ethanol selectivity of pure Cu and Cu@graphene (Cu-G), Cu-N-G has boosted the ethanol selectivity to 33.1% in total Faradic efficiency (FE) at −0.8 V vs. reversible hydrogen electrode (RHE). The experimental and density functional theory (DFT) results verify that the interconnected graphene coating can not only serve as the fast charge transport channel but also provide confined nanospace for mass transfer. The N doping can not only trigger the intrinsic interaction between N in N-G and CO₂ molecule for enriching the local concentration of reactants but also promote the average valence state of Cu for C–C coupling pathways. The confinement effect at the interface of Cu-N-G can not only provide high adsorbed hydrogen (H_ad) coverage but also stabilize the key *HCCHOH intermediate towards ethanol pathway. The provided interface-enhanced strategy herein is expected to inspire the design of Cu-based CO₂RR electrocatalysts towards multi-carbon products.

Since the advent of graphene in 2004, two-dimensional (2D) materials had ignited the development of fascinating functional materials for almost 20 years. Currently, the main members of 2D materials family are graphene, transition metal dichalcogenides (TMDs, MoS₂, WS₂, and others), MXenes (Ti₃C₂, Ta₄C₃, and others), Xenes (B, Si, P, Ge, and Sn), organic materials (COF, covalent organic frameworks), etc. The unique sheet-like morphology (single- or few-atomic-layer thickness) endow 2D materials with unconventional physicochemical properties for promising applications in catalysis, energy storage/conversion, electronics, biomedicine, sensors, etc. Nevertheless, the exploration and preparation of novel two-dimensional materials with desired characteristics through highly controlled strategy remains one of the major challenges in this field. In a recent work from Nature Chemistry published on 10 February 2022, Liu et al. reported a new member, clusterphene, in the family of two-dimensional materials.

The catalytic conversion of carbon dioxide (CO₂) into high value-added chemicals is of great significance to address the pressing carbon cycle issues. Reticular chemistry of metal-organic frameworks (MOFs)-based materials exhibits great potential and effectiveness to face CO₂ challenge from capture to conversion. To date, the integrated nanocomposites of nanostructure and MOF have emerged as a powerful heterogeneous catalysts featured with multifold advantages including synergistic effects between the two interfaces, confinement effect of meso- and micropores, tandem reaction triggered by multiple active sites, high stability and dispersion, and so on. Given burgeoning carbon cycle and nanostructure@MOFs, this review highlights some of important advancements to provide a full understanding on the synthesis and design of nanostructure@MOFs composites to facilitate carbon cycle through CO₂ photocatalytic, electrocatalytic, and thermal conversion. Afterward, the catalytic applications of some representative nanostructure@MOFs composites are categorized, in which the origin of activity or structure-activity relationship is summarized. Finally, the opportunities and challenges are proposed for inspiring the future development of nanostructure@MOFs composites for carbon cycle.

Electrocatalytic hydrogen production in alkaline media is extensively adopted in industry. Unfortunately, further performance improvement is severely impeded by the retarded kinetics, which requires the fine regulation of water dissociation, hydrogen recombination, and hydroxyl desorption. Herein, we develop a multi-interface engineering strategy to make an elaborate balance for the alkaline hydrogen evolution reaction (HER) kinetics. The graphene cross-linked three-phase nickel sulfide (NiS-NiS₂-Ni₃S₄) polymorph foam (G-NNNF) was constructed through hydrothermal sulfidation of graphene wrapped nickel foam as a three-dimensional (3D) scaffold template. The G-NNNF exhibits superior catalytic activity toward HER in alkaline electrolyte, which only requires an overpotential of 68 mV to drive 10 mA·cm⁻² and is better than most of the recently reported metal sulfides catalysts. Density functional theory (DFT) calculations verify the interfaces between nickel sulfides (NiS/NiS₂/Ni₃S₄) and cross-linked graphene can endow the electrocatalyst with preferable hydrogen adsorption as well as metallic nature. In addition, the electron transfer from Ni₃S₄/NiS₂ to NiS results in the electron accumulation on NiS and the hole accumulation on Ni₃S₄/NiS₂, respectively. The electron accumulation on NiS favors the optimization of the H* adsorption, whereas the hole accumulation on Ni₃S₄ is beneficial for the adsorption of H₂O. The work about multi-interface collaboration pushes forward the frontier of excellent polymorph catalysts design.