Search

Heterogeneous dual-atomic-site catalysts (DACs) hold great potential for diverse applications. However, to date, the synthesis of DACs primarily relies on different atoms freely colliding on the support during synthesis, principally leading to low yields. Herein, we report a general metal ion recognition (MIR) strategy for constructing a series of DACs, including but not limited to Fe1Sn1, Fe1Co1, Fe1Ni1, Fe1Cu1, Fe1Mn1, Co1Ni1, Co1Cu1, Co2, and Cu2. This strategy is achieved by coupling target inorganometallic cations and anions as ion pairs, which are sequentially adsorbed onto a nitrogen-doped carbon substrate as the precursor. Taking the oxygen reduction reaction as an example, we demonstrated that the Fe1Sn1-DAC synthesized through this strategy delivers a record peak power density of 1.218 W cm–2under 2.0 bar H2–O2conditions and enhanced stability compared to the single-atom-site FeN4. Further study revealed that the superior performance arises from the synergistic effect of Fe1Sn1dual vicinal sites, which effectively optimizes the adsorption of *OH and alleviates the troublesome Fenton-like reaction.

Constructing heterostructures of dual quantum-dots (QDs) is a promising way to achieve high performance in photocatalysis, but it still faces substantial synthetic challenges. Herein, we developed an in situ transformation strategy to coassemble ZnS QDs and C QDs into dual-quantum-dot heterostructural nanofibers (ZnS/C-DQDH). Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy results revealed the formation of strong Zn–O–C bonds at the interface between ZnS QDs and C QDs, improving the separation efficiency of photogenerated charge carriers. The ZnS/C-DQDH demonstrated remarkable photocatalytic activity in H2O2production, with generation rates of 2896.4 μmol gcat–1h–1without sacrificial agents and 9879.3 μmol gcat–1h–1with ethanol as the sacrificial agent, significantly higher than the QD counterparts and surpassed state-of-the-art photocatalysts. Moreover, due to the nanofibrous feature, ZnS/C-DQDH demonstrated excellent stability and facile recyclability. This work provides a facile and large scalable method to gain dual-quantum-dot heterostructures and a promising alternative for photocatalytic H2O2production.

Electrochemical oxidation of 5-hydroxymethylfurfural (HMF) has shown promising prospects in producing highly valuable chemicals. Herein, we report the synthesis of ultrasmall Ag nanoclusters anchored on NiCo-layered double hydroxide (NiCo-LDH) nanosheet arrays (Agn@NiCo-LDH) viaa facile electrodeposition strategy. The prepared Agn@NiCo-LDH nanosheet arrays exhibit excellent electrocatalytic HMF oxidation performance with a current density of 10 mA cm−2at 1.29 VRHEand the Faraday efficiency of nearly 100% for 2,5-furandicarboxylic acid production. This study offers an effective approach to rationally design nanoclusters to achieve high catalytic activity for sustainable energy conversion and production.

Single-atom catalysts (SACs) show great promise to improve the performance of catalysis because of their spatially isolated single-atom sites with unique electronic properties. Herein, we construct single Zn atoms anchored on ultrathin two-dimensional (2D) N-doped carbon nanosheets (Zn–SAs/UNCNS) as an efficient electrocatalyst for oxygen reduction reaction (ORR). The microenvironment of Zn–SAs/UNCNS with super ORR intrinsic activity was identified as the divacancy Zn–N3C–C8by both experiments and theoretical simulations. Density functional theory (DFT) calculations reveal that the divacancy Zn–N3C–C8sites exhibit near-Fermi electronic states distinct from those of graphene-enclosed Zn–N4–C10and divacancy trans-Zn–N2C2–C8sites, which greatly facilitate the ORR process. Furthermore, compared with 3D architecture, the single atomic divacancy Zn–N3C–C8sites anchored on ultrathin 2D carbon nanosheets show more active site exposure and fast electron transport, which collectively boost the ORR performance, showing a high half-wave potential of 0.91 V versus reversible hydrogen electrode [RHE] and a super turnover frequency (4.99 e−site−1s−1).

Exploiting photocatalysts for selective organic oxidation is important but still challenging. Boosting photocatalytic activity in benzylamine oxidation was found for Bi5O7I with a (010) facet through facet engineering. Further characterizations revealed that visible light absorption, charge separation, valence band and adsorption of benzylamine synergistically contribute to the outstanding activity.

Ternary NiCoFe-layered double hydroxide (LDH) hollow polyhedron (HP) exhibited excellent OER performance with overpotential of 276 mV at 10 mA cm−2in 1 M KOH, surpassing solid NiCoFe-LDH sheet powder (SP), Fe-free NiCo-LDH HP and commercially available IrO2.Image, graphical abstract

The development of artificial enzymes with superior catalytic properties to natural enzymes has been a long-standing goal of chemists. Herein, defect-rich CoFe-layered double hydroxides (d-CoFe-LDHs) nanosheets are developed and used as superior peroxidase-like nanozymes for the detection of ascorbic acid (AA). The d-CoFe-LDHs with an average thickness of ∼3 nm and a lateral size of ∼20 nm are synthesized through rapid nucleation in a colloid mill, which exhibited abundant unsaturated sites (oxygen vacancies and cobalt vacancies). Impressively, d-CoFe-LDHs exhibited excellent peroxidase-mimicking performance with strong substrate affinity and robustness in a wide pH range. Density functional theory calculations show that d-CoFe-LDHs have lower H2O2adsorption energy, which promotes the decomposition of H2O2, thereby improving the catalytic activity. The chromogenic system of d-CoFe-LDHs and 3,3′,5,5′-tetramethylbenzidine can be used to accurately detect the content of AA, and the detection limit is about 3.6 μM. This study opens up a new approach for the construction of highly active defective LDH peroxidases for the detection of biomolecules.

Grafting of 3-(2-aminoethylamino)propyltrimethoxysilane onto Ru/AlO(OH) resulted in an active and highly chemoselective heterogeneous catalyst for the transfer hydrogenation of α,β-unsaturated carbonyl compounds to the corresponding allylic alcohols. Potassium formate was used as a sustainable hydrogen donor. A range of substrates including cinnamaldehyde, α-amylcinnamaldehyde, citral, 3-methyl-2-butenal, trans-2-pentenal, and trans-hexenal were selectively hydrogenated at the CO moiety with >96% selectivity. In comparison, the unmodified 1 wt% Ru/AlO(OH) catalyzed hydrogenation of cinnamaldehyde at the CC bond, yielding 3-phenylpropanal as the product. Higher loaded samples with 2–10 wt% Ru exhibited 20–25% selectivity to cinnamyl alcohol. The results show that low coordination sites were more selective to hydrogenation of the internal CC than the terminal CO bond. Immobilization of the amine viachemical bonding with hydroxyl groups of the AlO(OH) support blocks adjacent exposed metal sites, increasing the chemoselective reduction of CO. Optimum results were achieved at an amine/Ru ratio of 6. The catalyst maintained high activity and chemoselectivity even after five cycles.