The oxygen evolution reaction (OER) is the bottleneck limiting the reaction process of water splitting. The OER process involves the recombination of oxygen from diamagnetic singlet state OH or H 2 O to paramagnetic triplet state O 2 . The spin conservation for oxygenated intermediates must play an important role in the OER. However, the dynamic mechanism of magnetic field-induced spin polarization is still in its infancy. Herein, based on the spin-coupling interaction of iron group elements, three typical iron group layered double hydroxides (LDHs) were constructed to study the relationship among magnetic field, spin polarization, and OER activity. Combining experimental and theoretical studies, we revealed the spin-magnetic effect of iron group LDHs for enhancing the OER process. There is a positive correlation between the saturation magnetization and OER performance of iron group LDHs under different magnetic fields. The NiCoFe-LDHs (NCFL) endows the strongest OER activity (η 10 = 230 mV) and saturation magnetization (M s = 44 emu mg −1 ) compared with that of CoFe-LDHs (CFL, η 10 = 372 mV, M s = 21 emu mg −1 ) and NiFe-LDHs (NFL, η 10 = 246 mV, M s = 29 emu mg −1 ). The density functional theory calculations show that the Fe sites of NCFL endow a stronger spin-coupling interaction with OH, and Raman spectroscopy further proves the promotion for the formation of the O−O bond of NCFL. Applying an external magnetic field, due to the spin magnetic effect of iron group LDHs, the enhancement amplitude of OER activity is also positively correlated with the magnetism of the catalyst. NCFL has the strongest spin magnetic effect about −34.8 mV T −1 compared with NFL (−27.0 mV T −1 ) and CFL (−16.7 mV T −1 ). The overpotential of NCFL is only 206 mV under the condition of 700 mT magnetic field. In conclusion, we demonstrate the mechanism of underlying influence of the spin magnetic effect on the OER performance and provide insights into the relationship between catalysts and oxygenated intermediates. These insights would help to understand and design catalysts at the spintronic level.

The development of high-efficiency electrocatalysts for large-scale water splitting is critical but also challenging.In this study,ahierarchical CoMoS x chalcogel was synthesized on anickel foam (NF) through an in situ metathesis reaction and demonstrated excellent activity and stability in the electrocatalytic hydrogen evolution reaction and oxygen evolution reaction in alkaline media. The high catalytic activity could be ascribed to the abundant active sites/defects in the amorphous framework and promotion of activity through cobalt doping. Furthermore,t he superhydrophilicity and superaerophobicity of micro-/nanostructured CoMoS x /NF promoted mass transfer by facilitating access of electrolytes and ensuring fast release of gas bubbles.B ye mploying CoMoS x /NF as bifunctional electrocatalysts,t he overall water splitting device delivered acurrent density of 500 mA cm À2 at alow voltage of 1.89 Vand maintained its activity without decayf or 100 h.

Metalloenzyme-like metal–nitrogen–carbon (M–N–C) single-atom catalysts (SACs) have received increasing attention in the synthesis of fine chemicals because of the abundant atomic sites and versatile catalytic properties. However, the organic transformations with high atom efficiency over SACs in aqueous media were less investigated. Inspired by the hydrophobic pockets of the metalloenzyme, herein we introduced a hydrophobic, atomically dispersed Pd catalyst (Pd1–S–C) in the sulfur-doped carbon based on metal–sulfur coordination chemistry. This hydrophobic Pd-based SAC displayed satisfying catalytic performance for aqueous-phase semihydrogenation of terminal alkynes with high chemoselectivity, friendly substrate scope, and fairly good stability. Molecular dynamics simulations revealed that the hydrophobicity of the Pd1–S–C catalyst could contribute to accelerated reaction kinetics by enriching the organic alkynes around the catalytic sites in aqueous media. Furthermore, the electron-rich PdS4 single sites were demonstrated to promote activation of H2 molecules and desorption of CC intermediates, which outperformed the electron-deficient PdN4 single sites. The current work highlights the potential of enzyme-inspired hydrophobic SACs in the conversion of organic substrates in aqueous media.