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Magnetic property (e.g. spin order) of support is of great importance in the rational design of heterogeneous catalysts. Herein, we have taken the Ni-supported ferromagnetic (FM) CrBr3 support (Nix/CrBr3) to thoroughly investigate the effect of spin-order on electrocatalytic oxygen reduction reaction (ORR) via spin-polarized density functional theory calculations. Specifically, Ni loading induces anti-FM coupling in Ni–Cr, leading to a transition from FM-to-ferrimagnetic (FIM) properties, while Ni–Ni metallic bonds create a robust FM direct exchange, benefiting the improvement of the phase transition temperature. Interestingly, with the increase in Ni loading, the easy magnetic axis changes from out-of-plane (2D-Heisenberg) to in-plane (2D-XY). The adsorption properties of Nix/CrBr3, involving O2 adsorption energy and configuration, are not governed by the d-band center but strongly correlate with magnetic anisotropy. It is noteworthy that the applied potential and electrolyte acidity triggers spin-order transition phenomena during the ORR and induces the catalytic pathway change from 4e− ORR to 2e− ORR with the excellent onset potential of 0.93 V/reversible hydrogen electrode, comparable to the existing most excellent noble-metal catalysts. Generally, these findings offer new avenues to understand and design heterogeneous catalysts with magnetic support. [ABSTRACT FROM AUTHOR]

Tailoring the specific properties to practical applications by structural modification is of vital importance for the envisioned development of two-dimensional ferroelectric materials. Herein, a comprehensive investigation on the effects of single doping on the ferroelectric properties and electronic transport in a monolayer of α-In2Se3 was carried out via the combination of first-principles density functional theory calculations and electron–phonon coupling simulations. Our results show that single-doping in In2Se3 can reduce effective mass of carriers and thereby enhance the high carrier mobility potential of the material. Moreover, the ferroelectric phonon mode in single-doped In2Se2X features a lower scattering rate, associating with the single-doping atom, and indicates reduced hindrance to carrier transport during ferroelectric switching. Compared to pristine In2Se3, the obtained smaller ferroelectric barriers (<1 eV) of single-doped ones promote more promising ferroelectricity from the analysis of the ferroelectric soft mode. Interestingly, the observed variations in ferroelectric behaviors resulting from doping of different elements highlight the significance of single-doping in modifying the ferroelectric properties of monolayers. Furthermore, strain engineering results reveal that single doping obviously affects the dependence of gap on strains: linear relationship for doping ones and nonlinearity for pristine one. Our study provides valuable insights into achieving higher carrier mobility in these critical materials. [ABSTRACT FROM AUTHOR]

The formation and transportation of short-lived species on/within the plasma-liquid interfacial layer plays a crucial role in various applications because of their high chemical reactivity. However, the experimental detection and quantification of these short-lived species, such as ˙OH radicals, at the gas–liquid interface still pose formidable challenges. This study confronts this challenge by employing incident microscopic laser-induced fluorescence (mLIF) method to capture the OH-LIF signals on the interfacial layer at different time moments of the post-discharge phase under high spatial resolution. The temporal evolution of ˙OH density is subsequently quantified by fitting the OH-LIF decay behavior to a reaction-dissolution model. Results reveal that increasing the pulse width serves better to enhance ˙OH generation on liquid surface, reaching a density of 1.25 × 1016 cm−3. Furthermore, the cathode-solution interface demonstrates significantly enhanced ˙OH production compared to the anode-solution interface. These results underscore the efficacy of incident mLIF in quantitatively probing short-lived ˙OH-radical production at the interfacial layer in pulsed-driven plasma-solution interactions, with potential applicability to other reactive species. [ABSTRACT FROM AUTHOR]

The search of excellent electrocatalysts for the two-electron O2-reduction reaction (2e− ORR) is of great importance for the green synthesis of H2O2. This study developed a computational framework using density functional theory (DFT) and ab initio molecular dynamic simulation (AIMD) to investigate the influence of acid electrolytes, particularly H coverage, on the s-band center of a single-atomic Ag catalyst, leading to improved catalytic selectivity for the ORR. Specially, the screened catalyst Ag@Ti2C exhibited remarkable intrinsic performance for 2e− ORR with an overpotential of only 0.06 V. In acidic electrolytes, Ag@Ti2C selectively bound to O-containing and H species, forming Ag@Ti2CO2Hx. The introduction of O functional groups improved the electron delocalization, enhancing O2–Ag interactions. Significantly, the surface O atom's p-band center exhibited a parabolic trend with the H coverage on Ag@Ti2CO2. Consequently, the catalyst exhibited an optimal overpotential of 0.08 V for 2e− ORR at an H atom coverage of 22.2%. It was found that the surface O p-state played a crucial role in mediating the s-band center of the single-atomic Ag catalyst, significantly influencing its catalytic performance in the ORR. [ABSTRACT FROM AUTHOR]

An excellent single-atomic photocatalyst, Ti@C4N3, is theoretically found to effectively convert CO2 to C2H6 by density functional theory (DFT) calculations and non-adiabatic molecular dynamics (NAMD) simulations. The Ti@C4N3 photocatalyst has remarkable stability both thermally, chemically, and mechanically. Electronically, it has strong absorption properties (λ = 327.77 and 529.61 nm), suitable band positions, and a long photogenerated electron lifetime (τe = 38.21 ps), allowing photogenerated electrons to migrate to the surface. Notably, the high-valence active site effectively activates two CO2 through dual activation: Under light irradiation, the weakly adsorbed CO2 undergoes photo-induced activation by the photoelectron of conduction band minimum (CBM); without light, the high Lewis acidity of the Ti site induces CO2 activation through back-donating π-bond. Contrast simulation results uncovered that dual activation of CO2 is attributed to the thermal and photonic synergy. Furthermore, two activated CO2 species under light easily couple to form oxalate with the barrier of 0.19 eV, and further reduced to C2H6 with a low activation energy of 1.09 eV. [ABSTRACT FROM AUTHOR]

We explored a co‐dissolved strategy to embed mono‐dispersed Pt center into V2O5 support via dissolving [PtV9O28]7− into [V10O28]6− aqueous solution. The uniform dispersion of [PtV9O28]7− in [V10O28]6− solution allows [PtV9O28]7− to be surrounded by [V10O28]6− clusters via a freeze‐drying process. The V centers in both [PtV9O28]7− and [V10O28]6− were converted into V2O5 via a calcination process to stabilize Pt center. These double separations can effectively prevent the Pt center agglomeration during the high‐temperature conversion process, and achieve 100 % utilization of Pt in [PtV9O28]7−. The resulting Pt‐V2O5 single‐atom‐site catalysts exhibit a CH4 yield of 247.6 μmol g−1 h−1, 25 times higher than that of Pt nanoparticle on the V2O5 support, which was accompanied by the lactic acid photooxidation to form pyruvic acid. Systematical investigations on this unambiguous structure demonstrate an important role of Pt−O atomic pair synergy for highly efficient CO2 photoreduction. [ABSTRACT FROM AUTHOR]

Atomically precise metal clusters serve as a unique model for unraveling the intricate mechanism of the catalytic reaction and exploring the complex relationship between structure and activity. Herein, three series of water-soluble heterometallic clusters LnCu 6 , abbreviated as LnCu 6 -AC (Ln = La, Nd, Gd, Er, Yb; HAC = acetic acid), LnCu 6 -IM (Ln = La and Nd; IM = Imidazole), and LnCu 6 -IDA (Ln = Nd; H 2 IDA = Iminodiacetic acid) are presented, each featuring a uniform metallic core stabilized by distinct protected ligands. Crystal structure analysis reveals a triangular prism topology formed by six Cu 2+ ions around one Ln 3+ ion in LnCu 6 , with variations in Cu···Cu distances attributed to different ligands. Electrocatalytic oxygen evolution reaction (OER) shows that these different LnCu 6 clusters exhibit different OER activities with remarkable turnover frequency of 135 s -1 for NdCu 6 -AC, 79 s -1 for NdCu 6 -IM and 32 s -1 for NdCu 6 -IDA. Structural analysis and Density Functional Theory (DFT) calculations underscore the correlation between shorter Cu···Cu distances and improves OER catalytic activity, emphasizing the pivotal role of active-site distance in regulating electrocatalytic OER activities. These results provide valuable insights into the OER mechanism and contribute to the design of efficient homogeneous OER electrocatalysts., (© 2024 Wiley‐VCH GmbH.)

Herein, combining density functional theory (DFT) calculations with nonadiabatic molecular dynamics (NAMD), we built a computational framework to rationally screen from a series of 2D conjugated carbon nitrides (CNs) to match with B 4 C 3 , resulting in the excellent direct Z-scheme photocatalyst (B 4 C 3 /C 6 N 6 ) for overall water splitting (OWS). Studies on interface engineering and ultrafast dynamics of carrier recombination-transfer show that in the B 4 C 3 /C 6 N 6 system, compared with the slower interlayer migration process of carriers, strong nonadiabatic coupling and longer quantum decoherence time accelerates weak carrier interlayer recombination on a subpicosecond time scale, enabling simultaneous triggering of hydrogen evolution reaction (HER) with Δ G = -0.23 eV and spontaneous oxygen evolution reaction (OER) in the absence of sacrificial or cocatalysts. In general, our work will promote the design of efficient direct Z-scheme photocatalysts from an ultrafast dynamics perspective.

We explored a co-dissolved strategy to embed mono-dispersed Pt center into V 2 O 5 support via dissolving [PtV 9 O 28 ] 7- into [V 10 O 28 ] 6- aqueous solution. The uniform dispersion of [PtV 9 O 28 ] 7- in [V 10 O 28 ] 6- solution allows [PtV 9 O 28 ] 7- to be surrounded by [V 10 O 28 ] 6- clusters via a freeze-drying process. The V centers in both [PtV 9 O 28 ] 7- and [V 10 O 28 ] 6- were converted into V 2 O 5 via a calcination process to stabilize Pt center. These double separations can effectively prevent the Pt center agglomeration during the high-temperature conversion process, and achieve 100 % utilization of Pt in [PtV 9 O 28 ] 7- . The resulting Pt-V 2 O 5 single-atom-site catalysts exhibit a CH 4 yield of 247.6 μmol g -1  h -1 , 25 times higher than that of Pt nanoparticle on the V 2 O 5 support, which was accompanied by the lactic acid photooxidation to form pyruvic acid. Systematical investigations on this unambiguous structure demonstrate an important role of Pt-O atomic pair synergy for highly efficient CO 2 photoreduction., (© 2022 Wiley-VCH GmbH.)