We study the formation of plasmon modes of small gold clusters by modeling the excitation spectra. The shape change of the longitudinal mode as a function of cluster size is studied using time-dependent Kohn-Sham theory and Gaussian basis sets. The presence of d electrons in gold atoms affect the plasmon formation process, resulting in a high excitation energy for transverse mode and a complicated spectra profile in general. The transverse mode can still be identified with the help of a frozen-orbital approximation.
The most striking feature of plant photosynthetic systems is that the electron transfer efficiency reaches 95% between photosystem I and photosystem II under mild conditions. [3] At the same time, the charge transfer efficiency of the photoexcited protein complex to the active interfacial reaction site has been significantly increased through an electron transport medium to achieve high catalytic efficiency. [4] Therefore, inspired by nature, high charge separation is achieved by constructing a biomimetic Z-scheme system. [5] However, the poor interfacial contact in the Z-scheme acting as a "wall" between multiphase seriously prevent efficient electron interaction, such as inefficient and traditional redox pairs (such as I − /IO 3 − , Fe 3+ /Fe 2+ , and [Co(bpy) 3 ] 3+ / 2+ ) severely limit electron transport. [6] Therefore, it is still critical to the practical design and accurately regulates the hybrids at the atomic scale to ensure the efficient charge transport and achieve an efficient and stable photocatalytic system.In the past few years, 2D materials with ultrathin thickness have constructed a clear structure-activity relationship given the atomic level. [7] The unique 2D ultrathin polymeric carbon nitride nanosheets (CNS) give materials good interfacial Charge separation and transfer are central issues dominating the underlying energy conversion mechanisms of photosynthetic systems.Here, inspired by nature, a multi-interfacial engineering strategy for constructing a strongly coupled interactive transmission network for stable and efficient photo catalytic hydrogen production is proposed. A multivariate all-solidstate Z-scheme with intimate electron interactions is formed through strong bridging bonds due to Ti orbit modulation and stacking hybridization between hybrids. The electron couple structure realizes an efficient carrier directional separation and transfer, enabling the charge separation efficiency to be enhanced dramatically by 7.2 times. Furthermore, the resulting material provides a highly stable photocatalytic hydrogen activity, up to 15.29 mmol h −1 g −1 , 18.8 times higher than pure carbon nitride, surpassing many reported photocatalysts. This work represents a significant development and helps develop a sound foundation for future design principles in accelerating charge transfer.
Semiconductor quantum dots (QDs) are promising photocatalysts for water splitting due to the large specific area, but the influence of surface trap states on the photocatalytic activity of QDs is still not fully understood yet. To answer this question, CdSe QDs with the same morphology, diameter, crystal structure, and energy level are prepared following a hydrazine hydrate (N 2 H 4 ) promoted synthesis strategy and conventional hydrothermal synthesis method. Through various characterizations and analysis, it is found that the conventional hydrothermal synthesized CdSe QDs (H-CdSe QDs) have a high concentration of Cdinvolved shallow electron trap states, which seriously hinder the charge separation and transfer between CdSe and cocatalysts. In contrast, the N 2 H 4 promoted synthesis strategy provides an energy-saving, low-cost, and facile pathway to eliminate the surface shallow electron traps, ensuring an efficient charge separation and H 2 production in CdSe QDs. As a result, the N 2 H 4promoted synthesized CdSe QDs (N-CdSe QDs) produce 44.5 mL (1998 μmol) H 2 in 7 h, roughly 1.6 times higher than that of H-CdSe QDs (27.5 mL, 1236 μmol). Because the surface trap states are widespread in semiconductor QDs, it is believed that our study provides valuable guidance on the design and preparation of QDs for photocatalysis.
Grain boundaries (GBs) attract much interest for its ability to tune the property of hybrid materials. Theoretically predicting the properties of hybrid graphene with GBs, even a linear GB remains challenging due to its inhomogeneous structure, which makes supercell model tough to choose in theoretic studies. For the first time, the applicability of supercells with different GBs and lattice-mismatches for describing armchair-zigzag hybrid graphene nanoribbons was validated by ab initio molecular dynamic simulations and first principles electronic structure calculations. And to what extent the electronic properties can be tuned by the strain effects resulting from the lattice-mismatch and the GBs distortion in supercells was demonstrated. This work showed that the intrinsic strain in such system plays a decisive role in determining the band structure and spin polarization properties. Hybrid graphene nanoribbon was found to be ferromagnetic in the ground state, especially for the case of using the supercell with nearly-perfect lattice match. Its high Curie temperature suggests the potential applications of this material in spintronics.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.