The reaction efficiency of reactants near plasmonic nanostructures can be enhanced significantly because of plasmonic effects. Herein, we propose that the catalytic activity of molecular catalysts near plasmonic nanostructures may also be enhanced dramatically. Based on this proposal, we develop a highly efficient and stable photocatalytic system for the hydrogen evolution reaction (HER) by compositing a molecular catalyst of cobalt porphyrin together with plasmonic gold nanoparticles, around which plasmonic effects of localized electromagnetic field, local heating, and enhanced hot carrier excitation exist. After optimization, the HER rate and turn-over frequency (TOF) reach 3.21 mol g⁻¹ h⁻¹ and 4650 h⁻¹, respectively. In addition, the catalytic system remains stable after 45-hour catalytic cycles, and the system is catalytically stable after being illuminated for two weeks. The enhanced reaction efficiency is attributed to the excitation of localized surface plasmon resonance, particularly plasmon-generated hot carriers. These findings may pave a new and convenient way for developing plasmon-based photocatalysts with high efficiency and stability.

Band degeneracy is effective in optimizing the power factors of thermoelectric (TE) materials by enhancing the Seebeck coefficients. In this study, we demonstrate this effect in model systems of layered oxyselenide family by the density functional theory (DFT) combined with semi-classical Boltzmann transport theory. TE transport performance of layered LaCuOSe and BiCuOSe are fully compared. The results show that due to the larger electrical conductivities caused by longer electron relaxation times, the n-type systems show better TE performance than p-type systems for both LaCuOSe and BiCuOSe. Besides, the conduction band degeneracy of LaCuOSe leads to a larger Seebeck coefficient and a higher optimal carrier concentration than n-type BiCuOSe, and thus a higher power factor. The optimal figure of merit (ZT) value of 1.46 for n-type LaCuOSe is 22% larger than that of 1.2 for n-type BiCuOSe. This study highlights the potential of wide band gap material LaCuOSe for highly efficient TE applications, and demonstrates that inducing band degeneracy by cations substitution is an effective way to enhance the TE performance of layered oxyselenides.

The thermal-electric performance of Bi ₂ O ₂ Se can be significantly improved by application of tensile strain and the Bi ₂ O ₂ Se monolayer has great potential as thermoelectric (TE) material.

Thermoelectric (TE) materials can convert temperature difffferences into electricity directly and reversibly without air pollution, which provides a viable route for alleviating global warming and the energy crisis. Here, we use first-principles calculations combined with semiclassical Boltzmann transport theory to assess the potential of layered $\mathrm{La}\mathrm{Cu}\mathrm{O}\mathrm{Se}$ for TE applications. Originating from the layered crystal structure, the electronic and thermal transport properties (i.e., Seebeck coefficient, electrical conductivity, and thermal conductivity) are highly anisotropic between the in-plane and out-of-plane directions. The optimal figure of merit of 2.71 is achieved along the out-of-plane direction for electron doping at 900 K. Such excellent TE properties can be attributed to desired $\mathrm{La}$-$\mathrm{Se}$ interlayer interaction between adjacent layers and relatively strong coupling between acoustic phonons and optical phonons, resulting in simultaneous enhancement of the electrical conductivity and suppression of the lattice thermal conductivity. This study provides an effective route to improve the TE performance of layered $\mathrm{La}\mathrm{Cu}\mathrm{O}\mathrm{Se}$ by utilizing the anisotropic character of transport properties and offers implications in promoting related experimental investigations.

The first-principles calculations show that band convergence can be achieved by decreasing the interlayer distance of bilayer Bi₂O₂Se, which is beneficial to improve its thermoelectric performance.