Interlayer coupling as a unique feature for two-dimensional (2D) materials may influence their thickness-dependent physical properties, especially the bandgap due to quantum confinement effect. Widely-studied 2D materials usually possess strong interlayer coupling such as most of transition metal dichalcogenides (TMDs), PtS₂ and so on. However, 2D materials with weak interlayer coupling are rarely referred that mainly focus on ReS₂, as well as its counterpart ReSe₂. Here we report a new member of weak interlayer coupling 2D materials, germanium disulfide (GeS₂). The interlayer interaction in GeS₂ is investigated from theory to experiment. By density functional theory calculations, we find that this extraordinarily weak interlayer coupling in GeS₂ originates from the weak hybridization of interlayer S atoms. Thickness-dependent Raman spectra of GeS₂ flakes exhibit that the Raman peaks remain unchanged when increasing the thickness; and a small first-order temperature coefficient of −0.00857 cm⁻¹·K⁻¹ is obtained from the temperature-dependent Raman spectra. These experimental results further confirm the weak interlayer coupling in GeS₂.

A solid oxide fuel cell (SOFC) is a clean, efficient energy conversion device with wide fuel applicability. Metal-supported solid oxide fuel cells (MS-SOFCs) exhibit better thermal shock resistance, better machinability, and faster startup than traditional SOFCs, making them more suitable for commercial applications, especially in mobile transportation. However, many challenges remain that hinder the development and application of MS-SOFCs. High temperature may accelerate these challenges. In this paper, the existing problems in MS-SOFCs, including high-temperature oxidation, cationic interdiffusion, thermal matching, and electrolyte defects, as well as lower temperature preparation technologies, including the infiltration method, spraying method, and sintering aids method, are summarized from different perspectives, and the improvement strategy of existing material structure optimization and technology integration is put forward.

Real-time monitoring of volatile organic compounds (VOCs) is crucial for both industrial production and daily life. However, the non-reactive nature of VOCs and their low concentrations pose a significant challenge for developing sensors. In this study, we investigated the adsorption behaviors of typical VOCs (C₂H₄, C₂H₆, and C₆H₆), on pristine and Pt-decorated SnS monolayers using density functional theory (DFT) calculations. Pristine SnS monolayers have limited charge transfer and long adsorption distances to VOC molecules, resulting in VOC insensitivity. The introduction of Pt atoms promotes charge transfer, creates new energy levels, and increases the overlap of the density of states, thereby enhancing electron excitation and improving gas sensitivity. Pt-decorated SnS monolayers exhibited high sensitivities of 241,921.7%, 35.7%, and 74.3% towards C₂H₄, C₂H₆, and C₆H₆, respectively. These values are 142,306.9, 23.8, and 82.6 times higher than those of pristine SnS monolayers, respectively. Moreover, the moderate adsorption energies of adsorbing C₂H₆ and C₆H₆ molecules ensure that Pt-decorated SnS monolayers possess good reversibility with a short recovery time at 298 K. When heated to 498 K, C₂H₄ molecules desorbs from the surface of Pt-decorated SnS monolayer in 162.33 s. Our results indicate that Pt-decorated SnS monolayers could be superior candidates for sensing VOCs with high selectivity, sensitivity, and reversibility.

In recent years, gold nanomaterials have become a hot topic in photothermal tumor therapy due to their unique surface plasmon resonance characteristics. The effectiveness of photothermal therapy is highly dependent on the shape and size of gold nanoparticles. In this work, we investigate the photothermal therapeutic effects of four different sizes of gold nanorods (GNRs). The results show that the uptake of short GNRs with aspect ratios 3.3–3.5 by cells is higher than that of GNRs with aspect ratios 4–5.5. Using a laser with single pulse energy as low as 28 pJ laser for 20 s can induce the death of liver cancer cells co-cultured with short GNRs. Long GNRs required twice the energy to achieve the same therapeutic effect. The dual-temperature model is used to simulate the photothermal response of intracellular clusters irradiated by a laser. It is found that small GNRs are easier to compact because of their morphological characteristics, and the electromagnetic coupling between GNRs is better, which increases the internal field enhancement, resulting in higher local temperature. Compared with a single GNR, GNR clusters are less dependent on polarization and wavelength, which is more conducive to the flexible selection of excitation laser sources.

This study explores the potential of MoS₂ monolayers as heavy metal sensors for As, Cd, Hg, and Pb using density functional theory (DFT) and Non-Equilibrium Green’s Function (NEGF) simulations. Our findings reveal that As and Pb adsorption significantly alters the surface structure and electronic properties of MoS₂, introducing impurity levels and reducing the band gap. Conversely, Cd and Hg exhibit weaker interactions with the MoS₂ surface. The MoS₂ monolayer sensors demonstrate exceptional sensitivity for all four target heavy metals, with values reaching 126,452.28% for As, 1862.67% for Cd, 427.71% for Hg, and 83,438.90% for Pb. Additionally, the sensors demonstrate selectivity for As and Pb through distinct response peaks at specific bias voltages. As and Pb adsorption also induces magnetism in the MoS₂ system, potentially enabling magnetic sensing applications. The MoS₂ monolayer’s moderate adsorption energy facilitates rapid sensor recovery at room temperature for As, Hg, and Cd. Notably, Pb recovery time can be significantly reduced at elevated temperatures, highlighting the reusability of the sensor. These results underscore the potential of MoS₂ monolayers as highly sensitive, selective, and regenerable sensors for real-time heavy metal detection.

Using the first principles density functional theory, diamond crystal doping with B or N atoms, and B/N with different ratios were investigated, based on previous experimental structure results. The formation energies were calculated while the most stable doped structures were obtained for the lowest energy. For comparison, the electronic structures and the micro-mechanism of the doping crystals were discussed. The electronic results show that the doping of N atom is prior to B while the symmetry B–N–B stable structure appears with the N:B = 1:2 doping ratio. And also, the absorption spectrum gives the same results with the experiment for the distinct redshift.