RESUMEN
The construction of two-dimensional (2D) van der Waals (vdW) heterostructures over black phosphorus (BP) has been attracting significant attention to better utilize its inherent properties. The sandwich of zero-dimensional (0D) noble metals within BP-based vdW heterostructures can provide efficient catalytic channels, modulating their surface redox potentials and therefore inducing versatile functionalities. Herein, we realize a 2D WS2-Au-BP heterostructure, in which Au nanoparticles are connected between BP and WS2 via ionic bonds. The ultralow conduction band minimum position, the reduced adsorption energies of O2, and the increased dissociation barrier energy of O2- into 2O contribute greatly to improving the long-term stability of BP in the air. The formation of heterostructures can reduce the potential barrier energy in target gas molecules, thus enhancing the absorption energy and charge transfer. Taking the paramagnetic NO2 gas molecules as a representative, a stable response magnitude of 2.11 to 100 ppb NO2 is achieved for 80 days, which is far larger than the initial responses of most BP-based materials. A practical gas sensing system is also developed to demonstrate its real-world implementation. This work provides a promising demonstration of 0D noble metal within 2D BP-based vdW heterostructure for simultaneously improving the long-term stability and room-temperature reversible gas sensing.
RESUMEN
Based on first-principles calculation, the adsorption of sulfur-based gas molecules (H2S, SO2, SO3) on various metal-decorated phosphorenes is researched systematically. Eleven metals (Li, Na, K, Rb, Cs, Ca, Sr, Ba, Ni, La, Tl) which can avoid the formation of clusters on the phosphorene are considered. Noticeably, all metal decorations can enhance the adsorption strength of phosphorene to sulfur-based gas molecules except for H2S on Tl-decorated phosphorene. Meanwhile, the adsorption energy (Eads) shows the trend of Eads(H2S) < Eads(SO2) < Eads(SO3) for the same metal decoration case. In addition, some metal-decorated phosphorene systems exhibit intriguing magnetic and electrical variation after sulfur-based gas molecule adsorptions, indicating that these systems are promising to be candidates for the detection and removal of sulfur-based gas molecules.
RESUMEN
Using the first-principles calculation based on density functional theory (DFT), the adsorption properties of nitrogen-based gases molecules (NH3, NO, NO2) on various metal (Li, Na, K, Rb, Cs, Ca, Sr, Ba, Ni, La, Tl) decorated phosphorene systems have been studied systematically. The results show that all metal decorations can improve the adsorption strength of phosphorene to nitrogen-based gases molecules except for Tl decoration. Especially, the adsorption energy of NH3 molecule on Ni decorated phosphorene is 1.305 eV, and the adsorption energies of NO and NO2 on La decorated phosphorene can be up to 2.475 and 3.734 eV, respectively. In addition, after NO and NO2 adsorptions, the electronic and magnetic properties of some metal decorated phosphorenes change, indicating that the metal decorated phosphorenes have great potential in NO and NO2 detection.