A 2D-0D-2D Sandwich Heterostructure toward High-Performance Room-Temperature Gas Sensing

Abstract

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 WS 2 -Au-BP heterostructure, in which Au nanoparticles are connected between BP and WS 2 via ionic bonds. The ultralow conduction band minimum position, the reduced adsorption energies of O 2 , and the increased dissociation barrier energy of O 2 − 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 NO 2 gas molecules as a representative, a stable response magnitude of 2.11 to 100 ppb NO 2 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.

Two-Dimensional OER Catalysts: Is There a Win-Win Solution for Their Activity and Stability?

“…The surfaces of 2D materials have high surface energy, making it easy to form a high density of various types of defects such as vacancy defects, − edge dislocations, and lattice distortions, as shown in Figure a. In addition to these as-synthesized defects, defects introduced through defect engineering, such as adatoms, dopants, and heterostructures, ,− can enhance catalytic activity.…”

“…These interface defects can provide additional active sites, increase the density of reaction centers, and promote the oxygen evolution reaction. In addition, the interface can also affect the diffusion behavior of solute on the catalyst surface and adjust the transport process of reactants and products, thus affecting the activity and stability of the catalyst. , Similarly, Zhang et al. developed a novel in situ hybrid heterojunction strategy, creating 2D porous codoped Ni/Ni 3 N heterostructure nanosheets (Co–Ni/Ni 3 N).…”