On the comparison of oxygen and sulfur transfer reactivities in phosphine and phosphorene: the case of R3Sb(X) carriers (X = O or S)

Easy and fast in situ functionalization of exfoliated 2D black phosphorus with gold nanoparticles

Heterostructures of single- and few-layer black phosphorus (2D bP) functionalized with gold nanoparticles (Au NPs) have been recently reported in the literature, exploiting their intriguing properties and biocompatibility for catalytic, therapeutical and diagnostic applications. However, a deeper insight on the structural and electronic properties at the interface of the 2D bP/Au NP heterostructure is still lacking. In this work, 2D bP is functionalized with Au nanoparticles (NPs) through in situ deposition-precipitation heterogeneous reaction. The smallest realized Au NPs have a diameter around 10 nm as revealed by atomic-force and scanning electron microscopy, and are partially positively charged as revealed by X-ray Photoelectron Spectroscopy (XPS). XPS, UV-vis and Raman spectroscopy, supported by density functional theory (DFT) calculations, confirmed that while the structural and electronic properties of 2D bP are overall preserved, a soft-pairing between P atoms at the surface of 2D bP and Au atoms at the surface of Au NPs occurs, leading to a partial charge transfer at the 2D bP/Au interface, with a positive charge being localized on the Au atoms directly bonded to 2D bP. DFT calculations also predicted a band gap lowering, by 0.8 eV, for phosphorene functionalized with a tetranuclear Au cluster. Larger effects are expected as the Au cluster nuclearity (and coverage) increases.

Interlayer Coordination of Pd-Pd Units in Exfoliated Black Phosphorus

The chemical functionalization of 2D exfoliated black phosphorus (2D BP) continues to attract great interest, although a satisfactory structural characterization of the functionalized material has seldom been achieved. Herein, we provide the first complete structural characterization of 2D BP functionalized with rare discrete Pd₂ units, obtained through a mild decomposition of the organometallic dimeric precursor [Pd(η³-C₃H₅)Cl]₂. A multitechnique approach, including HAADF-STEM, solid-state NMR, XPS, and XAS, was used to study in detail the morphology of the palladated nanosheets (Pd₂/BP) and to unravel the coordination of Pd₂ units to phosphorus atoms of 2D BP. In particular, XAS, backed up by DFT modeling, revealed the existence of unprecedented interlayer Pd–Pd units, sandwiched between stacked BP layers. The preliminary application of Pd₂/BP as a catalyst for the hydrogen evolution reaction (HER) in acidic medium highlighted an activity increase due to the presence of Pd₂ units.