Two Cu^II complexes with branched tetrapeptides undergo PCET and catalyse water oxidation, processes promoted by the presence of C-terminal histidine.

The behavior of single layer van der Waals (vdW) materials is profoundly influenced by the immediate atomic environment at their surface, a prime example being the myriad of emergent properties in artificial heterostructures. Equally significant are adsorbates deposited onto their surface from ambient. While vdW interfaces are well understood, our knowledge regarding atmospheric contamination is severely limited. Here we show that the common ambient contamination on the surface of: graphene, graphite, hBN and MoS₂ is composed of a self-organized molecular layer, which forms during a few days of ambient exposure. Using low-temperature STM measurements we image the atomic structure of this adlayer and in combination with infrared spectroscopy identify the contaminant molecules as normal alkanes with lengths of 20-26 carbon atoms. Through its ability to self-organize, the alkane layer displaces the manifold other airborne contaminant species, capping the surface of vdW materials and possibly dominating their interaction with the environment.

Among the main appeals of single-atom catalysts are the ultimate efficiency of material utilization and the well-defined nature of the active sites, holding the promise of rational catalyst design. A major challenge is the stable decoration of various substrates with a high density of individually dispersed and uniformly active monatomic sites. Transition metal chalcogenides (TMCs) are broadly investigated catalysts, limited by the relative inertness of their pristine basal plane. We propose that TMC single-layers modified by substitutional heteroatoms can harvest the synergistic benefits of stably anchored single-atom catalysts and activated TMC basal planes. These solid solution TMC catalysts offer advantages such as, simple and versatile synthesis, unmatched active site density, and stable and well-defined single-atom active site chemical environment. The unique features of heteroatom doped 2D TMC crystals at the origin of their catalytic activity are discussed through the examples of various TMC single layers doped with individual oxygen heteroatoms.