Transition metal atom doping of the basal plane of MoS monolayer nanosheets for electrochemical hydrogen evolution.

Surface sites of extensively exposed basal planes of MoS monolayer nanosheets, prepared BuLi exfoliation of MoS, have been doped with transition metal atoms for the first time to produce 2D monolayer catalysts used for the electrochemical hydrogen evolution reaction (HER). Their HER activity is significantly higher than the corresponding thin and bulk MoS layers. HAADF-STEM images show direct proof that single transition metal atoms reside at the surface basal sites, which subtly modify the electro-catalytic activity of the monolayer MoS, dependent on their electronic and stereospecific properties.

The influence of tree species composition on the storage and mobility of semivolatile organic compounds in forest soils.

Soil contamination with PCBs and PAHs in adjacent forest plots, characterized by a distinct composition in tree species (spruce only, mixed and beech only), was analyzed to investigate the influence of ecosystem type on contaminant mobility in soil under very similar climate and exposure conditions. Physical-chemical properties and contaminant concentrations in litter (L), organic (F, H) and mineral (A, B) soil horizons were analyzed. Contaminant distribution in the soil core varied both in relation to forest type and contaminant group/properties.

Spectroscopic and atomic force studies of the functionalisation of carbon surfaces: new insights into the role of the surface topography and specific chemical states.

The utility of carbon materials in applications as diverse as drug delivery and photocatalysis is often undermined by the complexity of their surface chemistry; different sources of carbon give rise to a varied mixture of functional groups and hence different properties. Considerable efforts have been made to identify specific groups at these surfaces and elucidate the complex interactions that take place but even on materials such as graphene and carbon nanotubes there remains uncertainty about the nature of the components present and their role in the nucleation of other functional materials at the surface. The present study uses highly ordered pyrolytic graphite (HOPG) as a model on which the fundamental properties of specific functional groups and their interactions with deposited nanoparticles can be characterised.