Two‐dimensional (2D) materials as tungsten disulphide (WS₂) are rising as the ideal platform for the next generation of nanoscale devices due to the excellent electric‐transport and optical properties. However, the presence of defects in the as grown samples represents one of the main limiting factors for commercial applications. At the same time, WS₂ properties are frequently tailored by introducing impurities at specific sites. Aim of this review paper is to present a complete description and discussion of the effects of both intentional and unintentional defects in WS₂, by an in depth analysis of the recent experimental and theoretical investigations reported in the literature. First, the most frequent intrinsic defects in WS₂ are presented and their effects in the readily synthetized material are discussed. Possible solutions to remove and heal unintentional defects are also analyzed. Following, different doping schemes are reported, including the traditional substitution approach and innovative techniques based on the surface charge transfer with adsorbed atoms or molecules. The plethora of WS₂ monolayer modifications presented in this review and the systematic analysis of the corresponding optical and electronic properties, represent strategic degrees of freedom the researchers may exploit to tailor WS₂ optical and electronic properties for specific device applications.

The development of efficient CO₂ capture and utilization technologies driven by renewable energy sources is mandatory to reduce the impact of climate change. Herein, seven imidazolium-based ionic liquids (ILs) with different anions and cations were tested as catholytes for the CO₂ electrocatalytic reduction to CO over Ag electrode. Relevant activity and stability, but different selectivities for CO₂ reduction or the side H₂ evolution were observed. Density functional theory results show that depending on the IL anions the CO₂ is captured or converted. Acetate anions (being strong Lewis bases) enhance CO₂ capture and H₂ evolution, while fluorinated anions (being weaker Lewis bases) favour the CO₂ electroreduction. Differently from the hydrolytically unstable 1-butyl-3-methylimidazolium tetrafluoroborate, 1-Butyl-3-Methylimidazolium Triflate was the most promising IL, showing the highest Faradaic efficiency to CO (>95%), and up to 8 h of stable operation at high current rates (−20 mA & −60 mA), which opens the way for a prospective process scale-up.

Ordered mesoporous carbons (OMCs) doped with nitrogen, phosphorus or boron were synthesised through a two-step nanocasting method and studied as electrocatalysts for the reduction of nitrobenzene to aniline in a half-cell setup. The nature of the dopant played a crucial role in the electrocatalytic performance of the doped OMCs, which was monitored by LSV with a rotating disk electrode setup. The incorporation of boron generated the electrocatalysts with the highest kinetic current density, whereas the incorporation of phosphorus led to the lowest overpotential. Doping with nitrogen led to intermediate behaviour in terms of onset potential and kinetic current density, but provided the highest selectivity towards aniline, thus resulting in the most promising electrocatalyst developed in this study. Density functional theory calculations allowed explaining the observed difference in the onset potentials between the various doped OMCs, and indicated that both graphitic N and pyrdinic N can generate active sites in the N-doped electrocatalyst. A chronoamperometric experiment over N-doped OMC performed at −0.75 V vs. Fc/Fc⁺ in an acidic environment, resulted in a conversion of 61% with an overall selectivity of 87% to aniline. These are the highest activity and selectivity ever reported for an electrocatalyst for the reduction of nitrobenzene to aniline, making N-doped OMC a promising candidate for the electrochemical cogeneration of this industrially relevant product and electricity in a fuel cell setup.