Metal Polysulfides of Groups 4–6: From Bulk Samples to Nanoscale Materials

The article discusses the current state of research concerning transition metal polysulfides of groups 4–6. We review the data on the preparation of nanoscale polychalcogenides from elements or molecular precursors and by exfoliating bulk samples. Particular attention is paid to the ultrasound liquid-phase exfoliation of typical polysulfides such as NbS₃, TaS₃, VS₄. The main feature of this class of compounds is the presence of disulfide groups (S–S)^2– which determine most important structural, physical, and chemical properties of these compounds to make them effective catalysts and electrodes in electrochemical cells.