Enhanced catalytic activity of edge-exposed 1T phase WS2 grown directly on a WO3 nanohelical array for water splitting†
A hierarchical electrode consisting of edge-exposed 1T phase WS2, grown on an array of surface-modified WO3 nanohelixes (NHs), and its enhanced catalytic performance in the hydrogen evolution reaction (HER) are presented. The oxygen-deficient WO3 NH surface modified by controlled annealing facilitates the formation of a rich edge-exposed WS2 during sulfurization. In addition, metallic 1T phase WS2 is preferentially grown on the WO3 NHs owing to the strain induced between WS2 and curved WO3 NHs. Such desirable structural properties, metallic 1T phase and a rich edge-exposed morphology of the catalytic electrode directly resulted in an enhanced HER performance in water splitting.