WS-WC-WO nano-hollow spheres as an efficient and durable catalyst for hydrogen evolution reaction.

Transition metal dichalcogenides (TMDs), transition metal carbides (TMCs), and transition metal oxides (TMOs) have been widely investigated for electrocatalytic applications owing to their abundant active sites, high stability, good conductivity, and various other fascinating properties. Therefore, the synthesis of composites of TMDs, TMCs, and TMOs is a new avenue for the preparation of efficient electrocatalysts. Herein, we propose a novel low-cost and facile method to prepare TMD-TMC-TMO nano-hollow spheres (WS-WC-WO NH) as an efficient catalyst for the hydrogen evolution reaction (HER). The crystallinity, morphology, chemical bonding, and composition of the composite material were comprehensively investigated using X-ray diffraction, Raman spectroscopy, field emission scanning electron microscopy, and X-ray photoelectron spectroscopy. The results confirmed the successful synthesis of the WS-WC-WO NH spheres. Interestingly, the presence of nitrogen significantly enhanced the electrical conductivity of the hybrid material, facilitating electron transfer during the catalytic process. As a result, the WS-WC-WO NH hybrid exhibited better HER performance than the pure WS nanoflowers, which can be attributed to the synergistic effect of the W-S, W-C, and W-O bonding in the composite. Remarkably, the Tafel slope of the WS-WC-WO NH spheres was 59 mV dec, which is significantly lower than that of the pure WS NFs (82 mV dec). The results also confirmed the unprecedented stability and superior electrocatalytic performance of the WS-WC-WO NH spheres toward the HER, which opens new avenues for the preparation of low-cost and highly effective materials for energy conversion and storage applications.