Co3O4 and W-Mo15S19 were synthesized respectively by solvothermal method, and then W-Mo15S19/Co3O4 composite was prepared by ultrasonic-assisted synthesis method. The morphology, structure, and composition of W-Mo15S19/Co3O4 composites were investigated by using various characterization techniques such as SEM, XRD, EDS, ICP-OES, and XPS. The electrocatalytic perform
