Effect of solution chemistry on the characteristics of hydrothermally grown WO3 for electroactive applications

•Hydrothermally grown WO3 coatings with controlled properties.•The choice of metal sulfate is important in determining their properties.•Flower-like hexagonal WO3 structures for electroactive applications.

Hydrothermally grown tungsten trioxide coatings were prepared at 95 °C using different metal sulfates. Morphology of the oxides was altered from grains to flower- and urchin-like structures using potassium sulfate, sodium sulfate and lithium sulfate, respectively. The flower-like structures presented the highest deintercalated charge, 35 mC cm− 2 with time response of 96 s. In addition, they indicated a charge transfer resistance across the tungsten trioxide–electrolyte interface of 752 Ω. These outcomes imply that they are promising candidates for electroactive applications.