“…In the context of the aforementioned prominent challenges, these main guidelines can provide the ground for identifying the potential new TMO NPs as the viable candidates for replacing the present electrode substances: 1) dimension control synthesis of the TMOhetero-structures for achieving the optimized active sites [182,183], 2) establishing 2D shape of the single or few atomic layers of the transition metal elements through the epitaxial overgrowth of the secondary metals [184], 3) constructing the nano-composites with the carbon nanomaterials like carbon nanotubes (CNTs), activated carbon, graphene and so on to enhance their catalytic activity and conductivity, and attain monodispersivity with lower dimensional NPs [185,186], 4) generating the nanocomposites with other metals to gain higher catalytic activities and sensitivities for diverse sensor platforms [187], 5) understanding basic associations of the morphological structure, dimensions, compositions and catalytic activities of the transition metal/oxide nano-materials [188,189], 6) optimizing the multimetal or oxide nanomaterials for amplification of the catalytic activities, charge storage capacity, and the prolonged stability [190,191], and 7) selecting the substances and designing the new nanocomposites with other materials such as alloys, dopants, and core-shell structures for enhancing the new functionalities, higher conductivity, longer chemical durability, and higher surface areas [192][193][194].…”