One of the keys to produce a very large specific surface area on a planar substrate is the use of 3D carbon nanostructures (vertical graphene nanowalls, VGNW) on a planar substrate, as a growth template for the growth of electrochemically active materials, such as for example, transition metal oxides (TMO). VGNF can achieve a very large specific surface area of up to 1100 m²/g. This value is comparable to or greater than that of carbon nanotubes, which is the reference material for use in high-performance supercapacitors or in other power-related applications that require a large active surface area. VGNF exhibit high vertical and in-plane electrical conductivity when deposited on metal electrodes, which benefits their use in electrochemical applications. We focus the discussion on the growth of VGNF on flexible stainless steel (SS310) substrates, in principle suitable for applications to electrodes of electrochemical systems (batteries, supercapacitors, catalysts). VGNF/SS310 samples were grown by inductively coupled plasma-assisted chemical vapor deposition (ICP-CVD) of methane, as a carbon precursor, in a wide range of temperatures (575 to 900°C). Although the graphene nanostructures usually reported are generally multilayer, we want to highlight the effect of temperature on the number of atomic layers of VGNF. At 700‑750ºC, in the plasma conditions we have explored, VGNFs are bilayer, which directly affects the magnitude of their specific surface area. Raman spectroscopy and field emission scanning electron microscopy provide the VGNF structural and morphological characteristics. The exceptional specific surface area of VGNFs up to 1100 m2/g hold promise for a diverse range of applications. The versatility of vertical graphene nanowalls opens up a spectrum of possibilities across various scientific and technological domains. Beyond their application in electrochemical systems, these nanostructures exhibit characteristics that make them suitable for a wide array of innovative applications, contributing to advancements in: 1) Energy Storage Devices: Apart from supercapacitors and batteries, VGNF can enhance the performance of other energy storage devices like fuel cells. The high specific surface area provides more active sites for electrochemical reactions, potentially improving energy conversion and storage efficiency. 2) Catalysis: The unique structural properties of VGNF make them suitable candidates for catalytic applications. The large surface area and the presence of transition metal oxides (TMO) can catalyze various chemical reactions, making VGNF valuable in the field of heterogeneous catalysis. 3) Sensors: The sensitivity of VGNF to changes in their environment, coupled with their high conductivity, makes them promising candidates for sensor applications. These can include gas sensors, biosensors, or environmental sensors, where their structural versatility can be tailored for specific sensing needs. 4) Electronics and Flexible Devices: Given their high vertical and in-plane electrical conductivity, VGNF can find applications in electronic devices, particularly in flexible electronics. Incorporating VGNF into flexible substrates could open up new possibilities for wearable electronics and flexible displays. 5) Water Purification: The large surface area and unique structure of VGNF make them potential candidates for water purification technologies. They can be employed for adsorption or catalytic degradation of pollutants, contributing to the development of efficient water treatment systems. 6) Biomedical Applications: The biocompatibility of graphene-based materials makes VGNF candidates for biomedical applications. They can be explored for drug delivery systems, biosensing platforms, or as substrates for cell growth in tissue engineering. 7) Photovoltaics: The conductive and high surface area properties of VGNW make them interesting for applications in photovoltaic devices. They can enhance the efficiency of solar cells by providing a larger interface for light absorption and charge separation.