Here, a green and sustainable functionalization of oxidized carbon black by dry ball milling with tetraphenyl phosphonium bromide (TPPBr) is reported. The reaction proceeds efficiently under solvent-free conditions, in the absence of a base, and in a reduced time with a reagent ratio of 1 to 1, much lower than the corresponding reaction in solution. The new mechanochemical approach provides the product with high stability, good mass efficiency, and high sustainability, meeting the green metrics related to waste prevention. This new procedure represents an easy way to realize new fillers and tailor their properties, such as the dispersibility in less polar environments, depending on their potential use.