Metal oxides of low-valence metal cations (M(II) and M(III); M = Al, Cr, Mn, Fe, Co, Ni, Cu, etc.) are essential in catalysis, sustainable energy, information technology, and environmental applications. In addition, the corresponding metal hydroxides present a 2D crystalline structure of hydroxide layers and interlayer anions and have attracted attention due to their properties, such as reversible and fast intercalation, deintercalation, and anisotropic transfer of ions. The wide variety of combination of the metal cations composing the 2D hydroxide layers and the interlayer anions leads to enhanced electrochemical, magnetic, optical, and catalytic properties. These phases in turn can be transformed into other layered phases such as sulfides that present interesting electronic properties.