LAUSR

The conventional thermal method of preparing hafnium alkoxides [Hf(OR) 4 , R is alkyl]-excellent precursors for gate-dielectric HfO 2 on semiconductors-was severely hindered by its unsatisfactory environment and economy burdens. Herein, we proposed a promising electrodissolution-coupled Hf(OR) 4 synthesis (EHS) system for green and efficient electro-synthesis of Hf(OR) 4 . The operational principle of the electrically-driven system consisted of two simultaneous heterogeneous reactions of Hf dissolution and alcohol dehydrogenation and a spontaneous solution-based combination reaction. In applying ethanol as solvent and Hf metal as electrodissolution medium, we achieved a waste-free production of high-purity hafnium ethoxide [Hf(OEt) 4 ] with an equivalent CO 2 emission reduction of 187.33 g CO 2 [kg Hf(OEt) 4 ] -1 and a high net profit of 30,477 USD [kg Hf(OEt) 4 ] -1 . These were very competitive with the thermal process, which unavoidably released substantial waste and CO 2 with a net profit of 27,700 USD [kg Hf(OEt) 4 ] -1 . We anticipated that the environme ntal and economic benefits of the EHS process would pave the way for its practical application.