A silicon photoanode for efficient ethanol oxidation under alkaline conditions

Abstract

Silicon (Si) is an attractive semiconductor which has broad applications in photovoltaic fields due to its low cost and narrow band gap (∼1.1 eV). Taking advantage of a Si-based metal–insulator–semiconductor (MIS) device, which has high electron–hole separation efficiency due to the confined electron and hole transport directions, for the first time, a Pt/ZrO₂/n-Si photoanode is directly employed as the anode for the ethanol oxidation reaction (EOR). When exposed to visible light irradiation, the Pt/ZrO₂/n-Si photoanode exhibits apparently improved EOR activity and durability. This work provides a simple way to fabricate Si-based EOR photoanodes, which has potential for application in direct ethanol fuel cells.