Photoelectrochemical study of p-GaP(100)|ZnO|AuNP devices: strategies for enhanced electron transfer and aqueous catalysis

Abstract

We report a photocathode device consisting of GaP, a metal oxide (Al₂O₃ or ZnO), a phosphonate-C₁₂-thiol monolayer, and gold nanoparticles (AuNPs). The AuNPs enhance electron transfer: in non-aqueous electrochemistry (EtV²⁺ in MeCN), p-GaP|Al₂O₃|O₃PC₁₂S|AuNP and …ZnO|…|AuNP rescued the photocurrent (24%, 59% of J_max-etch). Aqueous experiments (CO₂ saturated KCl) using the optimized ZnO-functionalized device exhibited H⁺ → H₂ (FY = 66%) and CO₂ → CO (FY = 6%).