A Non-Pt Electronically Coupled Semiconductor Heterojunction for Enhanced Oxygen Reduction Electrocatalytic Property

Hybrid faceted-Ag3PO4/cube-Cu2O composite materials have been fabricated and employed as oxygen reduction electrocatalysts for proton exchange membrane fuel cells (PEMFCs). The charge separation effect via the formation of PN junction has been demonstrated to boost the electrocatalysis toward oxygen reduction reaction. The as-prepared rhombic dodecahedron-Ag3PO4/cube-Cu2O/C hybrid catalyst shows a mass-specific activity of 109.80mA/mg(Ag), which is about 6.4 times that of pure rhombic dodecahedron-Ag3PO4/C catalyst (17.20mA/mg(Ag)). The density functional theory (DFT) calculation based on the density of states (DOS) further proved the optimal tunable effect, which is in pace with demonstration of electron transfer direction revealed by X-ray photoelectron spectroscopy (XPS) analysis. Our work establishes a theoretical and practical basis for the rational design of newly non-Pt hybrid catalysts, moreover, advances the future efficient application of PEMFCs.