CdS@Au micro-spheres as an active and durable bifunctional catalyst for the urea-assisted H2 evolution reaction

Hydrogen evolution reaction (HER) and urea oxidation reaction (UOR) limit the efficiency of overall water splitting and urea oxidation for hydrogen generation, respectively. In this paper, we synthesize CdS@Au catalysts with excellent electrocatalytic activity for HER and UOR by a simple condensate reflux method. Using urea oxidation as an alternative anode reaction, the anodic oxidation potential decreased significantly to 286.4 mV@10 mA cm−2. With CdS@Au as the anode, the cell voltage drops to 1.34 V@10 mA cm−2. By discussing the Au content, it was shown that Au has a strong Lewis acidity and electronegativity, favoring hydrogen evolution.