Enhanced Photoelectrochemical Performance of WO3 -Based Composite Photoanode Coupled with Carbon Quantum Dots and NiFe Layered Double Hydroxide.

An attractive photoanode material, WO3 , has suffered from its limited visible-light absorption and sluggish surface reaction kinetics, as well as poor stability in neutral electrolytes. Herein, a NiFe/CQD/WO3 composite photoanode was designed and fabricated, with loading of carbon quantum dots (CQDs) and electrodeposition of NiFe layered double hydroxide. The NiFe/CQD/WO3 photoanode obtained a photocurrent density of 1.43 mA cm-2 at 1.23 V vs. reversible hydrogen electrode, which is approximately three times higher than that of bare WO3 . During the test period of 3 h, the stability of WO3 was improved substantially after the loading of cocatalysts. Furthermore, mechanistic insights of the favored band structure and beneficial charge-transfer pathway elucidate the high photoelectrochemical performance of the NiFe/CQD/WO3 composite photoanode.