Photocatalytic hydrogen production from butanol-water mixture over noble-metal free CuO/NiO/NiFe2O4 heterostructure

The photocatalytic hydrogen (H2) production has gained much interest in the past decades. Alcohol was typically used as a sacrificial reagent for the H2 evolution reaction. In the present work, the effect of primary alcohol on the photocatalytic H2 production over the CuO/NiO/NiFe2O4 composite was investigated. The composite was derived by calcining a CuO/NiFe-layered double hydroxide mixture at 973 K for 4 h. Through the synergistic effect of three components, the composite exhibited higher photocatalytic activity than the pristine CuO and NiO/NiFe2O4 under UV-visible light. The H2 production over CuO/NiO/NiFe2O4 increased from 50.3 mu mol to 265.3 mu mol upon the changing of sacrificial reagent from methanol to butanol as supported by the increase of the cathodic photocurrent in butanol aqueous solution. The insight mechanism was detailed by theoretical calculation. The co-adsorption of butanol on the catalyst surface resulted in a decrease in hydrogen atom adsorption- desorption free energy, which consisted of the higher H2 evolution activity compared to that of methanol system.