Ni-CdS composited with ZnO for improved surface reaction and charge efficiency for photocatalytic hydrogen production from formic acid

Abstract

Formic acid (FA) is one of ideal liquid organic hydrogen carrier (LOHC). It is of great significance to construct and design an efficient and stable photocatalytic system for H2 generation from FA decomposition. Herein, enhanced photocatalytic H2 production performance was achieved by compositing surface nickel modified cadmium sulfide (Ni-CdS) with zinc oxide. The research results indicate that the introduction of zinc oxide can not only promote the migration of photo-generated charge carriers, but also facilitate the adsorption of water molecules on the photocatalyst surface, thereby enhancing the production of hydroxyl radicals, which is a key species in the photocatalytic FA decomposition process for H2 production. Without changing the photocatalytic FA decomposition reaction pathway, Ni-CdS@ZnO-X composite material exhibits excellent photocatalytic H2 production activity and recycling stability. The H2 production activity can reach 17 mmol/g/h, which is about 2.3 times that of single cadmium sulfide material and no significant decline in photocatalytic performance going by five cycles. This study provides a new modification route for efficient and stable photocatalytic H2 production from FA decomposition under mild condition.