Visible-light-enhanced hydrogen evolution from catalytic hydrolysis of ammonia borane using Ru nanoparticles supported on CdS-modified graphitic carbon nitride

Abstract

Photocatalytic hydrolysis of ammonia borane (AB) has been regarded as an efficient and safe approach for hydrogen evolution. In this work, an optimized CdS/C₃N₄ heterojunction was employed as the photoactive support, and ultrafine Ru nanoparticles were deposited by impregnation and chemical reduction, yielding a Ru/CdS/C₃N₄ photocatalyst for AB hydrolysis. A series of advanced techniques were used for material characterization involving micromorphology, phase structure, chemical composition, and optical properties. Compared with raw g-C₃N₄, the heterojunction possesses a stronger absorption ability in the visible-light region, which endows the prepared Ru/CdS/C₃N₄ with excellent photocatalytic activity. For AB hydrolysis, visible-light-enhanced TOF was measured to be 132.9 min⁻¹ (25 °C), which is 2.2-fold higher than the value obtained under dark conditions. The AB hydrolysis behavior and photocatalysis mechanism were investigated in detail. Additionally, Ru/CdS/C₃N₄ retains 86% of the initial activity after recycling five times, showing that the photocatalyst has a good prospect for practical applications.