In situ photodeposition of metalloid Ni2P co-catalyst on Mn0.5Cd0.5S for enhanced photocatalytic H2 evolution with visible light

Developing a suitable and low-cost co-catalyst is highly desired for promoting photocatalytic water splitting of H₂ production. Herein, we adopted a simple in situ photodeposition strategy by coupling Mn_0.5Cd_0.5S with non-noble co-catalyst Ni₂P to construct Ni₂P/Mn_0.5Cd_0.5S composites and achieved obviously improved H₂ amount (31.83 mmol/h/g) in visible-light region, which is nearly 2.8 times than that of pure Mn_0.5Cd_0.5S. Such photocatalytic performance is in a relatively superior position among Mn_xCd_1?xS-based photocatalysts. The apparent quantum efficiency of Ni₂P/Mn_0.5Cd_0.5S-7 composites reaches 32% at 420 nm. Through optical and photoelectrochemical measurements, a possible mechanism was proposed, it was found that the interface between metalloid Ni₂P and Mn_0.5Cd_0.5S contacts closely, which facilitates transfer and separation of charge carriers, thus promotes the reduction of H⁺ to H₂. This study provides a new design of cut-price, high-efficiency photocatalyst for H₂ evolution.