Efficient photocatalytic hydrogen evolution over carbon supported antiperovskite cobalt zinc nitride

Photocatalytic solar to chemical energy conversion is an important energy conversion process but suffer from low efficiency. Thus, development of efficient photocatalytic system using earth-abundant elements with low costs is highly desirable. Here, antiperovskite cobalt zinc nitride has been synthesized and coupled with carbon black (Co₃ZnN/C) for visible light driven hydrogen production in an Eosin Y-sensitized system. Replacement of cobalt atom by zinc atom leads to an improved charge transfer kinetics and catalytic properties compared with Co₄N. Density functional theory (DFT) calculations further reveal the adjusted electronic structure of Co₃ZnN by zinc atom introducing. The lower antibonding energy states of Co₃ZnN are beneficial for the hydrogen desorption. Moreover, carbon black as support effectively reduces the particle size of Co₃ZnN and benefits to the electron storage and adsorption capabilities. The optimal Co₃ZnN/C catalysts exhibit the H₂ evolution rate of 15.4 μmol mg⁻¹h⁻¹, which is over 6 times higher than that of monometallic Co₄N. It is even greater than those of most of Eosin Y-sensitized systems.