Novel non-noble metal catalyst with high efficiency and synergetic photocatalytic hydrolysis of ammonia borane and mechanism investigation

Herein, we successfully prepared a highly active non-noble metal CuNi/CNS, as a highly efficient synergistic catalyst for the hydrolysis of ammonia borane to hydrogen. 9.36% CuNi alloy nanoparticles loaded on the surface of g-C3N4 nanosheets at the molar ratio of 1:1 showed excellent photocatalytic activity for the hydrolysis of AB, and their TOF values under dark/visible light excitation were 12.6 and 26.6, respectively. Furthermore, after five cycles, the hydrogen production of Cu0.5Ni0.5/CNS in 10 min is only 5% lower than that of the fresh catalyst, fully demonstrating that the catalyst has excellent reusability. Photoelectrochemical characterizations and theoretical results indicate that the transition metal nanoparticles deposited on the g-C3N4 nanosheets modified the band structure, the bandgap value of 2.77 eV (CNS) reduce to 2.58 eV (Cu/CNS), 2.55 eV (Ni/CNS) and 2.52 eV (Cu0.5Ni0.5/CNS). The 3d orbits of Cu and Ni are mainly involved in the valence band composition of the catalyst system, which not only greatly changes the original orbital structure, reduces the bandgap, but also enhances the transmission of photoelectron and hole pair between the triazine rings. In addition, the synergistic effect of alloy effect, Mott-Schottky junction and the LSPR effect improve the photocatalytic activity of the CuNi/CNS catalyst.