Bimetallic Ni–Co nanoparticles confined within nitrogen defective carbon nitride nanotubes for enhanced photocatalytic hydrogen production

Abstract

This work for the first time reports bimetallic Ni–Co and monometallic (Ni and Co) nanoparticles (NPs)-engineered carbon nitride nanotubes with nitrogen vacancies (V-CNNTs) for visible-light photocatalytic H2 generation application. The bimetallic Ni–Co NPs have an average size of less than 5 nm and are homogenously dispersed along the nanochannels of V-CNNTs. The composition of the bimetallic NPs plays an essential role to maximize photocatalytic activity. With the optimal Ni/Co atom ratio of 3:1, Ni–Co/V-CNNTs nanohybrids yielded a H2 production rate of 4.19 μmol/h, which is higher than those of monometallic counterparts and V-CNNTs. The intimately loaded Ni–Co NPs and incorporated nitrogen vacancies enhance the photocatalytic performance through extended light absorption, abundant active sites, strong metal-support interaction, and efficient charge carrier transfer along the axial direction. This study presents a stable and highly efficient hybrid as a promising photocatalyst for visible light photocatalytic H2 production through water splitting.