Efficient charge separation between ZnIn2S4 nanoparticles and polyaniline nanorods for nitrogen photofixation

Abstract

Here, novel core–shell polyaniline@ZnIn₂S₄ (PANI@ZnIn₂S₄) heterostructure photocatalysts have been prepared using a simple synthesis process, and the ZnIn₂S₄ nanoparticles grow directly on the surface of PANI nanorods through strong interactions between the two semiconductors. The PANI@ZnIn₂S₄ heterostructure composites show extraordinary photocatalytic effects for the reduction of nitrogen in a natural environment. The PANI@ZnIn₂S₄ (ZnIn₂S₄ 15 wt%) composite reveals the highest catalytic activity, and the maximum efficiency for ammonia generation can reach 290 μmol L⁻¹ h⁻¹, which is 10.3 times as high as that of pure ZnIn₂S₄. This superior photocatalytic performance of PANI@ZnIn₂S₄ is ascribed to the increased light absorption capacity, rich reactive sites and strong nitrogen activation ability. In particular, the efficient interfacial interactions between the ZnIn₂S₄ nanoparticles and PANI nanorods facilitate the separation and transfer of photogenerated electrons and holes. This work provides an effective approach to construct novel photocatalytic systems for efficient photocatalytic nitrogen fixation.