Construct 3D NiCo-LDH/Cu2O p-n heterojunction via electrostatic self-assembly for enhanced photocatalytic hydrogen evolution

Hydrogen evolution of inorganic photocatalysts is currently a hot research topic. In order to prepare highly efficient catalysts for hydrogen evolution, p-n type heterojunctions were successfully constructed by closely combining p-type Cu2O and n-type NiCo-LDH with opposite electrical properties by a simple electrostatic self-assembly. In addition, because the positions of the two single catalysts NiCo-LDH and Cu2O Fermi levels are dissimilar from those of traditional p-n heterojunctions, the extremely high movement of Fermi levels forms a strong built-in electric field, which powerfully prevents the gradient diffusion of charge and facilitates the migration of intrinsic photocarriers. Furthermore, the flower cluster NiCo-LDH is composed of two-dimensional thin sheet structure, which has a large specific surface area and can prevent Cu2O agglomeration. Under the condition of using triethanolamine solution and eosin Y (EY) respectively as sacrifice reagent reducing agent and photosensitizer, the composite catalyst has reached 18332 mu mol.g(-1) in 5 h, which was increased by 8.5 times compared to the pure Cu2O. This research provides an innovative strategy to construct a heterojunction between a metal double-layer hydroxide and a non-noble metal oxide to realize an effective photocatalytic hydrogen production. (C) 2022 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.

Automated summary

The hydrogen evolution of inorganic photocatalysts is a hot research topic. By constructing p-n type heterojunctions, an internal electric field is formed to prevent charge diffusion and promote the migration of photocarriers. The two-dimensional thin sheet structure of flower cluster NiCo-LDH prevents the agglomeration of Cu2O. The composite catalyst shows significantly increased efficiency in hydrogen evolution under specific conditions, providing an innovative strategy for photocatalytic hydrogen production.