Construction of novel MoS2@COF-Ph heterojunction photocatalysts for boosted photocatalytic efficiency and hydrogen production performance under sunlight

Abstract

Heterojunction photocatalysts have been regarded as effective materials for photocatalysis. In this paper, because of the peculiar structure and characteristics of covalent organic frameworks (COFs), a novel nano-MoS₂@COF-Ph heterojunction photocatalyst was synthesized via a simple and easy solvothermal reaction. The nano-MoS₂@COF-Ph heterostructure displayed more high-efficiency photocatalytic performance than pure MoS₂ and pure COF-Ph in the degradation of tetracycline and hydrogen production under sunlight. The excellent photocatalytic performance of the heterojunction photocatalyst was primarily attributed to: (i) the π-conjugation system of COF-Ph and (ii) the efficient photogenerated charge separation and transfer by the compact interface contact of the MoS₂ nanospheres and COF-Ph. It is worth mentioning that the formation of coordination bonds between the MoS₂ nanospheres and COF-Ph provided a transfer channel for photogenerated carriers. Derived from the active free radical capture experiments and ESR tests, a reasonable Z-scheme electron transfer mechanism was proposed, which can account for the enhanced photocatalytic capability of the photocatalytic system. The photocatalytic performance of the heterojunction photocatalyst was studied, and its structure was entirely characterized by SEM, TEM, BET, FT-IR, XPS and PXRD. This study provides a promising viable strategy to design a high-efficiency photocatalyst to remove contaminants from the environment and produce clean energy.