Enhancement of Photocatalytic H2 Evolution on Pyrene-based Polymer Promoted by MoS2 and Visible Light

Abstract Conjugated polymers have gathered particular interests in photocatalysis because of their excellent properties such as optimization flexibility, cost-effective, and robust stability. The pyrene-based polymer (PyP), as one of the conjugated polymers, holds a great potential for water splitting because of their suitable band structure, visible light absorption, and high surface area. However, because of the fast charge carrier recombination confined by Frenkel excitons with high exciton binding energy, PyP in its pristine form remains barely active for photoctalytic hydrogen evolution. The concise construction of heterojunction is a feasible way to accelerate the charge separation, increase the lifetime of the photogenerated e − /h + pair and decrease the activation barriers of hydrogen evolution reaction. In this work, a series of transition metal sulfides as cocatalysts have been deposited on PyP to construct heterojunctions for photocatalytic H 2 evolution reaction (HER). The loading techniques (immersion, in-situ and photodeposition) and the loading contents of cocatalysts have been investigated. The optimized MoS 2 /PyP sample exhibited a 10-fold increase in comparison with pure PyP without modification. The extended π-conjugation, high surface area, and widely exposed 2D interface highlight the importance of PyP as effective supports for stabilizing the homogeneously dispersed MoS 2 , thereby resulting in an efficient photocatalytic activity. This study provides a new idea to construct low-cost, sustainable and efficient hybrid system for photocatalytic hydrogen production.