ZnO/ZnS-Polyvinyl Alcohol Hydrogel for Photocatalytic H2-Generation

Abstract

The separation of nanoparticles from a solution-based photocatalytic reaction is a significant problem in practical applications. To address the issue, we developed a new photocatalyst composite based on ZnO-ZnS heterojunction (ZnOS) embedded in polyvinyl alcohol (PVA) hydrogel, which showed satisfactory results for photocatalyst recycling. PVA-ZnOS composite hydrogel was fabricated by freezing-induced gelation, which enabled the encapsulation of ZnOS nanoparticles into polymeric matrices. PVA hydrogel served as a promising candidate in photocatalytic applications due to its excellent properties such as high transparency, porosity, hydrophilicity, and stability under ultraviolet (UV) light. PVA-ZnOS hydrogel showed worthy activity in H2 generation from Na2 S/Na2 SO3 aqueous solution under UV radiation with a production rate of 18.8 µmol·h−1. PVAZnOS composite hydrogel is a separation-free photocatalyst, which is prospective in a solution-based photocatalytic reactor.