Magnetically separable type-II semiconductor based ZnO/MoO3 photocatalyst: a proficient system for heteroarenes arylation and rhodamine B degradation under visible light

Abstract

Herein, a new strategy is used to systematically tailor the band arrangement in a ZnO-based heterostructure to realize its bifunctionality towards the synthesis of heteroarylated products and degradation of Rhodamine B under visible light. A Type-II band alignment transition is carried out via introducing MoO₃ rods which subsequently enhance its light-harvesting properties, prolonged charge separation and abundant active sites. The designed heterostructure displayed broad functional group compatibility for both electron-donating and electron-withdrawing group substituted substrates with good product yield. Comparably, their visible light driven heteroarylation process is significantly enhanced to more than 4 times that of pristine ZnO and is superior to most photocatalysts reported previously. ZnO/MoO₃ also displayed remarkable degradation ability of 96.8% towards RhB into innocuous products under neutral conditions without utilizing any oxidant. More impressively, the developed catalyst demonstrated long-term stability and excellent reusability up to five runs without any significant change in efficiency. Hence, this work not only for the first time exhibits the untapped potential of using a highly active, economically efficient and magnetically separable ZnO/MoO₃ core–shell heterostructure to substitute for expensive metals in photocatalysis but also presents a new opening for synthesising hybrid materials with excellent performance in environmental remediation.