Photocatalytic activity towards antibiotic degradation and H2 evolution by development of a Z-scheme heterojunction constructed from 1T/2H-MoS2 nanoflowers embellished on BCN nanosheets

Abstract

Currently, the design of efficient, cost-effective and sustainable photocatalysts to alleviate the ongoing crisis of ecological contamination is of huge interest. Herein, we have developed an all solid-state Z-scheme-mediated 1T/2H-MoS₂@BCN heterojunction via the coupling of 1T/2H-MoS₂ with boron-doped g-C₃N₄ (BCN) using a hydrothermal strategy. In the hybrid structure, the metallic 1T phase serves as a co-catalyst and is an excellent solid state mediator between BCN and the semiconducting 2H phase, thus prolonging the lifetime of the photoinduced charge carriers. Morphological analyses of 1T/2H-MoS₂@BCN indicate that the decoration of the BCN nanosheets with 1T/2H-MoS₂ nanoflowers and their subsequent close interfacial contact enhances the density of active sites resulting in efficient photocatalytic activity. Owing to the rapid charge separation efficiency of the 1T/2H-MoS₂@BCN-10 (10 wt% of 1T/2H-MoS₂ to BCN) photocatalyst, it exhibited an optimum photocatalytic hydrogen production of 290 μmol h⁻¹ under visible light irradiation. Moreover, the optimized photocatalyst displayed the highest TCH degradation efficiency (i.e., 95% in 60 min) which is 5.4 and 3.6 fold higher than the individual BCN and 1T/2H-MoS₂ components, respectively. Radical trapping experiments and electron paramagnetic resonance analysis confirmed that ˙O₂⁻ and ˙OH radicals are the predominant reactive species that result in the accelerated photocatalytic performance. This work opens up a new window towards the development of noble metal-free Z-scheme heterostructures for photocatalytic applications.