Cu2O/WO3: A promising S-scheme heterojunction for photocatalyzed degradation of carbamazepine and reduction of nitrobenzene

We developed S-scheme Cu2O/WO3 heterojunction via ultra-sonication and hydrothermal approach for photodegradation and photoreduction applications. The obtained results from X-ray photoelectron spectroscopy, scavenging experiment, electron spin resonance (ESR), and Density functional theory (DFT) calculations validate the S-scheme charge migration pathway and the active role of OH and O2¯ radicals. DFT calculations were employed to calculate the EHOMO, ELUMO, Fermi level, and work function to understand the distribution of electron density around the atoms. The heterojunction photodegraded ∼94 % of carbamazepine in 60 min at pH 7. While 88 % of the photoreduction of nitrobenzene into aniline was achieved in 150 min with 95 % selectivity. We find that OH radical is the major reactive oxidation species in photodegradation, while electrons play a crucial role in the photoreduction process. Further, LCMS and GCMS analysis investigates the formation of intermediates during photodegradation and photoreduction. Our novel heterojunction is highly cost-effective and can be recycled for up to seven consecutive photocatalytic cycles without experiencing a significant loss in photocatalytic efficiency. This study offers new insight into creating S-scheme heterojunction with enhanced photocatalytic capabilities, paving the way for potential advancements in a wide range of photocatalytic applications.