Fabricating α‐MnO₂@NiMoO₄ Heterostructure Architecture With Superior Photoelectrocatalytic Water Purification

ABSTRACT Heterostructure catalyst is highly efficient for photoelectrolytic (PEC) wastewater remediation, while rationally constructing the photoelectrocatalyst with a high‐quality interface is still challenging. Herein, a simple hydrothermal process prepares a heterostructure NiMoO 4 @α‐MnO 2 with a uniform interface between NiMoO 4 nanosheets and α‐MnO 2 nanowires. NiMoO 4 @α‐MnO 2 exhibited significant advantages as follows: (1) α‐MnO 2 nanowires act as charge transport channels like the arteries that transport nutrients, promoting the migration and separation of induced charges; (2) the pollutants can be electrostatically concentrated to the surface of the NiMoO 4 @α‐MnO 2 . Specifically, the gossamer‐like NiMoO 4 nanosheets adhering on the surface of the α‐MnO 2 have a large surface area, beneficial for electrolyte penetration and utilization of active sites. (3) Unfolded gossamer‐like NiMoO 4 , like a vast extended solar panel of an artificial satellite, can harvest more solar energy, generating lots of electron (e − )/hole (h + ) pairs and active species, offering multiple transfer pathways and speeding up the rate of the degradation reaction. The optimized heterostructured NiMoO 4 @α‐MnO 2 ‐3.5 catalysts showed superior PEC activity and remarkable stability for degrading reactive brilliant blue KN‐R. Z‐scheme heterojunction between α‐MnO 2 and NiMoO 4 is proposed based on their energy band structure and free radical quenching experiment.