Fabricating α‐MnO<sub>2</sub>@NiMoO<sub>4</sub> Heterostructure Architecture With Superior Photoelectrocatalytic Water Purification
Hongchao Ma, Yan Chen, Huijun Li, Yinghuan Fu, Dedong Sun, Guowen Wang, Xiang Guo, Shi Xue Dou, Vadivel Subramaniam, Ashish Kumar, K. Ramachandran, Xinghui Liu
Abstract
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.