Internal Electric Field Engineering Induced by Co₃O₄/Bi₂MoO₆ Nanotubes for Trifunctional Electrocatalytic and Photocatalytic Applications

Electrocatalytic water splitting is an intriguing technique for clean energy production, and engineering heterojunctions with an internal electric field (IEF) can significantly enhance the electrocatalytic performance. In this paper, Co3O4/Bi2MoO6 heterojunction nanotubes have been prepared via electrospinning and calcination and show stronger activity and stability than single-phase Co3O4 and Bi2MoO6 due to the so-called "1 + 1 > 2" synergistic effect induced by IEF. In particular, 1.00Co3O4/Bi2MoO6 nanotube catalyst performed the overpotential toward hydrogen evolution reaction (HER) with 197 mV and oxygen evolution reaction (OER) with 332 mV at 10 mA·cm–2. Based on the enhancement of IEF verified by density functional theory calculation, the extended photocatalytic degradation of tetracycline (TC) showed an efficiency of 68.5% within 200 min under visible light irradiation. This work provides a facile "one stone, three birds' strategy to construct nanotube heterojunctions and develops the IEF mechanism from photocatalytic to electrocatalytic application.