Novel three-dimensional macroporous PbO2 foam electrode for efficient electrocatalytic decolorization of dyes

Abstract

Electrode construction is a key factor for the efficient electrocatalytic degradation of organic contaminants. However, it is still a challenge to construct an electrode architecture with a large diffusion coefficient and high efficiency. Here, we used a facile method to successfully fabricate a three-dimensional macroporous foam architecture of a PbO₂ electrode that possesses the same framework as low-cost macroporous sponges found in kitchens. This 3D architecture is monolithic and possesses continuous macroporous throughout with high interconnection. Compared with the traditional planar PbO₂ electrode, the 3D macroporous PbO₂ foam has significantly lowered electrochemical impedance (29.2 versus 410 ohm), and greater diffusion coefficient (41.8 × 10⁻⁶ versus 2.29 × 10⁻⁶ cm² s⁻¹). Moreover, the electrocatalytic dye decolorization experiments show that the 3D macroporous PbO₂ foam possesses a much larger first-order kinetics constant (40.2 × 10⁻³ versus 10.0 × 10⁻³ min⁻¹ for highly concentrated orange II). Higher specific surface area, significantly enhanced mass transport, and excellent electrocatalytic activity of the as-fabricated PbO₂ foam can make it a promising electrocatalytic electrode for wastewater treatment.