Flower-like tin oxide membranes with robust three-dimensional channels for efficient removal of iron ions from hydrogen peroxide

Membrane technology has become the mainstream process for the production of electronic grade hydrogen peroxide (H₂O₂). But due to the oxidation degradation of the organic membranes (e.g. polyamide) by the strong oxidative radicals (e.g. ^[rad]OH) generated via the activation of H₂O₂ by iron ions (Fe³⁺), the short effective lifetime of membranes remains a challenge. Inorganic nano tin oxide (SnO₂) has great potential for the removal of Fe³⁺ in strongly oxidative H₂O₂ because of its ability to stabilize H₂O₂ and preferentially adsorb Fe³⁺. Herein, we have designed for the first time a flower-like robust SnO₂ membrane on the ceramic support by in situ template-free one-step hydrothermal method. The three-dimensional loose pore structure in the membrane built by interlacing SnO₂ nanosheets endows the SnO₂ membrane with a high specific surface area and abundant adsorption sites (–OH). Based on the coordination complexation and electrostatic attraction between the SnO₂ surface and Fe³⁺, the membrane shows a high Fe³⁺ removal efficiency (83%) and permeability (24 L·m⁻²·h⁻¹·MPa⁻¹) in H₂O₂. This study provides an innovative and simple approach to designing robust SnO₂ membranes for highly efficient removal of Fe³⁺ in harsh environments, such as strong oxidation conditions.