Mussel-inspired hydrogels have gained attention for underwater applications, including treatment of wastewater. However, they are typically limited by poor mechanical properties, short-term mechanical stability and by not being reusable. Here, we develop a mechanically stable and self-healing hydrogel with high mechanical strength for the degradation of dyes in wastewater, based on cellulose-derived co-polydopamine@Pd nanoparticles. A dynamic catechol redox system was achieved by reversible conversion between semiquinone and quinone/hydroquinone radicals, endowing the hydrogel with stable mechanical properties and self-healing behavior. Furthermore, a graphene oxide membrane is covalently grafted on to the hydrogel surface, which regulates its water permeability and intercepts some metal ions or large particles, protecting the hydrogel structure. High catalytic activity for anionic and cationic dyes is achieved, with the degradation rate reaching more than 95% after multiple cycles without significant deterioration in performance or hydrogel structure. Our work demonstrates a route to achieve mechanically stable hydrogels for degradation of organic dyes in wastewater.

受贻贝启发的水凝胶已在水下应用（包括废水处理）中获得关注。但是，它们通常受到不良的机械性能，短期机械稳定性以及不可重复使用的限制。在此，我们基于纤维素衍生的co-polydopamine @ Pd纳米粒子，开发了一种具有高机械强度的机械稳定且自修复的水凝胶，用于降解废水中的染料。通过在半醌和醌/对苯二酚自由基之间进行可逆转化，实现了动态邻苯二酚氧化还原系统，赋予水凝胶稳定的机械性能和自愈性能。此外，将氧化石墨烯膜共价接枝到水凝胶表面，调节其水渗透性并拦截一些金属离子或大颗粒，从而保护水凝胶结构。实现了对阴离子和阳离子染料的高催化活性，多次循环后降解率达到95％以上，而性能或水凝胶结构没有明显降低。我们的工作展示了一种实现机械稳定的水凝胶以降解废水中有机染料的途径。