Designing a self-breathing electrode modulated by spatial hydrophobic microenvironments with stabilized H2O2 generation for wastewater treatment

A novel self-breathing air-diffusion rod graphite electrode (ADE-RG) engineered with spatial hydrophobic microenvironments was developed to enhance H2O2 production without external air aeration. The microenvironments, created through thermal shaking-induced turbulence and centrifugal effect, significantly improved the air-diffusion capability. This innovation led to the increase in H2O2 generation (3.36 times higher than that in the unmodified system) due to a locally enhanced electric field, increased oxygen transfer rate, and improved selectivity for two-electron transfer process. Furthermore, incorporating polyepoxysuccinic acid into the electrolyte not only prevents electrode scaling but also minimizes H2O2 decomposition, culminating in the H2O2 concentration of 50.64 ± 2.92 mg L−1 cm−2. Notably, the system performed prominently in treating industrial rifampicin wastewater, achieving a degradation efficiency of 95.29 ± 0.47%, even under high-loading conditions (initial COD was 22,898.50 ± 405.17 mg L−1). These results indicate the significant potential of the self-breathing ADE-RG system in broad-scale wastewater treatment applications.