Probing self-optimization of carbon support in oxygen evolution reaction

Despite acknowledgment of structural reconstruction of materials following oxygen evolution reaction (OER) reaction, the role of support during the reconstruction process has been ignored. Given this, we directly in situ transform the residual iron present in raw single-walled carbon nanotubes (SWCNT) into Fe2O3 and thus build Fe2O3-CNT as the model system. Intriguingly, an anomalous self-optimization occurred on SWCNT and the derived components show satisfactory electrochemical performance. Soft X-ray absorption spectroscopy (sXAS) analysis and theory calculation correspondingly indicate that self-optimization yields stronger interaction between SWCNT and Fe2O3 nanoparticles, where the electrons migrate from Fe2O3 to optimized SWCNT. Such polarization will generate a positive charge center and thus boost the OER activity. This finding directly observes the self-optimization of support effect, providing a new perspective for OER and related electrochemical reactions.