Photothermal‐Expedited Ion Transport Kinetics for Efficient Electrocatalytic Hydrogen Evolution

ABSTRACT Ion transport kinetics plays a critical role in the timely supply of reactants for pushing the limit of electrocatalytic performance in addition to active site number increase and site‐activity enhancement. Here, the photothermal effect of two‐dimensional graphdiyne (GDY) is explored and fully leveraged to expedite interfacial ion transport and elevate intrinsic site activity in a synergistic manner toward a boosted hydrogen evolution reaction (HER). The converted heat can be well confined near the GDY surface owing to its outstanding photothermal conversion capability and low thermal conductivity. Multiple equivalent circuit models combined with theoretical calculations demonstrate that the induced temperature rise on the GDY surface not only substantially enhances ion diffusion but also spontaneously triggers ion convection via the formed local temperature gradient, thereby effectively alleviating the restriction of insufficient reactant supply on the overall HER performance. Meanwhile, the rise in near‐surface temperature is revealed to optimize hydrogen intermediate adsorption and reduce the HER energy barrier. Consequently, the HER performance is considerably improved to rank at the very forefront of nonmetallic carbon‐based electrocatalysts. This work provides an effective protocol for the synergistic enhancement of electrocatalytic performance from both sides of site‐activity elevation and ion transport facilitation.