Universal synthesis of single-atom electrocatalysts via in situ fluoride ion etching for hydrogen evolution

Single-atom catalysts (SACs) have attracted considerable interest in the field of electrocatalysis due to their high efficiency of metal utilization and catalytic activity. However, traditional methods of SACs fabrication are often complex and time-consuming. Herein, F-Ru@TiO N was synthesized using a straightforward and universal approach via in situ surface etching and heteroatoms immobilization on a vacancies-rich hierarchical TiO N nanorods array. The fluorine ion-etched TiO N nanorods could produce abundant oxygen vacancies and F-Ti/F-C bonds, which could capture and stabilize Ru heteroatoms by strong host-guest electronic interactions. Due to the synergistic effect of oxygen vacancies anchoring and F-C bonds-assisted stabilization of single atoms, F-Ru@TiO N revealed excellent electrocatalytic hydrogen evolution performance, a low overpotential of 20.8 mV at 10 mA cm^-2, a Tafel slope of 59.9 mV dec^-1 and robust stability at 100 mA cm^-2 over 48 h. Furthermore, this universal strategy could be applicable to various heterometals (Pd, Ir, Pt), which also exhibited high heteroatoms dispersity and high electrocatalytic HER activity/stability. This fabrication method is simple, easy-scalable and versatile, showcasing significant potential for electrocatalysts design and promising application prospects in electrocatalytic energy conversion.